/mandos/trunk : revision 708

9

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

10

*

11

* Everything else is

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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()

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62

*/

62

63

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

72

73

*/

73

74

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

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

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

76

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

76

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

77

unlinkat() */

78

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

77

79

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

78

80

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

79

81

argp_state, struct argp,

91

93

argz_delete(), argz_append(),

92

94

argz_stringify(), argz_add(),

93

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

94

98

95

99

#ifdef __linux__

96

100

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

138

142

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

139

143

char *connect_to = NULL;

140

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

141

146

uid_t uid = 65534;

142

147

gid_t gid = 65534;

143

148

154

159

155

160

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

156

161

typedef struct {

157

AvahiSimplePoll *simple_poll;

158

162

AvahiServer *server;

159

163

gnutls_certificate_credentials_t cred;

160

164

unsigned int dh_bits;

162

166

const char *priority;

163

167

gpgme_ctx_t ctx;

164

168

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

165

171

} mandos_context;

166

172

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 };

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

172

175

173

176

sig_atomic_t quit_now = 0;

174

177

int signal_received = 0;

182

185

perror(print_text);

183

186

}

184

187

185

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

188

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

186

189

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

187

190

va_list ap;

188

191

va_start (ap, format);

189

192

190

193

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

191

194

program_invocation_short_name));

192

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

195

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

193

196

}

194

197

195

198

/*

197

200

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

198

201

* "buffer_length" is how much is already used.

199

202

*/

203

__attribute__((nonnull, warn_unused_result))

200

204

size_t incbuffer(char **buffer, size_t buffer_length,

201

205

size_t buffer_capacity){

202

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

203

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

204

if(buffer == NULL){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

205

213

return 0;

206

214

}

215

*buffer = new_buf;

207

216

buffer_capacity += BUFFER_SIZE;

208

217

}

209

218

return buffer_capacity;

210

219

}

211

220

212

221

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

222

__attribute__((nonnull, warn_unused_result))

213

223

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

214

int af){

224

int af, server **current_server){

215

225

int ret;

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226

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

217

227

if(new_server == NULL){

226

236

perror_plus("strdup");

227

237

return false;

228

238

}

239

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

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

229

244

/* Special case of first server */

230

if (mc.current_server == NULL){

245

if(*current_server == NULL){

231

246

new_server->next = new_server;

232

247

new_server->prev = new_server;

233

mc.current_server = new_server;

234

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

248

*current_server = new_server;

235

249

} else {

236

new_server->next = mc.current_server;

237

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

250

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

251

new_server->next = *current_server;

252

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

238

253

new_server->prev->next = new_server;

239

mc.current_server->prev = new_server;

240

}

241

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

242

if(ret == -1){

243

perror_plus("clock_gettime");

244

return false;

254

(*current_server)->prev = new_server;

245

255

}

246

256

return true;

247

257

}

249

259

/*

250

260

* Initialize GPGME.

251

261

*/

252

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

253

const char *tempdir){

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){

254

267

gpgme_error_t rc;

255

268

gpgme_engine_info_t engine_info;

256

269

257

258

270

/*

259

271

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

260

272

*/

261

bool import_key(const char *filename){

273

bool import_key(const char * const filename){

262

274

int ret;

263

275

int fd;

264

276

gpgme_data_t pgp_data;

276

288

return false;

277

289

}

278

290

279

rc = gpgme_op_import(mc.ctx, pgp_data);

291

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

280

292

if(rc != GPG_ERR_NO_ERROR){

281

293

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

282

294

gpgme_strsource(rc), gpgme_strerror(rc));

326

338

}

327

339

328

340

/* Create new GPGME "context" */

329

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

341

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

330

342

if(rc != GPG_ERR_NO_ERROR){

331

343

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

332

344

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

345

357

* Decrypt OpenPGP data.

346

358

* Returns -1 on error

347

359

*/

360

__attribute__((nonnull, warn_unused_result))

348

361

static ssize_t pgp_packet_decrypt(const char *cryptotext,

349

362

size_t crypto_size,

350

char **plaintext){

363

char **plaintext,

364

mandos_context *mc){

351

365

gpgme_data_t dh_crypto, dh_plain;

352

366

gpgme_error_t rc;

353

367

ssize_t ret;

379

393

380

394

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

381

395

data buffer */

382

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

396

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

383

397

if(rc != GPG_ERR_NO_ERROR){

384

398

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

385

399

gpgme_strsource(rc), gpgme_strerror(rc));

386

400

plaintext_length = -1;

387

401

if(debug){

388

402

gpgme_decrypt_result_t result;

389

result = gpgme_op_decrypt_result(mc.ctx);

403

result = gpgme_op_decrypt_result(mc->ctx);

390

404

if(result == NULL){

391

405

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

392

406

} else {

469

483

return plaintext_length;

470

484

}

471

485

472

static const char * safer_gnutls_strerror(int value){

486

__attribute__((warn_unused_result))

487

static const char *safer_gnutls_strerror(int value){

473

488

const char *ret = gnutls_strerror(value);

474

489

if(ret == NULL)

475

490

ret = "(unknown)";

477

492

}

478

493

479

494

/* GnuTLS log function callback */

495

__attribute__((nonnull))

480

496

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

481

497

const char* string){

482

498

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

483

499

}

484

500

501

__attribute__((nonnull, warn_unused_result))

485

502

static int init_gnutls_global(const char *pubkeyfilename,

486

const char *seckeyfilename){

503

const char *seckeyfilename,

504

mandos_context *mc){

487

505

int ret;

488

506

489

507

if(debug){

506

524

}

507

525

508

526

/* OpenPGP credentials */

509

ret = gnutls_certificate_allocate_credentials(&mc.cred);

527

ret = gnutls_certificate_allocate_credentials(&mc->cred);

510

528

if(ret != GNUTLS_E_SUCCESS){

511

529

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

512

530

safer_gnutls_strerror(ret));

522

540

}

523

541

524

542

ret = gnutls_certificate_set_openpgp_key_file

525

(mc.cred, pubkeyfilename, seckeyfilename,

543

(mc->cred, pubkeyfilename, seckeyfilename,

526

544

GNUTLS_OPENPGP_FMT_BASE64);

527

545

if(ret != GNUTLS_E_SUCCESS){

528

546

fprintf_plus(stderr,

534

552

}

535

553

536

554

/* GnuTLS server initialization */

537

ret = gnutls_dh_params_init(&mc.dh_params);

555

ret = gnutls_dh_params_init(&mc->dh_params);

538

556

if(ret != GNUTLS_E_SUCCESS){

539

557

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

540

558

" initialization: %s\n",

541

559

safer_gnutls_strerror(ret));

542

560

goto globalfail;

543

561

}

544

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

562

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

545

563

if(ret != GNUTLS_E_SUCCESS){

546

564

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

547

565

safer_gnutls_strerror(ret));

548

566

goto globalfail;

549

567

}

550

568

551

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

569

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

552

570

553

571

return 0;

554

572

555

573

globalfail:

556

574

557

gnutls_certificate_free_credentials(mc.cred);

575

gnutls_certificate_free_credentials(mc->cred);

558

576

gnutls_global_deinit();

559

gnutls_dh_params_deinit(mc.dh_params);

577

gnutls_dh_params_deinit(mc->dh_params);

560

578

return -1;

561

579

}

562

580

563

static int init_gnutls_session(gnutls_session_t *session){

581

__attribute__((nonnull, warn_unused_result))

582

static int init_gnutls_session(gnutls_session_t *session,

583

mandos_context *mc){

564

584

int ret;

565

585

/* GnuTLS session creation */

566

586

do {

578

598

{

579

599

const char *err;

580

600

do {

581

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

601

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

582

602

if(quit_now){

583

603

gnutls_deinit(*session);

584

604

return -1;

595

615

596

616

do {

597

617

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

598

mc.cred);

618

mc->cred);

599

619

if(quit_now){

600

620

gnutls_deinit(*session);

601

621

return -1;

611

631

/* ignore client certificate if any. */

612

632

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

613

633

614

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

634

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

615

635

616

636

return 0;

617

637

}

621

641

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

622

642

623

643

/* Called when a Mandos server is found */

644

__attribute__((nonnull, warn_unused_result))

624

645

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

625

646

AvahiIfIndex if_index,

626

int af){

647

int af, mandos_context *mc){

627

648

int ret, tcp_sd = -1;

628

649

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

650

struct sockaddr_storage to;

633

651

char *buffer = NULL;

634

652

char *decrypted_buffer = NULL;

635

653

size_t buffer_length = 0;

659

677

return -1;

660

678

}

661

679

662

ret = init_gnutls_session(&session);

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);

663

713

if(ret != 0){

664

714

return -1;

665

715

}

684

734

685

735

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

686

736

if(af == AF_INET6){

687

to.in6.sin6_family = (sa_family_t)af;

688

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

737

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

738

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

689

739

} else { /* IPv4 */

690

to.in.sin_family = (sa_family_t)af;

691

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

740

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

741

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

692

742

}

693

743

if(ret < 0 ){

694

744

int e = errno;

703

753

goto mandos_end;

704

754

}

705

755

if(af == AF_INET6){

706

to.in6.sin6_port = htons(port);

707

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

708

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

709

-Wunreachable-code*/

756

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

757

if(IN6_IS_ADDR_LINKLOCAL

758

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

710

759

if(if_index == AVAHI_IF_UNSPEC){

711

760

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

712

761

" incomplete without a network interface\n");

714

763

goto mandos_end;

715

764

}

716

765

/* Set the network interface number as scope */

717

to.in6.sin6_scope_id = (uint32_t)if_index;

766

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

718

767

}

719

768

} else {

720

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

721

-Wconversion and

722

-Wunreachable-code */

769

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

723

770

}

724

771

725

772

if(quit_now){

742

789

}

743

790

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

744

791

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

745

const char *pcret;

746

792

if(af == AF_INET6){

747

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

748

sizeof(addrstr));

793

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

794

sizeof(struct sockaddr_in6),

795

addrstr, sizeof(addrstr), NULL, 0,

796

NI_NUMERICHOST);

749

797

} else {

750

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

751

sizeof(addrstr));

798

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

799

sizeof(struct sockaddr_in),

800

addrstr, sizeof(addrstr), NULL, 0,

801

NI_NUMERICHOST);

752

802

}

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

}

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);

759

809

}

760

810

}

761

811

765

815

}

766

816

767

817

if(af == AF_INET6){

768

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

818

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

819

sizeof(struct sockaddr_in6));

769

820

} else {

770

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

821

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

822

sizeof(struct sockaddr_in));

771

823

}

772

824

if(ret < 0){

773

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

825

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

774

826

int e = errno;

775

827

perror_plus("connect");

776

828

errno = e;

937

989

if(buffer_length > 0){

938

990

ssize_t decrypted_buffer_size;

939

991

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

940

&decrypted_buffer);

992

&decrypted_buffer, mc);

941

993

if(decrypted_buffer_size >= 0){

942

994

943

995

written = 0;

991

1043

return retval;

992

1044

}

993

1045

1046

__attribute__((nonnull))

994

1047

static void resolve_callback(AvahiSServiceResolver *r,

995

1048

AvahiIfIndex interface,

996

1049

AvahiProtocol proto,

1004

1057

AVAHI_GCC_UNUSED AvahiStringList *txt,

1005

1058

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1006

1059

flags,

1007

AVAHI_GCC_UNUSED void* userdata){

1060

void *mc){

1008

1061

if(r == NULL){

1009

1062

return;

1010

1063

}

1022

1075

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

1023

1076

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

1024

1077

domain,

1025

avahi_strerror(avahi_server_errno(mc.server)));

1078

avahi_strerror(avahi_server_errno

1079

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

1026

1080

break;

1027

1081

1028

1082

case AVAHI_RESOLVER_FOUND:

1036

1090

}

1037

1091

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

1038

1092

interface,

1039

avahi_proto_to_af(proto));

1093

avahi_proto_to_af(proto),

1094

mc);

1040

1095

if(ret == 0){

1041

avahi_simple_poll_quit(mc.simple_poll);

1096

avahi_simple_poll_quit(simple_poll);

1042

1097

} else {

1043

1098

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

1044

avahi_proto_to_af(proto))){

1099

avahi_proto_to_af(proto),

1100

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

1045

1101

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

1046

1102

" list\n", name);

1047

1103

}

1060

1116

const char *domain,

1061

1117

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1062

1118

flags,

1063

AVAHI_GCC_UNUSED void* userdata){

1119

void *mc){

1064

1120

if(b == NULL){

1065

1121

return;

1066

1122

}

1077

1133

case AVAHI_BROWSER_FAILURE:

1078

1134

1079

1135

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

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_simple_poll_quit(mc.simple_poll);

1136

avahi_strerror(avahi_server_errno

1137

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

1138

avahi_simple_poll_quit(simple_poll);

1082

1139

return;

1083

1140

1084

1141

case AVAHI_BROWSER_NEW:

1087

1144

the callback function is called the Avahi server will free the

1088

1145

resolver for us. */

1089

1146

1090

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

1091

name, type, domain, protocol, 0,

1092

resolve_callback, NULL) == NULL)

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)

1093

1151

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

1094

1152

" %s\n", name,

1095

avahi_strerror(avahi_server_errno(mc.server)));

1153

avahi_strerror(avahi_server_errno

1154

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

1096

1155

break;

1097

1156

1098

1157

case AVAHI_BROWSER_REMOVE:

1117

1176

signal_received = sig;

1118

1177

int old_errno = errno;

1119

1178

/* set main loop to exit */

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1179

if(simple_poll != NULL){

1180

avahi_simple_poll_quit(simple_poll);

1122

1181

}

1123

1182

errno = old_errno;

1124

1183

}

1125

1184

1185

__attribute__((nonnull, warn_unused_result))

1126

1186

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

1127

1187

int ret;

1128

1188

error_t ret_errno;

1147

1207

return true;

1148

1208

}

1149

1209

1210

__attribute__((nonnull, warn_unused_result))

1150

1211

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

1151

1212

1152

1213

/* Reject the loopback device */

1194

1255

* corresponds to an acceptable network device.

1195

1256

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

1196

1257

*/

1258

__attribute__((nonnull, warn_unused_result))

1197

1259

int good_interface(const struct dirent *if_entry){

1198

1260

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

1199

1261

return 0;

1217

1279

/*

1218

1280

* This function determines if a network interface is up.

1219

1281

*/

1282

__attribute__((nonnull, warn_unused_result))

1220

1283

bool interface_is_up(const char *interface){

1221

1284

struct ifreq ifr;

1222

1285

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

1233

1296

/*

1234

1297

* This function determines if a network interface is running

1235

1298

*/

1299

__attribute__((nonnull, warn_unused_result))

1236

1300

bool interface_is_running(const char *interface){

1237

1301

struct ifreq ifr;

1238

1302

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

1246

1310

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

1247

1311

}

1248

1312

1313

__attribute__((nonnull, pure, warn_unused_result))

1249

1314

int notdotentries(const struct dirent *direntry){

1250

1315

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

1251

1316

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

1258

1323

}

1259

1324

1260

1325

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

1326

__attribute__((nonnull, warn_unused_result))

1261

1327

int runnable_hook(const struct dirent *direntry){

1262

1328

int ret;

1263

1329

size_t sret;

1271

1337

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

1272

1338

"abcdefghijklmnopqrstuvwxyz"

1273

1339

"0123456789"

1274

"_-");

1340

"_.-");

1275

1341

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

1276

1342

/* Contains non-allowed characters */

1277

1343

if(debug){

1281

1347

return 0;

1282

1348

}

1283

1349

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);

1350

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

1292

1351

if(ret == -1){

1293

1352

if(debug){

1294

1353

perror_plus("Could not stat hook");

1318

1377

return 1;

1319

1378

}

1320

1379

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1380

__attribute__((nonnull, warn_unused_result))

1381

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1382

mandos_context *mc){

1322

1383

int ret;

1323

1384

struct timespec now;

1324

1385

struct timespec waited_time;

1325

1386

intmax_t block_time;

1326

1387

1327

1388

while(true){

1328

if(mc.current_server == NULL){

1329

if (debug){

1389

if(mc->current_server == NULL){

1390

if(debug){

1330

1391

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

1331

1392

" No timeout!\n");

1332

1393

}

1333

1394

ret = avahi_simple_poll_iterate(s, -1);

1334

1395

} else {

1335

if (debug){

1396

if(debug){

1336

1397

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

1337

1398

" it, or wait\n");

1338

1399

}

1345

1406

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

1346

1407

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

1347

1408

waited_time.tv_sec = (now.tv_sec

1348

- mc.current_server->last_seen.tv_sec);

1409

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

1349

1410

waited_time.tv_nsec = (now.tv_nsec

1350

- mc.current_server->last_seen.tv_nsec);

1411

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

1351

1412

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

1352

1413

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

1353

1414

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

1355

1416

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

1356

1417

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

1357

1418

1358

if (debug){

1419

if(debug){

1359

1420

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

1360

1421

block_time);

1361

1422

}

1362

1423

1363

1424

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);

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);

1368

1429

if(ret == 0){

1369

avahi_simple_poll_quit(mc.simple_poll);

1430

avahi_simple_poll_quit(s);

1370

1431

return 0;

1371

1432

}

1372

1433

ret = clock_gettime(CLOCK_MONOTONIC,

1373

&mc.current_server->last_seen);

1434

&mc->current_server->last_seen);

1374

1435

if(ret == -1){

1375

1436

perror_plus("clock_gettime");

1376

1437

return -1;

1377

1438

}

1378

mc.current_server = mc.current_server->next;

1439

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

1379

1440

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

1380

1441

servers, but don't block */

1381

1442

}

1383

1444

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

1384

1445

}

1385

1446

if(ret != 0){

1386

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

1447

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

1387

1448

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

1388

1449

}

1389

1450

}

1391

1452

}

1392

1453

1393

1454

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

1455

__attribute__((warn_unused_result))

1394

1456

error_t raise_privileges(void){

1395

1457

error_t old_errno = errno;

1396

1458

error_t ret_errno = 0;

1397

1459

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

1398

1460

ret_errno = errno;

1399

perror_plus("seteuid");

1400

1461

}

1401

1462

errno = old_errno;

1402

1463

return ret_errno;

1403

1464

}

1404

1465

1405

1466

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

1467

__attribute__((warn_unused_result))

1406

1468

error_t raise_privileges_permanently(void){

1407

1469

error_t old_errno = errno;

1408

1470

error_t ret_errno = raise_privileges();

1412

1474

}

1413

1475

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

1414

1476

ret_errno = errno;

1415

perror_plus("seteuid");

1416

1477

}

1417

1478

errno = old_errno;

1418

1479

return ret_errno;

1419

1480

}

1420

1481

1421

1482

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

1483

__attribute__((warn_unused_result))

1422

1484

error_t lower_privileges(void){

1423

1485

error_t old_errno = errno;

1424

1486

error_t ret_errno = 0;

1425

1487

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

1426

1488

ret_errno = errno;

1427

perror_plus("seteuid");

1428

1489

}

1429

1490

errno = old_errno;

1430

1491

return ret_errno;

1431

1492

}

1432

1493

1433

1494

/* Lower privileges permanently */

1495

__attribute__((warn_unused_result))

1434

1496

error_t lower_privileges_permanently(void){

1435

1497

error_t old_errno = errno;

1436

1498

error_t ret_errno = 0;

1437

1499

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

1438

1500

ret_errno = errno;

1439

perror_plus("setuid");

1440

1501

}

1441

1502

errno = old_errno;

1442

1503

return ret_errno;

1443

1504

}

1444

1505

1445

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

1506

__attribute__((nonnull))

1507

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

1446

1508

const float delay){

1447

struct dirent **direntries;

1448

struct dirent *direntry;

1449

int ret;

1450

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

1451

alphasort);

1509

struct dirent **direntries = NULL;

1510

if(hookdir_fd == -1){

1511

hookdir_fd = open(hookdir, O_RDONLY);

1512

if(hookdir_fd == -1){

1513

if(errno == ENOENT){

1514

if(debug){

1515

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

1516

" found\n", hookdir);

1517

}

1518

} else {

1519

perror_plus("open");

1520

}

1521

return;

1522

}

1523

}

1524

#ifdef __GLIBC__

1525

#if __GLIBC_PREREQ(2, 15)

1526

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

1527

runnable_hook, alphasort);

1528

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

1529

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

1530

alphasort);

1531

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

1532

#else /* not __GLIBC__ */

1533

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

1534

alphasort);

1535

#endif /* not __GLIBC__ */

1452

1536

if(numhooks == -1){

1453

1537

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){

1538

return;

1539

}

1540

struct dirent *direntry;

1541

int ret;

1542

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

1543

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

1544

direntry = direntries[i];

1545

if(debug){

1546

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

1547

direntry->d_name);

1548

}

1549

pid_t hook_pid = fork();

1550

if(hook_pid == 0){

1551

/* Child */

1552

/* Raise privileges */

1553

errno = raise_privileges_permanently();

1554

if(errno != 0){

1555

perror_plus("Failed to raise privileges");

1556

_exit(EX_NOPERM);

1557

}

1558

/* Set group */

1559

errno = 0;

1560

ret = setgid(0);

1561

if(ret == -1){

1562

perror_plus("setgid");

1563

_exit(EX_NOPERM);

1564

}

1565

/* Reset supplementary groups */

1566

errno = 0;

1567

ret = setgroups(0, NULL);

1568

if(ret == -1){

1569

perror_plus("setgroups");

1570

_exit(EX_NOPERM);

1571

}

1572

ret = dup2(devnull, STDIN_FILENO);

1573

if(ret == -1){

1574

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

1575

_exit(EX_OSERR);

1576

}

1577

ret = close(devnull);

1578

if(ret == -1){

1579

perror_plus("close");

1580

_exit(EX_OSERR);

1581

}

1582

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1583

if(ret == -1){

1584

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

1585

_exit(EX_OSERR);

1586

}

1587

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

1588

if(ret == -1){

1589

perror_plus("setenv");

1590

_exit(EX_OSERR);

1591

}

1592

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

1593

if(ret == -1){

1594

perror_plus("setenv");

1595

_exit(EX_OSERR);

1596

}

1597

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

1598

if(ret == -1){

1599

perror_plus("setenv");

1600

_exit(EX_OSERR);

1601

}

1602

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

1603

if(ret == -1){

1604

perror_plus("setenv");

1605

_exit(EX_OSERR);

1606

}

1607

char *delaystring;

1608

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

1609

if(ret == -1){

1461

1610

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

}

1611

_exit(EX_OSERR);

1612

}

1613

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

1614

if(ret == -1){

1520

1615

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

}

1616

perror_plus("setenv");

1617

_exit(EX_OSERR);

1618

}

1619

free(delaystring);

1620

if(connect_to != NULL){

1621

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

1622

if(ret == -1){

1623

perror_plus("setenv");

1624

_exit(EX_OSERR);

1625

}

1626

}

1627

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

1628

if(hook_fd == -1){

1629

perror_plus("openat");

1630

_exit(EXIT_FAILURE);

1631

}

1632

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

1633

perror_plus("close");

1634

_exit(EXIT_FAILURE);

1635

}

1636

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

1637

environ) == -1){

1638

perror_plus("fexecve");

1639

_exit(EXIT_FAILURE);

1640

}

1641

} else {

1642

int status;

1643

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

1644

perror_plus("waitpid");

1645

continue;

1646

}

1647

if(WIFEXITED(status)){

1648

if(WEXITSTATUS(status) != 0){

1649

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

1650

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

1651

WEXITSTATUS(status));

1652

continue;

1653

}

1654

} else if(WIFSIGNALED(status)){

1655

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

1656

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

1657

WTERMSIG(status));

1658

continue;

1532

1659

} 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;

1660

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

1661

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

1662

continue;

1663

}

1664

}

1665

if(debug){

1666

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

1667

direntry->d_name);

1668

}

1669

}

1670

free(direntries);

1671

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

1672

perror_plus("close");

1673

} else {

1674

hookdir_fd = -1;

1675

}

1676

close(devnull);

1569

1677

}

1570

1678

1679

__attribute__((nonnull, warn_unused_result))

1571

1680

error_t bring_up_interface(const char *const interface,

1572

1681

const float delay){

1573

int sd = -1;

1574

1682

error_t old_errno = errno;

1575

error_t ret_errno = 0;

1576

int ret, ret_setflags;

1683

int ret;

1577

1684

struct ifreq network;

1578

1685

unsigned int if_index = if_nametoindex(interface);

1579

1686

if(if_index == 0){

1588

1695

}

1589

1696

1590

1697

if(not interface_is_up(interface)){

1591

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

1698

error_t ret_errno = 0, ioctl_errno = 0;

1699

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

1592

1700

ret_errno = errno;

1593

1701

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

1594

1702

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

1703

errno = old_errno;

1595

1704

return ret_errno;

1596

1705

}

1597

network.ifr_flags |= IFF_UP;

1706

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

1598

1707

1599

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1600

if(sd < 0){

1708

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

1709

if(sd == -1){

1601

1710

ret_errno = errno;

1602

1711

perror_plus("socket");

1603

1712

errno = old_errno;

1604

1713

return ret_errno;

1605

1714

}

1606

1715

1607

1716

if(quit_now){

1608

close(sd);

1717

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

1718

if(ret == -1){

1719

perror_plus("close");

1720

}

1609

1721

errno = old_errno;

1610

1722

return EINTR;

1611

1723

}

1615

1727

interface);

1616

1728

}

1617

1729

1618

/* Raise priviliges */

1619

raise_privileges();

1730

/* Raise privileges */

1731

ret_errno = raise_privileges();

1732

if(ret_errno != 0){

1733

errno = ret_errno;

1734

perror_plus("Failed to raise privileges");

1735

}

1620

1736

1621

1737

#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");

1738

int ret_linux;

1739

bool restore_loglevel = false;

1740

if(ret_errno == 0){

1741

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1742

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

1743

ret_linux = klogctl(8, NULL, 5);

1744

if(ret_linux == -1){

1745

perror_plus("klogctl");

1746

} else {

1747

restore_loglevel = true;

1748

}

1629

1749

}

1630

1750

#endif /* __linux__ */

1631

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

1632

ret_errno = errno;

1751

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

1752

ioctl_errno = errno;

1633

1753

#ifdef __linux__

1634

1754

if(restore_loglevel){

1635

1755

ret_linux = klogctl(7, NULL, 0);

1639

1759

}

1640

1760

#endif /* __linux__ */

1641

1761

1642

/* Lower privileges */

1643

lower_privileges();

1762

/* If raise_privileges() succeeded above */

1763

if(ret_errno == 0){

1764

/* Lower privileges */

1765

ret_errno = lower_privileges();

1766

if(ret_errno != 0){

1767

errno = ret_errno;

1768

perror_plus("Failed to lower privileges");

1769

}

1770

}

1644

1771

1645

1772

/* Close the socket */

1646

1773

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

1649

1776

}

1650

1777

1651

1778

if(ret_setflags == -1){

1652

errno = ret_errno;

1779

errno = ioctl_errno;

1653

1780

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1654

1781

errno = old_errno;

1655

return ret_errno;

1782

return ioctl_errno;

1656

1783

}

1657

1784

} else if(debug){

1658

1785

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

1676

1803

return 0;

1677

1804

}

1678

1805

1806

__attribute__((nonnull, warn_unused_result))

1679

1807

error_t take_down_interface(const char *const interface){

1680

int sd = -1;

1681

1808

error_t old_errno = errno;

1682

error_t ret_errno = 0;

1683

int ret, ret_setflags;

1684

1809

struct ifreq network;

1685

1810

unsigned int if_index = if_nametoindex(interface);

1686

1811

if(if_index == 0){

1689

1814

return ENXIO;

1690

1815

}

1691

1816

if(interface_is_up(interface)){

1817

error_t ret_errno = 0, ioctl_errno = 0;

1692

1818

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

1693

1819

ret_errno = errno;

1694

1820

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

1695

1821

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

1822

errno = old_errno;

1696

1823

return ret_errno;

1697

1824

}

1698

1825

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

1699

1826

1700

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1701

if(sd < 0){

1827

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

1828

if(sd == -1){

1702

1829

ret_errno = errno;

1703

1830

perror_plus("socket");

1704

1831

errno = old_errno;

1710

1837

interface);

1711

1838

}

1712

1839

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();

1840

/* Raise privileges */

1841

ret_errno = raise_privileges();

1842

if(ret_errno != 0){

1843

errno = ret_errno;

1844

perror_plus("Failed to raise privileges");

1845

}

1846

1847

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

1848

ioctl_errno = errno;

1849

1850

/* If raise_privileges() succeeded above */

1851

if(ret_errno == 0){

1852

/* Lower privileges */

1853

ret_errno = lower_privileges();

1854

if(ret_errno != 0){

1855

errno = ret_errno;

1856

perror_plus("Failed to lower privileges");

1857

}

1858

}

1721

1859

1722

1860

/* Close the socket */

1723

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

1861

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

1724

1862

if(ret == -1){

1725

1863

perror_plus("close");

1726

1864

}

1727

1865

1728

1866

if(ret_setflags == -1){

1729

errno = ret_errno;

1867

errno = ioctl_errno;

1730

1868

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1731

1869

errno = old_errno;

1732

return ret_errno;

1870

return ioctl_errno;

1733

1871

}

1734

1872

} else if(debug){

1735

1873

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

1741

1879

}

1742

1880

1743

1881

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

1882

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

1883

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

1884

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

1885

.interfaces = NULL, .interfaces_size = 0 };

1744

1886

AvahiSServiceBrowser *sb = NULL;

1745

1887

error_t ret_errno;

1746

1888

int ret;

1747

1889

intmax_t tmpmax;

1748

1890

char *tmp;

1749

1891

int exitcode = EXIT_SUCCESS;

1750

char *interfaces = NULL;

1751

size_t interfaces_size = 0;

1752

1892

char *interfaces_to_take_down = NULL;

1753

1893

size_t interfaces_to_take_down_size = 0;

1754

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

1755

bool tempdir_created = false;

1894

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

1895

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

1896

char *tempdir = NULL;

1756

1897

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1757

1898

const char *seckey = PATHDIR "/" SECKEY;

1758

1899

const char *pubkey = PATHDIR "/" PUBKEY;

1759

1900

char *interfaces_hooks = NULL;

1760

size_t interfaces_hooks_size = 0;

1761

1901

1762

1902

bool gnutls_initialized = false;

1763

1903

bool gpgme_initialized = false;

1854

1994

connect_to = arg;

1855

1995

break;

1856

1996

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

1857

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

1858

(int)',');

1997

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

1998

arg, (int)',');

1859

1999

if(ret_errno != 0){

1860

2000

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

1861

2001

}

1941

2081

/* Work around Debian bug #633582:

1942

2082

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

1943

2083

1944

/* Re-raise priviliges */

1945

if(raise_privileges() == 0){

2084

/* Re-raise privileges */

2085

ret_errno = raise_privileges();

2086

if(ret_errno != 0){

2087

errno = ret_errno;

2088

perror_plus("Failed to raise privileges");

2089

} else {

1946

2090

struct stat st;

1947

2091

1948

2092

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

1988

2132

}

1989

2133

1990

2134

/* Lower privileges */

1991

errno = 0;

1992

ret = seteuid(uid);

1993

if(ret == -1){

1994

perror_plus("seteuid");

2135

ret_errno = lower_privileges();

2136

if(ret_errno != 0){

2137

errno = ret_errno;

2138

perror_plus("Failed to lower privileges");

1995

2139

}

1996

2140

}

1997

2141

}

1998

2142

1999

/* Remove empty interface names */

2143

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

2000

2144

{

2001

2145

char *interface = NULL;

2002

while((interface = argz_next(interfaces, interfaces_size,

2146

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

2003

2147

interface))){

2004

if(if_nametoindex(interface) == 0){

2005

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

2148

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

2149

and if_nametoindex(interface) == 0){

2150

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

2006

2151

fprintf_plus(stderr, "Not using nonexisting interface"

2007

2152

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

2008

2153

}

2009

argz_delete(&interfaces, &interfaces_size, interface);

2154

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

2010

2155

interface = NULL;

2011

2156

}

2012

2157

}

2014

2159

2015

2160

/* Run network hooks */

2016

2161

{

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

}

2162

if(mc.interfaces != NULL){

2163

interfaces_hooks = malloc(mc.interfaces_size);

2164

if(interfaces_hooks == NULL){

2165

perror_plus("malloc");

2166

goto end;

2167

}

2168

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

2169

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

2170

}

2171

run_network_hooks("start", interfaces_hooks != NULL ?

2172

interfaces_hooks : "", delay);

2028

2173

}

2029

2174

2030

2175

if(not debug){

2035

2180

from the signal handler */

2036

2181

/* Initialize the pseudo-RNG for Avahi */

2037

2182

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

2038

mc.simple_poll = avahi_simple_poll_new();

2039

if(mc.simple_poll == NULL){

2183

simple_poll = avahi_simple_poll_new();

2184

if(simple_poll == NULL){

2040

2185

fprintf_plus(stderr,

2041

2186

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

2042

2187

exitcode = EX_UNAVAILABLE;

2107

2252

}

2108

2253

2109

2254

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

2110

if(interfaces == NULL){

2111

struct dirent **direntries;

2255

if(mc.interfaces == NULL){

2256

struct dirent **direntries = NULL;

2112

2257

/* Look for any good interfaces */

2113

2258

ret = scandir(sys_class_net, &direntries, good_interface,

2114

2259

alphasort);

2115

2260

if(ret >= 1){

2116

2261

/* Add all found interfaces to interfaces list */

2117

2262

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

2118

ret_errno = argz_add(&interfaces, &interfaces_size,

2263

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

2119

2264

direntries[i]->d_name);

2120

2265

if(ret_errno != 0){

2266

errno = ret_errno;

2121

2267

perror_plus("argz_add");

2122

2268

continue;

2123

2269

}

2128

2274

}

2129

2275

free(direntries);

2130

2276

} else {

2131

free(direntries);

2277

if(ret == 0){

2278

free(direntries);

2279

}

2132

2280

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

2133

2281

exitcode = EXIT_FAILURE;

2134

2282

goto end;

2135

2283

}

2136

2284

}

2137

2285

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)){

2286

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

2287

{

2150

2288

char *interface = NULL;

2151

while((interface = argz_next(interfaces, interfaces_size,

2289

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

2152

2290

interface))){

2291

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

2292

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

2293

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

2294

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

2295

interface);

2296

interface = NULL;

2297

while((interface = argz_next(mc.interfaces,

2298

mc.interfaces_size, interface))){

2299

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

2300

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

2301

interface);

2302

interface = NULL;

2303

}

2304

}

2305

break;

2306

}

2153

2307

bool interface_was_up = interface_is_up(interface);

2154

ret = bring_up_interface(interface, delay);

2308

errno = bring_up_interface(interface, delay);

2155

2309

if(not interface_was_up){

2156

if(ret != 0){

2157

errno = ret;

2310

if(errno != 0){

2158

2311

perror_plus("Failed to bring up interface");

2159

2312

} else {

2160

ret_errno = argz_add(&interfaces_to_take_down,

2161

&interfaces_to_take_down_size,

2162

interface);

2313

errno = argz_add(&interfaces_to_take_down,

2314

&interfaces_to_take_down_size,

2315

interface);

2316

if(errno != 0){

2317

perror_plus("argz_add");

2318

}

2163

2319

}

2164

2320

}

2165

2321

}

2166

free(interfaces);

2167

interfaces = NULL;

2168

interfaces_size = 0;

2169

2322

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

2170

2323

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

2171

2324

}

2172

2325

}

2173

2326

2327

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

2328

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

2329

if(debug){

2330

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

2331

mc.interfaces);

2332

}

2333

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

2334

}

2335

2174

2336

if(quit_now){

2175

2337

goto end;

2176

2338

}

2177

2339

2178

ret = init_gnutls_global(pubkey, seckey);

2340

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

2179

2341

if(ret == -1){

2180

2342

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

2181

2343

exitcode = EX_UNAVAILABLE;

2188

2350

goto end;

2189

2351

}

2190

2352

2191

if(mkdtemp(tempdir) == NULL){

2353

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

2354

tempdir = mkdtemp(run_tempdir);

2355

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

2356

if(debug){

2357

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

2358

run_tempdir, old_tempdir);

2359

}

2360

tempdir = mkdtemp(old_tempdir);

2361

}

2362

if(tempdir == NULL){

2192

2363

perror_plus("mkdtemp");

2193

2364

goto end;

2194

2365

}

2195

tempdir_created = true;

2196

2366

2197

2367

if(quit_now){

2198

2368

goto end;

2199

2369

}

2200

2370

2201

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

2371

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

2202

2372

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

2203

2373

exitcode = EX_UNAVAILABLE;

2204

2374

goto end;

2234

2404

exitcode = EX_USAGE;

2235

2405

goto end;

2236

2406

}

2237

2407

2238

2408

if(quit_now){

2239

2409

goto end;

2240

2410

}

2261

2431

}

2262

2432

2263

2433

while(not quit_now){

2264

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

2434

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

2435

&mc);

2265

2436

if(quit_now or ret == 0){

2266

2437

break;

2267

2438

}

2269

2440

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

2270

2441

(int)retry_interval);

2271

2442

}

2272

sleep((int)retry_interval);

2443

sleep((unsigned int)retry_interval);

2273

2444

}

2274

2445

2275

if (not quit_now){

2446

if(not quit_now){

2276

2447

exitcode = EXIT_SUCCESS;

2277

2448

}

2278

2449

2293

2464

config.publish_domain = 0;

2294

2465

2295

2466

/* Allocate a new server */

2296

mc.server = avahi_server_new(avahi_simple_poll_get

2297

(mc.simple_poll), &config, NULL,

2298

NULL, &ret_errno);

2467

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2468

&config, NULL, NULL, &ret_errno);

2299

2469

2300

2470

/* Free the Avahi configuration data */

2301

2471

avahi_server_config_free(&config);

2316

2486

/* Create the Avahi service browser */

2317

2487

sb = avahi_s_service_browser_new(mc.server, if_index,

2318

2488

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2319

NULL, 0, browse_callback, NULL);

2489

NULL, 0, browse_callback,

2490

(void *)&mc);

2320

2491

if(sb == NULL){

2321

2492

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

2322

2493

avahi_strerror(avahi_server_errno(mc.server)));

2333

2504

if(debug){

2334

2505

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

2335

2506

}

2336

2337

ret = avahi_loop_with_timeout(mc.simple_poll,

2338

(int)(retry_interval * 1000));

2507

2508

ret = avahi_loop_with_timeout(simple_poll,

2509

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

2339

2510

if(debug){

2340

2511

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

2341

2512

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

2348

2519

}

2349

2520

2350

2521

/* Cleanup things */

2522

free(mc.interfaces);

2523

2351

2524

if(sb != NULL)

2352

2525

avahi_s_service_browser_free(sb);

2353

2526

2354

2527

if(mc.server != NULL)

2355

2528

avahi_server_free(mc.server);

2356

2529

2357

if(mc.simple_poll != NULL)

2358

avahi_simple_poll_free(mc.simple_poll);

2530

if(simple_poll != NULL)

2531

avahi_simple_poll_free(simple_poll);

2359

2532

2360

2533

if(gnutls_initialized){

2361

2534

gnutls_certificate_free_credentials(mc.cred);

2378

2551

}

2379

2552

}

2380

2553

2381

/* Re-raise priviliges */

2554

/* Re-raise privileges */

2382

2555

{

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();

2556

ret_errno = raise_privileges();

2557

if(ret_errno != 0){

2558

errno = ret_errno;

2559

perror_plus("Failed to raise privileges");

2560

} else {

2561

2562

/* Run network hooks */

2563

run_network_hooks("stop", interfaces_hooks != NULL ?

2564

interfaces_hooks : "", delay);

2565

2566

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

2567

{

2568

char *interface = NULL;

2569

while((interface=argz_next(interfaces_to_take_down,

2570

interfaces_to_take_down_size,

2571

interface))){

2572

ret_errno = take_down_interface(interface);

2573

if(ret_errno != 0){

2574

errno = ret_errno;

2575

perror_plus("Failed to take down interface");

2576

}

2577

}

2578

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

2579

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

2580

" down\n");

2581

}

2582

}

2583

}

2584

2585

ret_errno = lower_privileges_permanently();

2586

if(ret_errno != 0){

2587

errno = ret_errno;

2588

perror_plus("Failed to lower privileges permanently");

2589

}

2407

2590

}

2408

2591

2409

2592

free(interfaces_to_take_down);

2410

2593

free(interfaces_hooks);

2411

2594

2412

2595

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

2413

if(tempdir_created){

2596

if(tempdir != NULL){

2414

2597

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);

2598

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

2599

O_NOFOLLOW));

2600

if(tempdir_fd == -1){

2601

perror_plus("open");

2602

} else {

2603

#ifdef __GLIBC__

2604

#if __GLIBC_PREREQ(2, 15)

2605

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

2606

notdotentries, alphasort);

2607

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

2608

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

2609

alphasort);

2610

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

2611

#else /* not __GLIBC__ */

2612

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

2613

alphasort);

2614

#endif /* not __GLIBC__ */

2615

if(numentries >= 0){

2616

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

2617

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

2618

if(ret == -1){

2619

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

2620

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

2621

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

2622

}

2623

}

2624

2625

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

2626

free(direntries);

2627

if(numentries == -1){

2628

perror_plus("scandir");

2629

}

2630

ret = rmdir(tempdir);

2631

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

2632

perror_plus("rmdir");

2633

}

2434

2634

}

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");

2635

TEMP_FAILURE_RETRY(close(tempdir_fd));

2445

2636

}

2446

2637

}

2447

2638