/mandos/trunk : revision 634

9

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

10

*

11

* Everything else is

12

13

12

13

14

*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

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

41

42

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

43

stdout, ferror() */

43

stdout, ferror(), remove() */

44

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

45

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

46

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

55

opendir(), DIR */

56

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

57

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

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inet_pton(), connect() */

59

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

61

60

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

62

61

*/

63

62

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

73

72

*/

74

73

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

75

74

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

76

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

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unlinkat() */

78

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

75

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

76

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

79

77

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

80

78

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

81

79

argp_state, struct argp,

93

91

argz_delete(), argz_append(),

94

92

argz_stringify(), argz_add(),

95

93

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

98

94

99

95

#ifdef __linux__

100

96

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

142

138

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

143

139

char *connect_to = NULL;

144

140

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

141

uid_t uid = 65534;

147

142

gid_t gid = 65534;

148

143

185

180

perror(print_text);

186

181

}

187

182

188

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

183

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

189

184

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

190

185

va_list ap;

191

186

va_start (ap, format);

200

195

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

201

196

* "buffer_length" is how much is already used.

202

197

*/

203

__attribute__((nonnull, warn_unused_result))

204

198

size_t incbuffer(char **buffer, size_t buffer_length,

205

199

size_t buffer_capacity){

206

200

if(buffer_length + BUFFER_SIZE > buffer_capacity){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

201

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

202

if(buffer == NULL){

213

203

return 0;

214

204

}

215

*buffer = new_buf;

216

205

buffer_capacity += BUFFER_SIZE;

217

206

}

218

207

return buffer_capacity;

219

208

}

220

209

221

210

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

222

__attribute__((nonnull, warn_unused_result))

223

211

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

224

212

int af, server **current_server){

225

213

int ret;

234

222

.af = af };

235

223

if(new_server->ip == NULL){

236

224

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

free((char *)(new_server->ip));

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

252

225

return false;

253

226

}

254

227

/* Special case of first server */

256

229

new_server->next = new_server;

257

230

new_server->prev = new_server;

258

231

*current_server = new_server;

232

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

259

233

} else {

260

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

261

234

new_server->next = *current_server;

262

235

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

263

236

new_server->prev->next = new_server;

264

237

(*current_server)->prev = new_server;

265

238

}

239

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

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

266

244

return true;

267

245

}

268

246

269

247

/*

270

248

* Initialize GPGME.

271

249

*/

272

__attribute__((nonnull, warn_unused_result))

273

static bool init_gpgme(const char * const seckey,

274

const char * const pubkey,

275

const char * const tempdir,

276

mandos_context *mc){

250

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

251

const char *tempdir, mandos_context *mc){

277

252

gpgme_error_t rc;

278

253

gpgme_engine_info_t engine_info;

279

254

280

255

/*

281

256

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

282

257

*/

283

bool import_key(const char * const filename){

258

bool import_key(const char *filename){

284

259

int ret;

285

260

int fd;

286

261

gpgme_data_t pgp_data;

367

342

* Decrypt OpenPGP data.

368

343

* Returns -1 on error

369

344

*/

370

__attribute__((nonnull, warn_unused_result))

371

345

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

346

size_t crypto_size,

373

347

char **plaintext,

493

467

return plaintext_length;

494

468

}

495

469

496

__attribute__((warn_unused_result, const))

497

static const char *safe_string(const char *str){

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

503

__attribute__((warn_unused_result))

504

static const char *safer_gnutls_strerror(int value){

470

static const char * safer_gnutls_strerror(int value){

505

471

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

507

475

}

508

476

509

477

/* GnuTLS log function callback */

510

__attribute__((nonnull))

511

478

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

512

479

const char* string){

513

480

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

514

481

}

515

482

516

__attribute__((nonnull, warn_unused_result))

517

483

static int init_gnutls_global(const char *pubkeyfilename,

518

484

const char *seckeyfilename,

519

485

mandos_context *mc){

520

486

int ret;

521

unsigned int uret;

522

487

523

488

if(debug){

524

489

fprintf_plus(stderr, "Initializing GnuTLS\n");

575

540

safer_gnutls_strerror(ret));

576

541

goto globalfail;

577

542

}

578

if(mc->dh_bits == 0){

579

/* Find out the optimal number of DH bits */

580

/* Try to read the private key file */

581

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

582

{

583

int secfile = open(seckeyfilename, O_RDONLY);

584

size_t buffer_capacity = 0;

585

while(true){

586

buffer_capacity = incbuffer((char **)&buffer.data,

587

(size_t)buffer.size,

588

(size_t)buffer_capacity);

589

if(buffer_capacity == 0){

590

perror_plus("incbuffer");

591

free(buffer.data);

592

buffer.data = NULL;

593

break;

594

}

595

ssize_t bytes_read = read(secfile, buffer.data + buffer.size,

596

BUFFER_SIZE);

597

/* EOF */

598

if(bytes_read == 0){

599

break;

600

}

601

/* check bytes_read for failure */

602

if(bytes_read < 0){

603

perror_plus("read");

604

free(buffer.data);

605

buffer.data = NULL;

606

break;

607

}

608

buffer.size += (unsigned int)bytes_read;

609

}

610

close(secfile);

611

}

612

/* If successful, use buffer to parse private key */

613

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

614

if(buffer.data != NULL){

615

{

616

gnutls_openpgp_privkey_t privkey = NULL;

617

ret = gnutls_openpgp_privkey_init(&privkey);

618

if(ret != GNUTLS_E_SUCCESS){

619

fprintf_plus(stderr, "Error initializing OpenPGP key"

620

" structure: %s", safer_gnutls_strerror(ret));

621

free(buffer.data);

622

buffer.data = NULL;

623

} else {

624

ret = gnutls_openpgp_privkey_import(privkey, &buffer,

625

GNUTLS_OPENPGP_FMT_BASE64,

626

"", 0);

627

if(ret != GNUTLS_E_SUCCESS){

628

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

629

safer_gnutls_strerror(ret));

630

privkey = NULL;

631

}

632

free(buffer.data);

633

buffer.data = NULL;

634

if(privkey != NULL){

635

/* Use private key to suggest an appropriate sec_param */

636

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

637

gnutls_openpgp_privkey_deinit(privkey);

638

if(debug){

639

fprintf_plus(stderr, "This OpenPGP key implies using a"

640

" GnuTLS security parameter \"%s\".\n",

641

safe_string(gnutls_sec_param_get_name

642

(sec_param)));

643

}

644

}

645

}

646

}

647

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

648

/* Err on the side of caution */

649

sec_param = GNUTLS_SEC_PARAM_ULTRA;

650

if(debug){

651

fprintf_plus(stderr, "Falling back to security parameter"

652

" \"%s\"\n",

653

safe_string(gnutls_sec_param_get_name

654

(sec_param)));

655

}

656

}

657

}

658

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

659

if(uret != 0){

660

mc->dh_bits = uret;

661

if(debug){

662

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

663

" implies %u DH bits; using that.\n",

664

safe_string(gnutls_sec_param_get_name

665

(sec_param)),

666

mc->dh_bits);

667

}

668

} else {

669

fprintf_plus(stderr, "Failed to get implied number of DH"

670

" bits for security parameter \"%s\"): %s\n",

671

safe_string(gnutls_sec_param_get_name(sec_param)),

672

safer_gnutls_strerror(ret));

673

goto globalfail;

674

}

675

} else if(debug){

676

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

677

mc->dh_bits);

678

}

679

543

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

680

544

if(ret != GNUTLS_E_SUCCESS){

681

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u bits):"

682

" %s\n", mc->dh_bits, safer_gnutls_strerror(ret));

545

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

546

safer_gnutls_strerror(ret));

683

547

goto globalfail;

684

548

}

685

549

695

559

return -1;

696

560

}

697

561

698

__attribute__((nonnull, warn_unused_result))

699

562

static int init_gnutls_session(gnutls_session_t *session,

700

563

mandos_context *mc){

701

564

int ret;

757

620

static void empty_log(__attribute__((unused)) AvahiLogLevel level,

758

621

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

759

622

760

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

761

__attribute__((warn_unused_result))

762

error_t raise_privileges(void){

763

error_t old_errno = errno;

764

error_t ret_errno = 0;

765

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

766

ret_errno = errno;

767

}

768

errno = old_errno;

769

return ret_errno;

770

}

771

772

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

773

__attribute__((warn_unused_result))

774

error_t raise_privileges_permanently(void){

775

error_t old_errno = errno;

776

error_t ret_errno = raise_privileges();

777

if(ret_errno != 0){

778

errno = old_errno;

779

return ret_errno;

780

}

781

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

782

ret_errno = errno;

783

}

784

errno = old_errno;

785

return ret_errno;

786

}

787

788

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

789

__attribute__((warn_unused_result))

790

error_t lower_privileges(void){

791

error_t old_errno = errno;

792

error_t ret_errno = 0;

793

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

794

ret_errno = errno;

795

}

796

errno = old_errno;

797

return ret_errno;

798

}

799

800

/* Lower privileges permanently */

801

__attribute__((warn_unused_result))

802

error_t lower_privileges_permanently(void){

803

error_t old_errno = errno;

804

error_t ret_errno = 0;

805

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

806

ret_errno = errno;

807

}

808

errno = old_errno;

809

return ret_errno;

810

}

811

812

/* Helper function to add_local_route() and delete_local_route() */

813

__attribute__((nonnull, warn_unused_result))

814

static bool add_delete_local_route(const bool add,

815

const char *address,

816

AvahiIfIndex if_index){

817

int ret;

818

char helper[] = "mandos-client-iprouteadddel";

819

char add_arg[] = "add";

820

char delete_arg[] = "delete";

821

char debug_flag[] = "--debug";

822

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

823

if(pluginhelperdir == NULL){

824

if(debug){

825

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

826

" variable not set; cannot run helper\n");

827

}

828

return false;

829

}

830

831

char interface[IF_NAMESIZE];

832

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

833

perror_plus("if_indextoname");

834

return false;

835

}

836

837

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

838

if(devnull == -1){

839

perror_plus("open(\"/dev/null\", O_RDONLY)");

840

return false;

841

}

842

pid_t pid = fork();

843

if(pid == 0){

844

/* Child */

845

/* Raise privileges */

846

errno = raise_privileges_permanently();

847

if(errno != 0){

848

perror_plus("Failed to raise privileges");

849

/* _exit(EX_NOPERM); */

850

} else {

851

/* Set group */

852

errno = 0;

853

ret = setgid(0);

854

if(ret == -1){

855

perror_plus("setgid");

856

_exit(EX_NOPERM);

857

}

858

/* Reset supplementary groups */

859

errno = 0;

860

ret = setgroups(0, NULL);

861

if(ret == -1){

862

perror_plus("setgroups");

863

_exit(EX_NOPERM);

864

}

865

}

866

ret = dup2(devnull, STDIN_FILENO);

867

if(ret == -1){

868

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

869

_exit(EX_OSERR);

870

}

871

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

872

if(ret == -1){

873

perror_plus("close");

874

_exit(EX_OSERR);

875

}

876

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

877

if(ret == -1){

878

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

879

_exit(EX_OSERR);

880

}

881

int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,

882

O_RDONLY

883

| O_DIRECTORY

884

| O_PATH

885

| O_CLOEXEC));

886

if(helperdir_fd == -1){

887

perror_plus("open");

888

_exit(EX_UNAVAILABLE);

889

}

890

int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,

891

helper, O_RDONLY));

892

if(helper_fd == -1){

893

perror_plus("openat");

894

_exit(EX_UNAVAILABLE);

895

}

896

TEMP_FAILURE_RETRY(close(helperdir_fd));

897

#ifdef __GNUC__

898

#pragma GCC diagnostic push

899

#pragma GCC diagnostic ignored "-Wcast-qual"

900

#endif

901

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

902

{ helper, add ? add_arg : delete_arg, (char *)address,

903

interface, debug ? debug_flag : NULL, NULL },

904

environ) == -1){

905

#ifdef __GNUC__

906

#pragma GCC diagnostic pop

907

#endif

908

perror_plus("fexecve");

909

_exit(EXIT_FAILURE);

910

}

911

}

912

if(pid == -1){

913

perror_plus("fork");

914

return false;

915

}

916

int status;

917

pid_t pret = -1;

918

errno = 0;

919

do {

920

pret = waitpid(pid, &status, 0);

921

if(pret == -1 and errno == EINTR and quit_now){

922

int errno_raising = 0;

923

if((errno = raise_privileges()) != 0){

924

errno_raising = errno;

925

perror_plus("Failed to raise privileges in order to"

926

" kill helper program");

927

}

928

if(kill(pid, SIGTERM) == -1){

929

perror_plus("kill");

930

}

931

if((errno_raising == 0) and (errno = lower_privileges()) != 0){

932

perror_plus("Failed to lower privileges after killing"

933

" helper program");

934

}

935

return false;

936

}

937

} while(pret == -1 and errno == EINTR);

938

if(pret == -1){

939

perror_plus("waitpid");

940

return false;

941

}

942

if(WIFEXITED(status)){

943

if(WEXITSTATUS(status) != 0){

944

fprintf_plus(stderr, "Error: iprouteadddel exited"

945

" with status %d\n", WEXITSTATUS(status));

946

return false;

947

}

948

return true;

949

}

950

if(WIFSIGNALED(status)){

951

fprintf_plus(stderr, "Error: iprouteadddel died by"

952

" signal %d\n", WTERMSIG(status));

953

return false;

954

}

955

fprintf_plus(stderr, "Error: iprouteadddel crashed\n");

956

return false;

957

}

958

959

__attribute__((nonnull, warn_unused_result))

960

static bool add_local_route(const char *address,

961

AvahiIfIndex if_index){

962

if(debug){

963

fprintf_plus(stderr, "Adding route to %s\n", address);

964

}

965

return add_delete_local_route(true, address, if_index);

966

}

967

968

__attribute__((nonnull, warn_unused_result))

969

static bool delete_local_route(const char *address,

970

AvahiIfIndex if_index){

971

if(debug){

972

fprintf_plus(stderr, "Removing route to %s\n", address);

973

}

974

return add_delete_local_route(false, address, if_index);

975

}

976

977

623

/* Called when a Mandos server is found */

978

__attribute__((nonnull, warn_unused_result))

979

624

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

980

625

AvahiIfIndex if_index,

981

626

int af, mandos_context *mc){

982

627

int ret, tcp_sd = -1;

983

628

ssize_t sret;

984

struct sockaddr_storage to;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

985

633

char *buffer = NULL;

986

634

char *decrypted_buffer = NULL;

987

635

size_t buffer_length = 0;

990

638

int retval = -1;

991

639

gnutls_session_t session;

992

640

int pf; /* Protocol family */

993

bool route_added = false;

994

641

995

642

errno = 0;

996

643

1054

701

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

1055

702

}

1056

703

1057

tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);

704

tcp_sd = socket(pf, SOCK_STREAM, 0);

1058

705

if(tcp_sd < 0){

1059

706

int e = errno;

1060

707

perror_plus("socket");

1069

716

1070

717

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

1071

718

if(af == AF_INET6){

1072

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

1073

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

719

to.in6.sin6_family = (sa_family_t)af;

720

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

1074

721

} else { /* IPv4 */

1075

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

1076

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

722

to.in.sin_family = (sa_family_t)af;

723

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

1077

724

}

1078

725

if(ret < 0 ){

1079

726

int e = errno;

1088

735

goto mandos_end;

1089

736

}

1090

737

if(af == AF_INET6){

1091

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

1092

if(IN6_IS_ADDR_LINKLOCAL

1093

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

738

to.in6.sin6_port = htons(port);

739

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

740

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

741

-Wunreachable-code*/

1094

742

if(if_index == AVAHI_IF_UNSPEC){

1095

743

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

1096

744

" incomplete without a network interface\n");

1098

746

goto mandos_end;

1099

747

}

1100

748

/* Set the network interface number as scope */

1101

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

749

to.in6.sin6_scope_id = (uint32_t)if_index;

1102

750

}

1103

751

} else {

1104

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

752

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

753

-Wconversion and

754

-Wunreachable-code */

1105

755

}

1106

756

1107

757

if(quit_now){

1124

774

}

1125

775

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1126

776

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1127

if(af == AF_INET6){

1128

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

1129

sizeof(struct sockaddr_in6),

1130

addrstr, sizeof(addrstr), NULL, 0,

1131

NI_NUMERICHOST);

1132

} else {

1133

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

1134

sizeof(struct sockaddr_in),

1135

addrstr, sizeof(addrstr), NULL, 0,

1136

NI_NUMERICHOST);

1137

}

1138

if(ret == EAI_SYSTEM){

1139

perror_plus("getnameinfo");

1140

} else if(ret != 0) {

1141

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

1142

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

1143

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

1144

}

1145

}

1146

1147

if(quit_now){

1148

errno = EINTR;

1149

goto mandos_end;

1150

}

1151

1152

while(true){

1153

if(af == AF_INET6){

1154

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

1155

sizeof(struct sockaddr_in6));

1156

} else {

1157

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

1158

sizeof(struct sockaddr_in));

1159

}

1160

if(ret < 0){

1161

if(errno == ENETUNREACH

1162

and if_index != AVAHI_IF_UNSPEC

1163

and connect_to == NULL

1164

and not route_added and

1165

((af == AF_INET6 and not

1166

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1167

&to)->sin6_addr)))

1168

or (af == AF_INET and

1169

/* Not a a IPv4LL address */

1170

(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)

1171

& 0xFFFF0000L) != 0xA9FE0000L))){

1172

/* Work around Avahi bug - Avahi does not announce link-local

1173

addresses if it has a global address, so local hosts with

1174

*only* a link-local address (e.g. Mandos clients) cannot

1175

connect to a Mandos server announced by Avahi on a server

1176

host with a global address. Work around this by retrying

1177

with an explicit route added with the server's address.

1178

1179

Avahi bug reference:

1180

http://lists.freedesktop.org/archives/avahi/2010-February/001833.html

1181

https://bugs.debian.org/587961

1182

*/

1183

if(debug){

1184

fprintf_plus(stderr, "Mandos server unreachable, trying"

1185

" direct route\n");

1186

}

1187

int e = errno;

1188

route_added = add_local_route(ip, if_index);

1189

if(route_added){

1190

continue;

1191

}

1192

errno = e;

1193

}

1194

if(errno != ECONNREFUSED or debug){

1195

int e = errno;

1196

perror_plus("connect");

1197

errno = e;

1198

}

1199

goto mandos_end;

1200

}

1201

1202

if(quit_now){

1203

errno = EINTR;

1204

goto mandos_end;

1205

}

1206

break;

777

const char *pcret;

778

if(af == AF_INET6){

779

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

780

sizeof(addrstr));

781

} else {

782

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

783

sizeof(addrstr));

784

}

785

if(pcret == NULL){

786

perror_plus("inet_ntop");

787

} else {

788

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

789

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

790

}

791

}

792

}

793

794

if(quit_now){

795

errno = EINTR;

796

goto mandos_end;

797

}

798

799

if(af == AF_INET6){

800

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

801

} else {

802

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

803

}

804

if(ret < 0){

805

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

806

int e = errno;

807

perror_plus("connect");

808

errno = e;

809

}

810

goto mandos_end;

811

}

812

813

if(quit_now){

814

errno = EINTR;

815

goto mandos_end;

1207

816

}

1208

817

1209

818

const char *out = mandos_protocol_version;

1392

1001

1393

1002

mandos_end:

1394

1003

{

1395

if(route_added){

1396

if(not delete_local_route(ip, if_index)){

1397

fprintf_plus(stderr, "Failed to delete local route to %s on"

1398

" interface %d", ip, if_index);

1399

}

1400

}

1401

1004

int e = errno;

1402

1005

free(decrypted_buffer);

1403

1006

free(buffer);

1420

1023

return retval;

1421

1024

}

1422

1025

1423

__attribute__((nonnull))

1424

1026

static void resolve_callback(AvahiSServiceResolver *r,

1425

1027

AvahiIfIndex interface,

1426

1028

AvahiProtocol proto,

1434

1036

AVAHI_GCC_UNUSED AvahiStringList *txt,

1435

1037

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1436

1038

flags,

1437

void *mc){

1039

void* mc){

1438

1040

if(r == NULL){

1439

1041

return;

1440

1042

}

1443

1045

timed out */

1444

1046

1445

1047

if(quit_now){

1446

avahi_s_service_resolver_free(r);

1447

1048

return;

1448

1049

}

1449

1050

1494

1095

const char *domain,

1495

1096

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1496

1097

flags,

1497

void *mc){

1098

void* mc){

1498

1099

if(b == NULL){

1499

1100

return;

1500

1101

}

1560

1161

errno = old_errno;

1561

1162

}

1562

1163

1563

__attribute__((nonnull, warn_unused_result))

1564

1164

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

1565

1165

int ret;

1566

1166

error_t ret_errno;

1585

1185

return true;

1586

1186

}

1587

1187

1588

__attribute__((nonnull, warn_unused_result))

1589

1188

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

1590

1189

1591

1190

/* Reject the loopback device */

1633

1232

* corresponds to an acceptable network device.

1634

1233

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

1635

1234

*/

1636

__attribute__((nonnull, warn_unused_result))

1637

1235

int good_interface(const struct dirent *if_entry){

1638

1236

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

1639

1237

return 0;

1657

1255

/*

1658

1256

* This function determines if a network interface is up.

1659

1257

*/

1660

__attribute__((nonnull, warn_unused_result))

1661

1258

bool interface_is_up(const char *interface){

1662

1259

struct ifreq ifr;

1663

1260

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

1674

1271

/*

1675

1272

* This function determines if a network interface is running

1676

1273

*/

1677

__attribute__((nonnull, warn_unused_result))

1678

1274

bool interface_is_running(const char *interface){

1679

1275

struct ifreq ifr;

1680

1276

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

1688

1284

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

1689

1285

}

1690

1286

1691

__attribute__((nonnull, pure, warn_unused_result))

1692

1287

int notdotentries(const struct dirent *direntry){

1693

1288

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

1694

1289

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

1701

1296

}

1702

1297

1703

1298

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

1704

__attribute__((nonnull, warn_unused_result))

1705

1299

int runnable_hook(const struct dirent *direntry){

1706

1300

int ret;

1707

1301

size_t sret;

1715

1309

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

1716

1310

"abcdefghijklmnopqrstuvwxyz"

1717

1311

"0123456789"

1718

"_.-");

1312

"_-");

1719

1313

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

1720

1314

/* Contains non-allowed characters */

1721

1315

if(debug){

1725

1319

return 0;

1726

1320

}

1727

1321

1728

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

1322

char *fullname = NULL;

1323

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

1324

if(ret < 0){

1325

perror_plus("asprintf");

1326

return 0;

1327

}

1328

1329

ret = stat(fullname, &st);

1729

1330

if(ret == -1){

1730

1331

if(debug){

1731

1332

perror_plus("Could not stat hook");

1755

1356

return 1;

1756

1357

}

1757

1358

1758

__attribute__((nonnull, warn_unused_result))

1759

1359

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1760

1360

mandos_context *mc){

1761

1361

int ret;

1765

1365

1766

1366

while(true){

1767

1367

if(mc->current_server == NULL){

1768

if(debug){

1368

if (debug){

1769

1369

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

1770

1370

" No timeout!\n");

1771

1371

}

1772

1372

ret = avahi_simple_poll_iterate(s, -1);

1773

1373

} else {

1774

if(debug){

1374

if (debug){

1775

1375

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

1776

1376

" it, or wait\n");

1777

1377

}

1794

1394

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

1795

1395

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

1796

1396

1797

if(debug){

1397

if (debug){

1798

1398

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

1799

1399

block_time);

1800

1400

}

1822

1422

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

1823

1423

}

1824

1424

if(ret != 0){

1825

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

1425

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

1826

1426

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

1827

1427

}

1828

1428

}

1829

1429

}

1830

1430

}

1831

1431

1832

__attribute__((nonnull))

1833

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

1432

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

1433

error_t raise_privileges(void){

1434

error_t old_errno = errno;

1435

error_t ret_errno = 0;

1436

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

1437

ret_errno = errno;

1438

perror_plus("seteuid");

1439

}

1440

errno = old_errno;

1441

return ret_errno;

1442

}

1443

1444

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

1445

error_t raise_privileges_permanently(void){

1446

error_t old_errno = errno;

1447

error_t ret_errno = raise_privileges();

1448

if(ret_errno != 0){

1449

errno = old_errno;

1450

return ret_errno;

1451

}

1452

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

1453

ret_errno = errno;

1454

perror_plus("seteuid");

1455

}

1456

errno = old_errno;

1457

return ret_errno;

1458

}

1459

1460

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

1461

error_t lower_privileges(void){

1462

error_t old_errno = errno;

1463

error_t ret_errno = 0;

1464

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

1465

ret_errno = errno;

1466

perror_plus("seteuid");

1467

}

1468

errno = old_errno;

1469

return ret_errno;

1470

}

1471

1472

/* Lower privileges permanently */

1473

error_t lower_privileges_permanently(void){

1474

error_t old_errno = errno;

1475

error_t ret_errno = 0;

1476

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

1477

ret_errno = errno;

1478

perror_plus("setuid");

1479

}

1480

errno = old_errno;

1481

return ret_errno;

1482

}

1483

1484

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

1834

1485

const float delay){

1835

struct dirent **direntries = NULL;

1836

if(hookdir_fd == -1){

1837

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1838

| O_CLOEXEC);

1839

if(hookdir_fd == -1){

1840

if(errno == ENOENT){

1841

if(debug){

1842

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

1843

" found\n", hookdir);

1844

}

1845

} else {

1846

perror_plus("open");

1847

}

1848

return;

1849

}

1850

}

1851

#ifdef __GLIBC__

1852

#if __GLIBC_PREREQ(2, 15)

1853

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

1854

runnable_hook, alphasort);

1855

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

1856

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

1857

alphasort);

1858

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

1859

#else /* not __GLIBC__ */

1860

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

1861

alphasort);

1862

#endif /* not __GLIBC__ */

1486

struct dirent **direntries;

1487

struct dirent *direntry;

1488

int ret;

1489

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

1490

alphasort);

1863

1491

if(numhooks == -1){

1864

perror_plus("scandir");

1865

return;

1866

}

1867

struct dirent *direntry;

1868

int ret;

1869

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

1870

if(devnull == -1){

1871

perror_plus("open(\"/dev/null\", O_RDONLY)");

1872

return;

1873

}

1874

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

1875

direntry = direntries[i];

1876

if(debug){

1877

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

1878

direntry->d_name);

1492

if(errno == ENOENT){

1493

if(debug){

1494

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

1495

" found\n", hookdir);

1496

}

1497

} else {

1498

perror_plus("scandir");

1879

1499

}

1880

pid_t hook_pid = fork();

1881

if(hook_pid == 0){

1882

/* Child */

1883

/* Raise privileges */

1884

errno = raise_privileges_permanently();

1885

if(errno != 0){

1886

perror_plus("Failed to raise privileges");

1887

_exit(EX_NOPERM);

1888

}

1889

/* Set group */

1890

errno = 0;

1891

ret = setgid(0);

1892

if(ret == -1){

1893

perror_plus("setgid");

1894

_exit(EX_NOPERM);

1895

}

1896

/* Reset supplementary groups */

1897

errno = 0;

1898

ret = setgroups(0, NULL);

1899

if(ret == -1){

1900

perror_plus("setgroups");

1901

_exit(EX_NOPERM);

1902

}

1903

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

1904

if(ret == -1){

1905

perror_plus("setenv");

1906

_exit(EX_OSERR);

1907

}

1908

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

1909

if(ret == -1){

1910

perror_plus("setenv");

1911

_exit(EX_OSERR);

1912

}

1913

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

1914

if(ret == -1){

1915

perror_plus("setenv");

1916

_exit(EX_OSERR);

1917

}

1918

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

1919

if(ret == -1){

1920

perror_plus("setenv");

1921

_exit(EX_OSERR);

1922

}

1923

char *delaystring;

1924

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

1925

if(ret == -1){

1500

} else {

1501

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

1502

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

1503

direntry = direntries[i];

1504

char *fullname = NULL;

1505

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

1506

if(ret < 0){

1926

1507

perror_plus("asprintf");

1927

_exit(EX_OSERR);

1928

}

1929

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

1930

if(ret == -1){

1508

continue;

1509

}

1510

if(debug){

1511

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

1512

direntry->d_name);

1513

}

1514

pid_t hook_pid = fork();

1515

if(hook_pid == 0){

1516

/* Child */

1517

/* Raise privileges */

1518

raise_privileges_permanently();

1519

/* Set group */

1520

errno = 0;

1521

ret = setgid(0);

1522

if(ret == -1){

1523

perror_plus("setgid");

1524

}

1525

/* Reset supplementary groups */

1526

errno = 0;

1527

ret = setgroups(0, NULL);

1528

if(ret == -1){

1529

perror_plus("setgroups");

1530

}

1531

dup2(devnull, STDIN_FILENO);

1532

close(devnull);

1533

dup2(STDERR_FILENO, STDOUT_FILENO);

1534

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

1535

if(ret == -1){

1536

perror_plus("setenv");

1537

_exit(EX_OSERR);

1538

}

1539

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

1540

if(ret == -1){

1541

perror_plus("setenv");

1542

_exit(EX_OSERR);

1543

}

1544

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

1545

if(ret == -1){

1546

perror_plus("setenv");

1547

_exit(EX_OSERR);

1548

}

1549

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

1550

if(ret == -1){

1551

perror_plus("setenv");

1552

_exit(EX_OSERR);

1553

}

1554

char *delaystring;

1555

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

1556

if(ret == -1){

1557

perror_plus("asprintf");

1558

_exit(EX_OSERR);

1559

}

1560

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

1561

if(ret == -1){

1562

free(delaystring);

1563

perror_plus("setenv");

1564

_exit(EX_OSERR);

1565

}

1931

1566

free(delaystring);

1932

perror_plus("setenv");

1933

_exit(EX_OSERR);

1934

}

1935

free(delaystring);

1936

if(connect_to != NULL){

1937

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

1938

if(ret == -1){

1939

perror_plus("setenv");

1940

_exit(EX_OSERR);

1941

}

1942

}

1943

int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,

1944

direntry->d_name,

1945

O_RDONLY));

1946

if(hook_fd == -1){

1947

perror_plus("openat");

1948

_exit(EXIT_FAILURE);

1949

}

1950

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

1951

perror_plus("close");

1952

_exit(EXIT_FAILURE);

1953

}

1954

ret = dup2(devnull, STDIN_FILENO);

1955

if(ret == -1){

1956

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

1957

_exit(EX_OSERR);

1958

}

1959

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

1960

if(ret == -1){

1961

perror_plus("close");

1962

_exit(EX_OSERR);

1963

}

1964

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1965

if(ret == -1){

1966

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

1967

_exit(EX_OSERR);

1968

}

1969

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

1970

environ) == -1){

1971

perror_plus("fexecve");

1972

_exit(EXIT_FAILURE);

1973

}

1974

} else {

1975

if(hook_pid == -1){

1976

perror_plus("fork");

1977

free(direntry);

1978

continue;

1979

}

1980

int status;

1981

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

1982

perror_plus("waitpid");

1983

free(direntry);

1984

continue;

1985

}

1986

if(WIFEXITED(status)){

1987

if(WEXITSTATUS(status) != 0){

1988

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

1989

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

1990

WEXITSTATUS(status));

1991

free(direntry);

1992

continue;

1993

}

1994

} else if(WIFSIGNALED(status)){

1995

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

1996

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

1997

WTERMSIG(status));

1998

free(direntry);

1999

continue;

1567

if(connect_to != NULL){

1568

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

1569

if(ret == -1){

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1573

}

1574

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

1575

perror_plus("execl");

1576

_exit(EXIT_FAILURE);

1577

}

2000

1578

} else {

2001

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

2002

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

2003

free(direntry);

2004

continue;

2005

}

2006

}

2007

if(debug){

2008

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

2009

direntry->d_name);

2010

}

2011

free(direntry);

2012

}

2013

free(direntries);

2014

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

2015

perror_plus("close");

2016

} else {

2017

hookdir_fd = -1;

2018

}

2019

close(devnull);

1579

int status;

1580

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

1581

perror_plus("waitpid");

1582

free(fullname);

1583

continue;

1584

}

1585

if(WIFEXITED(status)){

1586

if(WEXITSTATUS(status) != 0){

1587

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

1588

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

1589

WEXITSTATUS(status));

1590

free(fullname);

1591

continue;

1592

}

1593

} else if(WIFSIGNALED(status)){

1594

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

1595

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

1596

WTERMSIG(status));

1597

free(fullname);

1598

continue;

1599

} else {

1600

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

1601

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

1602

free(fullname);

1603

continue;

1604

}

1605

}

1606

free(fullname);

1607

if(debug){

1608

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

1609

direntry->d_name);

1610

}

1611

}

1612

close(devnull);

1613

}

1614

return true;

2020

1615

}

2021

1616

2022

__attribute__((nonnull, warn_unused_result))

2023

1617

error_t bring_up_interface(const char *const interface,

2024

1618

const float delay){

1619

int sd = -1;

2025

1620

error_t old_errno = errno;

2026

int ret;

1621

error_t ret_errno = 0;

1622

int ret, ret_setflags;

2027

1623

struct ifreq network;

2028

1624

unsigned int if_index = if_nametoindex(interface);

2029

1625

if(if_index == 0){

2038

1634

}

2039

1635

2040

1636

if(not interface_is_up(interface)){

2041

error_t ret_errno = 0, ioctl_errno = 0;

2042

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

1637

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

2043

1638

ret_errno = errno;

2044

1639

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

2045

1640

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

2046

errno = old_errno;

2047

1641

return ret_errno;

2048

1642

}

2049

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

1643

network.ifr_flags |= IFF_UP;

2050

1644

2051

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

2052

if(sd == -1){

1645

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1646

if(sd < 0){

2053

1647

ret_errno = errno;

2054

1648

perror_plus("socket");

2055

1649

errno = old_errno;

2056

1650

return ret_errno;

2057

1651

}

2058

1652

2059

1653

if(quit_now){

2060

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

2061

if(ret == -1){

2062

perror_plus("close");

2063

}

1654

close(sd);

2064

1655

errno = old_errno;

2065

1656

return EINTR;

2066

1657

}

2070

1661

interface);

2071

1662

}

2072

1663

2073

/* Raise privileges */

2074

ret_errno = raise_privileges();

2075

if(ret_errno != 0){

2076

errno = ret_errno;

2077

perror_plus("Failed to raise privileges");

2078

}

1664

/* Raise priviliges */

1665

raise_privileges();

2079

1666

2080

1667

#ifdef __linux__

2081

int ret_linux;

2082

bool restore_loglevel = false;

2083

if(ret_errno == 0){

2084

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2085

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

2086

ret_linux = klogctl(8, NULL, 5);

2087

if(ret_linux == -1){

2088

perror_plus("klogctl");

2089

} else {

2090

restore_loglevel = true;

2091

}

1668

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1669

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

1670

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

1671

bool restore_loglevel = true;

1672

if(ret_linux == -1){

1673

restore_loglevel = false;

1674

perror_plus("klogctl");

2092

1675

}

2093

1676

#endif /* __linux__ */

2094

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

2095

ioctl_errno = errno;

1677

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

1678

ret_errno = errno;

2096

1679

#ifdef __linux__

2097

1680

if(restore_loglevel){

2098

1681

ret_linux = klogctl(7, NULL, 0);

2102

1685

}

2103

1686

#endif /* __linux__ */

2104

1687

2105

/* If raise_privileges() succeeded above */

2106

if(ret_errno == 0){

2107

/* Lower privileges */

2108

ret_errno = lower_privileges();

2109

if(ret_errno != 0){

2110

errno = ret_errno;

2111

perror_plus("Failed to lower privileges");

2112

}

2113

}

1688

/* Lower privileges */

1689

lower_privileges();

2114

1690

2115

1691

/* Close the socket */

2116

1692

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

2119

1695

}

2120

1696

2121

1697

if(ret_setflags == -1){

2122

errno = ioctl_errno;

1698

errno = ret_errno;

2123

1699

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2124

1700

errno = old_errno;

2125

return ioctl_errno;

1701

return ret_errno;

2126

1702

}

2127

1703

} else if(debug){

2128

1704

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

2146

1722

return 0;

2147

1723

}

2148

1724

2149

__attribute__((nonnull, warn_unused_result))

2150

1725

error_t take_down_interface(const char *const interface){

1726

int sd = -1;

2151

1727

error_t old_errno = errno;

1728

error_t ret_errno = 0;

1729

int ret, ret_setflags;

2152

1730

struct ifreq network;

2153

1731

unsigned int if_index = if_nametoindex(interface);

2154

1732

if(if_index == 0){

2157

1735

return ENXIO;

2158

1736

}

2159

1737

if(interface_is_up(interface)){

2160

error_t ret_errno = 0, ioctl_errno = 0;

2161

1738

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

2162

1739

ret_errno = errno;

2163

1740

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

2164

1741

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

2165

errno = old_errno;

2166

1742

return ret_errno;

2167

1743

}

2168

1744

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

2169

1745

2170

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

2171

if(sd == -1){

1746

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1747

if(sd < 0){

2172

1748

ret_errno = errno;

2173

1749

perror_plus("socket");

2174

1750

errno = old_errno;

2180

1756

interface);

2181

1757

}

2182

1758

2183

/* Raise privileges */

2184

ret_errno = raise_privileges();

2185

if(ret_errno != 0){

2186

errno = ret_errno;

2187

perror_plus("Failed to raise privileges");

2188

}

2189

2190

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

2191

ioctl_errno = errno;

2192

2193

/* If raise_privileges() succeeded above */

2194

if(ret_errno == 0){

2195

/* Lower privileges */

2196

ret_errno = lower_privileges();

2197

if(ret_errno != 0){

2198

errno = ret_errno;

2199

perror_plus("Failed to lower privileges");

2200

}

2201

}

1759

/* Raise priviliges */

1760

raise_privileges();

1761

1762

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

1763

ret_errno = errno;

1764

1765

/* Lower privileges */

1766

lower_privileges();

2202

1767

2203

1768

/* Close the socket */

2204

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

1769

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

2205

1770

if(ret == -1){

2206

1771

perror_plus("close");

2207

1772

}

2208

1773

2209

1774

if(ret_setflags == -1){

2210

errno = ioctl_errno;

1775

errno = ret_errno;

2211

1776

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2212

1777

errno = old_errno;

2213

return ioctl_errno;

1778

return ret_errno;

2214

1779

}

2215

1780

} else if(debug){

2216

1781

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

2222

1787

}

2223

1788

2224

1789

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

2225

mandos_context mc = { .server = NULL, .dh_bits = 0,

1790

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

2226

1791

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

2227

"+CTYPE-OPENPGP:!RSA", .current_server = NULL,

1792

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

2228

1793

.interfaces = NULL, .interfaces_size = 0 };

2229

1794

AvahiSServiceBrowser *sb = NULL;

2230

1795

error_t ret_errno;

2234

1799

int exitcode = EXIT_SUCCESS;

2235

1800

char *interfaces_to_take_down = NULL;

2236

1801

size_t interfaces_to_take_down_size = 0;

2237

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

2238

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

2239

char *tempdir = NULL;

1802

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

1803

bool tempdir_created = false;

2240

1804

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2241

1805

const char *seckey = PATHDIR "/" SECKEY;

2242

1806

const char *pubkey = PATHDIR "/" PUBKEY;

2243

1807

char *interfaces_hooks = NULL;

1808

size_t interfaces_hooks_size = 0;

2244

1809

2245

1810

bool gnutls_initialized = false;

2246

1811

bool gpgme_initialized = false;

2419

1984

goto end;

2420

1985

}

2421

1986

}

2422

1987

2423

1988

{

2424

1989

/* Work around Debian bug #633582:

2425

1990

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

2426

1991

2427

/* Re-raise privileges */

2428

ret_errno = raise_privileges();

2429

if(ret_errno != 0){

2430

errno = ret_errno;

2431

perror_plus("Failed to raise privileges");

2432

} else {

1992

/* Re-raise priviliges */

1993

if(raise_privileges() == 0){

2433

1994

struct stat st;

2434

1995

2435

1996

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

2452

2013

TEMP_FAILURE_RETRY(close(seckey_fd));

2453

2014

}

2454

2015

}

2455

2016

2456

2017

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

2457

2018

int pubkey_fd = open(pubkey, O_RDONLY);

2458

2019

if(pubkey_fd == -1){

2473

2034

TEMP_FAILURE_RETRY(close(pubkey_fd));

2474

2035

}

2475

2036

}

2476

2037

2477

2038

/* Lower privileges */

2478

ret_errno = lower_privileges();

2479

if(ret_errno != 0){

2480

errno = ret_errno;

2481

perror_plus("Failed to lower privileges");

2482

}

2039

lower_privileges();

2483

2040

}

2484

2041

}

2485

2042

2509

2066

goto end;

2510

2067

}

2511

2068

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

2512

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

2513

}

2514

run_network_hooks("start", interfaces_hooks != NULL ?

2515

interfaces_hooks : "", delay);

2069

interfaces_hooks_size = mc.interfaces_size;

2070

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2071

(int)',');

2072

}

2073

if(not run_network_hooks("start", interfaces_hooks != NULL ?

2074

interfaces_hooks : "", delay)){

2075

goto end;

2076

}

2516

2077

}

2517

2078

2518

2079

if(not debug){

2596

2157

2597

2158

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

2598

2159

if(mc.interfaces == NULL){

2599

struct dirent **direntries = NULL;

2160

struct dirent **direntries;

2600

2161

/* Look for any good interfaces */

2601

2162

ret = scandir(sys_class_net, &direntries, good_interface,

2602

2163

alphasort);

2606

2167

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

2607

2168

direntries[i]->d_name);

2608

2169

if(ret_errno != 0){

2609

errno = ret_errno;

2610

2170

perror_plus("argz_add");

2611

free(direntries[i]);

2612

2171

continue;

2613

2172

}

2614

2173

if(debug){

2615

2174

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

2616

2175

direntries[i]->d_name);

2617

2176

}

2618

free(direntries[i]);

2619

2177

}

2620

2178

free(direntries);

2621

2179

} else {

2622

if(ret == 0){

2623

free(direntries);

2624

}

2180

free(direntries);

2625

2181

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

2626

2182

exitcode = EXIT_FAILURE;

2627

2183

goto end;

2650

2206

break;

2651

2207

}

2652

2208

bool interface_was_up = interface_is_up(interface);

2653

errno = bring_up_interface(interface, delay);

2209

ret = bring_up_interface(interface, delay);

2654

2210

if(not interface_was_up){

2655

if(errno != 0){

2211

if(ret != 0){

2212

errno = ret;

2656

2213

perror_plus("Failed to bring up interface");

2657

2214

} else {

2658

errno = argz_add(&interfaces_to_take_down,

2659

&interfaces_to_take_down_size,

2660

interface);

2661

if(errno != 0){

2662

perror_plus("argz_add");

2663

}

2215

ret_errno = argz_add(&interfaces_to_take_down,

2216

&interfaces_to_take_down_size,

2217

interface);

2664

2218

}

2665

2219

}

2666

2220

}

2695

2249

goto end;

2696

2250

}

2697

2251

2698

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

2699

tempdir = mkdtemp(run_tempdir);

2700

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

2701

if(debug){

2702

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

2703

run_tempdir, old_tempdir);

2704

}

2705

tempdir = mkdtemp(old_tempdir);

2706

}

2707

if(tempdir == NULL){

2252

if(mkdtemp(tempdir) == NULL){

2708

2253

perror_plus("mkdtemp");

2709

2254

goto end;

2710

2255

}

2256

tempdir_created = true;

2711

2257

2712

2258

if(quit_now){

2713

2259

goto end;

2788

2334

sleep((unsigned int)retry_interval);

2789

2335

}

2790

2336

2791

if(not quit_now){

2337

if (not quit_now){

2792

2338

exitcode = EXIT_SUCCESS;

2793

2339

}

2794

2340

2849

2395

if(debug){

2850

2396

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

2851

2397

}

2852

2398

2853

2399

ret = avahi_loop_with_timeout(simple_poll,

2854

2400

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

2855

2401

if(debug){

2891

2437

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

2892

2438

while(mc.current_server != NULL){

2893

2439

server *next = mc.current_server->next;

2894

#ifdef __GNUC__

2895

#pragma GCC diagnostic push

2896

#pragma GCC diagnostic ignored "-Wcast-qual"

2897

#endif

2898

free((char *)(mc.current_server->ip));

2899

#ifdef __GNUC__

2900

#pragma GCC diagnostic pop

2901

#endif

2902

2440

free(mc.current_server);

2903

2441

mc.current_server = next;

2904

2442

}

2905

2443

}

2906

2444

2907

/* Re-raise privileges */

2445

/* Re-raise priviliges */

2908

2446

{

2909

ret_errno = raise_privileges();

2910

if(ret_errno != 0){

2911

errno = ret_errno;

2912

perror_plus("Failed to raise privileges");

2913

} else {

2914

2915

/* Run network hooks */

2916

run_network_hooks("stop", interfaces_hooks != NULL ?

2917

interfaces_hooks : "", delay);

2918

2919

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

2920

{

2921

char *interface = NULL;

2922

while((interface=argz_next(interfaces_to_take_down,

2923

interfaces_to_take_down_size,

2924

interface))){

2925

ret_errno = take_down_interface(interface);

2926

if(ret_errno != 0){

2927

errno = ret_errno;

2928

perror_plus("Failed to take down interface");

2929

}

2930

}

2931

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

2932

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

2933

" down\n");

2934

}

2935

}

2936

}

2937

2938

ret_errno = lower_privileges_permanently();

2939

if(ret_errno != 0){

2940

errno = ret_errno;

2941

perror_plus("Failed to lower privileges permanently");

2942

}

2447

raise_privileges();

2448

2449

/* Run network hooks */

2450

run_network_hooks("stop", interfaces_hooks != NULL ?

2451

interfaces_hooks : "", delay);

2452

2453

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

2454

{

2455

char *interface = NULL;

2456

while((interface=argz_next(interfaces_to_take_down,

2457

interfaces_to_take_down_size,

2458

interface))){

2459

ret_errno = take_down_interface(interface);

2460

if(ret_errno != 0){

2461

errno = ret_errno;

2462

perror_plus("Failed to take down interface");

2463

}

2464

}

2465

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

2466

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

2467

" down\n");

2468

}

2469

}

2470

2471

lower_privileges_permanently();

2943

2472

}

2944

2473

2945

2474

free(interfaces_to_take_down);

2946

2475

free(interfaces_hooks);

2947

2476

2948

2477

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

2949

if(tempdir != NULL){

2478

if(tempdir_created){

2950

2479

struct dirent **direntries = NULL;

2951

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

2952

| O_NOFOLLOW

2953

| O_DIRECTORY

2954

| O_PATH));

2955

if(tempdir_fd == -1){

2956

perror_plus("open");

2957

} else {

2958

#ifdef __GLIBC__

2959

#if __GLIBC_PREREQ(2, 15)

2960

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

2961

notdotentries, alphasort);

2962

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

2963

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

2964

alphasort);

2965

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

2966

#else /* not __GLIBC__ */

2967

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

2968

alphasort);

2969

#endif /* not __GLIBC__ */

2970

if(numentries >= 0){

2971

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

2972

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

2973

if(ret == -1){

2974

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

2975

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

2976

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

2977

}

2978

free(direntries[i]);

2979

}

2980

2981

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

2982

free(direntries);

2983

if(numentries == -1){

2984

perror_plus("scandir");

2985

}

2986

ret = rmdir(tempdir);

2987

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

2988

perror_plus("rmdir");

2989

}

2480

struct dirent *direntry = NULL;

2481

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

2482

alphasort);

2483

if (numentries > 0){

2484

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

2485

direntry = direntries[i];

2486

char *fullname = NULL;

2487

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

2488

direntry->d_name);

2489

if(ret < 0){

2490

perror_plus("asprintf");

2491

continue;

2492

}

2493

ret = remove(fullname);

2494

if(ret == -1){

2495

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

2496

strerror(errno));

2497

}

2498

free(fullname);

2990

2499

}

2991

TEMP_FAILURE_RETRY(close(tempdir_fd));

2500

}

2501

2502

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

2503

free(direntries);

2504

if (numentries == -1){

2505

perror_plus("scandir");

2506

}

2507

ret = rmdir(tempdir);

2508

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

2509

perror_plus("rmdir");

2992

2510

}

2993

2511

}

2994

2512