/mandos/trunk : revision 712

9

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

10

*

11

* Everything else is

12

13

12

13

14

*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif

38

#endif /* not _FILE_OFFSET_BITS */

39

40

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

41

42

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

43

stdout, ferror(), remove() */

43

stdout, ferror() */

44

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

45

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

46

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

55

opendir(), DIR */

56

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

57

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

58

inet_pton(), connect() */

59

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

61

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

61

62

*/

62

63

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

63

64

strtoimax() */

64

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

65

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

66

program_invocation_short_name */

67

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

73

*/

74

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

75

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

76

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

77

#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,

92

93

argz_delete(), argz_append(),

93

94

argz_stringify(), argz_add(),

94

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

95

98

96

99

#ifdef __linux__

97

100

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

139

142

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

140

143

char *connect_to = NULL;

141

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

142

146

uid_t uid = 65534;

143

147

gid_t gid = 65534;

144

148

145

149

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

146

150

typedef struct server{

147

151

const char *ip;

148

uint16_t port;

152

in_port_t port;

149

153

AvahiIfIndex if_index;

150

154

int af;

151

155

struct timespec last_seen;

155

159

156

160

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

157

161

typedef struct {

158

AvahiSimplePoll *simple_poll;

159

162

AvahiServer *server;

160

163

gnutls_certificate_credentials_t cred;

161

164

unsigned int dh_bits;

163

166

const char *priority;

164

167

gpgme_ctx_t ctx;

165

168

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

166

171

} mandos_context;

167

172

168

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

169

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

170

.dh_bits = 1024, .priority = "SECURE256"

171

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

172

.current_server = NULL };

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

173

175

174

176

sig_atomic_t quit_now = 0;

175

177

int signal_received = 0;

183

185

perror(print_text);

184

186

}

185

187

186

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

188

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

187

189

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

188

190

va_list ap;

189

191

va_start (ap, format);

190

192

191

193

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

192

194

program_invocation_short_name));

193

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

195

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

194

196

}

195

197

196

198

/*

198

200

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

199

201

* "buffer_length" is how much is already used.

200

202

*/

203

__attribute__((nonnull, warn_unused_result))

201

204

size_t incbuffer(char **buffer, size_t buffer_length,

202

205

size_t buffer_capacity){

203

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

204

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

205

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;

206

213

return 0;

207

214

}

215

*buffer = new_buf;

208

216

buffer_capacity += BUFFER_SIZE;

209

217

}

210

218

return buffer_capacity;

211

219

}

212

220

213

221

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

214

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

215

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){

216

225

int ret;

217

226

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

218

227

if(new_server == NULL){

225

234

.af = af };

226

235

if(new_server->ip == NULL){

227

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);

228

245

return false;

229

246

}

230

247

/* Special case of first server */

231

if (mc.current_server == NULL){

248

if(*current_server == NULL){

232

249

new_server->next = new_server;

233

250

new_server->prev = new_server;

234

mc.current_server = new_server;

235

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

251

*current_server = new_server;

236

252

} else {

237

new_server->next = mc.current_server;

238

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;

239

256

new_server->prev->next = new_server;

240

mc.current_server->prev = new_server;

241

}

242

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

243

if(ret == -1){

244

perror_plus("clock_gettime");

245

return false;

257

(*current_server)->prev = new_server;

246

258

}

247

259

return true;

248

260

}

250

262

/*

251

263

* Initialize GPGME.

252

264

*/

253

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

254

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){

255

270

gpgme_error_t rc;

256

271

gpgme_engine_info_t engine_info;

257

272

258

259

273

/*

260

274

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

261

275

*/

262

bool import_key(const char *filename){

276

bool import_key(const char * const filename){

263

277

int ret;

264

278

int fd;

265

279

gpgme_data_t pgp_data;

277

291

return false;

278

292

}

279

293

280

rc = gpgme_op_import(mc.ctx, pgp_data);

294

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

281

295

if(rc != GPG_ERR_NO_ERROR){

282

296

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

283

297

gpgme_strsource(rc), gpgme_strerror(rc));

327

341

}

328

342

329

343

/* Create new GPGME "context" */

330

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

344

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

331

345

if(rc != GPG_ERR_NO_ERROR){

332

346

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

333

347

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

346

360

* Decrypt OpenPGP data.

347

361

* Returns -1 on error

348

362

*/

363

__attribute__((nonnull, warn_unused_result))

349

364

static ssize_t pgp_packet_decrypt(const char *cryptotext,

350

365

size_t crypto_size,

351

char **plaintext){

366

char **plaintext,

367

mandos_context *mc){

352

368

gpgme_data_t dh_crypto, dh_plain;

353

369

gpgme_error_t rc;

354

370

ssize_t ret;

380

396

381

397

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

382

398

data buffer */

383

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

399

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

384

400

if(rc != GPG_ERR_NO_ERROR){

385

401

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

386

402

gpgme_strsource(rc), gpgme_strerror(rc));

387

403

plaintext_length = -1;

388

404

if(debug){

389

405

gpgme_decrypt_result_t result;

390

result = gpgme_op_decrypt_result(mc.ctx);

406

result = gpgme_op_decrypt_result(mc->ctx);

391

407

if(result == NULL){

392

408

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

393

409

} else {

470

486

return plaintext_length;

471

487

}

472

488

473

static const char * safer_gnutls_strerror(int value){

474

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

475

-Wunreachable-code */

489

__attribute__((warn_unused_result))

490

static const char *safer_gnutls_strerror(int value){

491

const char *ret = gnutls_strerror(value);

476

492

if(ret == NULL)

477

493

ret = "(unknown)";

478

494

return ret;

479

495

}

480

496

481

497

/* GnuTLS log function callback */

498

__attribute__((nonnull))

482

499

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

483

500

const char* string){

484

501

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

485

502

}

486

503

504

__attribute__((nonnull, warn_unused_result))

487

505

static int init_gnutls_global(const char *pubkeyfilename,

488

const char *seckeyfilename){

506

const char *seckeyfilename,

507

mandos_context *mc){

489

508

int ret;

490

509

491

510

if(debug){

508

527

}

509

528

510

529

/* OpenPGP credentials */

511

ret = gnutls_certificate_allocate_credentials(&mc.cred);

530

ret = gnutls_certificate_allocate_credentials(&mc->cred);

512

531

if(ret != GNUTLS_E_SUCCESS){

513

532

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

514

533

safer_gnutls_strerror(ret));

524

543

}

525

544

526

545

ret = gnutls_certificate_set_openpgp_key_file

527

(mc.cred, pubkeyfilename, seckeyfilename,

546

(mc->cred, pubkeyfilename, seckeyfilename,

528

547

GNUTLS_OPENPGP_FMT_BASE64);

529

548

if(ret != GNUTLS_E_SUCCESS){

530

549

fprintf_plus(stderr,

536

555

}

537

556

538

557

/* GnuTLS server initialization */

539

ret = gnutls_dh_params_init(&mc.dh_params);

558

ret = gnutls_dh_params_init(&mc->dh_params);

540

559

if(ret != GNUTLS_E_SUCCESS){

541

560

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

542

561

" initialization: %s\n",

543

562

safer_gnutls_strerror(ret));

544

563

goto globalfail;

545

564

}

546

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

565

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

547

566

if(ret != GNUTLS_E_SUCCESS){

548

567

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

549

568

safer_gnutls_strerror(ret));

550

569

goto globalfail;

551

570

}

552

571

553

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

572

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

554

573

555

574

return 0;

556

575

557

576

globalfail:

558

577

559

gnutls_certificate_free_credentials(mc.cred);

578

gnutls_certificate_free_credentials(mc->cred);

560

579

gnutls_global_deinit();

561

gnutls_dh_params_deinit(mc.dh_params);

580

gnutls_dh_params_deinit(mc->dh_params);

562

581

return -1;

563

582

}

564

583

565

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){

566

587

int ret;

567

588

/* GnuTLS session creation */

568

589

do {

580

601

{

581

602

const char *err;

582

603

do {

583

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

604

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

584

605

if(quit_now){

585

606

gnutls_deinit(*session);

586

607

return -1;

597

618

598

619

do {

599

620

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

600

mc.cred);

621

mc->cred);

601

622

if(quit_now){

602

623

gnutls_deinit(*session);

603

624

return -1;

613

634

/* ignore client certificate if any. */

614

635

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

615

636

616

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

637

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

617

638

618

639

return 0;

619

640

}

623

644

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

624

645

625

646

/* Called when a Mandos server is found */

626

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

647

__attribute__((nonnull, warn_unused_result))

648

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

627

649

AvahiIfIndex if_index,

628

int af){

650

int af, mandos_context *mc){

629

651

int ret, tcp_sd = -1;

630

652

ssize_t sret;

631

union {

632

struct sockaddr_in in;

633

struct sockaddr_in6 in6;

634

} to;

653

struct sockaddr_storage to;

635

654

char *buffer = NULL;

636

655

char *decrypted_buffer = NULL;

637

656

size_t buffer_length = 0;

661

680

return -1;

662

681

}

663

682

664

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);

665

716

if(ret != 0){

666

717

return -1;

667

718

}

668

719

669

720

if(debug){

670

721

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

671

PRIu16 "\n", ip, port);

722

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

672

723

}

673

724

674

725

tcp_sd = socket(pf, SOCK_STREAM, 0);

686

737

687

738

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

688

739

if(af == AF_INET6){

689

to.in6.sin6_family = (sa_family_t)af;

690

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);

691

742

} else { /* IPv4 */

692

to.in.sin_family = (sa_family_t)af;

693

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);

694

745

}

695

746

if(ret < 0 ){

696

747

int e = errno;

705

756

goto mandos_end;

706

757

}

707

758

if(af == AF_INET6){

708

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

709

-Wconversion and

710

-Wunreachable-code */

711

712

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

713

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

714

-Wunreachable-code*/

759

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

760

if(IN6_IS_ADDR_LINKLOCAL

761

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

715

762

if(if_index == AVAHI_IF_UNSPEC){

716

763

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

717

764

" incomplete without a network interface\n");

719

766

goto mandos_end;

720

767

}

721

768

/* Set the network interface number as scope */

722

to.in6.sin6_scope_id = (uint32_t)if_index;

769

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

723

770

}

724

771

} else {

725

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

726

-Wconversion and

727

-Wunreachable-code */

772

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

728

773

}

729

774

730

775

if(quit_now){

738

783

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

739

784

perror_plus("if_indextoname");

740

785

} else {

741

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

742

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

786

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

787

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

743

788

}

744

789

} else {

745

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

746

ip, port);

790

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

791

ip, (uintmax_t)port);

747

792

}

748

793

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

749

794

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

750

const char *pcret;

751

795

if(af == AF_INET6){

752

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

753

sizeof(addrstr));

796

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

797

sizeof(struct sockaddr_in6),

798

addrstr, sizeof(addrstr), NULL, 0,

799

NI_NUMERICHOST);

754

800

} else {

755

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

756

sizeof(addrstr));

801

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

802

sizeof(struct sockaddr_in),

803

addrstr, sizeof(addrstr), NULL, 0,

804

NI_NUMERICHOST);

757

805

}

758

if(pcret == NULL){

759

perror_plus("inet_ntop");

760

} else {

761

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

762

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

763

}

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);

764

812

}

765

813

}

766

814

770

818

}

771

819

772

820

if(af == AF_INET6){

773

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

821

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

822

sizeof(struct sockaddr_in6));

774

823

} else {

775

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

824

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

825

sizeof(struct sockaddr_in));

776

826

}

777

827

if(ret < 0){

778

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

828

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

779

829

int e = errno;

780

830

perror_plus("connect");

781

831

errno = e;

942

992

if(buffer_length > 0){

943

993

ssize_t decrypted_buffer_size;

944

994

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

945

&decrypted_buffer);

995

&decrypted_buffer, mc);

946

996

if(decrypted_buffer_size >= 0){

947

997

948

998

written = 0;

996

1046

return retval;

997

1047

}

998

1048

1049

__attribute__((nonnull))

999

1050

static void resolve_callback(AvahiSServiceResolver *r,

1000

1051

AvahiIfIndex interface,

1001

1052

AvahiProtocol proto,

1009

1060

AVAHI_GCC_UNUSED AvahiStringList *txt,

1010

1061

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1011

1062

flags,

1012

AVAHI_GCC_UNUSED void* userdata){

1013

assert(r);

1063

void *mc){

1064

if(r == NULL){

1065

return;

1066

}

1014

1067

1015

1068

/* Called whenever a service has been resolved successfully or

1016

1069

timed out */

1025

1078

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

1026

1079

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

1027

1080

domain,

1028

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_strerror(avahi_server_errno

1082

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

1029

1083

break;

1030

1084

1031

1085

case AVAHI_RESOLVER_FOUND:

1037

1091

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

1038

1092

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

1039

1093

}

1040

int ret = start_mandos_communication(ip, port, interface,

1041

avahi_proto_to_af(proto));

1094

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

1095

interface,

1096

avahi_proto_to_af(proto),

1097

mc);

1042

1098

if(ret == 0){

1043

avahi_simple_poll_quit(mc.simple_poll);

1099

avahi_simple_poll_quit(simple_poll);

1044

1100

} else {

1045

if(not add_server(ip, port, interface,

1046

avahi_proto_to_af(proto))){

1101

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

1102

avahi_proto_to_af(proto),

1103

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

1047

1104

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

1048

1105

" list\n", name);

1049

1106

}

1062

1119

const char *domain,

1063

1120

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1064

1121

flags,

1065

AVAHI_GCC_UNUSED void* userdata){

1066

assert(b);

1122

void *mc){

1123

if(b == NULL){

1124

return;

1125

}

1067

1126

1068

1127

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

1069

1128

is removed from the LAN */

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;

1448

struct dirent *direntry;

1449

int ret;

1450

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

1451

alphasort);

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__ */

1452

1539

if(numhooks == -1){

1453

1540

perror_plus("scandir");

1454

} else {

1455

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

1456

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

1457

direntry = direntries[i];

1458

char *fullname = NULL;

1459

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

1460

if(ret < 0){

1541

return;

1542

}

1543

struct dirent *direntry;

1544

int ret;

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);

1551

}

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){

1461

1613

perror_plus("asprintf");

1462

continue;

1463

}

1464

if(debug){

1465

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

1466

direntry->d_name);

1467

}

1468

pid_t hook_pid = fork();

1469

if(hook_pid == 0){

1470

/* Child */

1471

/* Raise privileges */

1472

raise_privileges_permanently();

1473

/* Set group */

1474

errno = 0;

1475

ret = setgid(0);

1476

if(ret == -1){

1477

perror_plus("setgid");

1478

}

1479

/* Reset supplementary groups */

1480

errno = 0;

1481

ret = setgroups(0, NULL);

1482

if(ret == -1){

1483

perror_plus("setgroups");

1484

}

1485

dup2(devnull, STDIN_FILENO);

1486

close(devnull);

1487

dup2(STDERR_FILENO, STDOUT_FILENO);

1488

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

1489

if(ret == -1){

1490

perror_plus("setenv");

1491

_exit(EX_OSERR);

1492

}

1493

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

1494

if(ret == -1){

1495

perror_plus("setenv");

1496

_exit(EX_OSERR);

1497

}

1498

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

1499

if(ret == -1){

1500

perror_plus("setenv");

1501

_exit(EX_OSERR);

1502

}

1503

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

1504

if(ret == -1){

1505

perror_plus("setenv");

1506

_exit(EX_OSERR);

1507

}

1508

char *delaystring;

1509

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

1510

if(ret == -1){

1511

perror_plus("asprintf");

1512

_exit(EX_OSERR);

1513

}

1514

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

1515

if(ret == -1){

1516

free(delaystring);

1517

perror_plus("setenv");

1518

_exit(EX_OSERR);

1519

}

1614

_exit(EX_OSERR);

1615

}

1616

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

1617

if(ret == -1){

1520

1618

free(delaystring);

1521

if(connect_to != NULL){

1522

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

1523

if(ret == -1){

1524

perror_plus("setenv");

1525

_exit(EX_OSERR);

1526

}

1527

}

1528

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

1529

perror_plus("execl");

1530

_exit(EXIT_FAILURE);

1531

}

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;

1532

1662

} else {

1533

int status;

1534

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

1535

perror_plus("waitpid");

1536

free(fullname);

1537

continue;

1538

}

1539

if(WIFEXITED(status)){

1540

if(WEXITSTATUS(status) != 0){

1541

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

1542

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

1543

WEXITSTATUS(status));

1544

free(fullname);

1545

continue;

1546

}

1547

} else if(WIFSIGNALED(status)){

1548

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

1549

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

1550

WTERMSIG(status));

1551

free(fullname);

1552

continue;

1553

} else {

1554

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

1555

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

1556

free(fullname);

1557

continue;

1558

}

1559

}

1560

free(fullname);

1561

if(debug){

1562

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

1563

direntry->d_name);

1564

}

1565

}

1566

close(devnull);

1567

}

1568

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);

1569

1680

}

1570

1681

1682

__attribute__((nonnull, warn_unused_result))

1571

1683

error_t bring_up_interface(const char *const interface,

1572

1684

const float delay){

1573

int sd = -1;

1574

1685

error_t old_errno = errno;

1575

error_t ret_errno = 0;

1576

int ret, ret_setflags;

1686

int ret;

1577

1687

struct ifreq network;

1578

1688

unsigned int if_index = if_nametoindex(interface);

1579

1689

if(if_index == 0){

1588

1698

}

1589

1699

1590

1700

if(not interface_is_up(interface)){

1591

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

1701

error_t ret_errno = 0, ioctl_errno = 0;

1702

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

1592

1703

ret_errno = errno;

1593

1704

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

1594

1705

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

1706

errno = old_errno;

1595

1707

return ret_errno;

1596

1708

}

1597

network.ifr_flags |= IFF_UP;

1709

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

1598

1710

1599

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1600

if(sd < 0){

1711

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

1712

if(sd == -1){

1601

1713

ret_errno = errno;

1602

1714

perror_plus("socket");

1603

1715

errno = old_errno;

1604

1716

return ret_errno;

1605

1717

}

1606

1718

1607

1719

if(quit_now){

1608

close(sd);

1720

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

1721

if(ret == -1){

1722

perror_plus("close");

1723

}

1609

1724

errno = old_errno;

1610

1725

return EINTR;

1611

1726

}

1615

1730

interface);

1616

1731

}

1617

1732

1618

/* Raise priviliges */

1619

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

}

1620

1739

1621

1740

#ifdef __linux__

1622

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1623

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

1624

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

1625

bool restore_loglevel = true;

1626

if(ret_linux == -1){

1627

restore_loglevel = false;

1628

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

}

1629

1752

}

1630

1753

#endif /* __linux__ */

1631

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

1632

ret_errno = errno;

1754

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

1755

ioctl_errno = errno;

1633

1756

#ifdef __linux__

1634

1757

if(restore_loglevel){

1635

1758

ret_linux = klogctl(7, NULL, 0);

1639

1762

}

1640

1763

#endif /* __linux__ */

1641

1764

1642

/* Lower privileges */

1643

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

}

1644

1774

1645

1775

/* Close the socket */

1646

1776

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

1649

1779

}

1650

1780

1651

1781

if(ret_setflags == -1){

1652

errno = ret_errno;

1782

errno = ioctl_errno;

1653

1783

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1654

1784

errno = old_errno;

1655

return ret_errno;

1785

return ioctl_errno;

1656

1786

}

1657

1787

} else if(debug){

1658

1788

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

1676

1806

return 0;

1677

1807

}

1678

1808

1809

__attribute__((nonnull, warn_unused_result))

1679

1810

error_t take_down_interface(const char *const interface){

1680

int sd = -1;

1681

1811

error_t old_errno = errno;

1682

error_t ret_errno = 0;

1683

int ret, ret_setflags;

1684

1812

struct ifreq network;

1685

1813

unsigned int if_index = if_nametoindex(interface);

1686

1814

if(if_index == 0){

1689

1817

return ENXIO;

1690

1818

}

1691

1819

if(interface_is_up(interface)){

1820

error_t ret_errno = 0, ioctl_errno = 0;

1692

1821

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

1693

1822

ret_errno = errno;

1694

1823

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

1695

1824

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

1825

errno = old_errno;

1696

1826

return ret_errno;

1697

1827

}

1698

1828

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

1699

1829

1700

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1701

if(sd < 0){

1830

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

1831

if(sd == -1){

1702

1832

ret_errno = errno;

1703

1833

perror_plus("socket");

1704

1834

errno = old_errno;

1710

1840

interface);

1711

1841

}

1712

1842

1713

/* Raise priviliges */

1714

raise_privileges();

1715

1716

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

1717

ret_errno = errno;

1718

1719

/* Lower privileges */

1720

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

}

1721

1862

1722

1863

/* Close the socket */

1723

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

1864

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

1724

1865

if(ret == -1){

1725

1866

perror_plus("close");

1726

1867

}

1727

1868

1728

1869

if(ret_setflags == -1){

1729

errno = ret_errno;

1870

errno = ioctl_errno;

1730

1871

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1731

1872

errno = old_errno;

1732

return ret_errno;

1873

return ioctl_errno;

1733

1874

}

1734

1875

} else if(debug){

1735

1876

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

1741

1882

}

1742

1883

1743

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 };

1744

1889

AvahiSServiceBrowser *sb = NULL;

1745

1890

error_t ret_errno;

1746

1891

int ret;

1747

1892

intmax_t tmpmax;

1748

1893

char *tmp;

1749

1894

int exitcode = EXIT_SUCCESS;

1750

char *interfaces = NULL;

1751

size_t interfaces_size = 0;

1752

1895

char *interfaces_to_take_down = NULL;

1753

1896

size_t interfaces_to_take_down_size = 0;

1754

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

1755

bool tempdir_created = false;

1897

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

1898

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

1899

char *tempdir = NULL;

1756

1900

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1757

1901

const char *seckey = PATHDIR "/" SECKEY;

1758

1902

const char *pubkey = PATHDIR "/" PUBKEY;

1759

1903

char *interfaces_hooks = NULL;

1760

size_t interfaces_hooks_size = 0;

1761

1904

1762

1905

bool gnutls_initialized = false;

1763

1906

bool gpgme_initialized = false;

1854

1997

connect_to = arg;

1855

1998

break;

1856

1999

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

1857

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

1858

(int)',');

2000

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

2001

arg, (int)',');

1859

2002

if(ret_errno != 0){

1860

2003

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

1861

2004

}

1941

2084

/* Work around Debian bug #633582:

1942

2085

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

1943

2086

1944

/* Re-raise priviliges */

1945

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 {

1946

2093

struct stat st;

1947

2094

1948

2095

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

1988

2135

}

1989

2136

1990

2137

/* Lower privileges */

1991

errno = 0;

1992

ret = seteuid(uid);

1993

if(ret == -1){

1994

perror_plus("seteuid");

2138

ret_errno = lower_privileges();

2139

if(ret_errno != 0){

2140

errno = ret_errno;

2141

perror_plus("Failed to lower privileges");

1995

2142

}

1996

2143

}

1997

2144

}

1998

2145

1999

/* Remove empty interface names */

2146

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

2000

2147

{

2001

2148

char *interface = NULL;

2002

while((interface = argz_next(interfaces, interfaces_size,

2149

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

2003

2150

interface))){

2004

if(if_nametoindex(interface) == 0){

2005

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'){

2006

2154

fprintf_plus(stderr, "Not using nonexisting interface"

2007

2155

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

2008

2156

}

2009

argz_delete(&interfaces, &interfaces_size, interface);

2157

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

2010

2158

interface = NULL;

2011

2159

}

2012

2160

}

2014

2162

2015

2163

/* Run network hooks */

2016

2164

{

2017

ret_errno = argz_append(&interfaces_hooks, &interfaces_hooks_size,

2018

interfaces, interfaces_size);

2019

if(ret_errno != 0){

2020

errno = ret_errno;

2021

perror_plus("argz_append");

2022

goto end;

2023

}

2024

argz_stringify(interfaces_hooks, interfaces_hooks_size, (int)',');

2025

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

2026

goto end;

2027

}

2165

if(mc.interfaces != NULL){

2166

interfaces_hooks = malloc(mc.interfaces_size);

2167

if(interfaces_hooks == NULL){

2168

perror_plus("malloc");

2169

goto end;

2170

}

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);

2028

2176

}

2029

2177

2030

2178

if(not debug){

2035

2183

from the signal handler */

2036

2184

/* Initialize the pseudo-RNG for Avahi */

2037

2185

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

2038

mc.simple_poll = avahi_simple_poll_new();

2039

if(mc.simple_poll == NULL){

2186

simple_poll = avahi_simple_poll_new();

2187

if(simple_poll == NULL){

2040

2188

fprintf_plus(stderr,

2041

2189

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

2042

2190

exitcode = EX_UNAVAILABLE;

2107

2255

}

2108

2256

2109

2257

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

2110

if(interfaces == NULL){

2111

struct dirent **direntries;

2258

if(mc.interfaces == NULL){

2259

struct dirent **direntries = NULL;

2112

2260

/* Look for any good interfaces */

2113

2261

ret = scandir(sys_class_net, &direntries, good_interface,

2114

2262

alphasort);

2115

2263

if(ret >= 1){

2116

2264

/* Add all found interfaces to interfaces list */

2117

2265

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

2118

ret_errno = argz_add(&interfaces, &interfaces_size,

2266

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

2119

2267

direntries[i]->d_name);

2120

2268

if(ret_errno != 0){

2269

errno = ret_errno;

2121

2270

perror_plus("argz_add");

2122

2271

continue;

2123

2272

}

2128

2277

}

2129

2278

free(direntries);

2130

2279

} else {

2131

free(direntries);

2280

if(ret == 0){

2281

free(direntries);

2282

}

2132

2283

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

2133

2284

exitcode = EXIT_FAILURE;

2134

2285

goto end;

2135

2286

}

2136

2287

}

2137

2288

2138

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

2139

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

2140

if(debug){

2141

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

2142

interfaces);

2143

}

2144

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2145

}

2146

2147

/* Bring up interfaces which are down */

2148

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

2149

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

2289

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

2290

{

2150

2291

char *interface = NULL;

2151

while((interface = argz_next(interfaces, interfaces_size,

2292

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

2152

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

}

2153

2310

bool interface_was_up = interface_is_up(interface);

2154

ret = bring_up_interface(interface, delay);

2311

errno = bring_up_interface(interface, delay);

2155

2312

if(not interface_was_up){

2156

if(ret != 0){

2157

errno = ret;

2313

if(errno != 0){

2158

2314

perror_plus("Failed to bring up interface");

2159

2315

} else {

2160

ret_errno = argz_add(&interfaces_to_take_down,

2161

&interfaces_to_take_down_size,

2162

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

}

2163

2322

}

2164

2323

}

2165

2324

}

2166

free(interfaces);

2167

interfaces = NULL;

2168

interfaces_size = 0;

2169

2325

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

2170

2326

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

2171

2327

}

2172

2328

}

2173

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

2174

2339

if(quit_now){

2175

2340

goto end;

2176

2341

}

2177

2342

2178

ret = init_gnutls_global(pubkey, seckey);

2343

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

2179

2344

if(ret == -1){

2180

2345

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

2181

2346

exitcode = EX_UNAVAILABLE;

2188

2353

goto end;

2189

2354

}

2190

2355

2191

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){

2192

2366

perror_plus("mkdtemp");

2193

2367

goto end;

2194

2368

}

2195

tempdir_created = true;

2196

2369

2197

2370

if(quit_now){

2198

2371

goto end;

2199

2372

}

2200

2373

2201

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

2374

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

2202

2375

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

2203

2376

exitcode = EX_UNAVAILABLE;

2204

2377

goto end;

2225

2398

goto end;

2226

2399

}

2227

2400

2228

uint16_t port;

2401

in_port_t port;

2229

2402

errno = 0;

2230

2403

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

2231

2404

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

2232

or tmpmax != (uint16_t)tmpmax){

2405

or tmpmax != (in_port_t)tmpmax){

2233

2406

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

2234

2407

exitcode = EX_USAGE;

2235

2408

goto end;

2236

2409

}

2237

2410

2238

2411

if(quit_now){

2239

2412

goto end;

2240

2413

}

2241

2414

2242

port = (uint16_t)tmpmax;

2415

port = (in_port_t)tmpmax;

2243

2416

*address = '\0';

2244

2417

/* Colon in address indicates IPv6 */

2245

2418

int af;

2261

2434

}

2262

2435

2263

2436

while(not quit_now){

2264

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

2437

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

2438

&mc);

2265

2439

if(quit_now or ret == 0){

2266

2440

break;

2267

2441

}

2269

2443

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

2270

2444

(int)retry_interval);

2271

2445

}

2272

sleep((int)retry_interval);

2446

sleep((unsigned int)retry_interval);

2273

2447

}

2274

2448

2275

if (not quit_now){

2449

if(not quit_now){

2276

2450

exitcode = EXIT_SUCCESS;

2277

2451

}

2278

2452

2293

2467

config.publish_domain = 0;

2294

2468

2295

2469

/* Allocate a new server */

2296

mc.server = avahi_server_new(avahi_simple_poll_get

2297

(mc.simple_poll), &config, NULL,

2298

NULL, &ret_errno);

2470

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2471

&config, NULL, NULL, &ret_errno);

2299

2472

2300

2473

/* Free the Avahi configuration data */

2301

2474

avahi_server_config_free(&config);

2316

2489

/* Create the Avahi service browser */

2317

2490

sb = avahi_s_service_browser_new(mc.server, if_index,

2318

2491

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2319

NULL, 0, browse_callback, NULL);

2492

NULL, 0, browse_callback,

2493

(void *)&mc);

2320

2494

if(sb == NULL){

2321

2495

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

2322

2496

avahi_strerror(avahi_server_errno(mc.server)));

2333

2507

if(debug){

2334

2508

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

2335

2509

}

2336

2337

ret = avahi_loop_with_timeout(mc.simple_poll,

2338

(int)(retry_interval * 1000));

2510

2511

ret = avahi_loop_with_timeout(simple_poll,

2512

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

2339

2513

if(debug){

2340

2514

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

2341

2515

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

2348

2522

}

2349

2523

2350

2524

/* Cleanup things */

2525

free(mc.interfaces);

2526

2351

2527

if(sb != NULL)

2352

2528

avahi_s_service_browser_free(sb);

2353

2529

2354

2530

if(mc.server != NULL)

2355

2531

avahi_server_free(mc.server);

2356

2532

2357

if(mc.simple_poll != NULL)

2358

avahi_simple_poll_free(mc.simple_poll);

2533

if(simple_poll != NULL)

2534

avahi_simple_poll_free(simple_poll);

2359

2535

2360

2536

if(gnutls_initialized){

2361

2537

gnutls_certificate_free_credentials(mc.cred);

2378

2554

}

2379

2555

}

2380

2556

2381

/* Re-raise priviliges */

2557

/* Re-raise privileges */

2382

2558

{

2383

raise_privileges();

2384

2385

/* Run network hooks */

2386

run_network_hooks("stop", interfaces_hooks, delay);

2387

2388

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

2389

{

2390

char *interface = NULL;

2391

while((interface=argz_next(interfaces_to_take_down,

2392

interfaces_to_take_down_size,

2393

interface))){

2394

ret_errno = take_down_interface(interface);

2395

if(ret_errno != 0){

2396

errno = ret_errno;

2397

perror_plus("Failed to take down interface");

2398

}

2399

}

2400

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

2401

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

2402

" down\n");

2403

}

2404

}

2405

2406

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

}

2407

2593

}

2408

2594

2409

2595

free(interfaces_to_take_down);

2410

2596

free(interfaces_hooks);

2411

2597

2412

2598

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

2413

if(tempdir_created){

2599

if(tempdir != NULL){

2414

2600

struct dirent **direntries = NULL;

2415

struct dirent *direntry = NULL;

2416

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

2417

alphasort);

2418

if (numentries > 0){

2419

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

2420

direntry = direntries[i];

2421

char *fullname = NULL;

2422

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

2423

direntry->d_name);

2424

if(ret < 0){

2425

perror_plus("asprintf");

2426

continue;

2427

}

2428

ret = remove(fullname);

2429

if(ret == -1){

2430

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

2431

strerror(errno));

2432

}

2433

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

}

2434

2637

}

2435

}

2436

2437

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

2438

free(direntries);

2439

if (numentries == -1){

2440

perror_plus("scandir");

2441

}

2442

ret = rmdir(tempdir);

2443

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

2444

perror_plus("rmdir");

2638

TEMP_FAILURE_RETRY(close(tempdir_fd));

2445

2639

}

2446

2640

}

2447

2641