/mandos/release : revision 237.11.13

9

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

10

*

11

* Everything else is

12

13

12

13

14

*

15

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

16

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

26

* along with this program. If not, see

27

* <http://www.gnu.org/licenses/>.

28

*

29

* Contact the authors at <mandos@fukt.bsnet.se>.

29

* Contact the authors at <mandos@recompile.se>.

30

*/

31

32

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

43

stdout, ferror(), remove() */

44

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

45

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

46

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

47

srand(), strtof(), abort() */

46

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

47

strtof(), abort() */

48

#include <stdbool.h> /* bool, false, true */

49

#include <string.h> /* memset(), strcmp(), strlen(),

50

strerror(), asprintf(), strcpy() */

62

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

63

strtoimax() */

64

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

65

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

66

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

65

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

66

program_invocation_short_name */

67

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

67

68

#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,

68

69

SIOCSIFFLAGS, if_indextoname(),

69

70

if_nametoindex(), IF_NAMESIZE */

73

74

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

74

75

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

75

76

setgid(), pause() */

76

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

77

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

77

78

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

78

79

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

79

80

argp_state, struct argp,

82

83

#include <signal.h> /* sigemptyset(), sigaddset(),

83

84

sigaction(), SIGTERM, sig_atomic_t,

84

85

raise() */

85

#include <sysexits.h> /* EX_OSERR, EX_USAGE */

86

#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,

87

EX_NOHOST, EX_IOERR, EX_PROTOCOL */

86

88

87

89

#ifdef __linux__

88

90

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

125

127

bool debug = false;

126

128

static const char mandos_protocol_version[] = "1";

127

129

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

128

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

130

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

131

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

132

char *connect_to = NULL;

133

134

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

135

typedef struct server{

136

const char *ip;

137

uint16_t port;

138

AvahiIfIndex if_index;

139

int af;

140

struct timespec last_seen;

141

struct server *next;

142

struct server *prev;

143

} server;

129

144

130

145

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

131

146

typedef struct {

136

151

gnutls_dh_params_t dh_params;

137

152

const char *priority;

138

153

gpgme_ctx_t ctx;

154

server *current_server;

139

155

} mandos_context;

140

156

141

157

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

142

158

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

143

159

.dh_bits = 1024, .priority = "SECURE256"

144

":!CTYPE-X.509:+CTYPE-OPENPGP" };

160

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

161

.current_server = NULL };

145

162

146

163

sig_atomic_t quit_now = 0;

147

164

int signal_received = 0;

148

165

166

/* Function to use when printing errors */

167

void perror_plus(const char *print_text){

168

fprintf(stderr, "Mandos plugin %s: ",

169

program_invocation_short_name);

170

perror(print_text);

171

}

172

149

173

/*

150

174

* Make additional room in "buffer" for at least BUFFER_SIZE more

151

175

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

163

187

return buffer_capacity;

164

188

}

165

189

190

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

191

int add_server(const char *ip, uint16_t port,

192

AvahiIfIndex if_index,

193

int af){

194

int ret;

195

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

196

if(new_server == NULL){

197

perror_plus("malloc");

198

return -1;

199

}

200

*new_server = (server){ .ip = strdup(ip),

201

.port = port,

202

.if_index = if_index,

203

.af = af };

204

if(new_server->ip == NULL){

205

perror_plus("strdup");

206

return -1;

207

}

208

/* Special case of first server */

209

if (mc.current_server == NULL){

210

new_server->next = new_server;

211

new_server->prev = new_server;

212

mc.current_server = new_server;

213

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

214

} else {

215

new_server->next = mc.current_server;

216

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

217

new_server->prev->next = new_server;

218

mc.current_server->prev = new_server;

219

}

220

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

221

if(ret == -1){

222

perror_plus("clock_gettime");

223

return -1;

224

}

225

return 0;

226

}

227

166

228

/*

167

229

* Initialize GPGME.

168

230

*/

182

244

183

245

fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));

184

246

if(fd == -1){

185

perror("open");

247

perror_plus("open");

186

248

return false;

187

249

}

188

250

202

264

203

265

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

204

266

if(ret == -1){

205

perror("close");

267

perror_plus("close");

206

268

}

207

269

gpgme_data_release(pgp_data);

208

270

return true;

221

283

return false;

222

284

}

223

285

224

/* Set GPGME home directory for the OpenPGP engine only */

286

/* Set GPGME home directory for the OpenPGP engine only */

225

287

rc = gpgme_get_engine_info(&engine_info);

226

288

if(rc != GPG_ERR_NO_ERROR){

227

289

fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",

333

395

334

396

/* Seek back to the beginning of the GPGME plaintext data buffer */

335

397

if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){

336

perror("gpgme_data_seek");

398

perror_plus("gpgme_data_seek");

337

399

plaintext_length = -1;

338

400

goto decrypt_end;

339

401

}

344

406

(size_t)plaintext_length,

345

407

plaintext_capacity);

346

408

if(plaintext_capacity == 0){

347

perror("incbuffer");

409

perror_plus("incbuffer");

348

410

plaintext_length = -1;

349

411

goto decrypt_end;

350

412

}

357

419

break;

358

420

}

359

421

if(ret < 0){

360

perror("gpgme_data_read");

422

perror_plus("gpgme_data_read");

361

423

plaintext_length = -1;

362

424

goto decrypt_end;

363

425

}

420

482

}

421

483

422

484

/* OpenPGP credentials */

423

gnutls_certificate_allocate_credentials(&mc.cred);

485

ret = gnutls_certificate_allocate_credentials(&mc.cred);

424

486

if(ret != GNUTLS_E_SUCCESS){

425

fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning

426

from

427

-Wunreachable-code

428

*/

487

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

429

488

safer_gnutls_strerror(ret));

430

489

gnutls_global_deinit();

431

490

return -1;

553

612

gnutls_session_t session;

554

613

int pf; /* Protocol family */

555

614

615

errno = 0;

616

556

617

if(quit_now){

618

errno = EINTR;

557

619

return -1;

558

620

}

559

621

566

628

break;

567

629

default:

568

630

fprintf(stderr, "Bad address family: %d\n", af);

631

errno = EINVAL;

569

632

return -1;

570

633

}

571

634

581

644

582

645

tcp_sd = socket(pf, SOCK_STREAM, 0);

583

646

if(tcp_sd < 0){

584

perror("socket");

647

int e = errno;

648

perror_plus("socket");

649

errno = e;

585

650

goto mandos_end;

586

651

}

587

652

588

653

if(quit_now){

654

errno = EINTR;

589

655

goto mandos_end;

590

656

}

591

657

598

664

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

599

665

}

600

666

if(ret < 0 ){

601

perror("inet_pton");

667

int e = errno;

668

perror_plus("inet_pton");

669

errno = e;

602

670

goto mandos_end;

603

671

}

604

672

if(ret == 0){

673

int e = errno;

605

674

fprintf(stderr, "Bad address: %s\n", ip);

675

errno = e;

606

676

goto mandos_end;

607

677

}

608

678

if(af == AF_INET6){

616

686

if(if_index == AVAHI_IF_UNSPEC){

617

687

fprintf(stderr, "An IPv6 link-local address is incomplete"

618

688

" without a network interface\n");

689

errno = EINVAL;

619

690

goto mandos_end;

620

691

}

621

692

/* Set the network interface number as scope */

628

699

}

629

700

630

701

if(quit_now){

702

errno = EINTR;

631

703

goto mandos_end;

632

704

}

633

705

635

707

if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){

636

708

char interface[IF_NAMESIZE];

637

709

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

638

perror("if_indextoname");

710

perror_plus("if_indextoname");

639

711

} else {

640

712

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

641

713

ip, interface, port);

655

727

sizeof(addrstr));

656

728

}

657

729

if(pcret == NULL){

658

perror("inet_ntop");

730

perror_plus("inet_ntop");

659

731

} else {

660

732

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

661

733

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

664

736

}

665

737

666

738

if(quit_now){

739

errno = EINTR;

667

740

goto mandos_end;

668

741

}

669

742

673

746

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

674

747

}

675

748

if(ret < 0){

676

perror("connect");

749

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

750

int e = errno;

751

perror_plus("connect");

752

errno = e;

753

}

677

754

goto mandos_end;

678

755

}

679

756

680

757

if(quit_now){

758

errno = EINTR;

681

759

goto mandos_end;

682

760

}

683

761

688

766

ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,

689

767

out_size - written));

690

768

if(ret == -1){

691

perror("write");

769

int e = errno;

770

perror_plus("write");

771

errno = e;

692

772

goto mandos_end;

693

773

}

694

774

written += (size_t)ret;

704

784

}

705

785

706

786

if(quit_now){

787

errno = EINTR;

707

788

goto mandos_end;

708

789

}

709

790

}

713

794

}

714

795

715

796

if(quit_now){

797

errno = EINTR;

716

798

goto mandos_end;

717

799

}

718

800

801

/* Spurious warning from -Wint-to-pointer-cast */

719

802

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

720

803

721

804

if(quit_now){

805

errno = EINTR;

722

806

goto mandos_end;

723

807

}

724

808

725

809

do {

726

810

ret = gnutls_handshake(session);

727

811

if(quit_now){

812

errno = EINTR;

728

813

goto mandos_end;

729

814

}

730

815

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

734

819

fprintf(stderr, "*** GnuTLS Handshake failed ***\n");

735

820

gnutls_perror(ret);

736

821

}

822

errno = EPROTO;

737

823

goto mandos_end;

738

824

}

739

825

747

833

while(true){

748

834

749

835

if(quit_now){

836

errno = EINTR;

750

837

goto mandos_end;

751

838

}

752

839

753

840

buffer_capacity = incbuffer(&buffer, buffer_length,

754

841

buffer_capacity);

755

842

if(buffer_capacity == 0){

756

perror("incbuffer");

843

int e = errno;

844

perror_plus("incbuffer");

845

errno = e;

757

846

goto mandos_end;

758

847

}

759

848

760

849

if(quit_now){

850

errno = EINTR;

761

851

goto mandos_end;

762

852

}

763

853

776

866

ret = gnutls_handshake(session);

777

867

778

868

if(quit_now){

869

errno = EINTR;

779

870

goto mandos_end;

780

871

}

781

872

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

782

873

if(ret < 0){

783

874

fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");

784

875

gnutls_perror(ret);

876

errno = EPROTO;

785

877

goto mandos_end;

786

878

}

787

879

break;

789

881

fprintf(stderr, "Unknown error while reading data from"

790

882

" encrypted session with Mandos server\n");

791

883

gnutls_bye(session, GNUTLS_SHUT_RDWR);

884

errno = EIO;

792

885

goto mandos_end;

793

886

}

794

887

} else {

801

894

}

802

895

803

896

if(quit_now){

897

errno = EINTR;

804

898

goto mandos_end;

805

899

}

806

900

807

901

do {

808

902

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

809

903

if(quit_now){

904

errno = EINTR;

810

905

goto mandos_end;

811

906

}

812

907

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

821

916

written = 0;

822

917

while(written < (size_t) decrypted_buffer_size){

823

918

if(quit_now){

919

errno = EINTR;

824

920

goto mandos_end;

825

921

}

826

922

828

924

(size_t)decrypted_buffer_size - written,

829

925

stdout);

830

926

if(ret == 0 and ferror(stdout)){

927

int e = errno;

831

928

if(debug){

832

929

fprintf(stderr, "Error writing encrypted data: %s\n",

833

930

strerror(errno));

834

931

}

932

errno = e;

835

933

goto mandos_end;

836

934

}

837

935

written += (size_t)ret;

843

941

/* Shutdown procedure */

844

942

845

943

mandos_end:

846

free(decrypted_buffer);

847

free(buffer);

848

if(tcp_sd >= 0){

849

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

850

}

851

if(ret == -1){

852

perror("close");

853

}

854

gnutls_deinit(session);

855

if(quit_now){

856

retval = -1;

944

{

945

int e = errno;

946

free(decrypted_buffer);

947

free(buffer);

948

if(tcp_sd >= 0){

949

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

950

}

951

if(ret == -1){

952

if(e == 0){

953

e = errno;

954

}

955

perror_plus("close");

956

}

957

gnutls_deinit(session);

958

errno = e;

959

if(quit_now){

960

errno = EINTR;

961

retval = -1;

962

}

857

963

}

858

964

return retval;

859

965

}

902

1008

avahi_proto_to_af(proto));

903

1009

if(ret == 0){

904

1010

avahi_simple_poll_quit(mc.simple_poll);

1011

} else {

1012

ret = add_server(ip, port, interface,

1013

avahi_proto_to_af(proto));

905

1014

}

906

1015

}

907

1016

}

961

1070

}

962

1071

}

963

1072

964

/* stop main loop after sigterm has been called */

1073

/* Signal handler that stops main loop after SIGTERM */

965

1074

static void handle_sigterm(int sig){

966

1075

if(quit_now){

967

1076

return;

969

1078

quit_now = 1;

970

1079

signal_received = sig;

971

1080

int old_errno = errno;

1081

/* set main loop to exit */

972

1082

if(mc.simple_poll != NULL){

973

1083

avahi_simple_poll_quit(mc.simple_poll);

974

1084

}

975

1085

errno = old_errno;

976

1086

}

977

1087

1088

/*

1089

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

1090

* corresponds to an acceptable network device.

1091

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

1092

*/

1093

int good_interface(const struct dirent *if_entry){

1094

ssize_t ssret;

1095

char *flagname = NULL;

1096

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

1097

return 0;

1098

}

1099

int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,

1100

if_entry->d_name);

1101

if(ret < 0){

1102

perror_plus("asprintf");

1103

return 0;

1104

}

1105

int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));

1106

if(flags_fd == -1){

1107

perror_plus("open");

1108

free(flagname);

1109

return 0;

1110

}

1111

free(flagname);

1112

typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */

1113

/* read line from flags_fd */

1114

ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */

1115

char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */

1116

flagstring[(size_t)to_read] = '\0';

1117

if(flagstring == NULL){

1118

perror_plus("malloc");

1119

close(flags_fd);

1120

return 0;

1121

}

1122

while(to_read > 0){

1123

ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,

1124

(size_t)to_read));

1125

if(ssret == -1){

1126

perror_plus("read");

1127

free(flagstring);

1128

close(flags_fd);

1129

return 0;

1130

}

1131

to_read -= ssret;

1132

if(ssret == 0){

1133

break;

1134

}

1135

}

1136

close(flags_fd);

1137

intmax_t tmpmax;

1138

char *tmp;

1139

errno = 0;

1140

tmpmax = strtoimax(flagstring, &tmp, 0);

1141

if(errno != 0 or tmp == flagstring or (*tmp != '\0'

1142

and not (isspace(*tmp)))

1143

or tmpmax != (ifreq_flags)tmpmax){

1144

if(debug){

1145

fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",

1146

flagstring, if_entry->d_name);

1147

}

1148

free(flagstring);

1149

return 0;

1150

}

1151

free(flagstring);

1152

ifreq_flags flags = (ifreq_flags)tmpmax;

1153

/* Reject the loopback device */

1154

if(flags & IFF_LOOPBACK){

1155

if(debug){

1156

fprintf(stderr, "Rejecting loopback interface \"%s\"\n",

1157

if_entry->d_name);

1158

}

1159

return 0;

1160

}

1161

/* Accept point-to-point devices only if connect_to is specified */

1162

if(connect_to != NULL and (flags & IFF_POINTOPOINT)){

1163

if(debug){

1164

fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",

1165

if_entry->d_name);

1166

}

1167

return 1;

1168

}

1169

/* Otherwise, reject non-broadcast-capable devices */

1170

if(not (flags & IFF_BROADCAST)){

1171

if(debug){

1172

fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",

1173

if_entry->d_name);

1174

}

1175

return 0;

1176

}

1177

/* Reject non-ARP interfaces (including dummy interfaces) */

1178

if(flags & IFF_NOARP){

1179

if(debug){

1180

fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",

1181

if_entry->d_name);

1182

}

1183

return 0;

1184

}

1185

/* Accept this device */

1186

if(debug){

1187

fprintf(stderr, "Interface \"%s\" is acceptable\n",

1188

if_entry->d_name);

1189

}

1190

return 1;

1191

}

1192

1193

int notdotentries(const struct dirent *direntry){

1194

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

1195

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

1196

and (direntry->d_name[1] == '\0'

1197

or (direntry->d_name[1] == '.'

1198

and direntry->d_name[2] == '\0'))){

1199

return 0;

1200

}

1201

return 1;

1202

}

1203

1204

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1205

int ret;

1206

struct timespec now;

1207

struct timespec waited_time;

1208

intmax_t block_time;

1209

1210

while(true){

1211

if(mc.current_server == NULL){

1212

if (debug){

1213

fprintf(stderr,

1214

"Wait until first server is found. No timeout!\n");

1215

}

1216

ret = avahi_simple_poll_iterate(s, -1);

1217

} else {

1218

if (debug){

1219

fprintf(stderr, "Check current_server if we should run it,"

1220

" or wait\n");

1221

}

1222

/* the current time */

1223

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1224

if(ret == -1){

1225

perror_plus("clock_gettime");

1226

return -1;

1227

}

1228

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

1229

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

1230

waited_time.tv_sec = (now.tv_sec

1231

- mc.current_server->last_seen.tv_sec);

1232

waited_time.tv_nsec = (now.tv_nsec

1233

- mc.current_server->last_seen.tv_nsec);

1234

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

1235

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

1236

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

1237

block_time = ((retry_interval

1238

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

1239

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

1240

1241

if (debug){

1242

fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);

1243

}

1244

1245

if(block_time <= 0){

1246

ret = start_mandos_communication(mc.current_server->ip,

1247

mc.current_server->port,

1248

mc.current_server->if_index,

1249

mc.current_server->af);

1250

if(ret == 0){

1251

avahi_simple_poll_quit(mc.simple_poll);

1252

return 0;

1253

}

1254

ret = clock_gettime(CLOCK_MONOTONIC,

1255

&mc.current_server->last_seen);

1256

if(ret == -1){

1257

perror_plus("clock_gettime");

1258

return -1;

1259

}

1260

mc.current_server = mc.current_server->next;

1261

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

1262

servers, but don't block */

1263

}

1264

1265

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

1266

}

1267

if(ret != 0){

1268

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

1269

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

1270

}

1271

}

1272

}

1273

}

1274

978

1275

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

979

1276

AvahiSServiceBrowser *sb = NULL;

980

1277

int error;

982

1279

intmax_t tmpmax;

983

1280

char *tmp;

984

1281

int exitcode = EXIT_SUCCESS;

985

const char *interface = "eth0";

1282

const char *interface = "";

986

1283

struct ifreq network;

987

1284

int sd = -1;

988

1285

bool take_down_interface = false;

989

1286

uid_t uid;

990

1287

gid_t gid;

991

char *connect_to = NULL;

992

1288

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

993

1289

bool tempdir_created = false;

994

1290

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

998

1294

bool gnutls_initialized = false;

999

1295

bool gpgme_initialized = false;

1000

1296

float delay = 2.5f;

1297

double retry_interval = 10; /* 10s between trying a server and

1298

retrying the same server again */

1001

1299

1002

1300

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1003

1301

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1009

1307

errno = 0;

1010

1308

ret = setgid(gid);

1011

1309

if(ret == -1){

1012

perror("setgid");

1310

perror_plus("setgid");

1013

1311

}

1014

1312

1015

1313

/* Lower user privileges (temporarily) */

1016

1314

errno = 0;

1017

1315

ret = seteuid(uid);

1018

1316

if(ret == -1){

1019

perror("seteuid");

1317

perror_plus("seteuid");

1020

1318

}

1021

1319

1022

1320

if(quit_now){

1057

1355

.arg = "SECONDS",

1058

1356

.doc = "Maximum delay to wait for interface startup",

1059

1357

.group = 2 },

1358

{ .name = "retry", .key = 132,

1359

.arg = "SECONDS",

1360

.doc = "Retry interval used when denied by the mandos server",

1361

.group = 2 },

1060

1362

/*

1061

1363

* These reproduce what we would get without ARGP_NO_HELP

1062

1364

*/

1106

1408

if(errno != 0 or tmp == arg or *tmp != '\0'){

1107

1409

argp_error(state, "Bad delay");

1108

1410

}

1411

case 132: /* --retry */

1412

errno = 0;

1413

retry_interval = strtod(arg, &tmp);

1414

if(errno != 0 or tmp == arg or *tmp != '\0'

1415

or (retry_interval * 1000) > INT_MAX

1416

or retry_interval < 0){

1417

argp_error(state, "Bad retry interval");

1418

}

1109

1419

break;

1110

1420

/*

1111

1421

* These reproduce what we would get without ARGP_NO_HELP

1139

1449

case ENOMEM:

1140

1450

default:

1141

1451

errno = ret;

1142

perror("argp_parse");

1452

perror_plus("argp_parse");

1143

1453

exitcode = EX_OSERR;

1144

1454

goto end;

1145

1455

case EINVAL:

1147

1457

goto end;

1148

1458

}

1149

1459

}

1460

1461

{

1462

/* Work around Debian bug #633582:

1463

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

1464

struct stat st;

1465

1466

/* Re-raise priviliges */

1467

errno = 0;

1468

ret = seteuid(0);

1469

if(ret == -1){

1470

perror_plus("seteuid");

1471

}

1472

1473

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

1474

int seckey_fd = open(seckey, O_RDONLY);

1475

if(seckey_fd == -1){

1476

perror_plus("open");

1477

} else {

1478

ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));

1479

if(ret == -1){

1480

perror_plus("fstat");

1481

} else {

1482

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1483

ret = fchown(seckey_fd, uid, gid);

1484

if(ret == -1){

1485

perror_plus("fchown");

1486

}

1487

}

1488

}

1489

TEMP_FAILURE_RETRY(close(seckey_fd));

1490

}

1491

}

1492

1493

if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){

1494

int pubkey_fd = open(pubkey, O_RDONLY);

1495

if(pubkey_fd == -1){

1496

perror_plus("open");

1497

} else {

1498

ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));

1499

if(ret == -1){

1500

perror_plus("fstat");

1501

} else {

1502

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1503

ret = fchown(pubkey_fd, uid, gid);

1504

if(ret == -1){

1505

perror_plus("fchown");

1506

}

1507

}

1508

}

1509

TEMP_FAILURE_RETRY(close(pubkey_fd));

1510

}

1511

}

1512

1513

/* Lower privileges */

1514

errno = 0;

1515

ret = seteuid(uid);

1516

if(ret == -1){

1517

perror_plus("seteuid");

1518

}

1519

}

1150

1520

1151

1521

if(not debug){

1152

1522

avahi_set_log_function(empty_log);

1153

1523

}

1524

1525

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

1526

struct dirent **direntries;

1527

ret = scandir(sys_class_net, &direntries, good_interface,

1528

alphasort);

1529

if(ret >= 1){

1530

/* Pick the first good interface */

1531

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

1532

if(debug){

1533

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

1534

}

1535

if(interface == NULL){

1536

perror_plus("malloc");

1537

free(direntries);

1538

exitcode = EXIT_FAILURE;

1539

goto end;

1540

}

1541

free(direntries);

1542

} else {

1543

free(direntries);

1544

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

1545

exitcode = EXIT_FAILURE;

1546

goto end;

1547

}

1548

}

1154

1549

1155

1550

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

1156

1551

from the signal handler */

1159

1554

mc.simple_poll = avahi_simple_poll_new();

1160

1555

if(mc.simple_poll == NULL){

1161

1556

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

1162

exitcode = EXIT_FAILURE;

1557

exitcode = EX_UNAVAILABLE;

1163

1558

goto end;

1164

1559

}

1165

1560

1166

1561

sigemptyset(&sigterm_action.sa_mask);

1167

1562

ret = sigaddset(&sigterm_action.sa_mask, SIGINT);

1168

1563

if(ret == -1){

1169

perror("sigaddset");

1170

exitcode = EXIT_FAILURE;

1564

perror_plus("sigaddset");

1565

exitcode = EX_OSERR;

1171

1566

goto end;

1172

1567

}

1173

1568

ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);

1174

1569

if(ret == -1){

1175

perror("sigaddset");

1176

exitcode = EXIT_FAILURE;

1570

perror_plus("sigaddset");

1571

exitcode = EX_OSERR;

1177

1572

goto end;

1178

1573

}

1179

1574

ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);

1180

1575

if(ret == -1){

1181

perror("sigaddset");

1182

exitcode = EXIT_FAILURE;

1576

perror_plus("sigaddset");

1577

exitcode = EX_OSERR;

1183

1578

goto end;

1184

1579

}

1185

1580

/* Need to check if the handler is SIG_IGN before handling:

1188

1583

*/

1189

1584

ret = sigaction(SIGINT, NULL, &old_sigterm_action);

1190

1585

if(ret == -1){

1191

perror("sigaction");

1192

return EXIT_FAILURE;

1586

perror_plus("sigaction");

1587

return EX_OSERR;

1193

1588

}

1194

1589

if(old_sigterm_action.sa_handler != SIG_IGN){

1195

1590

ret = sigaction(SIGINT, &sigterm_action, NULL);

1196

1591

if(ret == -1){

1197

perror("sigaction");

1198

exitcode = EXIT_FAILURE;

1592

perror_plus("sigaction");

1593

exitcode = EX_OSERR;

1199

1594

goto end;

1200

1595

}

1201

1596

}

1202

1597

ret = sigaction(SIGHUP, NULL, &old_sigterm_action);

1203

1598

if(ret == -1){

1204

perror("sigaction");

1205

return EXIT_FAILURE;

1599

perror_plus("sigaction");

1600

return EX_OSERR;

1206

1601

}

1207

1602

if(old_sigterm_action.sa_handler != SIG_IGN){

1208

1603

ret = sigaction(SIGHUP, &sigterm_action, NULL);

1209

1604

if(ret == -1){

1210

perror("sigaction");

1211

exitcode = EXIT_FAILURE;

1605

perror_plus("sigaction");

1606

exitcode = EX_OSERR;

1212

1607

goto end;

1213

1608

}

1214

1609

}

1215

1610

ret = sigaction(SIGTERM, NULL, &old_sigterm_action);

1216

1611

if(ret == -1){

1217

perror("sigaction");

1218

return EXIT_FAILURE;

1612

perror_plus("sigaction");

1613

return EX_OSERR;

1219

1614

}

1220

1615

if(old_sigterm_action.sa_handler != SIG_IGN){

1221

1616

ret = sigaction(SIGTERM, &sigterm_action, NULL);

1222

1617

if(ret == -1){

1223

perror("sigaction");

1224

exitcode = EXIT_FAILURE;

1618

perror_plus("sigaction");

1619

exitcode = EX_OSERR;

1225

1620

goto end;

1226

1621

}

1227

1622

}

1228

1623

1229

1624

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

1230

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

1625

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

1231

1626

if_index = (AvahiIfIndex) if_nametoindex(interface);

1232

1627

if(if_index == 0){

1233

1628

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

1234

exitcode = EXIT_FAILURE;

1629

exitcode = EX_UNAVAILABLE;

1235

1630

goto end;

1236

1631

}

1237

1632

1243

1638

errno = 0;

1244

1639

ret = seteuid(0);

1245

1640

if(ret == -1){

1246

perror("seteuid");

1641

perror_plus("seteuid");

1247

1642

}

1248

1643

1249

1644

#ifdef __linux__

1253

1648

bool restore_loglevel = true;

1254

1649

if(ret == -1){

1255

1650

restore_loglevel = false;

1256

perror("klogctl");

1651

perror_plus("klogctl");

1257

1652

}

1258

1653

#endif /* __linux__ */

1259

1654

1260

1655

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1261

1656

if(sd < 0){

1262

perror("socket");

1263

exitcode = EXIT_FAILURE;

1657

perror_plus("socket");

1658

exitcode = EX_OSERR;

1264

1659

#ifdef __linux__

1265

1660

if(restore_loglevel){

1266

1661

ret = klogctl(7, NULL, 0);

1267

1662

if(ret == -1){

1268

perror("klogctl");

1663

perror_plus("klogctl");

1269

1664

}

1270

1665

}

1271

1666

#endif /* __linux__ */

1273

1668

errno = 0;

1274

1669

ret = seteuid(uid);

1275

1670

if(ret == -1){

1276

perror("seteuid");

1671

perror_plus("seteuid");

1277

1672

}

1278

1673

goto end;

1279

1674

}

1280

1675

strcpy(network.ifr_name, interface);

1281

1676

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

1282

1677

if(ret == -1){

1283

perror("ioctl SIOCGIFFLAGS");

1678

perror_plus("ioctl SIOCGIFFLAGS");

1284

1679

#ifdef __linux__

1285

1680

if(restore_loglevel){

1286

1681

ret = klogctl(7, NULL, 0);

1287

1682

if(ret == -1){

1288

perror("klogctl");

1683

perror_plus("klogctl");

1289

1684

}

1290

1685

}

1291

1686

#endif /* __linux__ */

1292

exitcode = EXIT_FAILURE;

1687

exitcode = EX_OSERR;

1293

1688

/* Lower privileges */

1294

1689

errno = 0;

1295

1690

ret = seteuid(uid);

1296

1691

if(ret == -1){

1297

perror("seteuid");

1692

perror_plus("seteuid");

1298

1693

}

1299

1694

goto end;

1300

1695

}

1304

1699

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

1305

1700

if(ret == -1){

1306

1701

take_down_interface = false;

1307

perror("ioctl SIOCSIFFLAGS");

1308

exitcode = EXIT_FAILURE;

1702

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1703

exitcode = EX_OSERR;

1309

1704

#ifdef __linux__

1310

1705

if(restore_loglevel){

1311

1706

ret = klogctl(7, NULL, 0);

1312

1707

if(ret == -1){

1313

perror("klogctl");

1708

perror_plus("klogctl");

1314

1709

}

1315

1710

}

1316

1711

#endif /* __linux__ */

1318

1713

errno = 0;

1319

1714

ret = seteuid(uid);

1320

1715

if(ret == -1){

1321

perror("seteuid");

1716

perror_plus("seteuid");

1322

1717

}

1323

1718

goto end;

1324

1719

}

1325

1720

}

1326

/* sleep checking until interface is running */

1721

/* Sleep checking until interface is running.

1722

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

1327

1723

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

1328

1724

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

1329

1725

if(ret == -1){

1330

perror("ioctl SIOCGIFFLAGS");

1726

perror_plus("ioctl SIOCGIFFLAGS");

1331

1727

} else if(network.ifr_flags & IFF_RUNNING){

1332

1728

break;

1333

1729

}

1334

1730

struct timespec sleeptime = { .tv_nsec = 250000000 };

1335

1731

ret = nanosleep(&sleeptime, NULL);

1336

1732

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

1337

perror("nanosleep");

1733

perror_plus("nanosleep");

1338

1734

}

1339

1735

}

1340

1736

if(not take_down_interface){

1341

1737

/* We won't need the socket anymore */

1342

1738

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

1343

1739

if(ret == -1){

1344

perror("close");

1740

perror_plus("close");

1345

1741

}

1346

1742

}

1347

1743

#ifdef __linux__

1349

1745

/* Restores kernel loglevel to default */

1350

1746

ret = klogctl(7, NULL, 0);

1351

1747

if(ret == -1){

1352

perror("klogctl");

1748

perror_plus("klogctl");

1353

1749

}

1354

1750

}

1355

1751

#endif /* __linux__ */

1359

1755

/* Lower privileges */

1360

1756

ret = seteuid(uid);

1361

1757

if(ret == -1){

1362

perror("seteuid");

1758

perror_plus("seteuid");

1363

1759

}

1364

1760

} else {

1365

1761

/* Lower privileges permanently */

1366

1762

ret = setuid(uid);

1367

1763

if(ret == -1){

1368

perror("setuid");

1764

perror_plus("setuid");

1369

1765

}

1370

1766

}

1371

1767

}

1377

1773

ret = init_gnutls_global(pubkey, seckey);

1378

1774

if(ret == -1){

1379

1775

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

1380

exitcode = EXIT_FAILURE;

1776

exitcode = EX_UNAVAILABLE;

1381

1777

goto end;

1382

1778

} else {

1383

1779

gnutls_initialized = true;

1387

1783

goto end;

1388

1784

}

1389

1785

1786

if(mkdtemp(tempdir) == NULL){

1787

perror_plus("mkdtemp");

1788

goto end;

1789

}

1390

1790

tempdir_created = true;

1391

if(mkdtemp(tempdir) == NULL){

1392

tempdir_created = false;

1393

perror("mkdtemp");

1394

goto end;

1395

}

1396

1791

1397

1792

if(quit_now){

1398

1793

goto end;

1400

1795

1401

1796

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

1402

1797

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

1403

exitcode = EXIT_FAILURE;

1798

exitcode = EX_UNAVAILABLE;

1404

1799

goto end;

1405

1800

} else {

1406

1801

gpgme_initialized = true;

1416

1811

char *address = strrchr(connect_to, ':');

1417

1812

if(address == NULL){

1418

1813

fprintf(stderr, "No colon in address\n");

1419

exitcode = EXIT_FAILURE;

1814

exitcode = EX_USAGE;

1420

1815

goto end;

1421

1816

}

1422

1817

1430

1825

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

1431

1826

or tmpmax != (uint16_t)tmpmax){

1432

1827

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

1433

exitcode = EXIT_FAILURE;

1828

exitcode = EX_USAGE;

1434

1829

goto end;

1435

1830

}

1436

1831

1440

1835

1441

1836

port = (uint16_t)tmpmax;

1442

1837

*address = '\0';

1443

address = connect_to;

1444

1838

/* Colon in address indicates IPv6 */

1445

1839

int af;

1446

if(strchr(address, ':') != NULL){

1840

if(strchr(connect_to, ':') != NULL){

1447

1841

af = AF_INET6;

1842

/* Accept [] around IPv6 address - see RFC 5952 */

1843

if(connect_to[0] == '[' and address[-1] == ']')

1844

{

1845

connect_to++;

1846

address[-1] = '\0';

1847

}

1448

1848

} else {

1449

1849

af = AF_INET;

1450

1850

}

1851

address = connect_to;

1451

1852

1452

1853

if(quit_now){

1453

1854

goto end;

1454

1855

}

1455

1856

1456

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

1457

if(ret < 0){

1458

exitcode = EXIT_FAILURE;

1459

} else {

1857

while(not quit_now){

1858

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

1859

if(quit_now or ret == 0){

1860

break;

1861

}

1862

if(debug){

1863

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

1864

(int)retry_interval);

1865

}

1866

sleep((int)retry_interval);

1867

}

1868

1869

if (not quit_now){

1460

1870

exitcode = EXIT_SUCCESS;

1461

1871

}

1872

1462

1873

goto end;

1463

1874

}

1464

1875

1488

1899

if(mc.server == NULL){

1489

1900

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

1490

1901

avahi_strerror(error));

1491

exitcode = EXIT_FAILURE;

1902

exitcode = EX_UNAVAILABLE;

1492

1903

goto end;

1493

1904

}

1494

1905

1503

1914

if(sb == NULL){

1504

1915

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

1505

1916

avahi_strerror(avahi_server_errno(mc.server)));

1506

exitcode = EXIT_FAILURE;

1917

exitcode = EX_UNAVAILABLE;

1507

1918

goto end;

1508

1919

}

1509

1920

1516

1927

if(debug){

1517

1928

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

1518

1929

}

1519

1520

avahi_simple_poll_loop(mc.simple_poll);

1930

1931

ret = avahi_loop_with_timeout(mc.simple_poll,

1932

(int)(retry_interval * 1000));

1933

if(debug){

1934

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

1935

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

1936

}

1521

1937

1522

1938

end:

1523

1939

1544

1960

if(gpgme_initialized){

1545

1961

gpgme_release(mc.ctx);

1546

1962

}

1963

1964

/* Cleans up the circular linked list of Mandos servers the client

1965

has seen */

1966

if(mc.current_server != NULL){

1967

mc.current_server->prev->next = NULL;

1968

while(mc.current_server != NULL){

1969

server *next = mc.current_server->next;

1970

free(mc.current_server);

1971

mc.current_server = next;

1972

}

1973

}

1547

1974

1548

1975

/* Take down the network interface */

1549

1976

if(take_down_interface){

1551

1978

errno = 0;

1552

1979

ret = seteuid(0);

1553

1980

if(ret == -1){

1554

perror("seteuid");

1981

perror_plus("seteuid");

1555

1982

}

1556

1983

if(geteuid() == 0){

1557

1984

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

1558

1985

if(ret == -1){

1559

perror("ioctl SIOCGIFFLAGS");

1986

perror_plus("ioctl SIOCGIFFLAGS");

1560

1987

} else if(network.ifr_flags & IFF_UP) {

1561

1988

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

1562

1989

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

1563

1990

if(ret == -1){

1564

perror("ioctl SIOCSIFFLAGS");

1991

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1565

1992

}

1566

1993

}

1567

1994

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

1568

1995

if(ret == -1){

1569

perror("close");

1996

perror_plus("close");

1570

1997

}

1571

1998

/* Lower privileges permanently */

1572

1999

errno = 0;

1573

2000

ret = setuid(uid);

1574

2001

if(ret == -1){

1575

perror("setuid");

2002

perror_plus("setuid");

1576

2003

}

1577

2004

}

1578

2005

}

1579

2006

1580

/* Removes the temp directory used by GPGME */

2007

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

1581

2008

if(tempdir_created){

1582

DIR *d;

1583

struct dirent *direntry;

1584

d = opendir(tempdir);

1585

if(d == NULL){

1586

if(errno != ENOENT){

1587

perror("opendir");

1588

}

1589

} else {

1590

while(true){

1591

direntry = readdir(d);

1592

if(direntry == NULL){

1593

break;

1594

}

1595

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

1596

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

1597

and (direntry->d_name[1] == '\0'

1598

or (direntry->d_name[1] == '.'

1599

and direntry->d_name[2] == '\0'))){

1600

continue;

1601

}

2009

struct dirent **direntries = NULL;

2010

struct dirent *direntry = NULL;

2011

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

2012

alphasort);

2013

if (numentries > 0){

2014

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

2015

direntry = direntries[i];

1602

2016

char *fullname = NULL;

1603

2017

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

1604

2018

direntry->d_name);

1605

2019

if(ret < 0){

1606

perror("asprintf");

2020

perror_plus("asprintf");

1607

2021

continue;

1608

2022

}

1609

2023

ret = remove(fullname);

1613

2027

}

1614

2028

free(fullname);

1615

2029

}

1616

closedir(d);

2030

}

2031

2032

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

2033

free(direntries);

2034

if (numentries == -1){

2035

perror_plus("scandir");

1617

2036

}

1618

2037

ret = rmdir(tempdir);

1619

2038

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

1620

perror("rmdir");

2039

perror_plus("rmdir");

1621

2040

}

1622

2041

}

1623

2042

1628

2047

&old_sigterm_action,

1629

2048

NULL));

1630

2049

if(ret == -1){

1631

perror("sigaction");

2050

perror_plus("sigaction");

1632

2051

}

1633

2052

do {

1634

2053

ret = raise(signal_received);

1635

2054

} while(ret != 0 and errno == EINTR);

1636

2055

if(ret != 0){

1637

perror("raise");

2056

perror_plus("raise");

1638

2057

abort();

1639

2058

}

1640

2059

TEMP_FAILURE_RETRY(pause());