/mandos/release : revision 237.22.2

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

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() */

58

inet_pton(), connect() */

60

59

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

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60

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

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61

*/

63

62

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

64

63

strtoimax() */

64

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

65

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

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program_invocation_short_name */

67

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

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

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

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

77

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

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

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

79

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

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argp_state, struct argp,

88

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

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WEXITSTATUS(), WTERMSIG() */

90

#include <grp.h> /* setgroups() */

91

#include <argz.h> /* argz_add_sep(), argz_next(),

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

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argz_count() */

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

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EAI_SYSTEM, gai_strerror() */

97

91

98

92

#ifdef __linux__

99

93

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

136

130

137

131

bool debug = false;

138

132

static const char mandos_protocol_version[] = "1";

139

const char * argp_program_version = "mandos-client " VERSION;

140

const char * argp_program_bug_address = "<mandos@recompile.se>";

133

const char *argp_program_version = "mandos-client " VERSION;

134

const char *argp_program_bug_address = "<mandos@recompile.se>";

141

135

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

142

136

char *connect_to = NULL;

143

137

const char *hookdir = HOOKDIR;

147

141

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

148

142

typedef struct server{

149

143

const char *ip;

150

in_port_t port;

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uint16_t port;

151

145

AvahiIfIndex if_index;

152

146

int af;

153

147

struct timespec last_seen;

157

151

158

152

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

159

153

typedef struct {

154

AvahiSimplePoll *simple_poll;

160

155

AvahiServer *server;

161

156

gnutls_certificate_credentials_t cred;

162

157

unsigned int dh_bits;

164

159

const char *priority;

165

160

gpgme_ctx_t ctx;

166

161

server *current_server;

167

char *interfaces;

168

size_t interfaces_size;

169

162

} mandos_context;

170

163

171

/* global so signal handler can reach it*/

172

AvahiSimplePoll *simple_poll;

164

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

165

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

166

.dh_bits = 1024, .priority = "SECURE256"

167

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

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.current_server = NULL };

173

169

174

170

sig_atomic_t quit_now = 0;

175

171

int signal_received = 0;

183

179

perror(print_text);

184

180

}

185

181

186

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

182

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

187

183

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

188

184

va_list ap;

189

185

va_start (ap, format);

190

186

191

187

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

192

188

program_invocation_short_name));

193

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

189

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

194

190

}

195

191

196

192

/*

198

194

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

199

195

* "buffer_length" is how much is already used.

200

196

*/

201

__attribute__((nonnull, warn_unused_result))

202

197

size_t incbuffer(char **buffer, size_t buffer_length,

203

198

size_t buffer_capacity){

204

199

if(buffer_length + BUFFER_SIZE > buffer_capacity){

205

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

206

if(new_buf == NULL){

207

int old_errno = errno;

208

free(*buffer);

209

errno = old_errno;

210

*buffer = NULL;

200

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

201

if(buffer == NULL){

211

202

return 0;

212

203

}

213

*buffer = new_buf;

214

204

buffer_capacity += BUFFER_SIZE;

215

205

}

216

206

return buffer_capacity;

217

207

}

218

208

219

209

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

220

__attribute__((nonnull, warn_unused_result))

221

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

222

int af, server **current_server){

210

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

211

int af){

223

212

int ret;

224

213

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

225

214

if(new_server == NULL){

234

223

perror_plus("strdup");

235

224

return false;

236

225

}

237

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

238

if(ret == -1){

239

perror_plus("clock_gettime");

240

return false;

241

}

242

226

/* Special case of first server */

243

if(*current_server == NULL){

227

if (mc.current_server == NULL){

244

228

new_server->next = new_server;

245

229

new_server->prev = new_server;

246

*current_server = new_server;

230

mc.current_server = new_server;

231

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

247

232

} else {

248

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

249

new_server->next = *current_server;

250

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

233

new_server->next = mc.current_server;

234

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

251

235

new_server->prev->next = new_server;

252

(*current_server)->prev = new_server;

236

mc.current_server->prev = new_server;

237

}

238

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

239

if(ret == -1){

240

perror_plus("clock_gettime");

241

return false;

253

242

}

254

243

return true;

255

244

}

257

246

/*

258

247

* Initialize GPGME.

259

248

*/

260

__attribute__((nonnull, warn_unused_result))

261

static bool init_gpgme(const char * const seckey,

262

const char * const pubkey,

263

const char * const tempdir,

264

mandos_context *mc){

249

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

250

const char *tempdir){

265

251

gpgme_error_t rc;

266

252

gpgme_engine_info_t engine_info;

267

253

254

268

255

/*

269

256

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

270

257

*/

271

bool import_key(const char * const filename){

258

bool import_key(const char *filename){

272

259

int ret;

273

260

int fd;

274

261

gpgme_data_t pgp_data;

286

273

return false;

287

274

}

288

275

289

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

276

rc = gpgme_op_import(mc.ctx, pgp_data);

290

277

if(rc != GPG_ERR_NO_ERROR){

291

278

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

292

279

gpgme_strsource(rc), gpgme_strerror(rc));

336

323

}

337

324

338

325

/* Create new GPGME "context" */

339

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

326

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

340

327

if(rc != GPG_ERR_NO_ERROR){

341

328

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

342

329

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

355

342

* Decrypt OpenPGP data.

356

343

* Returns -1 on error

357

344

*/

358

__attribute__((nonnull, warn_unused_result))

359

345

static ssize_t pgp_packet_decrypt(const char *cryptotext,

360

346

size_t crypto_size,

361

char **plaintext,

362

mandos_context *mc){

347

char **plaintext){

363

348

gpgme_data_t dh_crypto, dh_plain;

364

349

gpgme_error_t rc;

365

350

ssize_t ret;

391

376

392

377

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

393

378

data buffer */

394

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

379

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

395

380

if(rc != GPG_ERR_NO_ERROR){

396

381

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

397

382

gpgme_strsource(rc), gpgme_strerror(rc));

398

383

plaintext_length = -1;

399

384

if(debug){

400

385

gpgme_decrypt_result_t result;

401

result = gpgme_op_decrypt_result(mc->ctx);

386

result = gpgme_op_decrypt_result(mc.ctx);

402

387

if(result == NULL){

403

388

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

404

389

} else {

481

466

return plaintext_length;

482

467

}

483

468

484

__attribute__((warn_unused_result))

485

static const char *safer_gnutls_strerror(int value){

486

const char *ret = gnutls_strerror(value);

469

static const char * safer_gnutls_strerror(int value){

470

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

471

-Wunreachable-code */

487

472

if(ret == NULL)

488

473

ret = "(unknown)";

489

474

return ret;

490

475

}

491

476

492

477

/* GnuTLS log function callback */

493

__attribute__((nonnull))

494

478

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

495

479

const char* string){

496

480

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

497

481

}

498

482

499

__attribute__((nonnull, warn_unused_result))

500

483

static int init_gnutls_global(const char *pubkeyfilename,

501

const char *seckeyfilename,

502

mandos_context *mc){

484

const char *seckeyfilename){

503

485

int ret;

504

486

505

487

if(debug){

522

504

}

523

505

524

506

/* OpenPGP credentials */

525

ret = gnutls_certificate_allocate_credentials(&mc->cred);

507

ret = gnutls_certificate_allocate_credentials(&mc.cred);

526

508

if(ret != GNUTLS_E_SUCCESS){

527

509

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

528

510

safer_gnutls_strerror(ret));

538

520

}

539

521

540

522

ret = gnutls_certificate_set_openpgp_key_file

541

(mc->cred, pubkeyfilename, seckeyfilename,

523

(mc.cred, pubkeyfilename, seckeyfilename,

542

524

GNUTLS_OPENPGP_FMT_BASE64);

543

525

if(ret != GNUTLS_E_SUCCESS){

544

526

fprintf_plus(stderr,

550

532

}

551

533

552

534

/* GnuTLS server initialization */

553

ret = gnutls_dh_params_init(&mc->dh_params);

535

ret = gnutls_dh_params_init(&mc.dh_params);

554

536

if(ret != GNUTLS_E_SUCCESS){

555

537

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

556

538

" initialization: %s\n",

557

539

safer_gnutls_strerror(ret));

558

540

goto globalfail;

559

541

}

560

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

542

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

561

543

if(ret != GNUTLS_E_SUCCESS){

562

544

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

563

545

safer_gnutls_strerror(ret));

564

546

goto globalfail;

565

547

}

566

548

567

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

549

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

568

550

569

551

return 0;

570

552

571

553

globalfail:

572

554

573

gnutls_certificate_free_credentials(mc->cred);

555

gnutls_certificate_free_credentials(mc.cred);

574

556

gnutls_global_deinit();

575

gnutls_dh_params_deinit(mc->dh_params);

557

gnutls_dh_params_deinit(mc.dh_params);

576

558

return -1;

577

559

}

578

560

579

__attribute__((nonnull, warn_unused_result))

580

static int init_gnutls_session(gnutls_session_t *session,

581

mandos_context *mc){

561

static int init_gnutls_session(gnutls_session_t *session){

582

562

int ret;

583

563

/* GnuTLS session creation */

584

564

do {

596

576

{

597

577

const char *err;

598

578

do {

599

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

579

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

600

580

if(quit_now){

601

581

gnutls_deinit(*session);

602

582

return -1;

613

593

614

594

do {

615

595

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

616

mc->cred);

596

mc.cred);

617

597

if(quit_now){

618

598

gnutls_deinit(*session);

619

599

return -1;

629

609

/* ignore client certificate if any. */

630

610

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

631

611

632

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

612

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

633

613

634

614

return 0;

635

615

}

639

619

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

640

620

641

621

/* Called when a Mandos server is found */

642

__attribute__((nonnull, warn_unused_result))

643

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

622

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

644

623

AvahiIfIndex if_index,

645

int af, mandos_context *mc){

624

int af){

646

625

int ret, tcp_sd = -1;

647

626

ssize_t sret;

648

struct sockaddr_storage to;

627

union {

628

struct sockaddr_in in;

629

struct sockaddr_in6 in6;

630

} to;

649

631

char *buffer = NULL;

650

632

char *decrypted_buffer = NULL;

651

633

size_t buffer_length = 0;

675

657

return -1;

676

658

}

677

659

678

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

679

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

680

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

681

bool match = false;

682

{

683

char *interface = NULL;

684

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

685

interface))){

686

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

687

match = true;

688

break;

689

}

690

}

691

}

692

if(not match){

693

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

694

connect to the server */

695

if(debug){

696

char interface[IF_NAMESIZE];

697

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

698

perror_plus("if_indextoname");

699

} else {

700

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

701

" \"%s\"\n",

702

if_indextoname((unsigned int)if_index,

703

interface));

704

}

705

}

706

return -1;

707

}

708

}

709

710

ret = init_gnutls_session(&session, mc);

660

ret = init_gnutls_session(&session);

711

661

if(ret != 0){

712

662

return -1;

713

663

}

714

664

715

665

if(debug){

716

666

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

717

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

667

PRIu16 "\n", ip, port);

718

668

}

719

669

720

670

tcp_sd = socket(pf, SOCK_STREAM, 0);

732

682

733

683

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

734

684

if(af == AF_INET6){

735

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

736

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

685

to.in6.sin6_family = (sa_family_t)af;

686

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

737

687

} else { /* IPv4 */

738

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

739

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

688

to.in.sin_family = (sa_family_t)af;

689

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

740

690

}

741

691

if(ret < 0 ){

742

692

int e = errno;

751

701

goto mandos_end;

752

702

}

753

703

if(af == AF_INET6){

754

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

755

if(IN6_IS_ADDR_LINKLOCAL

756

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

704

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

705

-Wconversion and

706

-Wunreachable-code */

707

708

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

709

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

710

-Wunreachable-code*/

757

711

if(if_index == AVAHI_IF_UNSPEC){

758

712

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

759

713

" incomplete without a network interface\n");

761

715

goto mandos_end;

762

716

}

763

717

/* Set the network interface number as scope */

764

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

718

to.in6.sin6_scope_id = (uint32_t)if_index;

765

719

}

766

720

} else {

767

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

721

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

722

-Wconversion and

723

-Wunreachable-code */

768

724

}

769

725

770

726

if(quit_now){

778

734

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

779

735

perror_plus("if_indextoname");

780

736

} else {

781

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

782

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

737

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

738

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

783

739

}

784

740

} else {

785

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

786

ip, (uintmax_t)port);

741

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

742

ip, port);

787

743

}

788

744

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

789

745

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

746

const char *pcret;

790

747

if(af == AF_INET6){

791

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

792

sizeof(struct sockaddr_in6),

793

addrstr, sizeof(addrstr), NULL, 0,

794

NI_NUMERICHOST);

748

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

749

sizeof(addrstr));

795

750

} else {

796

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

797

sizeof(struct sockaddr_in),

798

addrstr, sizeof(addrstr), NULL, 0,

799

NI_NUMERICHOST);

751

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

752

sizeof(addrstr));

800

753

}

801

if(ret == EAI_SYSTEM){

802

perror_plus("getnameinfo");

803

} else if(ret != 0) {

804

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

805

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

806

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

754

if(pcret == NULL){

755

perror_plus("inet_ntop");

756

} else {

757

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

758

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

759

}

807

760

}

808

761

}

809

762

813

766

}

814

767

815

768

if(af == AF_INET6){

816

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

817

sizeof(struct sockaddr_in6));

769

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

818

770

} else {

819

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

820

sizeof(struct sockaddr_in));

771

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

821

772

}

822

773

if(ret < 0){

823

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

774

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

824

775

int e = errno;

825

776

perror_plus("connect");

826

777

errno = e;

987

938

if(buffer_length > 0){

988

939

ssize_t decrypted_buffer_size;

989

940

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

990

&decrypted_buffer, mc);

941

&decrypted_buffer);

991

942

if(decrypted_buffer_size >= 0){

992

943

993

944

written = 0;

1041

992

return retval;

1042

993

}

1043

994

1044

__attribute__((nonnull))

1045

995

static void resolve_callback(AvahiSServiceResolver *r,

1046

996

AvahiIfIndex interface,

1047

997

AvahiProtocol proto,

1055

1005

AVAHI_GCC_UNUSED AvahiStringList *txt,

1056

1006

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1057

1007

flags,

1058

void *mc){

1059

if(r == NULL){

1060

return;

1061

}

1008

AVAHI_GCC_UNUSED void* userdata){

1009

assert(r);

1062

1010

1063

1011

/* Called whenever a service has been resolved successfully or

1064

1012

timed out */

1073

1021

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

1074

1022

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

1075

1023

domain,

1076

avahi_strerror(avahi_server_errno

1077

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

1024

avahi_strerror(avahi_server_errno(mc.server)));

1078

1025

break;

1079

1026

1080

1027

case AVAHI_RESOLVER_FOUND:

1086

1033

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

1087

1034

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

1088

1035

}

1089

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

1090

interface,

1091

avahi_proto_to_af(proto),

1092

mc);

1036

int ret = start_mandos_communication(ip, port, interface,

1037

avahi_proto_to_af(proto));

1093

1038

if(ret == 0){

1094

avahi_simple_poll_quit(simple_poll);

1039

avahi_simple_poll_quit(mc.simple_poll);

1095

1040

} else {

1096

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

1097

avahi_proto_to_af(proto),

1098

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

1041

if(not add_server(ip, port, interface,

1042

avahi_proto_to_af(proto))){

1099

1043

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

1100

1044

" list\n", name);

1101

1045

}

1114

1058

const char *domain,

1115

1059

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1116

1060

flags,

1117

void *mc){

1118

if(b == NULL){

1119

return;

1120

}

1061

AVAHI_GCC_UNUSED void* userdata){

1062

assert(b);

1121

1063

1122

1064

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

1123

1065

is removed from the LAN */

1131

1073

case AVAHI_BROWSER_FAILURE:

1132

1074

1133

1075

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

1134

avahi_strerror(avahi_server_errno

1135

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

1136

avahi_simple_poll_quit(simple_poll);

1076

avahi_strerror(avahi_server_errno(mc.server)));

1077

avahi_simple_poll_quit(mc.simple_poll);

1137

1078

return;

1138

1079

1139

1080

case AVAHI_BROWSER_NEW:

1142

1083

the callback function is called the Avahi server will free the

1143

1084

resolver for us. */

1144

1085

1145

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

1146

interface, protocol, name, type,

1147

domain, protocol, 0,

1148

resolve_callback, mc) == NULL)

1086

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

1087

name, type, domain, protocol, 0,

1088

resolve_callback, NULL) == NULL)

1149

1089

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

1150

1090

" %s\n", name,

1151

avahi_strerror(avahi_server_errno

1152

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

1091

avahi_strerror(avahi_server_errno(mc.server)));

1153

1092

break;

1154

1093

1155

1094

case AVAHI_BROWSER_REMOVE:

1174

1113

signal_received = sig;

1175

1114

int old_errno = errno;

1176

1115

/* set main loop to exit */

1177

if(simple_poll != NULL){

1178

avahi_simple_poll_quit(simple_poll);

1116

if(mc.simple_poll != NULL){

1117

avahi_simple_poll_quit(mc.simple_poll);

1179

1118

}

1180

1119

errno = old_errno;

1181

1120

}

1182

1121

1183

__attribute__((nonnull, warn_unused_result))

1184

1122

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

1185

1123

int ret;

1186

error_t ret_errno;

1187

1124

1188

1125

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

1189

1126

if(s < 0){

1190

ret_errno = errno;

1191

1127

perror_plus("socket");

1192

errno = ret_errno;

1193

1128

return false;

1194

1129

}

1195

1130

strcpy(ifr->ifr_name, ifname);

1196

1131

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1197

1132

if(ret == -1){

1198

1133

if(debug){

1199

ret_errno = errno;

1200

1134

perror_plus("ioctl SIOCGIFFLAGS");

1201

errno = ret_errno;

1202

1135

}

1203

1136

return false;

1204

1137

}

1205

1138

return true;

1206

1139

}

1207

1140

1208

__attribute__((nonnull, warn_unused_result))

1209

1141

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

1210

1142

1211

1143

/* Reject the loopback device */

1253

1185

* corresponds to an acceptable network device.

1254

1186

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

1255

1187

*/

1256

__attribute__((nonnull, warn_unused_result))

1257

1188

int good_interface(const struct dirent *if_entry){

1258

1189

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

1259

1190

return 0;

1275

1206

}

1276

1207

1277

1208

/*

1278

* This function determines if a network interface is up.

1279

*/

1280

__attribute__((nonnull, warn_unused_result))

1281

bool interface_is_up(const char *interface){

1282

struct ifreq ifr;

1283

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

1284

if(debug){

1285

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

1286

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

1287

}

1288

return false;

1289

}

1290

1291

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

1292

}

1293

1294

/*

1295

* This function determines if a network interface is running

1296

*/

1297

__attribute__((nonnull, warn_unused_result))

1298

bool interface_is_running(const char *interface){

1299

struct ifreq ifr;

1300

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

1301

if(debug){

1302

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

1303

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

1304

}

1305

return false;

1306

}

1307

1308

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

1309

}

1310

1311

__attribute__((nonnull, pure, warn_unused_result))

1209

* This function determines if a directory entry in /sys/class/net

1210

* corresponds to an acceptable network device which is up.

1211

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

1212

*/

1213

int up_interface(const struct dirent *if_entry){

1214

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

1215

return 0;

1216

}

1217

1218

struct ifreq ifr;

1219

if(not get_flags(if_entry->d_name, &ifr)){

1220

if(debug){

1221

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

1222

"\"%s\"\n", if_entry->d_name);

1223

}

1224

return 0;

1225

}

1226

1227

/* Reject down interfaces */

1228

if(not (ifr.ifr_flags & IFF_UP)){

1229

if(debug){

1230

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

1231

if_entry->d_name);

1232

}

1233

return 0;

1234

}

1235

1236

/* Reject non-running interfaces */

1237

if(not (ifr.ifr_flags & IFF_RUNNING)){

1238

if(debug){

1239

fprintf_plus(stderr, "Rejecting non-running interface \"%s\"\n",

1240

if_entry->d_name);

1241

}

1242

return 0;

1243

}

1244

1245

if(not good_flags(if_entry->d_name, &ifr)){

1246

return 0;

1247

}

1248

return 1;

1249

}

1250

1312

1251

int notdotentries(const struct dirent *direntry){

1313

1252

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

1314

1253

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

1321

1260

}

1322

1261

1323

1262

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

1324

__attribute__((nonnull, warn_unused_result))

1325

1263

int runnable_hook(const struct dirent *direntry){

1326

1264

int ret;

1327

1265

size_t sret;

1382

1320

return 1;

1383

1321

}

1384

1322

1385

__attribute__((nonnull, warn_unused_result))

1386

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1387

mandos_context *mc){

1323

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1388

1324

int ret;

1389

1325

struct timespec now;

1390

1326

struct timespec waited_time;

1391

1327

intmax_t block_time;

1392

1328

1393

1329

while(true){

1394

if(mc->current_server == NULL){

1395

if(debug){

1330

if(mc.current_server == NULL){

1331

if (debug){

1396

1332

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

1397

1333

" No timeout!\n");

1398

1334

}

1399

1335

ret = avahi_simple_poll_iterate(s, -1);

1400

1336

} else {

1401

if(debug){

1337

if (debug){

1402

1338

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

1403

1339

" it, or wait\n");

1404

1340

}

1411

1347

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

1412

1348

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

1413

1349

waited_time.tv_sec = (now.tv_sec

1414

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

1350

- mc.current_server->last_seen.tv_sec);

1415

1351

waited_time.tv_nsec = (now.tv_nsec

1416

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

1352

- mc.current_server->last_seen.tv_nsec);

1417

1353

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

1418

1354

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

1419

1355

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

1421

1357

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

1422

1358

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

1423

1359

1424

if(debug){

1360

if (debug){

1425

1361

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

1426

1362

block_time);

1427

1363

}

1428

1364

1429

1365

if(block_time <= 0){

1430

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

1431

mc->current_server->port,

1432

mc->current_server->if_index,

1433

mc->current_server->af, mc);

1366

ret = start_mandos_communication(mc.current_server->ip,

1367

mc.current_server->port,

1368

mc.current_server->if_index,

1369

mc.current_server->af);

1434

1370

if(ret == 0){

1435

avahi_simple_poll_quit(s);

1371

avahi_simple_poll_quit(mc.simple_poll);

1436

1372

return 0;

1437

1373

}

1438

1374

ret = clock_gettime(CLOCK_MONOTONIC,

1439

&mc->current_server->last_seen);

1375

&mc.current_server->last_seen);

1440

1376

if(ret == -1){

1441

1377

perror_plus("clock_gettime");

1442

1378

return -1;

1443

1379

}

1444

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

1380

mc.current_server = mc.current_server->next;

1445

1381

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

1446

1382

servers, but don't block */

1447

1383

}

1449

1385

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

1450

1386

}

1451

1387

if(ret != 0){

1452

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

1388

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

1453

1389

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

1454

1390

}

1455

1391

}

1457

1393

}

1458

1394

1459

1395

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

1460

__attribute__((warn_unused_result))

1461

error_t raise_privileges(void){

1462

error_t old_errno = errno;

1463

error_t ret_errno = 0;

1396

int raise_privileges(void){

1397

int old_errno = errno;

1398

int ret_errno = 0;

1399

errno = 0;

1464

1400

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

1465

ret_errno = errno;

1466

1401

perror_plus("seteuid");

1467

1402

}

1403

ret_errno = errno;

1468

1404

errno = old_errno;

1469

1405

return ret_errno;

1470

1406

}

1471

1407

1472

1408

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

1473

__attribute__((warn_unused_result))

1474

error_t raise_privileges_permanently(void){

1475

error_t old_errno = errno;

1476

error_t ret_errno = raise_privileges();

1409

int raise_privileges_permanently(void){

1410

int old_errno = errno;

1411

int ret_errno = raise_privileges();

1477

1412

if(ret_errno != 0){

1478

1413

errno = old_errno;

1479

1414

return ret_errno;

1480

1415

}

1416

errno = 0;

1481

1417

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

1482

ret_errno = errno;

1483

1418

perror_plus("seteuid");

1484

1419

}

1420

ret_errno = errno;

1485

1421

errno = old_errno;

1486

1422

return ret_errno;

1487

1423

}

1488

1424

1489

1425

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

1490

__attribute__((warn_unused_result))

1491

error_t lower_privileges(void){

1492

error_t old_errno = errno;

1493

error_t ret_errno = 0;

1426

int lower_privileges(void){

1427

int old_errno = errno;

1428

int ret_errno = 0;

1429

errno = 0;

1494

1430

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

1495

ret_errno = errno;

1496

1431

perror_plus("seteuid");

1497

1432

}

1498

errno = old_errno;

1499

return ret_errno;

1500

}

1501

1502

/* Lower privileges permanently */

1503

__attribute__((warn_unused_result))

1504

error_t lower_privileges_permanently(void){

1505

error_t old_errno = errno;

1506

error_t ret_errno = 0;

1507

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

1508

ret_errno = errno;

1509

perror_plus("setuid");

1510

}

1511

errno = old_errno;

1512

return ret_errno;

1513

}

1514

1515

__attribute__((nonnull))

1516

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

1433

ret_errno = errno;

1434

errno = old_errno;

1435

return ret_errno;

1436

}

1437

1438

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

1517

1439

const float delay){

1518

1440

struct dirent **direntries;

1441

struct dirent *direntry;

1442

int ret;

1519

1443

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

1520

1444

alphasort);

1521

1445

if(numhooks == -1){

1522

if(errno == ENOENT){

1523

if(debug){

1524

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

1525

" found\n", hookdir);

1526

}

1527

} else {

1528

perror_plus("scandir");

1529

}

1446

perror_plus("scandir");

1530

1447

} else {

1531

struct dirent *direntry;

1532

int ret;

1533

1448

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

1534

1449

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

1535

1450

direntry = direntries[i];

1547

1462

if(hook_pid == 0){

1548

1463

/* Child */

1549

1464

/* Raise privileges */

1550

if(raise_privileges_permanently() != 0){

1551

perror_plus("Failed to raise privileges");

1552

_exit(EX_NOPERM);

1553

}

1465

raise_privileges_permanently();

1554

1466

/* Set group */

1555

1467

errno = 0;

1556

1468

ret = setgid(0);

1557

1469

if(ret == -1){

1558

1470

perror_plus("setgid");

1559

_exit(EX_NOPERM);

1560

1471

}

1561

1472

/* Reset supplementary groups */

1562

1473

errno = 0;

1563

1474

ret = setgroups(0, NULL);

1564

1475

if(ret == -1){

1565

1476

perror_plus("setgroups");

1566

_exit(EX_NOPERM);

1567

}

1568

ret = dup2(devnull, STDIN_FILENO);

1569

if(ret == -1){

1570

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

1571

_exit(EX_OSERR);

1572

}

1573

ret = close(devnull);

1574

if(ret == -1){

1575

perror_plus("close");

1576

_exit(EX_OSERR);

1577

}

1578

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1579

if(ret == -1){

1580

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

1581

_exit(EX_OSERR);

1582

}

1477

}

1478

dup2(devnull, STDIN_FILENO);

1479

close(devnull);

1480

dup2(STDERR_FILENO, STDOUT_FILENO);

1583

1481

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

1584

1482

if(ret == -1){

1585

1483

perror_plus("setenv");

1601

1499

_exit(EX_OSERR);

1602

1500

}

1603

1501

char *delaystring;

1604

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

1502

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

1605

1503

if(ret == -1){

1606

1504

perror_plus("asprintf");

1607

1505

_exit(EX_OSERR);

1660

1558

}

1661

1559

close(devnull);

1662

1560

}

1561

return true;

1663

1562

}

1664

1563

1665

__attribute__((nonnull, warn_unused_result))

1666

error_t bring_up_interface(const char *const interface,

1667

const float delay){

1668

error_t old_errno = errno;

1564

int bring_up_interface(const char * const interface, const float delay){

1565

int sd = -1;

1566

int old_errno = errno;

1567

int ret_errno = 0;

1669

1568

int ret;

1670

1569

struct ifreq network;

1671

unsigned int if_index = if_nametoindex(interface);

1570

AvahiIfIndex if_index = (AvahiIfIndex)if_nametoindex(interface);

1672

1571

if(if_index == 0){

1673

1572

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

1674

1573

errno = old_errno;

1680

1579

return EINTR;

1681

1580

}

1682

1581

1683

if(not interface_is_up(interface)){

1684

error_t ret_errno = 0, ioctl_errno = 0;

1685

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

1686

ret_errno = errno;

1687

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

1688

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

1689

errno = old_errno;

1690

return ret_errno;

1691

}

1692

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

1693

1694

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

1695

if(sd == -1){

1696

ret_errno = errno;

1697

perror_plus("socket");

1698

errno = old_errno;

1699

return ret_errno;

1700

}

1701

1702

if(quit_now){

1703

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

1704

if(ret == -1){

1705

perror_plus("close");

1706

}

1707

errno = old_errno;

1708

return EINTR;

1709

}

1710

1711

if(debug){

1712

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

1713

interface);

1714

}

1715

1716

/* Raise privileges */

1717

ret_errno = raise_privileges();

1718

bool restore_loglevel = false;

1719

if(ret_errno != 0){

1720

perror_plus("Failed to raise privileges");

1721

}

1722

#ifdef __linux__

1723

int ret_linux;

1724

if(ret_errno == 0){

1725

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1726

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

1727

ret_linux = klogctl(8, NULL, 5);

1728

if(ret_linux == -1){

1729

perror_plus("klogctl");

1730

} else {

1731

restore_loglevel = true;

1732

}

1733

}

1734

#endif /* __linux__ */

1735

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

1736

ioctl_errno = errno;

1737

#ifdef __linux__

1738

if(restore_loglevel){

1739

ret_linux = klogctl(7, NULL, 0);

1740

if(ret_linux == -1){

1741

perror_plus("klogctl");

1742

}

1743

}

1744

#endif /* __linux__ */

1745

1746

/* If raise_privileges() succeeded above */

1747

if(ret_errno == 0){

1748

/* Lower privileges */

1749

ret_errno = lower_privileges();

1750

if(ret_errno != 0){

1751

errno = ret_errno;

1752

perror_plus("Failed to lower privileges");

1753

}

1754

}

1755

1756

/* Close the socket */

1757

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

1582

/* Re-raise priviliges */

1583

raise_privileges();

1584

1585

#ifdef __linux__

1586

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1587

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

1588

ret = klogctl(8, NULL, 5);

1589

bool restore_loglevel = true;

1590

if(ret == -1){

1591

restore_loglevel = false;

1592

perror_plus("klogctl");

1593

}

1594

#endif /* __linux__ */

1595

1596

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1597

if(sd < 0){

1598

ret_errno = errno;

1599

perror_plus("socket");

1600

#ifdef __linux__

1601

if(restore_loglevel){

1602

ret = klogctl(7, NULL, 0);

1603

if(ret == -1){

1604

perror_plus("klogctl");

1605

}

1606

}

1607

#endif /* __linux__ */

1608

/* Lower privileges */

1609

lower_privileges();

1610

errno = old_errno;

1611

return ret_errno;

1612

}

1613

strcpy(network.ifr_name, interface);

1614

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

1615

if(ret == -1){

1616

ret_errno = errno;

1617

perror_plus("ioctl SIOCGIFFLAGS");

1618

#ifdef __linux__

1619

if(restore_loglevel){

1620

ret = klogctl(7, NULL, 0);

1621

if(ret == -1){

1622

perror_plus("klogctl");

1623

}

1624

}

1625

#endif /* __linux__ */

1626

/* Lower privileges */

1627

lower_privileges();

1628

errno = old_errno;

1629

return ret_errno;

1630

}

1631

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

1632

network.ifr_flags |= IFF_UP;

1633

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

1758

1634

if(ret == -1){

1759

perror_plus("close");

1760

}

1761

1762

if(ret_setflags == -1){

1763

errno = ioctl_errno;

1635

ret_errno = errno;

1764

1636

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1637

#ifdef __linux__

1638

if(restore_loglevel){

1639

ret = klogctl(7, NULL, 0);

1640

if(ret == -1){

1641

perror_plus("klogctl");

1642

}

1643

}

1644

#endif /* __linux__ */

1645

/* Lower privileges */

1646

lower_privileges();

1765

1647

errno = old_errno;

1766

return ioctl_errno;

1648

return ret_errno;

1767

1649

}

1768

} else if(debug){

1769

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

1770

interface);

1771

1650

}

1772

1773

1651

/* Sleep checking until interface is running.

1774

1652

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

1775

1653

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

1776

if(interface_is_running(interface)){

1654

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

1655

if(ret == -1){

1656

perror_plus("ioctl SIOCGIFFLAGS");

1657

} else if(network.ifr_flags & IFF_RUNNING){

1777

1658

break;

1778

1659

}

1779

1660

struct timespec sleeptime = { .tv_nsec = 250000000 };

1782

1663

perror_plus("nanosleep");

1783

1664

}

1784

1665

}

1785

1786

errno = old_errno;

1787

return 0;

1788

}

1789

1790

__attribute__((nonnull, warn_unused_result))

1791

error_t take_down_interface(const char *const interface){

1792

error_t old_errno = errno;

1793

struct ifreq network;

1794

unsigned int if_index = if_nametoindex(interface);

1795

if(if_index == 0){

1796

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

1797

errno = old_errno;

1798

return ENXIO;

1666

/* Close the socket */

1667

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

1668

if(ret == -1){

1669

perror_plus("close");

1799

1670

}

1800

if(interface_is_up(interface)){

1801

error_t ret_errno = 0, ioctl_errno = 0;

1802

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

1803

ret_errno = errno;

1804

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

1805

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

1806

errno = old_errno;

1807

return ret_errno;

1808

}

1809

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

1810

1811

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

1812

if(sd == -1){

1813

ret_errno = errno;

1814

perror_plus("socket");

1815

errno = old_errno;

1816

return ret_errno;

1817

}

1818

1819

if(debug){

1820

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

1821

interface);

1822

}

1823

1824

/* Raise privileges */

1825

ret_errno = raise_privileges();

1826

if(ret_errno != 0){

1827

perror_plus("Failed to raise privileges");

1828

}

1829

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

1830

ioctl_errno = errno;

1831

1832

/* If raise_privileges() succeeded above */

1833

if(ret_errno == 0){

1834

/* Lower privileges */

1835

ret_errno = lower_privileges();

1836

if(ret_errno != 0){

1837

errno = ret_errno;

1838

perror_plus("Failed to lower privileges");

1839

}

1840

}

1841

1842

/* Close the socket */

1843

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

1671

#ifdef __linux__

1672

if(restore_loglevel){

1673

/* Restores kernel loglevel to default */

1674

ret = klogctl(7, NULL, 0);

1844

1675

if(ret == -1){

1845

perror_plus("close");

1846

}

1847

1848

if(ret_setflags == -1){

1849

errno = ioctl_errno;

1850

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1851

errno = old_errno;

1852

return ioctl_errno;

1853

}

1854

} else if(debug){

1855

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

1856

interface);

1676

perror_plus("klogctl");

1677

}

1857

1678

}

1858

1679

#endif /* __linux__ */

1680

/* Lower privileges */

1681

lower_privileges();

1859

1682

errno = old_errno;

1860

1683

return 0;

1861

1684

}

1862

1685

1863

1686

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

1864

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

1865

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

1866

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

1867

.interfaces = NULL, .interfaces_size = 0 };

1868

1687

AvahiSServiceBrowser *sb = NULL;

1869

error_t ret_errno;

1688

int error;

1870

1689

int ret;

1871

1690

intmax_t tmpmax;

1872

1691

char *tmp;

1873

1692

int exitcode = EXIT_SUCCESS;

1874

char *interfaces_to_take_down = NULL;

1875

size_t interfaces_to_take_down_size = 0;

1876

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

1877

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

1878

char *tempdir = NULL;

1693

const char *interface = "";

1694

struct ifreq network;

1695

int sd = -1;

1696

bool take_down_interface = false;

1697

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

1698

bool tempdir_created = false;

1879

1699

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1880

1700

const char *seckey = PATHDIR "/" SECKEY;

1881

1701

const char *pubkey = PATHDIR "/" PUBKEY;

1882

char *interfaces_hooks = NULL;

1883

1702

1884

1703

bool gnutls_initialized = false;

1885

1704

bool gpgme_initialized = false;

1976

1795

connect_to = arg;

1977

1796

break;

1978

1797

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

1979

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

1980

arg, (int)',');

1981

if(ret_errno != 0){

1982

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

1983

}

1798

interface = arg;

1984

1799

break;

1985

1800

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

1986

1801

seckey = arg;

2063

1878

/* Work around Debian bug #633582:

2064

1879

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

2065

1880

2066

/* Re-raise privileges */

2067

ret_errno = raise_privileges();

2068

if(ret_errno != 0){

2069

errno = ret_errno;

2070

perror_plus("Failed to raise privileges");

2071

} else {

1881

/* Re-raise priviliges */

1882

if(raise_privileges() == 0){

2072

1883

struct stat st;

2073

1884

2074

1885

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

2114

1925

}

2115

1926

2116

1927

/* Lower privileges */

2117

ret_errno = lower_privileges();

2118

if(ret_errno != 0){

2119

errno = ret_errno;

2120

perror_plus("Failed to lower privileges");

2121

}

2122

}

2123

}

2124

2125

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

2126

{

2127

char *interface = NULL;

2128

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

2129

interface))){

2130

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

2131

and if_nametoindex(interface) == 0){

2132

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

2133

fprintf_plus(stderr, "Not using nonexisting interface"

2134

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

2135

}

2136

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

2137

interface = NULL;

1928

errno = 0;

1929

ret = seteuid(uid);

1930

if(ret == -1){

1931

perror_plus("seteuid");

2138

1932

}

2139

1933

}

2140

1934

}

2141

1935

2142

1936

/* Run network hooks */

2143

{

2144

if(mc.interfaces != NULL){

2145

interfaces_hooks = malloc(mc.interfaces_size);

2146

if(interfaces_hooks == NULL){

1937

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

1938

goto end;

1939

}

1940

1941

if(not debug){

1942

avahi_set_log_function(empty_log);

1943

}

1944

1945

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

1946

struct dirent **direntries;

1947

/* First look for interfaces that are up */

1948

ret = scandir(sys_class_net, &direntries, up_interface,

1949

alphasort);

1950

if(ret == 0){

1951

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

1952

free(direntries);

1953

ret = scandir(sys_class_net, &direntries, good_interface,

1954

alphasort);

1955

}

1956

if(ret >= 1){

1957

/* Pick the first interface returned */

1958

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

1959

if(debug){

1960

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

1961

}

1962

if(interface == NULL){

2147

1963

perror_plus("malloc");

1964

free(direntries);

1965

exitcode = EXIT_FAILURE;

2148

1966

goto end;

2149

1967

}

2150

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

2151

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

1968

free(direntries);

1969

} else {

1970

free(direntries);

1971

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

1972

exitcode = EXIT_FAILURE;

1973

goto end;

2152

1974

}

2153

run_network_hooks("start", interfaces_hooks != NULL ?

2154

interfaces_hooks : "", delay);

2155

}

2156

2157

if(not debug){

2158

avahi_set_log_function(empty_log);

2159

1975

}

2160

1976

2161

1977

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

2162

1978

from the signal handler */

2163

1979

/* Initialize the pseudo-RNG for Avahi */

2164

1980

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

2165

simple_poll = avahi_simple_poll_new();

2166

if(simple_poll == NULL){

1981

mc.simple_poll = avahi_simple_poll_new();

1982

if(mc.simple_poll == NULL){

2167

1983

fprintf_plus(stderr,

2168

1984

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

2169

1985

exitcode = EX_UNAVAILABLE;

2233

2049

}

2234

2050

}

2235

2051

2236

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

2237

if(mc.interfaces == NULL){

2238

struct dirent **direntries;

2239

/* Look for any good interfaces */

2240

ret = scandir(sys_class_net, &direntries, good_interface,

2241

alphasort);

2242

if(ret >= 1){

2243

/* Add all found interfaces to interfaces list */

2244

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

2245

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

2246

direntries[i]->d_name);

2247

if(ret_errno != 0){

2248

errno = ret_errno;

2249

perror_plus("argz_add");

2250

continue;

2251

}

2252

if(debug){

2253

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

2254

direntries[i]->d_name);

2255

}

2256

}

2257

free(direntries);

2258

} else {

2259

free(direntries);

2260

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

2261

exitcode = EXIT_FAILURE;

2262

goto end;

2263

}

2264

}

2265

2266

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

2267

{

2268

char *interface = NULL;

2269

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

2270

interface))){

2271

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

2272

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

2273

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

2274

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

2275

interface);

2276

interface = NULL;

2277

while((interface = argz_next(mc.interfaces,

2278

mc.interfaces_size, interface))){

2279

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

2280

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

2281

interface);

2282

interface = NULL;

2283

}

2284

}

2285

break;

2286

}

2287

bool interface_was_up = interface_is_up(interface);

2288

errno = bring_up_interface(interface, delay);

2289

if(not interface_was_up){

2290

if(errno != 0){

2291

perror_plus("Failed to bring up interface");

2292

} else {

2293

errno = argz_add(&interfaces_to_take_down,

2294

&interfaces_to_take_down_size,

2295

interface);

2296

if(errno != 0){

2297

perror_plus("argz_add");

2298

}

2299

}

2300

}

2301

}

2302

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

2303

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

2304

}

2305

}

2306

2307

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

2308

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

2309

if(debug){

2310

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

2311

mc.interfaces);

2312

}

2313

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

2052

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

2053

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

2054

ret = bring_up_interface(interface, delay);

2055

if(ret != 0){

2056

errno = ret;

2057

perror_plus("Failed to bring up interface");

2058

}

2314

2059

}

2315

2060

2316

2061

if(quit_now){

2317

2062

goto end;

2318

2063

}

2319

2064

2320

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

2065

ret = init_gnutls_global(pubkey, seckey);

2321

2066

if(ret == -1){

2322

2067

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

2323

2068

exitcode = EX_UNAVAILABLE;

2330

2075

goto end;

2331

2076

}

2332

2077

2333

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

2334

tempdir = mkdtemp(run_tempdir);

2335

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

2336

if(debug){

2337

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

2338

run_tempdir, old_tempdir);

2339

}

2340

tempdir = mkdtemp(old_tempdir);

2341

}

2342

if(tempdir == NULL){

2078

if(mkdtemp(tempdir) == NULL){

2343

2079

perror_plus("mkdtemp");

2344

2080

goto end;

2345

2081

}

2082

tempdir_created = true;

2346

2083

2347

2084

if(quit_now){

2348

2085

goto end;

2349

2086

}

2350

2087

2351

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

2088

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

2352

2089

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

2353

2090

exitcode = EX_UNAVAILABLE;

2354

2091

goto end;

2375

2112

goto end;

2376

2113

}

2377

2114

2378

in_port_t port;

2115

uint16_t port;

2379

2116

errno = 0;

2380

2117

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

2381

2118

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

2382

or tmpmax != (in_port_t)tmpmax){

2119

or tmpmax != (uint16_t)tmpmax){

2383

2120

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

2384

2121

exitcode = EX_USAGE;

2385

2122

goto end;

2386

2123

}

2387

2124

2388

2125

if(quit_now){

2389

2126

goto end;

2390

2127

}

2391

2128

2392

port = (in_port_t)tmpmax;

2129

port = (uint16_t)tmpmax;

2393

2130

*address = '\0';

2394

2131

/* Colon in address indicates IPv6 */

2395

2132

int af;

2411

2148

}

2412

2149

2413

2150

while(not quit_now){

2414

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

2415

&mc);

2151

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

2416

2152

if(quit_now or ret == 0){

2417

2153

break;

2418

2154

}

2420

2156

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

2421

2157

(int)retry_interval);

2422

2158

}

2423

sleep((unsigned int)retry_interval);

2159

sleep((int)retry_interval);

2424

2160

}

2425

2161

2426

if(not quit_now){

2162

if (not quit_now){

2427

2163

exitcode = EXIT_SUCCESS;

2428

2164

}

2429

2165

2444

2180

config.publish_domain = 0;

2445

2181

2446

2182

/* Allocate a new server */

2447

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2448

&config, NULL, NULL, &ret_errno);

2183

mc.server = avahi_server_new(avahi_simple_poll_get

2184

(mc.simple_poll), &config, NULL,

2185

NULL, &error);

2449

2186

2450

2187

/* Free the Avahi configuration data */

2451

2188

avahi_server_config_free(&config);

2454

2191

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

2455

2192

if(mc.server == NULL){

2456

2193

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

2457

avahi_strerror(ret_errno));

2194

avahi_strerror(error));

2458

2195

exitcode = EX_UNAVAILABLE;

2459

2196

goto end;

2460

2197

}

2466

2203

/* Create the Avahi service browser */

2467

2204

sb = avahi_s_service_browser_new(mc.server, if_index,

2468

2205

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2469

NULL, 0, browse_callback,

2470

(void *)&mc);

2206

NULL, 0, browse_callback, NULL);

2471

2207

if(sb == NULL){

2472

2208

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

2473

2209

avahi_strerror(avahi_server_errno(mc.server)));

2485

2221

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

2486

2222

}

2487

2223

2488

ret = avahi_loop_with_timeout(simple_poll,

2489

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

2224

ret = avahi_loop_with_timeout(mc.simple_poll,

2225

(int)(retry_interval * 1000));

2490

2226

if(debug){

2491

2227

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

2492

2228

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

2499

2235

}

2500

2236

2501

2237

/* Cleanup things */

2502

free(mc.interfaces);

2503

2504

2238

if(sb != NULL)

2505

2239

avahi_s_service_browser_free(sb);

2506

2240

2507

2241

if(mc.server != NULL)

2508

2242

avahi_server_free(mc.server);

2509

2243

2510

if(simple_poll != NULL)

2511

avahi_simple_poll_free(simple_poll);

2244

if(mc.simple_poll != NULL)

2245

avahi_simple_poll_free(mc.simple_poll);

2512

2246

2513

2247

if(gnutls_initialized){

2514

2248

gnutls_certificate_free_credentials(mc.cred);

2531

2265

}

2532

2266

}

2533

2267

2534

/* Re-raise privileges */

2268

/* Run network hooks */

2269

run_network_hooks("stop", interface, delay);

2270

2271

/* Re-raise priviliges */

2535

2272

{

2536

ret_errno = raise_privileges();

2537

if(ret_errno != 0){

2538

perror_plus("Failed to raise privileges");

2539

} else {

2540

2541

/* Run network hooks */

2542

run_network_hooks("stop", interfaces_hooks != NULL ?

2543

interfaces_hooks : "", delay);

2544

2545

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

2546

{

2547

char *interface = NULL;

2548

while((interface=argz_next(interfaces_to_take_down,

2549

interfaces_to_take_down_size,

2550

interface))){

2551

ret_errno = take_down_interface(interface);

2552

if(ret_errno != 0){

2553

errno = ret_errno;

2554

perror_plus("Failed to take down interface");

2555

}

2556

}

2557

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

2558

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

2559

" down\n");

2560

}

2561

}

2562

}

2563

ret_errno = lower_privileges_permanently();

2564

if(ret_errno != 0){

2565

perror_plus("Failed to lower privileges permanently");

2566

}

2567

}

2568

2569

free(interfaces_to_take_down);

2570

free(interfaces_hooks);

2273

raise_privileges();

2274

2275

/* Take down the network interface */

2276

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

2277

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

2278

if(ret == -1){

2279

perror_plus("ioctl SIOCGIFFLAGS");

2280

} else if(network.ifr_flags & IFF_UP){

2281

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

2282

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

2283

if(ret == -1){

2284

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2285

}

2286

}

2287

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

2288

if(ret == -1){

2289

perror_plus("close");

2290

}

2291

}

2292

}

2293

/* Lower privileges permanently */

2294

errno = 0;

2295

ret = setuid(uid);

2296

if(ret == -1){

2297

perror_plus("setuid");

2298

}

2571

2299

2572

2300

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

2573

if(tempdir != NULL){

2301

if(tempdir_created){

2574

2302

struct dirent **direntries = NULL;

2575

2303

struct dirent *direntry = NULL;

2576

2304

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

2577

2305

alphasort);

2578

if(numentries > 0){

2306

if (numentries > 0){

2579

2307

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

2580

2308

direntry = direntries[i];

2581

2309

char *fullname = NULL;

2596

2324

2597

2325

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

2598

2326

free(direntries);

2599

if(numentries == -1){

2327

if (numentries == -1){

2600

2328

perror_plus("scandir");

2601

2329

}

2602

2330

ret = rmdir(tempdir);