/mandos/trunk : revision 599

9

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

10

*

11

* Everything else is

12

13

12

13

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*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

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

41

42

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

43

stdout, ferror() */

43

stdout, ferror(), remove() */

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

getnameinfo() */

60

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

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inet_pton(), connect() */

59

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

61

60

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

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61

*/

63

62

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

73

72

*/

74

73

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

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74

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

76

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

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unlinkat() */

78

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

75

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

76

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

79

77

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

80

78

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

81

79

argp_state, struct argp,

93

91

argz_delete(), argz_append(),

94

92

argz_stringify(), argz_add(),

95

93

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

98

94

99

95

#ifdef __linux__

100

96

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

142

138

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

143

139

char *connect_to = NULL;

144

140

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

141

uid_t uid = 65534;

147

142

gid_t gid = 65534;

148

143

159

154

160

155

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

161

156

typedef struct {

157

AvahiSimplePoll *simple_poll;

162

158

AvahiServer *server;

163

159

gnutls_certificate_credentials_t cred;

164

160

unsigned int dh_bits;

166

162

const char *priority;

167

163

gpgme_ctx_t ctx;

168

164

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

171

165

} mandos_context;

172

166

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

167

/* 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 };

175

172

176

173

sig_atomic_t quit_now = 0;

177

174

int signal_received = 0;

185

182

perror(print_text);

186

183

}

187

184

188

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

185

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

189

186

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

190

187

va_list ap;

191

188

va_start (ap, format);

192

189

193

190

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

194

191

program_invocation_short_name));

195

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

192

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

196

193

}

197

194

198

195

/*

200

197

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

201

198

* "buffer_length" is how much is already used.

202

199

*/

203

__attribute__((nonnull, warn_unused_result))

204

200

size_t incbuffer(char **buffer, size_t buffer_length,

205

201

size_t buffer_capacity){

206

202

if(buffer_length + BUFFER_SIZE > buffer_capacity){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

203

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

204

if(buffer == NULL){

213

205

return 0;

214

206

}

215

*buffer = new_buf;

216

207

buffer_capacity += BUFFER_SIZE;

217

208

}

218

209

return buffer_capacity;

219

210

}

220

211

221

212

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

222

__attribute__((nonnull, warn_unused_result))

223

213

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

224

int af, server **current_server){

214

int af){

225

215

int ret;

226

216

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

227

217

if(new_server == NULL){

236

226

perror_plus("strdup");

237

227

return false;

238

228

}

239

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

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

244

229

/* Special case of first server */

245

if(*current_server == NULL){

230

if (mc.current_server == NULL){

246

231

new_server->next = new_server;

247

232

new_server->prev = new_server;

248

*current_server = new_server;

233

mc.current_server = new_server;

234

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

249

235

} else {

250

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

251

new_server->next = *current_server;

252

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

236

new_server->next = mc.current_server;

237

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

253

238

new_server->prev->next = new_server;

254

(*current_server)->prev = 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;

255

245

}

256

246

return true;

257

247

}

259

249

/*

260

250

* Initialize GPGME.

261

251

*/

262

__attribute__((nonnull, warn_unused_result))

263

static bool init_gpgme(const char * const seckey,

264

const char * const pubkey,

265

const char * const tempdir,

266

mandos_context *mc){

252

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

253

const char *tempdir){

267

254

gpgme_error_t rc;

268

255

gpgme_engine_info_t engine_info;

269

256

257

270

258

/*

271

259

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

272

260

*/

273

bool import_key(const char * const filename){

261

bool import_key(const char *filename){

274

262

int ret;

275

263

int fd;

276

264

gpgme_data_t pgp_data;

288

276

return false;

289

277

}

290

278

291

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

279

rc = gpgme_op_import(mc.ctx, pgp_data);

292

280

if(rc != GPG_ERR_NO_ERROR){

293

281

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

294

282

gpgme_strsource(rc), gpgme_strerror(rc));

338

326

}

339

327

340

328

/* Create new GPGME "context" */

341

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

329

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

342

330

if(rc != GPG_ERR_NO_ERROR){

343

331

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

344

332

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

357

345

* Decrypt OpenPGP data.

358

346

* Returns -1 on error

359

347

*/

360

__attribute__((nonnull, warn_unused_result))

361

348

static ssize_t pgp_packet_decrypt(const char *cryptotext,

362

349

size_t crypto_size,

363

char **plaintext,

364

mandos_context *mc){

350

char **plaintext){

365

351

gpgme_data_t dh_crypto, dh_plain;

366

352

gpgme_error_t rc;

367

353

ssize_t ret;

393

379

394

380

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

395

381

data buffer */

396

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

382

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

397

383

if(rc != GPG_ERR_NO_ERROR){

398

384

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

399

385

gpgme_strsource(rc), gpgme_strerror(rc));

400

386

plaintext_length = -1;

401

387

if(debug){

402

388

gpgme_decrypt_result_t result;

403

result = gpgme_op_decrypt_result(mc->ctx);

389

result = gpgme_op_decrypt_result(mc.ctx);

404

390

if(result == NULL){

405

391

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

406

392

} else {

483

469

return plaintext_length;

484

470

}

485

471

486

__attribute__((warn_unused_result))

487

static const char *safer_gnutls_strerror(int value){

472

static const char * safer_gnutls_strerror(int value){

488

473

const char *ret = gnutls_strerror(value);

489

474

if(ret == NULL)

490

475

ret = "(unknown)";

492

477

}

493

478

494

479

/* GnuTLS log function callback */

495

__attribute__((nonnull))

496

480

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

497

481

const char* string){

498

482

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

499

483

}

500

484

501

__attribute__((nonnull, warn_unused_result))

502

485

static int init_gnutls_global(const char *pubkeyfilename,

503

const char *seckeyfilename,

504

mandos_context *mc){

486

const char *seckeyfilename){

505

487

int ret;

506

488

507

489

if(debug){

524

506

}

525

507

526

508

/* OpenPGP credentials */

527

ret = gnutls_certificate_allocate_credentials(&mc->cred);

509

ret = gnutls_certificate_allocate_credentials(&mc.cred);

528

510

if(ret != GNUTLS_E_SUCCESS){

529

511

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

530

512

safer_gnutls_strerror(ret));

540

522

}

541

523

542

524

ret = gnutls_certificate_set_openpgp_key_file

543

(mc->cred, pubkeyfilename, seckeyfilename,

525

(mc.cred, pubkeyfilename, seckeyfilename,

544

526

GNUTLS_OPENPGP_FMT_BASE64);

545

527

if(ret != GNUTLS_E_SUCCESS){

546

528

fprintf_plus(stderr,

552

534

}

553

535

554

536

/* GnuTLS server initialization */

555

ret = gnutls_dh_params_init(&mc->dh_params);

537

ret = gnutls_dh_params_init(&mc.dh_params);

556

538

if(ret != GNUTLS_E_SUCCESS){

557

539

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

558

540

" initialization: %s\n",

559

541

safer_gnutls_strerror(ret));

560

542

goto globalfail;

561

543

}

562

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

544

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

563

545

if(ret != GNUTLS_E_SUCCESS){

564

546

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

565

547

safer_gnutls_strerror(ret));

566

548

goto globalfail;

567

549

}

568

550

569

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

551

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

570

552

571

553

return 0;

572

554

573

555

globalfail:

574

556

575

gnutls_certificate_free_credentials(mc->cred);

557

gnutls_certificate_free_credentials(mc.cred);

576

558

gnutls_global_deinit();

577

gnutls_dh_params_deinit(mc->dh_params);

559

gnutls_dh_params_deinit(mc.dh_params);

578

560

return -1;

579

561

}

580

562

581

__attribute__((nonnull, warn_unused_result))

582

static int init_gnutls_session(gnutls_session_t *session,

583

mandos_context *mc){

563

static int init_gnutls_session(gnutls_session_t *session){

584

564

int ret;

585

565

/* GnuTLS session creation */

586

566

do {

598

578

{

599

579

const char *err;

600

580

do {

601

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

581

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

602

582

if(quit_now){

603

583

gnutls_deinit(*session);

604

584

return -1;

615

595

616

596

do {

617

597

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

618

mc->cred);

598

mc.cred);

619

599

if(quit_now){

620

600

gnutls_deinit(*session);

621

601

return -1;

631

611

/* ignore client certificate if any. */

632

612

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

633

613

634

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

614

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

635

615

636

616

return 0;

637

617

}

641

621

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

642

622

643

623

/* Called when a Mandos server is found */

644

__attribute__((nonnull, warn_unused_result))

645

624

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

646

625

AvahiIfIndex if_index,

647

int af, mandos_context *mc){

626

int af){

648

627

int ret, tcp_sd = -1;

649

628

ssize_t sret;

650

struct sockaddr_storage to;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

651

633

char *buffer = NULL;

652

634

char *decrypted_buffer = NULL;

653

635

size_t buffer_length = 0;

677

659

return -1;

678

660

}

679

661

680

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

681

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

682

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

683

bool match = false;

684

{

685

char *interface = NULL;

686

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

687

interface))){

688

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

689

match = true;

690

break;

691

}

692

}

693

}

694

if(not match){

695

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

696

connect to the server */

697

if(debug){

698

char interface[IF_NAMESIZE];

699

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

700

perror_plus("if_indextoname");

701

} else {

702

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

703

" \"%s\"\n",

704

if_indextoname((unsigned int)if_index,

705

interface));

706

}

707

}

708

return -1;

709

}

710

}

711

712

ret = init_gnutls_session(&session, mc);

662

ret = init_gnutls_session(&session);

713

663

if(ret != 0){

714

664

return -1;

715

665

}

734

684

735

685

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

736

686

if(af == AF_INET6){

737

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

738

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

687

to.in6.sin6_family = (sa_family_t)af;

688

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

739

689

} else { /* IPv4 */

740

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

741

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

690

to.in.sin_family = (sa_family_t)af;

691

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

742

692

}

743

693

if(ret < 0 ){

744

694

int e = errno;

753

703

goto mandos_end;

754

704

}

755

705

if(af == AF_INET6){

756

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

757

if(IN6_IS_ADDR_LINKLOCAL

758

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

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

710

if(if_index == AVAHI_IF_UNSPEC){

760

711

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

761

712

" incomplete without a network interface\n");

763

714

goto mandos_end;

764

715

}

765

716

/* Set the network interface number as scope */

766

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

717

to.in6.sin6_scope_id = (uint32_t)if_index;

767

718

}

768

719

} else {

769

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

720

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

721

-Wconversion and

722

-Wunreachable-code */

770

723

}

771

724

772

725

if(quit_now){

789

742

}

790

743

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

791

744

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

745

const char *pcret;

792

746

if(af == AF_INET6){

793

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

794

sizeof(struct sockaddr_in6),

795

addrstr, sizeof(addrstr), NULL, 0,

796

NI_NUMERICHOST);

747

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

748

sizeof(addrstr));

797

749

} else {

798

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

799

sizeof(struct sockaddr_in),

800

addrstr, sizeof(addrstr), NULL, 0,

801

NI_NUMERICHOST);

750

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

751

sizeof(addrstr));

802

752

}

803

if(ret == EAI_SYSTEM){

804

perror_plus("getnameinfo");

805

} else if(ret != 0) {

806

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

807

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

808

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

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

}

809

759

}

810

760

}

811

761

815

765

}

816

766

817

767

if(af == AF_INET6){

818

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

819

sizeof(struct sockaddr_in6));

768

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

820

769

} else {

821

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

822

sizeof(struct sockaddr_in));

770

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

823

771

}

824

772

if(ret < 0){

825

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

773

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

826

774

int e = errno;

827

775

perror_plus("connect");

828

776

errno = e;

989

937

if(buffer_length > 0){

990

938

ssize_t decrypted_buffer_size;

991

939

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

992

&decrypted_buffer, mc);

940

&decrypted_buffer);

993

941

if(decrypted_buffer_size >= 0){

994

942

995

943

written = 0;

1043

991

return retval;

1044

992

}

1045

993

1046

__attribute__((nonnull))

1047

994

static void resolve_callback(AvahiSServiceResolver *r,

1048

995

AvahiIfIndex interface,

1049

996

AvahiProtocol proto,

1057

1004

AVAHI_GCC_UNUSED AvahiStringList *txt,

1058

1005

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1059

1006

flags,

1060

void *mc){

1007

AVAHI_GCC_UNUSED void* userdata){

1061

1008

if(r == NULL){

1062

1009

return;

1063

1010

}

1075

1022

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

1076

1023

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

1077

1024

domain,

1078

avahi_strerror(avahi_server_errno

1079

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

1025

avahi_strerror(avahi_server_errno(mc.server)));

1080

1026

break;

1081

1027

1082

1028

case AVAHI_RESOLVER_FOUND:

1090

1036

}

1091

1037

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

1092

1038

interface,

1093

avahi_proto_to_af(proto),

1094

mc);

1039

avahi_proto_to_af(proto));

1095

1040

if(ret == 0){

1096

avahi_simple_poll_quit(simple_poll);

1041

avahi_simple_poll_quit(mc.simple_poll);

1097

1042

} else {

1098

1043

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

1099

avahi_proto_to_af(proto),

1100

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

1044

avahi_proto_to_af(proto))){

1101

1045

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

1102

1046

" list\n", name);

1103

1047

}

1116

1060

const char *domain,

1117

1061

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1118

1062

flags,

1119

void *mc){

1063

AVAHI_GCC_UNUSED void* userdata){

1120

1064

if(b == NULL){

1121

1065

return;

1122

1066

}

1133

1077

case AVAHI_BROWSER_FAILURE:

1134

1078

1135

1079

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

1136

avahi_strerror(avahi_server_errno

1137

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

1138

avahi_simple_poll_quit(simple_poll);

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_simple_poll_quit(mc.simple_poll);

1139

1082

return;

1140

1083

1141

1084

case AVAHI_BROWSER_NEW:

1144

1087

the callback function is called the Avahi server will free the

1145

1088

resolver for us. */

1146

1089

1147

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

1148

interface, protocol, name, type,

1149

domain, protocol, 0,

1150

resolve_callback, mc) == NULL)

1090

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

1091

name, type, domain, protocol, 0,

1092

resolve_callback, NULL) == NULL)

1151

1093

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

1152

1094

" %s\n", name,

1153

avahi_strerror(avahi_server_errno

1154

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

1095

avahi_strerror(avahi_server_errno(mc.server)));

1155

1096

break;

1156

1097

1157

1098

case AVAHI_BROWSER_REMOVE:

1176

1117

signal_received = sig;

1177

1118

int old_errno = errno;

1178

1119

/* set main loop to exit */

1179

if(simple_poll != NULL){

1180

avahi_simple_poll_quit(simple_poll);

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1181

1122

}

1182

1123

errno = old_errno;

1183

1124

}

1184

1125

1185

__attribute__((nonnull, warn_unused_result))

1186

1126

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

1187

1127

int ret;

1188

1128

error_t ret_errno;

1207

1147

return true;

1208

1148

}

1209

1149

1210

__attribute__((nonnull, warn_unused_result))

1211

1150

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

1212

1151

1213

1152

/* Reject the loopback device */

1255

1194

* corresponds to an acceptable network device.

1256

1195

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

1257

1196

*/

1258

__attribute__((nonnull, warn_unused_result))

1259

1197

int good_interface(const struct dirent *if_entry){

1260

1198

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

1261

1199

return 0;

1279

1217

/*

1280

1218

* This function determines if a network interface is up.

1281

1219

*/

1282

__attribute__((nonnull, warn_unused_result))

1283

1220

bool interface_is_up(const char *interface){

1284

1221

struct ifreq ifr;

1285

1222

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

1296

1233

/*

1297

1234

* This function determines if a network interface is running

1298

1235

*/

1299

__attribute__((nonnull, warn_unused_result))

1300

1236

bool interface_is_running(const char *interface){

1301

1237

struct ifreq ifr;

1302

1238

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

1310

1246

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

1311

1247

}

1312

1248

1313

__attribute__((nonnull, pure, warn_unused_result))

1314

1249

int notdotentries(const struct dirent *direntry){

1315

1250

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

1316

1251

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

1323

1258

}

1324

1259

1325

1260

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

1326

__attribute__((nonnull, warn_unused_result))

1327

1261

int runnable_hook(const struct dirent *direntry){

1328

1262

int ret;

1329

1263

size_t sret;

1337

1271

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

1338

1272

"abcdefghijklmnopqrstuvwxyz"

1339

1273

"0123456789"

1340

"_.-");

1274

"_-");

1341

1275

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

1342

1276

/* Contains non-allowed characters */

1343

1277

if(debug){

1347

1281

return 0;

1348

1282

}

1349

1283

1350

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

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);

1351

1292

if(ret == -1){

1352

1293

if(debug){

1353

1294

perror_plus("Could not stat hook");

1377

1318

return 1;

1378

1319

}

1379

1320

1380

__attribute__((nonnull, warn_unused_result))

1381

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1382

mandos_context *mc){

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1383

1322

int ret;

1384

1323

struct timespec now;

1385

1324

struct timespec waited_time;

1386

1325

intmax_t block_time;

1387

1326

1388

1327

while(true){

1389

if(mc->current_server == NULL){

1390

if(debug){

1328

if(mc.current_server == NULL){

1329

if (debug){

1391

1330

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

1392

1331

" No timeout!\n");

1393

1332

}

1394

1333

ret = avahi_simple_poll_iterate(s, -1);

1395

1334

} else {

1396

if(debug){

1335

if (debug){

1397

1336

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

1398

1337

" it, or wait\n");

1399

1338

}

1406

1345

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

1407

1346

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

1408

1347

waited_time.tv_sec = (now.tv_sec

1409

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

1348

- mc.current_server->last_seen.tv_sec);

1410

1349

waited_time.tv_nsec = (now.tv_nsec

1411

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

1350

- mc.current_server->last_seen.tv_nsec);

1412

1351

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

1413

1352

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

1414

1353

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

1416

1355

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

1417

1356

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

1418

1357

1419

if(debug){

1358

if (debug){

1420

1359

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

1421

1360

block_time);

1422

1361

}

1423

1362

1424

1363

if(block_time <= 0){

1425

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

1426

mc->current_server->port,

1427

mc->current_server->if_index,

1428

mc->current_server->af, mc);

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);

1429

1368

if(ret == 0){

1430

avahi_simple_poll_quit(s);

1369

avahi_simple_poll_quit(mc.simple_poll);

1431

1370

return 0;

1432

1371

}

1433

1372

ret = clock_gettime(CLOCK_MONOTONIC,

1434

&mc->current_server->last_seen);

1373

&mc.current_server->last_seen);

1435

1374

if(ret == -1){

1436

1375

perror_plus("clock_gettime");

1437

1376

return -1;

1438

1377

}

1439

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

1378

mc.current_server = mc.current_server->next;

1440

1379

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

1441

1380

servers, but don't block */

1442

1381

}

1444

1383

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

1445

1384

}

1446

1385

if(ret != 0){

1447

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

1386

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

1448

1387

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

1449

1388

}

1450

1389

}

1452

1391

}

1453

1392

1454

1393

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

1455

__attribute__((warn_unused_result))

1456

1394

error_t raise_privileges(void){

1457

1395

error_t old_errno = errno;

1458

1396

error_t ret_errno = 0;

1465

1403

}

1466

1404

1467

1405

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

1468

__attribute__((warn_unused_result))

1469

1406

error_t raise_privileges_permanently(void){

1470

1407

error_t old_errno = errno;

1471

1408

error_t ret_errno = raise_privileges();

1482

1419

}

1483

1420

1484

1421

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

1485

__attribute__((warn_unused_result))

1486

1422

error_t lower_privileges(void){

1487

1423

error_t old_errno = errno;

1488

1424

error_t ret_errno = 0;

1495

1431

}

1496

1432

1497

1433

/* Lower privileges permanently */

1498

__attribute__((warn_unused_result))

1499

1434

error_t lower_privileges_permanently(void){

1500

1435

error_t old_errno = errno;

1501

1436

error_t ret_errno = 0;

1507

1442

return ret_errno;

1508

1443

}

1509

1444

1510

#ifndef O_CLOEXEC

1511

/*

1512

* Based on the example in the GNU LibC manual chapter 13.13 "File

1513

* Descriptor Flags".

1514

| [[info:libc:Descriptor%20Flags][File Descriptor Flags]] |

1515

*/

1516

__attribute__((warn_unused_result))

1517

static int set_cloexec_flag(int fd){

1518

int ret = (int)TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD, 0));

1519

/* If reading the flags failed, return error indication now. */

1520

if(ret < 0){

1521

return ret;

1522

}

1523

/* Store modified flag word in the descriptor. */

1524

return (int)TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD,

1525

ret | FD_CLOEXEC));

1526

}

1527

#endif /* not O_CLOEXEC */

1528

1529

__attribute__((nonnull))

1530

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

1445

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

1531

1446

const float delay){

1532

1447

struct dirent **direntries;

1533

if(hookdir_fd == -1){

1534

hookdir_fd = open(hookdir, O_RDONLY |

1535

#ifdef O_CLOEXEC

1536

O_CLOEXEC

1537

#else /* not O_CLOEXEC */

1538

0

1539

#endif /* not O_CLOEXEC */

1540

);

1541

if(hookdir_fd == -1){

1542

if(errno == ENOENT){

1543

if(debug){

1544

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

1545

" found\n", hookdir);

1546

}

1547

} else {

1548

perror_plus("open");

1549

}

1550

return;

1551

}

1552

#ifndef O_CLOEXEC

1553

if(set_cloexec_flag(hookdir_fd) < 0){

1554

perror_plus("set_cloexec_flag");

1555

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

1556

perror_plus("close");

1557

} else {

1558

hookdir_fd = -1;

1559

}

1560

return;

1561

}

1562

#endif /* not O_CLOEXEC */

1563

}

1564

#ifdef __GLIBC__

1565

#if __GLIBC_PREREQ(2, 15)

1566

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

1567

runnable_hook, alphasort);

1568

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

1569

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

1570

alphasort);

1571

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

1572

#else /* not __GLIBC__ */

1573

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

1574

alphasort);

1575

#endif /* not __GLIBC__ */

1448

struct dirent *direntry;

1449

int ret;

1450

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

1451

alphasort);

1576

1452

if(numhooks == -1){

1577

perror_plus("scandir");

1578

return;

1579

}

1580

struct dirent *direntry;

1581

int ret;

1582

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

1583

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

1584

direntry = direntries[i];

1585

if(debug){

1586

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

1587

direntry->d_name);

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");

1588

1460

}

1589

pid_t hook_pid = fork();

1590

if(hook_pid == 0){

1591

/* Child */

1592

/* Raise privileges */

1593

if(raise_privileges_permanently() != 0){

1594

perror_plus("Failed to raise privileges");

1595

_exit(EX_NOPERM);

1596

}

1597

/* Set group */

1598

errno = 0;

1599

ret = setgid(0);

1600

if(ret == -1){

1601

perror_plus("setgid");

1602

_exit(EX_NOPERM);

1603

}

1604

/* Reset supplementary groups */

1605

errno = 0;

1606

ret = setgroups(0, NULL);

1607

if(ret == -1){

1608

perror_plus("setgroups");

1609

_exit(EX_NOPERM);

1610

}

1611

ret = dup2(devnull, STDIN_FILENO);

1612

if(ret == -1){

1613

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

1614

_exit(EX_OSERR);

1615

}

1616

ret = close(devnull);

1617

if(ret == -1){

1618

perror_plus("close");

1619

_exit(EX_OSERR);

1620

}

1621

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1622

if(ret == -1){

1623

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

1624

_exit(EX_OSERR);

1625

}

1626

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

1627

if(ret == -1){

1628

perror_plus("setenv");

1629

_exit(EX_OSERR);

1630

}

1631

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

1632

if(ret == -1){

1633

perror_plus("setenv");

1634

_exit(EX_OSERR);

1635

}

1636

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

1637

if(ret == -1){

1638

perror_plus("setenv");

1639

_exit(EX_OSERR);

1640

}

1641

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

1642

if(ret == -1){

1643

perror_plus("setenv");

1644

_exit(EX_OSERR);

1645

}

1646

char *delaystring;

1647

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

1648

if(ret == -1){

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){

1649

1468

perror_plus("asprintf");

1650

_exit(EX_OSERR);

1651

}

1652

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

1653

if(ret == -1){

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

}

1654

1527

free(delaystring);

1655

perror_plus("setenv");

1656

_exit(EX_OSERR);

1657

}

1658

free(delaystring);

1659

if(connect_to != NULL){

1660

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

1661

if(ret == -1){

1662

perror_plus("setenv");

1663

_exit(EX_OSERR);

1664

}

1665

}

1666

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

1667

{ direntry->d_name, NULL }, environ) == -1){

1668

perror_plus("fexecve");

1669

_exit(EXIT_FAILURE);

1670

}

1671

} else {

1672

int status;

1673

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

1674

perror_plus("waitpid");

1675

continue;

1676

}

1677

if(WIFEXITED(status)){

1678

if(WEXITSTATUS(status) != 0){

1679

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

1680

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

1681

WEXITSTATUS(status));

1682

continue;

1683

}

1684

} else if(WIFSIGNALED(status)){

1685

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

1686

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

1687

WTERMSIG(status));

1688

continue;

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

}

1689

1539

} else {

1690

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

1691

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

1692

continue;

1693

}

1694

}

1695

if(debug){

1696

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

1697

direntry->d_name);

1698

}

1699

}

1700

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

1701

perror_plus("close");

1702

} else {

1703

hookdir_fd = -1;

1704

}

1705

close(devnull);

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;

1706

1576

}

1707

1577

1708

__attribute__((nonnull, warn_unused_result))

1709

1578

error_t bring_up_interface(const char *const interface,

1710

1579

const float delay){

1580

int sd = -1;

1711

1581

error_t old_errno = errno;

1712

int ret;

1582

error_t ret_errno = 0;

1583

int ret, ret_setflags;

1713

1584

struct ifreq network;

1714

1585

unsigned int if_index = if_nametoindex(interface);

1715

1586

if(if_index == 0){

1724

1595

}

1725

1596

1726

1597

if(not interface_is_up(interface)){

1727

error_t ret_errno = 0, ioctl_errno = 0;

1728

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

1598

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

1729

1599

ret_errno = errno;

1730

1600

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

1731

1601

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

1732

errno = old_errno;

1733

1602

return ret_errno;

1734

1603

}

1735

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

1604

network.ifr_flags |= IFF_UP;

1736

1605

1737

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

1738

if(sd == -1){

1606

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1607

if(sd < 0){

1739

1608

ret_errno = errno;

1740

1609

perror_plus("socket");

1741

1610

errno = old_errno;

1742

1611

return ret_errno;

1743

1612

}

1744

1613

1745

1614

if(quit_now){

1746

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

1747

if(ret == -1){

1748

perror_plus("close");

1749

}

1615

close(sd);

1750

1616

errno = old_errno;

1751

1617

return EINTR;

1752

1618

}

1756

1622

interface);

1757

1623

}

1758

1624

1759

/* Raise privileges */

1760

ret_errno = raise_privileges();

1761

if(ret_errno != 0){

1762

perror_plus("Failed to raise privileges");

1763

}

1625

/* Raise priviliges */

1626

raise_privileges();

1764

1627

1765

1628

#ifdef __linux__

1766

int ret_linux;

1767

bool restore_loglevel = false;

1768

if(ret_errno == 0){

1769

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1770

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

1771

ret_linux = klogctl(8, NULL, 5);

1772

if(ret_linux == -1){

1773

perror_plus("klogctl");

1774

} else {

1775

restore_loglevel = true;

1776

}

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");

1777

1636

}

1778

1637

#endif /* __linux__ */

1779

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

1780

ioctl_errno = errno;

1638

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

1639

ret_errno = errno;

1781

1640

#ifdef __linux__

1782

1641

if(restore_loglevel){

1783

1642

ret_linux = klogctl(7, NULL, 0);

1787

1646

}

1788

1647

#endif /* __linux__ */

1789

1648

1790

/* If raise_privileges() succeeded above */

1791

if(ret_errno == 0){

1792

/* Lower privileges */

1793

ret_errno = lower_privileges();

1794

if(ret_errno != 0){

1795

errno = ret_errno;

1796

perror_plus("Failed to lower privileges");

1797

}

1798

}

1649

/* Lower privileges */

1650

lower_privileges();

1799

1651

1800

1652

/* Close the socket */

1801

1653

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

1804

1656

}

1805

1657

1806

1658

if(ret_setflags == -1){

1807

errno = ioctl_errno;

1659

errno = ret_errno;

1808

1660

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1809

1661

errno = old_errno;

1810

return ioctl_errno;

1662

return ret_errno;

1811

1663

}

1812

1664

} else if(debug){

1813

1665

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

1831

1683

return 0;

1832

1684

}

1833

1685

1834

__attribute__((nonnull, warn_unused_result))

1835

1686

error_t take_down_interface(const char *const interface){

1687

int sd = -1;

1836

1688

error_t old_errno = errno;

1689

error_t ret_errno = 0;

1690

int ret, ret_setflags;

1837

1691

struct ifreq network;

1838

1692

unsigned int if_index = if_nametoindex(interface);

1839

1693

if(if_index == 0){

1842

1696

return ENXIO;

1843

1697

}

1844

1698

if(interface_is_up(interface)){

1845

error_t ret_errno = 0, ioctl_errno = 0;

1846

1699

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

1847

1700

ret_errno = errno;

1848

1701

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

1849

1702

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

1850

errno = old_errno;

1851

1703

return ret_errno;

1852

1704

}

1853

1705

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

1854

1706

1855

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

1856

if(sd == -1){

1707

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1708

if(sd < 0){

1857

1709

ret_errno = errno;

1858

1710

perror_plus("socket");

1859

1711

errno = old_errno;

1865

1717

interface);

1866

1718

}

1867

1719

1868

/* Raise privileges */

1869

ret_errno = raise_privileges();

1870

if(ret_errno != 0){

1871

perror_plus("Failed to raise privileges");

1872

}

1873

1874

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

1875

ioctl_errno = errno;

1876

1877

/* If raise_privileges() succeeded above */

1878

if(ret_errno == 0){

1879

/* Lower privileges */

1880

ret_errno = lower_privileges();

1881

if(ret_errno != 0){

1882

errno = ret_errno;

1883

perror_plus("Failed to lower privileges");

1884

}

1885

}

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();

1886

1728

1887

1729

/* Close the socket */

1888

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

1730

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

1889

1731

if(ret == -1){

1890

1732

perror_plus("close");

1891

1733

}

1892

1734

1893

1735

if(ret_setflags == -1){

1894

errno = ioctl_errno;

1736

errno = ret_errno;

1895

1737

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1896

1738

errno = old_errno;

1897

return ioctl_errno;

1739

return ret_errno;

1898

1740

}

1899

1741

} else if(debug){

1900

1742

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

1906

1748

}

1907

1749

1908

1750

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

1909

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

1910

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

1911

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

1912

.interfaces = NULL, .interfaces_size = 0 };

1913

1751

AvahiSServiceBrowser *sb = NULL;

1914

1752

error_t ret_errno;

1915

1753

int ret;

1916

1754

intmax_t tmpmax;

1917

1755

char *tmp;

1918

1756

int exitcode = EXIT_SUCCESS;

1757

char *interfaces = NULL;

1758

size_t interfaces_size = 0;

1919

1759

char *interfaces_to_take_down = NULL;

1920

1760

size_t interfaces_to_take_down_size = 0;

1921

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

1922

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

1923

char *tempdir = NULL;

1761

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

1762

bool tempdir_created = false;

1924

1763

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1925

1764

const char *seckey = PATHDIR "/" SECKEY;

1926

1765

const char *pubkey = PATHDIR "/" PUBKEY;

1927

1766

char *interfaces_hooks = NULL;

1767

size_t interfaces_hooks_size = 0;

1928

1768

1929

1769

bool gnutls_initialized = false;

1930

1770

bool gpgme_initialized = false;

2021

1861

connect_to = arg;

2022

1862

break;

2023

1863

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

2024

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

2025

arg, (int)',');

1864

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

1865

(int)',');

2026

1866

if(ret_errno != 0){

2027

1867

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

2028

1868

}

2108

1948

/* Work around Debian bug #633582:

2109

1949

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

2110

1950

2111

/* Re-raise privileges */

2112

ret_errno = raise_privileges();

2113

if(ret_errno != 0){

2114

errno = ret_errno;

2115

perror_plus("Failed to raise privileges");

2116

} else {

1951

/* Re-raise priviliges */

1952

if(raise_privileges() == 0){

2117

1953

struct stat st;

2118

1954

2119

1955

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

2159

1995

}

2160

1996

2161

1997

/* Lower privileges */

2162

ret_errno = lower_privileges();

2163

if(ret_errno != 0){

2164

errno = ret_errno;

2165

perror_plus("Failed to lower privileges");

1998

errno = 0;

1999

ret = seteuid(uid);

2000

if(ret == -1){

2001

perror_plus("seteuid");

2166

2002

}

2167

2003

}

2168

2004

}

2169

2005

2170

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

2006

/* Remove empty interface names */

2171

2007

{

2172

2008

char *interface = NULL;

2173

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

2009

while((interface = argz_next(interfaces, interfaces_size,

2174

2010

interface))){

2175

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

2176

and if_nametoindex(interface) == 0){

2177

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

2011

if(if_nametoindex(interface) == 0){

2012

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

2178

2013

fprintf_plus(stderr, "Not using nonexisting interface"

2179

2014

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

2180

2015

}

2181

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

2016

argz_delete(&interfaces, &interfaces_size, interface);

2182

2017

interface = NULL;

2183

2018

}

2184

2019

}

2186

2021

2187

2022

/* Run network hooks */

2188

2023

{

2189

if(mc.interfaces != NULL){

2190

interfaces_hooks = malloc(mc.interfaces_size);

2024

2025

if(interfaces != NULL){

2026

interfaces_hooks = malloc(interfaces_size);

2191

2027

if(interfaces_hooks == NULL){

2192

2028

perror_plus("malloc");

2193

2029

goto end;

2194

2030

}

2195

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

2196

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

2197

}

2198

run_network_hooks("start", interfaces_hooks != NULL ?

2199

interfaces_hooks : "", delay);

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

}

2200

2040

}

2201

2041

2202

2042

if(not debug){

2207

2047

from the signal handler */

2208

2048

/* Initialize the pseudo-RNG for Avahi */

2209

2049

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

2210

simple_poll = avahi_simple_poll_new();

2211

if(simple_poll == NULL){

2050

mc.simple_poll = avahi_simple_poll_new();

2051

if(mc.simple_poll == NULL){

2212

2052

fprintf_plus(stderr,

2213

2053

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

2214

2054

exitcode = EX_UNAVAILABLE;

2279

2119

}

2280

2120

2281

2121

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

2282

if(mc.interfaces == NULL){

2122

if(interfaces == NULL){

2283

2123

struct dirent **direntries;

2284

2124

/* Look for any good interfaces */

2285

2125

ret = scandir(sys_class_net, &direntries, good_interface,

2287

2127

if(ret >= 1){

2288

2128

/* Add all found interfaces to interfaces list */

2289

2129

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

2290

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

2130

ret_errno = argz_add(&interfaces, &interfaces_size,

2291

2131

direntries[i]->d_name);

2292

2132

if(ret_errno != 0){

2293

errno = ret_errno;

2294

2133

perror_plus("argz_add");

2295

2134

continue;

2296

2135

}

2308

2147

}

2309

2148

}

2310

2149

2311

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

2312

{

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)){

2313

2162

char *interface = NULL;

2314

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

2163

while((interface = argz_next(interfaces, interfaces_size,

2315

2164

interface))){

2316

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

2317

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

2318

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

2319

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

2320

interface);

2321

interface = NULL;

2322

while((interface = argz_next(mc.interfaces,

2323

mc.interfaces_size, interface))){

2324

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

2325

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

2326

interface);

2327

interface = NULL;

2328

}

2329

}

2330

break;

2331

}

2332

2165

bool interface_was_up = interface_is_up(interface);

2333

errno = bring_up_interface(interface, delay);

2166

ret = bring_up_interface(interface, delay);

2334

2167

if(not interface_was_up){

2335

if(errno != 0){

2168

if(ret != 0){

2169

errno = ret;

2336

2170

perror_plus("Failed to bring up interface");

2337

2171

} else {

2338

errno = argz_add(&interfaces_to_take_down,

2339

&interfaces_to_take_down_size,

2340

interface);

2341

if(errno != 0){

2342

perror_plus("argz_add");

2343

}

2172

ret_errno = argz_add(&interfaces_to_take_down,

2173

&interfaces_to_take_down_size,

2174

interface);

2344

2175

}

2345

2176

}

2346

2177

}

2178

free(interfaces);

2179

interfaces = NULL;

2180

interfaces_size = 0;

2347

2181

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

2348

2182

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

2349

2183

}

2350

2184

}

2351

2185

2352

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

2353

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

2354

if(debug){

2355

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

2356

mc.interfaces);

2357

}

2358

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

2359

}

2360

2361

2186

if(quit_now){

2362

2187

goto end;

2363

2188

}

2364

2189

2365

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

2190

ret = init_gnutls_global(pubkey, seckey);

2366

2191

if(ret == -1){

2367

2192

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

2368

2193

exitcode = EX_UNAVAILABLE;

2375

2200

goto end;

2376

2201

}

2377

2202

2378

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

2379

tempdir = mkdtemp(run_tempdir);

2380

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

2381

if(debug){

2382

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

2383

run_tempdir, old_tempdir);

2384

}

2385

tempdir = mkdtemp(old_tempdir);

2386

}

2387

if(tempdir == NULL){

2203

if(mkdtemp(tempdir) == NULL){

2388

2204

perror_plus("mkdtemp");

2389

2205

goto end;

2390

2206

}

2207

tempdir_created = true;

2391

2208

2392

2209

if(quit_now){

2393

2210

goto end;

2394

2211

}

2395

2212

2396

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

2213

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

2397

2214

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

2398

2215

exitcode = EX_UNAVAILABLE;

2399

2216

goto end;

2429

2246

exitcode = EX_USAGE;

2430

2247

goto end;

2431

2248

}

2432

2249

2433

2250

if(quit_now){

2434

2251

goto end;

2435

2252

}

2456

2273

}

2457

2274

2458

2275

while(not quit_now){

2459

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

2460

&mc);

2276

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

2461

2277

if(quit_now or ret == 0){

2462

2278

break;

2463

2279

}

2465

2281

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

2466

2282

(int)retry_interval);

2467

2283

}

2468

sleep((unsigned int)retry_interval);

2284

sleep((int)retry_interval);

2469

2285

}

2470

2286

2471

if(not quit_now){

2287

if (not quit_now){

2472

2288

exitcode = EXIT_SUCCESS;

2473

2289

}

2474

2290

2489

2305

config.publish_domain = 0;

2490

2306

2491

2307

/* Allocate a new server */

2492

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2493

&config, NULL, NULL, &ret_errno);

2308

mc.server = avahi_server_new(avahi_simple_poll_get

2309

(mc.simple_poll), &config, NULL,

2310

NULL, &ret_errno);

2494

2311

2495

2312

/* Free the Avahi configuration data */

2496

2313

avahi_server_config_free(&config);

2511

2328

/* Create the Avahi service browser */

2512

2329

sb = avahi_s_service_browser_new(mc.server, if_index,

2513

2330

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2514

NULL, 0, browse_callback,

2515

(void *)&mc);

2331

NULL, 0, browse_callback, NULL);

2516

2332

if(sb == NULL){

2517

2333

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

2518

2334

avahi_strerror(avahi_server_errno(mc.server)));

2529

2345

if(debug){

2530

2346

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

2531

2347

}

2532

2533

ret = avahi_loop_with_timeout(simple_poll,

2534

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

2348

2349

ret = avahi_loop_with_timeout(mc.simple_poll,

2350

(int)(retry_interval * 1000));

2535

2351

if(debug){

2536

2352

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

2537

2353

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

2544

2360

}

2545

2361

2546

2362

/* Cleanup things */

2547

free(mc.interfaces);

2548

2549

2363

if(sb != NULL)

2550

2364

avahi_s_service_browser_free(sb);

2551

2365

2552

2366

if(mc.server != NULL)

2553

2367

avahi_server_free(mc.server);

2554

2368

2555

if(simple_poll != NULL)

2556

avahi_simple_poll_free(simple_poll);

2369

if(mc.simple_poll != NULL)

2370

avahi_simple_poll_free(mc.simple_poll);

2557

2371

2558

2372

if(gnutls_initialized){

2559

2373

gnutls_certificate_free_credentials(mc.cred);

2576

2390

}

2577

2391

}

2578

2392

2579

/* Re-raise privileges */

2393

/* Re-raise priviliges */

2580

2394

{

2581

ret_errno = raise_privileges();

2582

if(ret_errno != 0){

2583

perror_plus("Failed to raise privileges");

2584

} else {

2585

2586

/* Run network hooks */

2587

run_network_hooks("stop", interfaces_hooks != NULL ?

2588

interfaces_hooks : "", delay);

2589

2590

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

2591

{

2592

char *interface = NULL;

2593

while((interface=argz_next(interfaces_to_take_down,

2594

interfaces_to_take_down_size,

2595

interface))){

2596

ret_errno = take_down_interface(interface);

2597

if(ret_errno != 0){

2598

errno = ret_errno;

2599

perror_plus("Failed to take down interface");

2600

}

2601

}

2602

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

2603

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

2604

" down\n");

2605

}

2606

}

2607

}

2608

2609

ret_errno = lower_privileges_permanently();

2610

if(ret_errno != 0){

2611

perror_plus("Failed to lower privileges permanently");

2612

}

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();

2613

2420

}

2614

2421

2615

2422

free(interfaces_to_take_down);

2616

2423

free(interfaces_hooks);

2617

2424

2618

2425

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

2619

if(tempdir != NULL){

2426

if(tempdir_created){

2620

2427

struct dirent **direntries = NULL;

2621

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

2622

if(tempdir_fd == -1){

2623

perror_plus("open");

2624

} else {

2625

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

2626

alphasort);

2627

if(numentries > 0){

2628

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

2629

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

2630

if(ret == -1){

2631

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

2632

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

2633

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

2634

}

2635

}

2636

2637

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

2638

free(direntries);

2639

if(numentries == -1){

2640

perror_plus("scandir");

2641

}

2642

ret = rmdir(tempdir);

2643

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

2644

perror_plus("rmdir");

2645

}

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);

2646

2447

}

2647

TEMP_FAILURE_RETRY(close(tempdir_fd));

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");

2648

2458

}

2649

2459

}

2650

2460