/mandos/trunk : revision 713

9

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

10

*

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* Everything else is

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13

12

13

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*

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* 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

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#endif /* not _FILE_OFFSET_BITS */

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40

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

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

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stdout, ferror(), remove() */

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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(),

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opendir(), DIR */

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#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(),

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getnameinfo() */

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

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61

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

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62

*/

62

63

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

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*/

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() */

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

76

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

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unlinkat() */

78

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

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

78

80

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

79

81

argp_state, struct argp,

91

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argz_delete(), argz_append(),

92

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argz_stringify(), argz_add(),

93

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

94

98

95

99

#ifdef __linux__

96

100

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

138

142

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

139

143

char *connect_to = NULL;

140

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const char *hookdir = HOOKDIR;

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int hookdir_fd = -1;

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146

uid_t uid = 65534;

142

147

gid_t gid = 65534;

143

148

154

159

155

160

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

156

161

typedef struct {

157

AvahiSimplePoll *simple_poll;

158

162

AvahiServer *server;

159

163

gnutls_certificate_credentials_t cred;

160

164

unsigned int dh_bits;

162

166

const char *priority;

163

167

gpgme_ctx_t ctx;

164

168

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

165

171

} mandos_context;

166

172

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

168

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

169

.dh_bits = 1024, .priority = "SECURE256"

170

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

171

.current_server = NULL };

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

172

175

173

176

sig_atomic_t quit_now = 0;

174

177

int signal_received = 0;

182

185

perror(print_text);

183

186

}

184

187

185

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

188

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

186

189

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

187

190

va_list ap;

188

191

va_start (ap, format);

189

192

190

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

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194

program_invocation_short_name));

192

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

195

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

193

196

}

194

197

195

198

/*

197

200

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

198

201

* "buffer_length" is how much is already used.

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202

*/

203

__attribute__((nonnull, warn_unused_result))

200

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size_t incbuffer(char **buffer, size_t buffer_length,

201

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size_t buffer_capacity){

202

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

203

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

204

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;

205

213

return 0;

206

214

}

215

*buffer = new_buf;

207

216

buffer_capacity += BUFFER_SIZE;

208

217

}

209

218

return buffer_capacity;

210

219

}

211

220

212

221

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

222

__attribute__((nonnull, warn_unused_result))

213

223

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

214

int af){

224

int af, server **current_server){

215

225

int ret;

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226

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

217

227

if(new_server == NULL){

224

234

.af = af };

225

235

if(new_server->ip == NULL){

226

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

free(new_server->ip);

244

free(new_server);

227

245

return false;

228

246

}

229

247

/* Special case of first server */

230

if (mc.current_server == NULL){

248

if(*current_server == NULL){

231

249

new_server->next = new_server;

232

250

new_server->prev = new_server;

233

mc.current_server = new_server;

234

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

251

*current_server = new_server;

235

252

} else {

236

new_server->next = mc.current_server;

237

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

253

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

254

new_server->next = *current_server;

255

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

238

256

new_server->prev->next = new_server;

239

mc.current_server->prev = new_server;

240

}

241

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

242

if(ret == -1){

243

perror_plus("clock_gettime");

244

return false;

257

(*current_server)->prev = new_server;

245

258

}

246

259

return true;

247

260

}

249

262

/*

250

263

* Initialize GPGME.

251

264

*/

252

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

253

const char *tempdir){

265

__attribute__((nonnull, warn_unused_result))

266

static bool init_gpgme(const char * const seckey,

267

const char * const pubkey,

268

const char * const tempdir,

269

mandos_context *mc){

254

270

gpgme_error_t rc;

255

271

gpgme_engine_info_t engine_info;

256

272

257

258

273

/*

259

274

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

260

275

*/

261

bool import_key(const char *filename){

276

bool import_key(const char * const filename){

262

277

int ret;

263

278

int fd;

264

279

gpgme_data_t pgp_data;

276

291

return false;

277

292

}

278

293

279

rc = gpgme_op_import(mc.ctx, pgp_data);

294

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

280

295

if(rc != GPG_ERR_NO_ERROR){

281

296

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

282

297

gpgme_strsource(rc), gpgme_strerror(rc));

326

341

}

327

342

328

343

/* Create new GPGME "context" */

329

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

344

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

330

345

if(rc != GPG_ERR_NO_ERROR){

331

346

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

332

347

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

345

360

* Decrypt OpenPGP data.

346

361

* Returns -1 on error

347

362

*/

363

__attribute__((nonnull, warn_unused_result))

348

364

static ssize_t pgp_packet_decrypt(const char *cryptotext,

349

365

size_t crypto_size,

350

char **plaintext){

366

char **plaintext,

367

mandos_context *mc){

351

368

gpgme_data_t dh_crypto, dh_plain;

352

369

gpgme_error_t rc;

353

370

ssize_t ret;

379

396

380

397

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

381

398

data buffer */

382

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

399

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

383

400

if(rc != GPG_ERR_NO_ERROR){

384

401

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

385

402

gpgme_strsource(rc), gpgme_strerror(rc));

386

403

plaintext_length = -1;

387

404

if(debug){

388

405

gpgme_decrypt_result_t result;

389

result = gpgme_op_decrypt_result(mc.ctx);

406

result = gpgme_op_decrypt_result(mc->ctx);

390

407

if(result == NULL){

391

408

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

392

409

} else {

469

486

return plaintext_length;

470

487

}

471

488

472

static const char * safer_gnutls_strerror(int value){

489

__attribute__((warn_unused_result))

490

static const char *safer_gnutls_strerror(int value){

473

491

const char *ret = gnutls_strerror(value);

474

492

if(ret == NULL)

475

493

ret = "(unknown)";

477

495

}

478

496

479

497

/* GnuTLS log function callback */

498

__attribute__((nonnull))

480

499

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

481

500

const char* string){

482

501

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

483

502

}

484

503

504

__attribute__((nonnull, warn_unused_result))

485

505

static int init_gnutls_global(const char *pubkeyfilename,

486

const char *seckeyfilename){

506

const char *seckeyfilename,

507

mandos_context *mc){

487

508

int ret;

488

509

489

510

if(debug){

506

527

}

507

528

508

529

/* OpenPGP credentials */

509

ret = gnutls_certificate_allocate_credentials(&mc.cred);

530

ret = gnutls_certificate_allocate_credentials(&mc->cred);

510

531

if(ret != GNUTLS_E_SUCCESS){

511

532

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

512

533

safer_gnutls_strerror(ret));

522

543

}

523

544

524

545

ret = gnutls_certificate_set_openpgp_key_file

525

(mc.cred, pubkeyfilename, seckeyfilename,

546

(mc->cred, pubkeyfilename, seckeyfilename,

526

547

GNUTLS_OPENPGP_FMT_BASE64);

527

548

if(ret != GNUTLS_E_SUCCESS){

528

549

fprintf_plus(stderr,

534

555

}

535

556

536

557

/* GnuTLS server initialization */

537

ret = gnutls_dh_params_init(&mc.dh_params);

558

ret = gnutls_dh_params_init(&mc->dh_params);

538

559

if(ret != GNUTLS_E_SUCCESS){

539

560

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

540

561

" initialization: %s\n",

541

562

safer_gnutls_strerror(ret));

542

563

goto globalfail;

543

564

}

544

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

565

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

545

566

if(ret != GNUTLS_E_SUCCESS){

546

567

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

547

568

safer_gnutls_strerror(ret));

548

569

goto globalfail;

549

570

}

550

571

551

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

572

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

552

573

553

574

return 0;

554

575

555

576

globalfail:

556

577

557

gnutls_certificate_free_credentials(mc.cred);

578

gnutls_certificate_free_credentials(mc->cred);

558

579

gnutls_global_deinit();

559

gnutls_dh_params_deinit(mc.dh_params);

580

gnutls_dh_params_deinit(mc->dh_params);

560

581

return -1;

561

582

}

562

583

563

static int init_gnutls_session(gnutls_session_t *session){

584

__attribute__((nonnull, warn_unused_result))

585

static int init_gnutls_session(gnutls_session_t *session,

586

mandos_context *mc){

564

587

int ret;

565

588

/* GnuTLS session creation */

566

589

do {

578

601

{

579

602

const char *err;

580

603

do {

581

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

604

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

582

605

if(quit_now){

583

606

gnutls_deinit(*session);

584

607

return -1;

595

618

596

619

do {

597

620

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

598

mc.cred);

621

mc->cred);

599

622

if(quit_now){

600

623

gnutls_deinit(*session);

601

624

return -1;

611

634

/* ignore client certificate if any. */

612

635

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

613

636

614

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

637

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

615

638

616

639

return 0;

617

640

}

621

644

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

622

645

623

646

/* Called when a Mandos server is found */

647

__attribute__((nonnull, warn_unused_result))

624

648

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

625

649

AvahiIfIndex if_index,

626

int af){

650

int af, mandos_context *mc){

627

651

int ret, tcp_sd = -1;

628

652

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

653

struct sockaddr_storage to;

633

654

char *buffer = NULL;

634

655

char *decrypted_buffer = NULL;

635

656

size_t buffer_length = 0;

659

680

return -1;

660

681

}

661

682

662

ret = init_gnutls_session(&session);

683

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

684

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

685

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

686

bool match = false;

687

{

688

char *interface = NULL;

689

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

690

interface))){

691

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

692

match = true;

693

break;

694

}

695

}

696

}

697

if(not match){

698

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

699

connect to the server */

700

if(debug){

701

char interface[IF_NAMESIZE];

702

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

703

perror_plus("if_indextoname");

704

} else {

705

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

706

" \"%s\"\n",

707

if_indextoname((unsigned int)if_index,

708

interface));

709

}

710

}

711

return -1;

712

}

713

}

714

715

ret = init_gnutls_session(&session, mc);

663

716

if(ret != 0){

664

717

return -1;

665

718

}

684

737

685

738

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

686

739

if(af == AF_INET6){

687

to.in6.sin6_family = (sa_family_t)af;

688

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

740

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

741

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

689

742

} else { /* IPv4 */

690

to.in.sin_family = (sa_family_t)af;

691

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

743

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

744

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

692

745

}

693

746

if(ret < 0 ){

694

747

int e = errno;

703

756

goto mandos_end;

704

757

}

705

758

if(af == AF_INET6){

706

to.in6.sin6_port = htons(port);

707

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

708

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

709

-Wunreachable-code*/

759

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

760

if(IN6_IS_ADDR_LINKLOCAL

761

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

710

762

if(if_index == AVAHI_IF_UNSPEC){

711

763

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

712

764

" incomplete without a network interface\n");

714

766

goto mandos_end;

715

767

}

716

768

/* Set the network interface number as scope */

717

to.in6.sin6_scope_id = (uint32_t)if_index;

769

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

718

770

}

719

771

} else {

720

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

721

-Wconversion and

722

-Wunreachable-code */

772

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

723

773

}

724

774

725

775

if(quit_now){

742

792

}

743

793

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

744

794

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

745

const char *pcret;

746

795

if(af == AF_INET6){

747

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

748

sizeof(addrstr));

796

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

797

sizeof(struct sockaddr_in6),

798

addrstr, sizeof(addrstr), NULL, 0,

799

NI_NUMERICHOST);

749

800

} else {

750

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

751

sizeof(addrstr));

801

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

802

sizeof(struct sockaddr_in),

803

addrstr, sizeof(addrstr), NULL, 0,

804

NI_NUMERICHOST);

752

805

}

753

if(pcret == NULL){

754

perror_plus("inet_ntop");

755

} else {

756

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

757

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

758

}

806

if(ret == EAI_SYSTEM){

807

perror_plus("getnameinfo");

808

} else if(ret != 0) {

809

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

810

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

811

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

759

812

}

760

813

}

761

814

765

818

}

766

819

767

820

if(af == AF_INET6){

768

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

821

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

822

sizeof(struct sockaddr_in6));

769

823

} else {

770

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

824

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

825

sizeof(struct sockaddr_in));

771

826

}

772

827

if(ret < 0){

773

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

828

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

774

829

int e = errno;

775

830

perror_plus("connect");

776

831

errno = e;

937

992

if(buffer_length > 0){

938

993

ssize_t decrypted_buffer_size;

939

994

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

940

&decrypted_buffer);

995

&decrypted_buffer, mc);

941

996

if(decrypted_buffer_size >= 0){

942

997

943

998

written = 0;

991

1046

return retval;

992

1047

}

993

1048

1049

__attribute__((nonnull))

994

1050

static void resolve_callback(AvahiSServiceResolver *r,

995

1051

AvahiIfIndex interface,

996

1052

AvahiProtocol proto,

1004

1060

AVAHI_GCC_UNUSED AvahiStringList *txt,

1005

1061

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1006

1062

flags,

1007

AVAHI_GCC_UNUSED void* userdata){

1063

void *mc){

1008

1064

if(r == NULL){

1009

1065

return;

1010

1066

}

1022

1078

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

1023

1079

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

1024

1080

domain,

1025

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_strerror(avahi_server_errno

1082

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

1026

1083

break;

1027

1084

1028

1085

case AVAHI_RESOLVER_FOUND:

1036

1093

}

1037

1094

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

1038

1095

interface,

1039

avahi_proto_to_af(proto));

1096

avahi_proto_to_af(proto),

1097

mc);

1040

1098

if(ret == 0){

1041

avahi_simple_poll_quit(mc.simple_poll);

1099

avahi_simple_poll_quit(simple_poll);

1042

1100

} else {

1043

1101

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

1044

avahi_proto_to_af(proto))){

1102

avahi_proto_to_af(proto),

1103

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

1045

1104

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

1046

1105

" list\n", name);

1047

1106

}

1060

1119

const char *domain,

1061

1120

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1062

1121

flags,

1063

AVAHI_GCC_UNUSED void* userdata){

1122

void *mc){

1064

1123

if(b == NULL){

1065

1124

return;

1066

1125

}

1077

1136

case AVAHI_BROWSER_FAILURE:

1078

1137

1079

1138

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

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_simple_poll_quit(mc.simple_poll);

1139

avahi_strerror(avahi_server_errno

1140

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

1141

avahi_simple_poll_quit(simple_poll);

1082

1142

return;

1083

1143

1084

1144

case AVAHI_BROWSER_NEW:

1087

1147

the callback function is called the Avahi server will free the

1088

1148

resolver for us. */

1089

1149

1090

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

1091

name, type, domain, protocol, 0,

1092

resolve_callback, NULL) == NULL)

1150

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

1151

interface, protocol, name, type,

1152

domain, protocol, 0,

1153

resolve_callback, mc) == NULL)

1093

1154

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

1094

1155

" %s\n", name,

1095

avahi_strerror(avahi_server_errno(mc.server)));

1156

avahi_strerror(avahi_server_errno

1157

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

1096

1158

break;

1097

1159

1098

1160

case AVAHI_BROWSER_REMOVE:

1117

1179

signal_received = sig;

1118

1180

int old_errno = errno;

1119

1181

/* set main loop to exit */

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1182

if(simple_poll != NULL){

1183

avahi_simple_poll_quit(simple_poll);

1122

1184

}

1123

1185

errno = old_errno;

1124

1186

}

1125

1187

1188

__attribute__((nonnull, warn_unused_result))

1126

1189

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

1127

1190

int ret;

1128

1191

error_t ret_errno;

1147

1210

return true;

1148

1211

}

1149

1212

1213

__attribute__((nonnull, warn_unused_result))

1150

1214

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

1151

1215

1152

1216

/* Reject the loopback device */

1194

1258

* corresponds to an acceptable network device.

1195

1259

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

1196

1260

*/

1261

__attribute__((nonnull, warn_unused_result))

1197

1262

int good_interface(const struct dirent *if_entry){

1198

1263

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

1199

1264

return 0;

1217

1282

/*

1218

1283

* This function determines if a network interface is up.

1219

1284

*/

1285

__attribute__((nonnull, warn_unused_result))

1220

1286

bool interface_is_up(const char *interface){

1221

1287

struct ifreq ifr;

1222

1288

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

1233

1299

/*

1234

1300

* This function determines if a network interface is running

1235

1301

*/

1302

__attribute__((nonnull, warn_unused_result))

1236

1303

bool interface_is_running(const char *interface){

1237

1304

struct ifreq ifr;

1238

1305

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

1246

1313

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

1247

1314

}

1248

1315

1316

__attribute__((nonnull, pure, warn_unused_result))

1249

1317

int notdotentries(const struct dirent *direntry){

1250

1318

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

1251

1319

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

1258

1326

}

1259

1327

1260

1328

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

1329

__attribute__((nonnull, warn_unused_result))

1261

1330

int runnable_hook(const struct dirent *direntry){

1262

1331

int ret;

1263

1332

size_t sret;

1271

1340

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

1272

1341

"abcdefghijklmnopqrstuvwxyz"

1273

1342

"0123456789"

1274

"_-");

1343

"_.-");

1275

1344

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

1276

1345

/* Contains non-allowed characters */

1277

1346

if(debug){

1281

1350

return 0;

1282

1351

}

1283

1352

1284

char *fullname = NULL;

1285

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

1286

if(ret < 0){

1287

perror_plus("asprintf");

1288

return 0;

1289

}

1290

1291

ret = stat(fullname, &st);

1353

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

1292

1354

if(ret == -1){

1293

1355

if(debug){

1294

1356

perror_plus("Could not stat hook");

1318

1380

return 1;

1319

1381

}

1320

1382

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1383

__attribute__((nonnull, warn_unused_result))

1384

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1385

mandos_context *mc){

1322

1386

int ret;

1323

1387

struct timespec now;

1324

1388

struct timespec waited_time;

1325

1389

intmax_t block_time;

1326

1390

1327

1391

while(true){

1328

if(mc.current_server == NULL){

1329

if (debug){

1392

if(mc->current_server == NULL){

1393

if(debug){

1330

1394

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

1331

1395

" No timeout!\n");

1332

1396

}

1333

1397

ret = avahi_simple_poll_iterate(s, -1);

1334

1398

} else {

1335

if (debug){

1399

if(debug){

1336

1400

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

1337

1401

" it, or wait\n");

1338

1402

}

1345

1409

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

1346

1410

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

1347

1411

waited_time.tv_sec = (now.tv_sec

1348

- mc.current_server->last_seen.tv_sec);

1412

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

1349

1413

waited_time.tv_nsec = (now.tv_nsec

1350

- mc.current_server->last_seen.tv_nsec);

1414

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

1351

1415

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

1352

1416

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

1353

1417

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

1355

1419

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

1356

1420

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

1357

1421

1358

if (debug){

1422

if(debug){

1359

1423

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

1360

1424

block_time);

1361

1425

}

1362

1426

1363

1427

if(block_time <= 0){

1364

ret = start_mandos_communication(mc.current_server->ip,

1365

mc.current_server->port,

1366

mc.current_server->if_index,

1367

mc.current_server->af);

1428

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

1429

mc->current_server->port,

1430

mc->current_server->if_index,

1431

mc->current_server->af, mc);

1368

1432

if(ret == 0){

1369

avahi_simple_poll_quit(mc.simple_poll);

1433

avahi_simple_poll_quit(s);

1370

1434

return 0;

1371

1435

}

1372

1436

ret = clock_gettime(CLOCK_MONOTONIC,

1373

&mc.current_server->last_seen);

1437

&mc->current_server->last_seen);

1374

1438

if(ret == -1){

1375

1439

perror_plus("clock_gettime");

1376

1440

return -1;

1377

1441

}

1378

mc.current_server = mc.current_server->next;

1442

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

1379

1443

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

1380

1444

servers, but don't block */

1381

1445

}

1383

1447

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

1384

1448

}

1385

1449

if(ret != 0){

1386

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

1450

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

1387

1451

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

1388

1452

}

1389

1453

}

1391

1455

}

1392

1456

1393

1457

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

1458

__attribute__((warn_unused_result))

1394

1459

error_t raise_privileges(void){

1395

1460

error_t old_errno = errno;

1396

1461

error_t ret_errno = 0;

1397

1462

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

1398

1463

ret_errno = errno;

1399

perror_plus("seteuid");

1400

1464

}

1401

1465

errno = old_errno;

1402

1466

return ret_errno;

1403

1467

}

1404

1468

1405

1469

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

1470

__attribute__((warn_unused_result))

1406

1471

error_t raise_privileges_permanently(void){

1407

1472

error_t old_errno = errno;

1408

1473

error_t ret_errno = raise_privileges();

1412

1477

}

1413

1478

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

1414

1479

ret_errno = errno;

1415

perror_plus("seteuid");

1416

1480

}

1417

1481

errno = old_errno;

1418

1482

return ret_errno;

1419

1483

}

1420

1484

1421

1485

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

1486

__attribute__((warn_unused_result))

1422

1487

error_t lower_privileges(void){

1423

1488

error_t old_errno = errno;

1424

1489

error_t ret_errno = 0;

1425

1490

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

1426

1491

ret_errno = errno;

1427

perror_plus("seteuid");

1428

1492

}

1429

1493

errno = old_errno;

1430

1494

return ret_errno;

1431

1495

}

1432

1496

1433

1497

/* Lower privileges permanently */

1498

__attribute__((warn_unused_result))

1434

1499

error_t lower_privileges_permanently(void){

1435

1500

error_t old_errno = errno;

1436

1501

error_t ret_errno = 0;

1437

1502

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

1438

1503

ret_errno = errno;

1439

perror_plus("setuid");

1440

1504

}

1441

1505

errno = old_errno;

1442

1506

return ret_errno;

1443

1507

}

1444

1508

1445

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

1509

__attribute__((nonnull))

1510

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

1446

1511

const float delay){

1447

struct dirent **direntries;

1512

struct dirent **direntries = NULL;

1513

if(hookdir_fd == -1){

1514

hookdir_fd = open(hookdir, O_RDONLY);

1515

if(hookdir_fd == -1){

1516

if(errno == ENOENT){

1517

if(debug){

1518

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

1519

" found\n", hookdir);

1520

}

1521

} else {

1522

perror_plus("open");

1523

}

1524

return;

1525

}

1526

}

1527

#ifdef __GLIBC__

1528

#if __GLIBC_PREREQ(2, 15)

1529

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

1530

runnable_hook, alphasort);

1531

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

1532

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

1533

alphasort);

1534

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

1535

#else /* not __GLIBC__ */

1536

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

1537

alphasort);

1538

#endif /* not __GLIBC__ */

1539

if(numhooks == -1){

1540

perror_plus("scandir");

1541

return;

1542

}

1448

1543

struct dirent *direntry;

1449

1544

int ret;

1450

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

1451

alphasort);

1452

if(numhooks == -1){

1453

if(errno == ENOENT){

1454

if(debug){

1455

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

1456

" found\n", hookdir);

1457

}

1458

} else {

1459

perror_plus("scandir");

1545

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

1546

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

1547

direntry = direntries[i];

1548

if(debug){

1549

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

1550

direntry->d_name);

1460

1551

}

1461

} else {

1462

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

1463

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

1464

direntry = direntries[i];

1465

char *fullname = NULL;

1466

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

1467

if(ret < 0){

1552

pid_t hook_pid = fork();

1553

if(hook_pid == 0){

1554

/* Child */

1555

/* Raise privileges */

1556

errno = raise_privileges_permanently();

1557

if(errno != 0){

1558

perror_plus("Failed to raise privileges");

1559

_exit(EX_NOPERM);

1560

}

1561

/* Set group */

1562

errno = 0;

1563

ret = setgid(0);

1564

if(ret == -1){

1565

perror_plus("setgid");

1566

_exit(EX_NOPERM);

1567

}

1568

/* Reset supplementary groups */

1569

errno = 0;

1570

ret = setgroups(0, NULL);

1571

if(ret == -1){

1572

perror_plus("setgroups");

1573

_exit(EX_NOPERM);

1574

}

1575

ret = dup2(devnull, STDIN_FILENO);

1576

if(ret == -1){

1577

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

1578

_exit(EX_OSERR);

1579

}

1580

ret = close(devnull);

1581

if(ret == -1){

1582

perror_plus("close");

1583

_exit(EX_OSERR);

1584

}

1585

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1586

if(ret == -1){

1587

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

1588

_exit(EX_OSERR);

1589

}

1590

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

1591

if(ret == -1){

1592

perror_plus("setenv");

1593

_exit(EX_OSERR);

1594

}

1595

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

1596

if(ret == -1){

1597

perror_plus("setenv");

1598

_exit(EX_OSERR);

1599

}

1600

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

1601

if(ret == -1){

1602

perror_plus("setenv");

1603

_exit(EX_OSERR);

1604

}

1605

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

1606

if(ret == -1){

1607

perror_plus("setenv");

1608

_exit(EX_OSERR);

1609

}

1610

char *delaystring;

1611

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

1612

if(ret == -1){

1468

1613

perror_plus("asprintf");

1469

continue;

1470

}

1471

if(debug){

1472

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

1473

direntry->d_name);

1474

}

1475

pid_t hook_pid = fork();

1476

if(hook_pid == 0){

1477

/* Child */

1478

/* Raise privileges */

1479

raise_privileges_permanently();

1480

/* Set group */

1481

errno = 0;

1482

ret = setgid(0);

1483

if(ret == -1){

1484

perror_plus("setgid");

1485

}

1486

/* Reset supplementary groups */

1487

errno = 0;

1488

ret = setgroups(0, NULL);

1489

if(ret == -1){

1490

perror_plus("setgroups");

1491

}

1492

dup2(devnull, STDIN_FILENO);

1493

close(devnull);

1494

dup2(STDERR_FILENO, STDOUT_FILENO);

1495

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

1496

if(ret == -1){

1497

perror_plus("setenv");

1498

_exit(EX_OSERR);

1499

}

1500

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

1501

if(ret == -1){

1502

perror_plus("setenv");

1503

_exit(EX_OSERR);

1504

}

1505

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

1506

if(ret == -1){

1507

perror_plus("setenv");

1508

_exit(EX_OSERR);

1509

}

1510

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

1511

if(ret == -1){

1512

perror_plus("setenv");

1513

_exit(EX_OSERR);

1514

}

1515

char *delaystring;

1516

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

1517

if(ret == -1){

1518

perror_plus("asprintf");

1519

_exit(EX_OSERR);

1520

}

1521

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

1522

if(ret == -1){

1523

free(delaystring);

1524

perror_plus("setenv");

1525

_exit(EX_OSERR);

1526

}

1614

_exit(EX_OSERR);

1615

}

1616

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

1617

if(ret == -1){

1527

1618

free(delaystring);

1528

if(connect_to != NULL){

1529

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

1530

if(ret == -1){

1531

perror_plus("setenv");

1532

_exit(EX_OSERR);

1533

}

1534

}

1535

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

1536

perror_plus("execl");

1537

_exit(EXIT_FAILURE);

1538

}

1619

perror_plus("setenv");

1620

_exit(EX_OSERR);

1621

}

1622

free(delaystring);

1623

if(connect_to != NULL){

1624

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

1625

if(ret == -1){

1626

perror_plus("setenv");

1627

_exit(EX_OSERR);

1628

}

1629

}

1630

int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);

1631

if(hook_fd == -1){

1632

perror_plus("openat");

1633

_exit(EXIT_FAILURE);

1634

}

1635

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

1636

perror_plus("close");

1637

_exit(EXIT_FAILURE);

1638

}

1639

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

1640

environ) == -1){

1641

perror_plus("fexecve");

1642

_exit(EXIT_FAILURE);

1643

}

1644

} else {

1645

int status;

1646

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

1647

perror_plus("waitpid");

1648

continue;

1649

}

1650

if(WIFEXITED(status)){

1651

if(WEXITSTATUS(status) != 0){

1652

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

1653

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

1654

WEXITSTATUS(status));

1655

continue;

1656

}

1657

} else if(WIFSIGNALED(status)){

1658

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

1659

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

1660

WTERMSIG(status));

1661

continue;

1539

1662

} else {

1540

int status;

1541

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

1542

perror_plus("waitpid");

1543

free(fullname);

1544

continue;

1545

}

1546

if(WIFEXITED(status)){

1547

if(WEXITSTATUS(status) != 0){

1548

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

1549

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

1550

WEXITSTATUS(status));

1551

free(fullname);

1552

continue;

1553

}

1554

} else if(WIFSIGNALED(status)){

1555

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

1556

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

1557

WTERMSIG(status));

1558

free(fullname);

1559

continue;

1560

} else {

1561

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

1562

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

1563

free(fullname);

1564

continue;

1565

}

1566

}

1567

free(fullname);

1568

if(debug){

1569

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

1570

direntry->d_name);

1571

}

1572

}

1573

close(devnull);

1574

}

1575

return true;

1663

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

1664

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

1665

continue;

1666

}

1667

}

1668

if(debug){

1669

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

1670

direntry->d_name);

1671

}

1672

}

1673

free(direntries);

1674

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

1675

perror_plus("close");

1676

} else {

1677

hookdir_fd = -1;

1678

}

1679

close(devnull);

1576

1680

}

1577

1681

1682

__attribute__((nonnull, warn_unused_result))

1578

1683

error_t bring_up_interface(const char *const interface,

1579

1684

const float delay){

1580

int sd = -1;

1581

1685

error_t old_errno = errno;

1582

error_t ret_errno = 0;

1583

int ret, ret_setflags;

1686

int ret;

1584

1687

struct ifreq network;

1585

1688

unsigned int if_index = if_nametoindex(interface);

1586

1689

if(if_index == 0){

1595

1698

}

1596

1699

1597

1700

if(not interface_is_up(interface)){

1598

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

1701

error_t ret_errno = 0, ioctl_errno = 0;

1702

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

1599

1703

ret_errno = errno;

1600

1704

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

1601

1705

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

1706

errno = old_errno;

1602

1707

return ret_errno;

1603

1708

}

1604

network.ifr_flags |= IFF_UP;

1709

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

1605

1710

1606

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1607

if(sd < 0){

1711

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

1712

if(sd == -1){

1608

1713

ret_errno = errno;

1609

1714

perror_plus("socket");

1610

1715

errno = old_errno;

1611

1716

return ret_errno;

1612

1717

}

1613

1718

1614

1719

if(quit_now){

1615

close(sd);

1720

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

1721

if(ret == -1){

1722

perror_plus("close");

1723

}

1616

1724

errno = old_errno;

1617

1725

return EINTR;

1618

1726

}

1622

1730

interface);

1623

1731

}

1624

1732

1625

/* Raise priviliges */

1626

raise_privileges();

1733

/* Raise privileges */

1734

ret_errno = raise_privileges();

1735

if(ret_errno != 0){

1736

errno = ret_errno;

1737

perror_plus("Failed to raise privileges");

1738

}

1627

1739

1628

1740

#ifdef __linux__

1629

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1630

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

1631

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

1632

bool restore_loglevel = true;

1633

if(ret_linux == -1){

1634

restore_loglevel = false;

1635

perror_plus("klogctl");

1741

int ret_linux;

1742

bool restore_loglevel = false;

1743

if(ret_errno == 0){

1744

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1745

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

1746

ret_linux = klogctl(8, NULL, 5);

1747

if(ret_linux == -1){

1748

perror_plus("klogctl");

1749

} else {

1750

restore_loglevel = true;

1751

}

1636

1752

}

1637

1753

#endif /* __linux__ */

1638

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

1639

ret_errno = errno;

1754

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

1755

ioctl_errno = errno;

1640

1756

#ifdef __linux__

1641

1757

if(restore_loglevel){

1642

1758

ret_linux = klogctl(7, NULL, 0);

1646

1762

}

1647

1763

#endif /* __linux__ */

1648

1764

1649

/* Lower privileges */

1650

lower_privileges();

1765

/* If raise_privileges() succeeded above */

1766

if(ret_errno == 0){

1767

/* Lower privileges */

1768

ret_errno = lower_privileges();

1769

if(ret_errno != 0){

1770

errno = ret_errno;

1771

perror_plus("Failed to lower privileges");

1772

}

1773

}

1651

1774

1652

1775

/* Close the socket */

1653

1776

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

1656

1779

}

1657

1780

1658

1781

if(ret_setflags == -1){

1659

errno = ret_errno;

1782

errno = ioctl_errno;

1660

1783

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1661

1784

errno = old_errno;

1662

return ret_errno;

1785

return ioctl_errno;

1663

1786

}

1664

1787

} else if(debug){

1665

1788

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

1683

1806

return 0;

1684

1807

}

1685

1808

1809

__attribute__((nonnull, warn_unused_result))

1686

1810

error_t take_down_interface(const char *const interface){

1687

int sd = -1;

1688

1811

error_t old_errno = errno;

1689

error_t ret_errno = 0;

1690

int ret, ret_setflags;

1691

1812

struct ifreq network;

1692

1813

unsigned int if_index = if_nametoindex(interface);

1693

1814

if(if_index == 0){

1696

1817

return ENXIO;

1697

1818

}

1698

1819

if(interface_is_up(interface)){

1820

error_t ret_errno = 0, ioctl_errno = 0;

1699

1821

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

1700

1822

ret_errno = errno;

1701

1823

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

1702

1824

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

1825

errno = old_errno;

1703

1826

return ret_errno;

1704

1827

}

1705

1828

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

1706

1829

1707

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1708

if(sd < 0){

1830

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

1831

if(sd == -1){

1709

1832

ret_errno = errno;

1710

1833

perror_plus("socket");

1711

1834

errno = old_errno;

1717

1840

interface);

1718

1841

}

1719

1842

1720

/* Raise priviliges */

1721

raise_privileges();

1722

1723

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

1724

ret_errno = errno;

1725

1726

/* Lower privileges */

1727

lower_privileges();

1843

/* Raise privileges */

1844

ret_errno = raise_privileges();

1845

if(ret_errno != 0){

1846

errno = ret_errno;

1847

perror_plus("Failed to raise privileges");

1848

}

1849

1850

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

1851

ioctl_errno = errno;

1852

1853

/* If raise_privileges() succeeded above */

1854

if(ret_errno == 0){

1855

/* Lower privileges */

1856

ret_errno = lower_privileges();

1857

if(ret_errno != 0){

1858

errno = ret_errno;

1859

perror_plus("Failed to lower privileges");

1860

}

1861

}

1728

1862

1729

1863

/* Close the socket */

1730

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

1864

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

1731

1865

if(ret == -1){

1732

1866

perror_plus("close");

1733

1867

}

1734

1868

1735

1869

if(ret_setflags == -1){

1736

errno = ret_errno;

1870

errno = ioctl_errno;

1737

1871

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1738

1872

errno = old_errno;

1739

return ret_errno;

1873

return ioctl_errno;

1740

1874

}

1741

1875

} else if(debug){

1742

1876

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

1748

1882

}

1749

1883

1750

1884

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

1885

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

1886

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

1887

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

1888

.interfaces = NULL, .interfaces_size = 0 };

1751

1889

AvahiSServiceBrowser *sb = NULL;

1752

1890

error_t ret_errno;

1753

1891

int ret;

1754

1892

intmax_t tmpmax;

1755

1893

char *tmp;

1756

1894

int exitcode = EXIT_SUCCESS;

1757

char *interfaces = NULL;

1758

size_t interfaces_size = 0;

1759

1895

char *interfaces_to_take_down = NULL;

1760

1896

size_t interfaces_to_take_down_size = 0;

1761

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

1762

bool tempdir_created = false;

1897

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

1898

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

1899

char *tempdir = NULL;

1763

1900

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1764

1901

const char *seckey = PATHDIR "/" SECKEY;

1765

1902

const char *pubkey = PATHDIR "/" PUBKEY;

1766

1903

char *interfaces_hooks = NULL;

1767

size_t interfaces_hooks_size = 0;

1768

1904

1769

1905

bool gnutls_initialized = false;

1770

1906

bool gpgme_initialized = false;

1861

1997

connect_to = arg;

1862

1998

break;

1863

1999

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

1864

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

1865

(int)',');

2000

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

2001

arg, (int)',');

1866

2002

if(ret_errno != 0){

1867

2003

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

1868

2004

}

1948

2084

/* Work around Debian bug #633582:

1949

2085

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

1950

2086

1951

/* Re-raise priviliges */

1952

if(raise_privileges() == 0){

2087

/* Re-raise privileges */

2088

ret_errno = raise_privileges();

2089

if(ret_errno != 0){

2090

errno = ret_errno;

2091

perror_plus("Failed to raise privileges");

2092

} else {

1953

2093

struct stat st;

1954

2094

1955

2095

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

1995

2135

}

1996

2136

1997

2137

/* Lower privileges */

1998

errno = 0;

1999

ret = seteuid(uid);

2000

if(ret == -1){

2001

perror_plus("seteuid");

2138

ret_errno = lower_privileges();

2139

if(ret_errno != 0){

2140

errno = ret_errno;

2141

perror_plus("Failed to lower privileges");

2002

2142

}

2003

2143

}

2004

2144

}

2005

2145

2006

/* Remove empty interface names */

2146

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

2007

2147

{

2008

2148

char *interface = NULL;

2009

while((interface = argz_next(interfaces, interfaces_size,

2149

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

2010

2150

interface))){

2011

if(if_nametoindex(interface) == 0){

2012

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

2151

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

2152

and if_nametoindex(interface) == 0){

2153

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

2013

2154

fprintf_plus(stderr, "Not using nonexisting interface"

2014

2155

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

2015

2156

}

2016

argz_delete(&interfaces, &interfaces_size, interface);

2157

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

2017

2158

interface = NULL;

2018

2159

}

2019

2160

}

2021

2162

2022

2163

/* Run network hooks */

2023

2164

{

2024

2025

if(interfaces != NULL){

2026

interfaces_hooks = malloc(interfaces_size);

2165

if(mc.interfaces != NULL){

2166

interfaces_hooks = malloc(mc.interfaces_size);

2027

2167

if(interfaces_hooks == NULL){

2028

2168

perror_plus("malloc");

2029

2169

goto end;

2030

2170

}

2031

memcpy(interfaces_hooks, interfaces, interfaces_size);

2032

interfaces_hooks_size = interfaces_size;

2033

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2034

(int)',');

2035

}

2036

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

2037

interfaces_hooks : "", delay)){

2038

goto end;

2039

}

2171

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

2172

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

2173

}

2174

run_network_hooks("start", interfaces_hooks != NULL ?

2175

interfaces_hooks : "", delay);

2040

2176

}

2041

2177

2042

2178

if(not debug){

2047

2183

from the signal handler */

2048

2184

/* Initialize the pseudo-RNG for Avahi */

2049

2185

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

2050

mc.simple_poll = avahi_simple_poll_new();

2051

if(mc.simple_poll == NULL){

2186

simple_poll = avahi_simple_poll_new();

2187

if(simple_poll == NULL){

2052

2188

fprintf_plus(stderr,

2053

2189

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

2054

2190

exitcode = EX_UNAVAILABLE;

2119

2255

}

2120

2256

2121

2257

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

2122

if(interfaces == NULL){

2123

struct dirent **direntries;

2258

if(mc.interfaces == NULL){

2259

struct dirent **direntries = NULL;

2124

2260

/* Look for any good interfaces */

2125

2261

ret = scandir(sys_class_net, &direntries, good_interface,

2126

2262

alphasort);

2127

2263

if(ret >= 1){

2128

2264

/* Add all found interfaces to interfaces list */

2129

2265

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

2130

ret_errno = argz_add(&interfaces, &interfaces_size,

2266

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

2131

2267

direntries[i]->d_name);

2132

2268

if(ret_errno != 0){

2269

errno = ret_errno;

2133

2270

perror_plus("argz_add");

2134

2271

continue;

2135

2272

}

2140

2277

}

2141

2278

free(direntries);

2142

2279

} else {

2143

free(direntries);

2280

if(ret == 0){

2281

free(direntries);

2282

}

2144

2283

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

2145

2284

exitcode = EXIT_FAILURE;

2146

2285

goto end;

2147

2286

}

2148

2287

}

2149

2288

2150

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

2151

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

2152

if(debug){

2153

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

2154

interfaces);

2155

}

2156

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2157

}

2158

2159

/* Bring up interfaces which are down */

2160

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

2161

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

2289

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

2290

{

2162

2291

char *interface = NULL;

2163

while((interface = argz_next(interfaces, interfaces_size,

2292

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

2164

2293

interface))){

2294

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

2295

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

2296

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

2297

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

2298

interface);

2299

interface = NULL;

2300

while((interface = argz_next(mc.interfaces,

2301

mc.interfaces_size, interface))){

2302

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

2303

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

2304

interface);

2305

interface = NULL;

2306

}

2307

}

2308

break;

2309

}

2165

2310

bool interface_was_up = interface_is_up(interface);

2166

ret = bring_up_interface(interface, delay);

2311

errno = bring_up_interface(interface, delay);

2167

2312

if(not interface_was_up){

2168

if(ret != 0){

2169

errno = ret;

2313

if(errno != 0){

2170

2314

perror_plus("Failed to bring up interface");

2171

2315

} else {

2172

ret_errno = argz_add(&interfaces_to_take_down,

2173

&interfaces_to_take_down_size,

2174

interface);

2316

errno = argz_add(&interfaces_to_take_down,

2317

&interfaces_to_take_down_size,

2318

interface);

2319

if(errno != 0){

2320

perror_plus("argz_add");

2321

}

2175

2322

}

2176

2323

}

2177

2324

}

2178

free(interfaces);

2179

interfaces = NULL;

2180

interfaces_size = 0;

2181

2325

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

2182

2326

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

2183

2327

}

2184

2328

}

2185

2329

2330

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

2331

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

2332

if(debug){

2333

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

2334

mc.interfaces);

2335

}

2336

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

2337

}

2338

2186

2339

if(quit_now){

2187

2340

goto end;

2188

2341

}

2189

2342

2190

ret = init_gnutls_global(pubkey, seckey);

2343

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

2191

2344

if(ret == -1){

2192

2345

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

2193

2346

exitcode = EX_UNAVAILABLE;

2200

2353

goto end;

2201

2354

}

2202

2355

2203

if(mkdtemp(tempdir) == NULL){

2356

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

2357

tempdir = mkdtemp(run_tempdir);

2358

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

2359

if(debug){

2360

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

2361

run_tempdir, old_tempdir);

2362

}

2363

tempdir = mkdtemp(old_tempdir);

2364

}

2365

if(tempdir == NULL){

2204

2366

perror_plus("mkdtemp");

2205

2367

goto end;

2206

2368

}

2207

tempdir_created = true;

2208

2369

2209

2370

if(quit_now){

2210

2371

goto end;

2211

2372

}

2212

2373

2213

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

2374

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

2214

2375

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

2215

2376

exitcode = EX_UNAVAILABLE;

2216

2377

goto end;

2246

2407

exitcode = EX_USAGE;

2247

2408

goto end;

2248

2409

}

2249

2410

2250

2411

if(quit_now){

2251

2412

goto end;

2252

2413

}

2273

2434

}

2274

2435

2275

2436

while(not quit_now){

2276

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

2437

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

2438

&mc);

2277

2439

if(quit_now or ret == 0){

2278

2440

break;

2279

2441

}

2281

2443

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

2282

2444

(int)retry_interval);

2283

2445

}

2284

sleep((int)retry_interval);

2446

sleep((unsigned int)retry_interval);

2285

2447

}

2286

2448

2287

if (not quit_now){

2449

if(not quit_now){

2288

2450

exitcode = EXIT_SUCCESS;

2289

2451

}

2290

2452

2305

2467

config.publish_domain = 0;

2306

2468

2307

2469

/* Allocate a new server */

2308

mc.server = avahi_server_new(avahi_simple_poll_get

2309

(mc.simple_poll), &config, NULL,

2310

NULL, &ret_errno);

2470

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2471

&config, NULL, NULL, &ret_errno);

2311

2472

2312

2473

/* Free the Avahi configuration data */

2313

2474

avahi_server_config_free(&config);

2328

2489

/* Create the Avahi service browser */

2329

2490

sb = avahi_s_service_browser_new(mc.server, if_index,

2330

2491

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2331

NULL, 0, browse_callback, NULL);

2492

NULL, 0, browse_callback,

2493

(void *)&mc);

2332

2494

if(sb == NULL){

2333

2495

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

2334

2496

avahi_strerror(avahi_server_errno(mc.server)));

2345

2507

if(debug){

2346

2508

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

2347

2509

}

2348

2349

ret = avahi_loop_with_timeout(mc.simple_poll,

2350

(int)(retry_interval * 1000));

2510

2511

ret = avahi_loop_with_timeout(simple_poll,

2512

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

2351

2513

if(debug){

2352

2514

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

2353

2515

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

2360

2522

}

2361

2523

2362

2524

/* Cleanup things */

2525

free(mc.interfaces);

2526

2363

2527

if(sb != NULL)

2364

2528

avahi_s_service_browser_free(sb);

2365

2529

2366

2530

if(mc.server != NULL)

2367

2531

avahi_server_free(mc.server);

2368

2532

2369

if(mc.simple_poll != NULL)

2370

avahi_simple_poll_free(mc.simple_poll);

2533

if(simple_poll != NULL)

2534

avahi_simple_poll_free(simple_poll);

2371

2535

2372

2536

if(gnutls_initialized){

2373

2537

gnutls_certificate_free_credentials(mc.cred);

2390

2554

}

2391

2555

}

2392

2556

2393

/* Re-raise priviliges */

2557

/* Re-raise privileges */

2394

2558

{

2395

raise_privileges();

2396

2397

/* Run network hooks */

2398

run_network_hooks("stop", interfaces_hooks != NULL ?

2399

interfaces_hooks : "", delay);

2400

2401

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

2402

{

2403

char *interface = NULL;

2404

while((interface=argz_next(interfaces_to_take_down,

2405

interfaces_to_take_down_size,

2406

interface))){

2407

ret_errno = take_down_interface(interface);

2408

if(ret_errno != 0){

2409

errno = ret_errno;

2410

perror_plus("Failed to take down interface");

2411

}

2412

}

2413

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

2414

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

2415

" down\n");

2416

}

2417

}

2418

2419

lower_privileges_permanently();

2559

ret_errno = raise_privileges();

2560

if(ret_errno != 0){

2561

errno = ret_errno;

2562

perror_plus("Failed to raise privileges");

2563

} else {

2564

2565

/* Run network hooks */

2566

run_network_hooks("stop", interfaces_hooks != NULL ?

2567

interfaces_hooks : "", delay);

2568

2569

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

2570

{

2571

char *interface = NULL;

2572

while((interface=argz_next(interfaces_to_take_down,

2573

interfaces_to_take_down_size,

2574

interface))){

2575

ret_errno = take_down_interface(interface);

2576

if(ret_errno != 0){

2577

errno = ret_errno;

2578

perror_plus("Failed to take down interface");

2579

}

2580

}

2581

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

2582

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

2583

" down\n");

2584

}

2585

}

2586

}

2587

2588

ret_errno = lower_privileges_permanently();

2589

if(ret_errno != 0){

2590

errno = ret_errno;

2591

perror_plus("Failed to lower privileges permanently");

2592

}

2420

2593

}

2421

2594

2422

2595

free(interfaces_to_take_down);

2423

2596

free(interfaces_hooks);

2424

2597

2425

2598

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

2426

if(tempdir_created){

2599

if(tempdir != NULL){

2427

2600

struct dirent **direntries = NULL;

2428

struct dirent *direntry = NULL;

2429

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

2430

alphasort);

2431

if (numentries > 0){

2432

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

2433

direntry = direntries[i];

2434

char *fullname = NULL;

2435

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

2436

direntry->d_name);

2437

if(ret < 0){

2438

perror_plus("asprintf");

2439

continue;

2440

}

2441

ret = remove(fullname);

2442

if(ret == -1){

2443

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

2444

strerror(errno));

2445

}

2446

free(fullname);

2601

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

2602

O_NOFOLLOW));

2603

if(tempdir_fd == -1){

2604

perror_plus("open");

2605

} else {

2606

#ifdef __GLIBC__

2607

#if __GLIBC_PREREQ(2, 15)

2608

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

2609

notdotentries, alphasort);

2610

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

2611

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

2612

alphasort);

2613

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

2614

#else /* not __GLIBC__ */

2615

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

2616

alphasort);

2617

#endif /* not __GLIBC__ */

2618

if(numentries >= 0){

2619

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

2620

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

2621

if(ret == -1){

2622

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

2623

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

2624

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

2625

}

2626

}

2627

2628

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

2629

free(direntries);

2630

if(numentries == -1){

2631

perror_plus("scandir");

2632

}

2633

ret = rmdir(tempdir);

2634

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

2635

perror_plus("rmdir");

2636

}

2447

2637

}

2448

}

2449

2450

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

2451

free(direntries);

2452

if (numentries == -1){

2453

perror_plus("scandir");

2454

}

2455

ret = rmdir(tempdir);

2456

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

2457

perror_plus("rmdir");

2638

TEMP_FAILURE_RETRY(close(tempdir_fd));

2458

2639

}

2459

2640

}

2460

2641