/mandos/trunk : revision 738.1.5

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

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif

38

#endif /* not _FILE_OFFSET_BITS */

39

40

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

41

42

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

43

stdout, ferror(), remove() */

43

stdout, ferror() */

44

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

45

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

46

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

55

opendir(), DIR */

56

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

57

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

58

inet_pton(), connect() */

59

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

61

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

61

62

*/

62

63

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

72

73

*/

73

74

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

74

75

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

75

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

76

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

76

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

77

unlinkat() */

78

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

77

79

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

78

80

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

79

81

argp_state, struct argp,

91

93

argz_delete(), argz_append(),

92

94

argz_stringify(), argz_add(),

93

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

94

98

95

99

#ifdef __linux__

96

100

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

138

142

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

139

143

char *connect_to = NULL;

140

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

141

146

uid_t uid = 65534;

142

147

gid_t gid = 65534;

143

148

161

166

const char *priority;

162

167

gpgme_ctx_t ctx;

163

168

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

164

171

} mandos_context;

165

172

166

173

/* global so signal handler can reach it*/

178

185

perror(print_text);

179

186

}

180

187

181

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

188

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

182

189

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

183

190

va_list ap;

184

191

va_start (ap, format);

185

192

186

193

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

187

194

program_invocation_short_name));

188

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

195

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

189

196

}

190

197

191

198

/*

193

200

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

194

201

* "buffer_length" is how much is already used.

195

202

*/

203

__attribute__((nonnull, warn_unused_result))

196

204

size_t incbuffer(char **buffer, size_t buffer_length,

197

205

size_t buffer_capacity){

198

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

199

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

200

if(buffer == NULL){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

201

213

return 0;

202

214

}

215

*buffer = new_buf;

203

216

buffer_capacity += BUFFER_SIZE;

204

217

}

205

218

return buffer_capacity;

206

219

}

207

220

208

221

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

222

__attribute__((nonnull, warn_unused_result))

209

223

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

210

224

int af, server **current_server){

211

225

int ret;

220

234

.af = af };

221

235

if(new_server->ip == NULL){

222

236

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);

223

252

return false;

224

253

}

225

254

/* Special case of first server */

227

256

new_server->next = new_server;

228

257

new_server->prev = new_server;

229

258

*current_server = new_server;

230

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

231

259

} else {

260

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

232

261

new_server->next = *current_server;

233

262

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

234

263

new_server->prev->next = new_server;

235

264

(*current_server)->prev = new_server;

236

265

}

237

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

238

if(ret == -1){

239

perror_plus("clock_gettime");

240

return false;

241

}

242

266

return true;

243

267

}

244

268

245

269

/*

246

270

* Initialize GPGME.

247

271

*/

248

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

249

const char *tempdir, mandos_context *mc){

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

277

gpgme_error_t rc;

251

278

gpgme_engine_info_t engine_info;

252

279

253

280

/*

254

281

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

255

282

*/

256

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

257

284

int ret;

258

285

int fd;

259

286

gpgme_data_t pgp_data;

340

367

* Decrypt OpenPGP data.

341

368

* Returns -1 on error

342

369

*/

370

__attribute__((nonnull, warn_unused_result))

343

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

344

372

size_t crypto_size,

345

373

char **plaintext,

465

493

return plaintext_length;

466

494

}

467

495

468

static const char * safer_gnutls_strerror(int value){

496

__attribute__((warn_unused_result))

497

static const char *safer_gnutls_strerror(int value){

469

498

const char *ret = gnutls_strerror(value);

470

499

if(ret == NULL)

471

500

ret = "(unknown)";

473

502

}

474

503

475

504

/* GnuTLS log function callback */

505

__attribute__((nonnull))

476

506

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

477

507

const char* string){

478

508

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

479

509

}

480

510

511

__attribute__((nonnull, warn_unused_result))

481

512

static int init_gnutls_global(const char *pubkeyfilename,

482

513

const char *seckeyfilename,

483

514

mandos_context *mc){

557

588

return -1;

558

589

}

559

590

591

__attribute__((nonnull, warn_unused_result))

560

592

static int init_gnutls_session(gnutls_session_t *session,

561

593

mandos_context *mc){

562

594

int ret;

618

650

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

619

651

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

620

652

653

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

654

__attribute__((warn_unused_result))

655

error_t raise_privileges(void){

656

error_t old_errno = errno;

657

error_t ret_errno = 0;

658

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

659

ret_errno = errno;

660

}

661

errno = old_errno;

662

return ret_errno;

663

}

664

665

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

666

__attribute__((warn_unused_result))

667

error_t raise_privileges_permanently(void){

668

error_t old_errno = errno;

669

error_t ret_errno = raise_privileges();

670

if(ret_errno != 0){

671

errno = old_errno;

672

return ret_errno;

673

}

674

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

675

ret_errno = errno;

676

}

677

errno = old_errno;

678

return ret_errno;

679

}

680

681

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

682

__attribute__((warn_unused_result))

683

error_t lower_privileges(void){

684

error_t old_errno = errno;

685

error_t ret_errno = 0;

686

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

687

ret_errno = errno;

688

}

689

errno = old_errno;

690

return ret_errno;

691

}

692

693

/* Lower privileges permanently */

694

__attribute__((warn_unused_result))

695

error_t lower_privileges_permanently(void){

696

error_t old_errno = errno;

697

error_t ret_errno = 0;

698

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

699

ret_errno = errno;

700

}

701

errno = old_errno;

702

return ret_errno;

703

}

704

705

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

706

__attribute__((nonnull, warn_unused_result))

707

static bool add_remove_local_route(const bool add,

708

const char *address,

709

AvahiIfIndex if_index){

710

int ret;

711

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

712

char add_arg[] = "add";

713

char delete_arg[] = "delete";

714

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

715

if(pluginhelperdir == NULL){

716

if(debug){

717

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

718

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

719

}

720

return false;

721

}

722

723

char interface[IF_NAMESIZE];

724

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

725

perror_plus("if_indextoname");

726

return false;

727

}

728

729

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

730

if(devnull == -1){

731

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

732

return false;

733

}

734

pid_t pid = fork();

735

if(pid == 0){

736

/* Child */

737

/* Raise privileges */

738

errno = raise_privileges_permanently();

739

if(errno != 0){

740

perror_plus("Failed to raise privileges");

741

/* _exit(EX_NOPERM); */

742

} else {

743

/* Set group */

744

errno = 0;

745

ret = setgid(0);

746

if(ret == -1){

747

perror_plus("setgid");

748

_exit(EX_NOPERM);

749

}

750

/* Reset supplementary groups */

751

errno = 0;

752

ret = setgroups(0, NULL);

753

if(ret == -1){

754

perror_plus("setgroups");

755

_exit(EX_NOPERM);

756

}

757

}

758

ret = dup2(devnull, STDIN_FILENO);

759

if(ret == -1){

760

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

761

_exit(EX_OSERR);

762

}

763

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

764

if(ret == -1){

765

perror_plus("close");

766

_exit(EX_OSERR);

767

}

768

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

769

if(ret == -1){

770

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

771

_exit(EX_OSERR);

772

}

773

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

774

O_RDONLY

775

| O_DIRECTORY

776

| O_PATH

777

| O_CLOEXEC));

778

if(helperdir_fd == -1){

779

perror_plus("open");

780

_exit(EX_UNAVAILABLE);

781

}

782

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

783

helper, O_RDONLY));

784

if(helper_fd == -1){

785

perror_plus("openat");

786

_exit(EX_UNAVAILABLE);

787

}

788

TEMP_FAILURE_RETRY(close(helperdir_fd));

789

#ifdef __GNUC__

790

#pragma GCC diagnostic push

791

#pragma GCC diagnostic ignored "-Wcast-qual"

792

#endif

793

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

794

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

795

interface, NULL }, environ) == -1){

796

#ifdef __GNUC__

797

#pragma GCC diagnostic pop

798

#endif

799

perror_plus("fexecve");

800

_exit(EXIT_FAILURE);

801

}

802

}

803

if(pid == -1){

804

perror_plus("fork");

805

return false;

806

}

807

int status;

808

pid_t pret = -1;

809

errno = 0;

810

do {

811

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

812

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

813

int errno_raising = 0;

814

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

815

errno_raising = errno;

816

perror_plus("Failed to raise privileges in order to"

817

" kill helper program");

818

}

819

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

820

perror_plus("kill");

821

}

822

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

823

perror_plus("Failed to lower privileges after killing"

824

" helper program");

825

}

826

return false;

827

}

828

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

829

if(pret == -1){

830

perror_plus("waitpid");

831

return false;

832

}

833

if(WIFEXITED(status)){

834

if(WEXITSTATUS(status) != 0){

835

fprintf_plus(stderr, "Error: iprouteadddel exited"

836

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

837

return false;

838

}

839

return true;

840

}

841

if(WIFSIGNALED(status)){

842

fprintf_plus(stderr, "Error: iprouteadddel died by"

843

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

844

return false;

845

}

846

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

847

return false;

848

}

849

850

__attribute__((nonnull, warn_unused_result))

851

static bool add_local_route(const char *address,

852

AvahiIfIndex if_index){

853

return add_remove_local_route(true, address, if_index);

854

}

855

856

__attribute__((nonnull, warn_unused_result))

857

static bool remove_local_route(const char *address,

858

AvahiIfIndex if_index){

859

return add_remove_local_route(false, address, if_index);

860

}

861

621

862

/* Called when a Mandos server is found */

863

__attribute__((nonnull, warn_unused_result))

622

864

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

623

865

AvahiIfIndex if_index,

624

866

int af, mandos_context *mc){

625

867

int ret, tcp_sd = -1;

626

868

ssize_t sret;

627

union {

628

struct sockaddr_in in;

629

struct sockaddr_in6 in6;

630

} to;

869

struct sockaddr_storage to;

631

870

char *buffer = NULL;

632

871

char *decrypted_buffer = NULL;

633

872

size_t buffer_length = 0;

636

875

int retval = -1;

637

876

gnutls_session_t session;

638

877

int pf; /* Protocol family */

878

bool route_added = false;

639

879

640

880

errno = 0;

641

881

657

897

return -1;

658

898

}

659

899

900

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

901

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

902

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

903

bool match = false;

904

{

905

char *interface = NULL;

906

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

907

interface))){

908

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

909

match = true;

910

break;

911

}

912

}

913

}

914

if(not match){

915

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

916

connect to the server */

917

if(debug){

918

char interface[IF_NAMESIZE];

919

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

920

perror_plus("if_indextoname");

921

} else {

922

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

923

" \"%s\"\n",

924

if_indextoname((unsigned int)if_index,

925

interface));

926

}

927

}

928

return -1;

929

}

930

}

931

660

932

ret = init_gnutls_session(&session, mc);

661

933

if(ret != 0){

662

934

return -1;

667

939

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

668

940

}

669

941

670

tcp_sd = socket(pf, SOCK_STREAM, 0);

942

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

671

943

if(tcp_sd < 0){

672

944

int e = errno;

673

945

perror_plus("socket");

682

954

683

955

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

684

956

if(af == AF_INET6){

685

to.in6.sin6_family = (sa_family_t)af;

686

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

957

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

958

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

687

959

} else { /* IPv4 */

688

to.in.sin_family = (sa_family_t)af;

689

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

960

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

961

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

690

962

}

691

963

if(ret < 0 ){

692

964

int e = errno;

701

973

goto mandos_end;

702

974

}

703

975

if(af == AF_INET6){

704

to.in6.sin6_port = htons(port);

705

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

706

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

707

-Wunreachable-code*/

976

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

977

if(IN6_IS_ADDR_LINKLOCAL

978

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

708

979

if(if_index == AVAHI_IF_UNSPEC){

709

980

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

710

981

" incomplete without a network interface\n");

712

983

goto mandos_end;

713

984

}

714

985

/* Set the network interface number as scope */

715

to.in6.sin6_scope_id = (uint32_t)if_index;

986

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

716

987

}

717

988

} else {

718

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

719

-Wconversion and

720

-Wunreachable-code */

989

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

721

990

}

722

991

723

992

if(quit_now){

740

1009

}

741

1010

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

742

1011

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

743

const char *pcret;

744

if(af == AF_INET6){

745

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

746

sizeof(addrstr));

747

} else {

748

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

749

sizeof(addrstr));

750

}

751

if(pcret == NULL){

752

perror_plus("inet_ntop");

753

} else {

754

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

755

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

756

}

757

}

758

}

759

760

if(quit_now){

761

errno = EINTR;

762

goto mandos_end;

763

}

764

765

if(af == AF_INET6){

766

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

767

} else {

768

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

769

}

770

if(ret < 0){

771

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

772

int e = errno;

773

perror_plus("connect");

774

errno = e;

775

}

776

goto mandos_end;

777

}

778

779

if(quit_now){

780

errno = EINTR;

781

goto mandos_end;

1012

if(af == AF_INET6){

1013

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

1014

sizeof(struct sockaddr_in6),

1015

addrstr, sizeof(addrstr), NULL, 0,

1016

NI_NUMERICHOST);

1017

} else {

1018

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

1019

sizeof(struct sockaddr_in),

1020

addrstr, sizeof(addrstr), NULL, 0,

1021

NI_NUMERICHOST);

1022

}

1023

if(ret == EAI_SYSTEM){

1024

perror_plus("getnameinfo");

1025

} else if(ret != 0) {

1026

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

1027

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

1028

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

1029

}

1030

}

1031

1032

if(quit_now){

1033

errno = EINTR;

1034

goto mandos_end;

1035

}

1036

1037

while(true){

1038

if(af == AF_INET6){

1039

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

1040

sizeof(struct sockaddr_in6));

1041

} else {

1042

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

1043

sizeof(struct sockaddr_in));

1044

}

1045

if(ret < 0){

1046

if(errno == ENETUNREACH

1047

and if_index != AVAHI_IF_UNSPEC

1048

and connect_to == NULL

1049

and not route_added and

1050

((af == AF_INET6 and not

1051

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1052

&to)->sin6_addr)))

1053

or (af == AF_INET and

1054

/* Not a a IPv4LL address */

1055

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

1056

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

1057

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

1058

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

1059

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

1060

connect to a Mandos server announced by Avahi on a server

1061

host with a global address. Work around this by retrying

1062

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

1063

1064

Avahi bug reference:

1065

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

1066

https://bugs.debian.org/587961

1067

*/

1068

int e = errno;

1069

route_added = add_local_route(ip, if_index);

1070

if(route_added){

1071

continue;

1072

}

1073

errno = e;

1074

}

1075

if(errno != ECONNREFUSED or debug){

1076

int e = errno;

1077

perror_plus("connect");

1078

errno = e;

1079

}

1080

goto mandos_end;

1081

}

1082

1083

if(quit_now){

1084

errno = EINTR;

1085

goto mandos_end;

1086

}

1087

break;

782

1088

}

783

1089

784

1090

const char *out = mandos_protocol_version;

967

1273

968

1274

mandos_end:

969

1275

{

1276

if(route_added){

1277

if(not remove_local_route(ip, if_index)){

1278

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

1279

" interface %d", ip, if_index);

1280

}

1281

}

970

1282

int e = errno;

971

1283

free(decrypted_buffer);

972

1284

free(buffer);

989

1301

return retval;

990

1302

}

991

1303

1304

__attribute__((nonnull))

992

1305

static void resolve_callback(AvahiSServiceResolver *r,

993

1306

AvahiIfIndex interface,

994

1307

AvahiProtocol proto,

1002

1315

AVAHI_GCC_UNUSED AvahiStringList *txt,

1003

1316

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1004

1317

flags,

1005

void* mc){

1318

void *mc){

1006

1319

if(r == NULL){

1007

1320

return;

1008

1321

}

1011

1324

timed out */

1012

1325

1013

1326

if(quit_now){

1327

avahi_s_service_resolver_free(r);

1014

1328

return;

1015

1329

}

1016

1330

1061

1375

const char *domain,

1062

1376

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1063

1377

flags,

1064

void* mc){

1378

void *mc){

1065

1379

if(b == NULL){

1066

1380

return;

1067

1381

}

1127

1441

errno = old_errno;

1128

1442

}

1129

1443

1444

__attribute__((nonnull, warn_unused_result))

1130

1445

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

1131

1446

int ret;

1132

1447

error_t ret_errno;

1151

1466

return true;

1152

1467

}

1153

1468

1469

__attribute__((nonnull, warn_unused_result))

1154

1470

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

1155

1471

1156

1472

/* Reject the loopback device */

1198

1514

* corresponds to an acceptable network device.

1199

1515

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

1200

1516

*/

1517

__attribute__((nonnull, warn_unused_result))

1201

1518

int good_interface(const struct dirent *if_entry){

1202

1519

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

1203

1520

return 0;

1221

1538

/*

1222

1539

* This function determines if a network interface is up.

1223

1540

*/

1541

__attribute__((nonnull, warn_unused_result))

1224

1542

bool interface_is_up(const char *interface){

1225

1543

struct ifreq ifr;

1226

1544

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

1237

1555

/*

1238

1556

* This function determines if a network interface is running

1239

1557

*/

1558

__attribute__((nonnull, warn_unused_result))

1240

1559

bool interface_is_running(const char *interface){

1241

1560

struct ifreq ifr;

1242

1561

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

1250

1569

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

1251

1570

}

1252

1571

1572

__attribute__((nonnull, pure, warn_unused_result))

1253

1573

int notdotentries(const struct dirent *direntry){

1254

1574

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

1255

1575

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

1262

1582

}

1263

1583

1264

1584

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

1585

__attribute__((nonnull, warn_unused_result))

1265

1586

int runnable_hook(const struct dirent *direntry){

1266

1587

int ret;

1267

1588

size_t sret;

1275

1596

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

1276

1597

"abcdefghijklmnopqrstuvwxyz"

1277

1598

"0123456789"

1278

"_-");

1599

"_.-");

1279

1600

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

1280

1601

/* Contains non-allowed characters */

1281

1602

if(debug){

1285

1606

return 0;

1286

1607

}

1287

1608

1288

char *fullname = NULL;

1289

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

1290

if(ret < 0){

1291

perror_plus("asprintf");

1292

return 0;

1293

}

1294

1295

ret = stat(fullname, &st);

1609

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

1296

1610

if(ret == -1){

1297

1611

if(debug){

1298

1612

perror_plus("Could not stat hook");

1322

1636

return 1;

1323

1637

}

1324

1638

1639

__attribute__((nonnull, warn_unused_result))

1325

1640

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1326

1641

mandos_context *mc){

1327

1642

int ret;

1331

1646

1332

1647

while(true){

1333

1648

if(mc->current_server == NULL){

1334

if (debug){

1649

if(debug){

1335

1650

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

1336

1651

" No timeout!\n");

1337

1652

}

1338

1653

ret = avahi_simple_poll_iterate(s, -1);

1339

1654

} else {

1340

if (debug){

1655

if(debug){

1341

1656

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

1342

1657

" it, or wait\n");

1343

1658

}

1360

1675

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

1361

1676

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

1362

1677

1363

if (debug){

1678

if(debug){

1364

1679

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

1365

1680

block_time);

1366

1681

}

1388

1703

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

1389

1704

}

1390

1705

if(ret != 0){

1391

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

1706

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

1392

1707

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

1393

1708

}

1394

1709

}

1395

1710

}

1396

1711

}

1397

1712

1398

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

1399

error_t raise_privileges(void){

1400

error_t old_errno = errno;

1401

error_t ret_errno = 0;

1402

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

1403

ret_errno = errno;

1404

perror_plus("seteuid");

1405

}

1406

errno = old_errno;

1407

return ret_errno;

1408

}

1409

1410

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

1411

error_t raise_privileges_permanently(void){

1412

error_t old_errno = errno;

1413

error_t ret_errno = raise_privileges();

1414

if(ret_errno != 0){

1415

errno = old_errno;

1416

return ret_errno;

1417

}

1418

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

1419

ret_errno = errno;

1420

perror_plus("seteuid");

1421

}

1422

errno = old_errno;

1423

return ret_errno;

1424

}

1425

1426

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

1427

error_t lower_privileges(void){

1428

error_t old_errno = errno;

1429

error_t ret_errno = 0;

1430

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

1431

ret_errno = errno;

1432

perror_plus("seteuid");

1433

}

1434

errno = old_errno;

1435

return ret_errno;

1436

}

1437

1438

/* Lower privileges permanently */

1439

error_t lower_privileges_permanently(void){

1440

error_t old_errno = errno;

1441

error_t ret_errno = 0;

1442

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

1443

ret_errno = errno;

1444

perror_plus("setuid");

1445

}

1446

errno = old_errno;

1447

return ret_errno;

1448

}

1449

1450

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

1713

__attribute__((nonnull))

1714

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

1451

1715

const float delay){

1452

struct dirent **direntries;

1716

struct dirent **direntries = NULL;

1717

if(hookdir_fd == -1){

1718

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1719

| O_CLOEXEC);

1720

if(hookdir_fd == -1){

1721

if(errno == ENOENT){

1722

if(debug){

1723

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

1724

" found\n", hookdir);

1725

}

1726

} else {

1727

perror_plus("open");

1728

}

1729

return;

1730

}

1731

}

1732

#ifdef __GLIBC__

1733

#if __GLIBC_PREREQ(2, 15)

1734

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

1735

runnable_hook, alphasort);

1736

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

1737

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

1738

alphasort);

1739

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

1740

#else /* not __GLIBC__ */

1741

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

1742

alphasort);

1743

#endif /* not __GLIBC__ */

1744

if(numhooks == -1){

1745

perror_plus("scandir");

1746

return;

1747

}

1453

1748

struct dirent *direntry;

1454

1749

int ret;

1455

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

1456

alphasort);

1457

if(numhooks == -1){

1458

if(errno == ENOENT){

1459

if(debug){

1460

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

1461

" found\n", hookdir);

1462

}

1463

} else {

1464

perror_plus("scandir");

1750

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

1751

if(devnull == -1){

1752

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

1753

return;

1754

}

1755

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

1756

direntry = direntries[i];

1757

if(debug){

1758

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

1759

direntry->d_name);

1465

1760

}

1466

} else {

1467

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

1468

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

1469

direntry = direntries[i];

1470

char *fullname = NULL;

1471

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

1472

if(ret < 0){

1761

pid_t hook_pid = fork();

1762

if(hook_pid == 0){

1763

/* Child */

1764

/* Raise privileges */

1765

errno = raise_privileges_permanently();

1766

if(errno != 0){

1767

perror_plus("Failed to raise privileges");

1768

_exit(EX_NOPERM);

1769

}

1770

/* Set group */

1771

errno = 0;

1772

ret = setgid(0);

1773

if(ret == -1){

1774

perror_plus("setgid");

1775

_exit(EX_NOPERM);

1776

}

1777

/* Reset supplementary groups */

1778

errno = 0;

1779

ret = setgroups(0, NULL);

1780

if(ret == -1){

1781

perror_plus("setgroups");

1782

_exit(EX_NOPERM);

1783

}

1784

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

1785

if(ret == -1){

1786

perror_plus("setenv");

1787

_exit(EX_OSERR);

1788

}

1789

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

1790

if(ret == -1){

1791

perror_plus("setenv");

1792

_exit(EX_OSERR);

1793

}

1794

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

1795

if(ret == -1){

1796

perror_plus("setenv");

1797

_exit(EX_OSERR);

1798

}

1799

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

1800

if(ret == -1){

1801

perror_plus("setenv");

1802

_exit(EX_OSERR);

1803

}

1804

char *delaystring;

1805

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

1806

if(ret == -1){

1473

1807

perror_plus("asprintf");

1474

continue;

1475

}

1476

if(debug){

1477

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

1478

direntry->d_name);

1479

}

1480

pid_t hook_pid = fork();

1481

if(hook_pid == 0){

1482

/* Child */

1483

/* Raise privileges */

1484

raise_privileges_permanently();

1485

/* Set group */

1486

errno = 0;

1487

ret = setgid(0);

1488

if(ret == -1){

1489

perror_plus("setgid");

1490

}

1491

/* Reset supplementary groups */

1492

errno = 0;

1493

ret = setgroups(0, NULL);

1494

if(ret == -1){

1495

perror_plus("setgroups");

1496

}

1497

dup2(devnull, STDIN_FILENO);

1498

close(devnull);

1499

dup2(STDERR_FILENO, STDOUT_FILENO);

1500

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

1501

if(ret == -1){

1502

perror_plus("setenv");

1503

_exit(EX_OSERR);

1504

}

1505

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

1506

if(ret == -1){

1507

perror_plus("setenv");

1508

_exit(EX_OSERR);

1509

}

1510

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

1511

if(ret == -1){

1512

perror_plus("setenv");

1513

_exit(EX_OSERR);

1514

}

1515

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

1516

if(ret == -1){

1517

perror_plus("setenv");

1518

_exit(EX_OSERR);

1519

}

1520

char *delaystring;

1521

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

1522

if(ret == -1){

1523

perror_plus("asprintf");

1524

_exit(EX_OSERR);

1525

}

1526

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

1527

if(ret == -1){

1528

free(delaystring);

1529

perror_plus("setenv");

1530

_exit(EX_OSERR);

1531

}

1808

_exit(EX_OSERR);

1809

}

1810

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

1811

if(ret == -1){

1532

1812

free(delaystring);

1533

if(connect_to != NULL){

1534

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

1535

if(ret == -1){

1536

perror_plus("setenv");

1537

_exit(EX_OSERR);

1538

}

1539

}

1540

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

1541

perror_plus("execl");

1542

_exit(EXIT_FAILURE);

1543

}

1813

perror_plus("setenv");

1814

_exit(EX_OSERR);

1815

}

1816

free(delaystring);

1817

if(connect_to != NULL){

1818

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

1819

if(ret == -1){

1820

perror_plus("setenv");

1821

_exit(EX_OSERR);

1822

}

1823

}

1824

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

1825

direntry->d_name,

1826

O_RDONLY));

1827

if(hook_fd == -1){

1828

perror_plus("openat");

1829

_exit(EXIT_FAILURE);

1830

}

1831

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

1832

perror_plus("close");

1833

_exit(EXIT_FAILURE);

1834

}

1835

ret = dup2(devnull, STDIN_FILENO);

1836

if(ret == -1){

1837

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

1838

_exit(EX_OSERR);

1839

}

1840

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

1841

if(ret == -1){

1842

perror_plus("close");

1843

_exit(EX_OSERR);

1844

}

1845

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1846

if(ret == -1){

1847

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

1848

_exit(EX_OSERR);

1849

}

1850

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

1851

environ) == -1){

1852

perror_plus("fexecve");

1853

_exit(EXIT_FAILURE);

1854

}

1855

} else {

1856

if(hook_pid == -1){

1857

perror_plus("fork");

1858

free(direntry);

1859

continue;

1860

}

1861

int status;

1862

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

1863

perror_plus("waitpid");

1864

free(direntry);

1865

continue;

1866

}

1867

if(WIFEXITED(status)){

1868

if(WEXITSTATUS(status) != 0){

1869

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

1870

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

1871

WEXITSTATUS(status));

1872

free(direntry);

1873

continue;

1874

}

1875

} else if(WIFSIGNALED(status)){

1876

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

1877

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

1878

WTERMSIG(status));

1879

free(direntry);

1880

continue;

1544

1881

} else {

1545

int status;

1546

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

1547

perror_plus("waitpid");

1548

free(fullname);

1549

continue;

1550

}

1551

if(WIFEXITED(status)){

1552

if(WEXITSTATUS(status) != 0){

1553

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

1554

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

1555

WEXITSTATUS(status));

1556

free(fullname);

1557

continue;

1558

}

1559

} else if(WIFSIGNALED(status)){

1560

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

1561

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

1562

WTERMSIG(status));

1563

free(fullname);

1564

continue;

1565

} else {

1566

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

1567

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

1568

free(fullname);

1569

continue;

1570

}

1571

}

1572

free(fullname);

1573

if(debug){

1574

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

1575

direntry->d_name);

1576

}

1577

}

1578

close(devnull);

1579

}

1580

return true;

1882

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

1883

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

1884

free(direntry);

1885

continue;

1886

}

1887

}

1888

if(debug){

1889

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

1890

direntry->d_name);

1891

}

1892

free(direntry);

1893

}

1894

free(direntries);

1895

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

1896

perror_plus("close");

1897

} else {

1898

hookdir_fd = -1;

1899

}

1900

close(devnull);

1581

1901

}

1582

1902

1903

__attribute__((nonnull, warn_unused_result))

1583

1904

error_t bring_up_interface(const char *const interface,

1584

1905

const float delay){

1585

int sd = -1;

1586

1906

error_t old_errno = errno;

1587

error_t ret_errno = 0;

1588

int ret, ret_setflags;

1907

int ret;

1589

1908

struct ifreq network;

1590

1909

unsigned int if_index = if_nametoindex(interface);

1591

1910

if(if_index == 0){

1600

1919

}

1601

1920

1602

1921

if(not interface_is_up(interface)){

1603

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

1922

error_t ret_errno = 0, ioctl_errno = 0;

1923

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

1604

1924

ret_errno = errno;

1605

1925

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

1606

1926

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

1927

errno = old_errno;

1607

1928

return ret_errno;

1608

1929

}

1609

network.ifr_flags |= IFF_UP;

1930

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

1610

1931

1611

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1612

if(sd < 0){

1932

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

1933

if(sd == -1){

1613

1934

ret_errno = errno;

1614

1935

perror_plus("socket");

1615

1936

errno = old_errno;

1616

1937

return ret_errno;

1617

1938

}

1618

1939

1619

1940

if(quit_now){

1620

close(sd);

1941

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

1942

if(ret == -1){

1943

perror_plus("close");

1944

}

1621

1945

errno = old_errno;

1622

1946

return EINTR;

1623

1947

}

1627

1951

interface);

1628

1952

}

1629

1953

1630

/* Raise priviliges */

1631

raise_privileges();

1954

/* Raise privileges */

1955

ret_errno = raise_privileges();

1956

if(ret_errno != 0){

1957

errno = ret_errno;

1958

perror_plus("Failed to raise privileges");

1959

}

1632

1960

1633

1961

#ifdef __linux__

1634

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1635

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

1636

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

1637

bool restore_loglevel = true;

1638

if(ret_linux == -1){

1639

restore_loglevel = false;

1640

perror_plus("klogctl");

1962

int ret_linux;

1963

bool restore_loglevel = false;

1964

if(ret_errno == 0){

1965

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1966

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

1967

ret_linux = klogctl(8, NULL, 5);

1968

if(ret_linux == -1){

1969

perror_plus("klogctl");

1970

} else {

1971

restore_loglevel = true;

1972

}

1641

1973

}

1642

1974

#endif /* __linux__ */

1643

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

1644

ret_errno = errno;

1975

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

1976

ioctl_errno = errno;

1645

1977

#ifdef __linux__

1646

1978

if(restore_loglevel){

1647

1979

ret_linux = klogctl(7, NULL, 0);

1651

1983

}

1652

1984

#endif /* __linux__ */

1653

1985

1654

/* Lower privileges */

1655

lower_privileges();

1986

/* If raise_privileges() succeeded above */

1987

if(ret_errno == 0){

1988

/* Lower privileges */

1989

ret_errno = lower_privileges();

1990

if(ret_errno != 0){

1991

errno = ret_errno;

1992

perror_plus("Failed to lower privileges");

1993

}

1994

}

1656

1995

1657

1996

/* Close the socket */

1658

1997

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

1661

2000

}

1662

2001

1663

2002

if(ret_setflags == -1){

1664

errno = ret_errno;

2003

errno = ioctl_errno;

1665

2004

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1666

2005

errno = old_errno;

1667

return ret_errno;

2006

return ioctl_errno;

1668

2007

}

1669

2008

} else if(debug){

1670

2009

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

1688

2027

return 0;

1689

2028

}

1690

2029

2030

__attribute__((nonnull, warn_unused_result))

1691

2031

error_t take_down_interface(const char *const interface){

1692

int sd = -1;

1693

2032

error_t old_errno = errno;

1694

error_t ret_errno = 0;

1695

int ret, ret_setflags;

1696

2033

struct ifreq network;

1697

2034

unsigned int if_index = if_nametoindex(interface);

1698

2035

if(if_index == 0){

1701

2038

return ENXIO;

1702

2039

}

1703

2040

if(interface_is_up(interface)){

2041

error_t ret_errno = 0, ioctl_errno = 0;

1704

2042

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

1705

2043

ret_errno = errno;

1706

2044

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

1707

2045

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

2046

errno = old_errno;

1708

2047

return ret_errno;

1709

2048

}

1710

2049

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

1711

2050

1712

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1713

if(sd < 0){

2051

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

2052

if(sd == -1){

1714

2053

ret_errno = errno;

1715

2054

perror_plus("socket");

1716

2055

errno = old_errno;

1722

2061

interface);

1723

2062

}

1724

2063

1725

/* Raise priviliges */

1726

raise_privileges();

1727

1728

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

1729

ret_errno = errno;

1730

1731

/* Lower privileges */

1732

lower_privileges();

2064

/* Raise privileges */

2065

ret_errno = raise_privileges();

2066

if(ret_errno != 0){

2067

errno = ret_errno;

2068

perror_plus("Failed to raise privileges");

2069

}

2070

2071

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

2072

ioctl_errno = errno;

2073

2074

/* If raise_privileges() succeeded above */

2075

if(ret_errno == 0){

2076

/* Lower privileges */

2077

ret_errno = lower_privileges();

2078

if(ret_errno != 0){

2079

errno = ret_errno;

2080

perror_plus("Failed to lower privileges");

2081

}

2082

}

1733

2083

1734

2084

/* Close the socket */

1735

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

2085

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

1736

2086

if(ret == -1){

1737

2087

perror_plus("close");

1738

2088

}

1739

2089

1740

2090

if(ret_setflags == -1){

1741

errno = ret_errno;

2091

errno = ioctl_errno;

1742

2092

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1743

2093

errno = old_errno;

1744

return ret_errno;

2094

return ioctl_errno;

1745

2095

}

1746

2096

} else if(debug){

1747

2097

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

1755

2105

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

1756

2106

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

1757

2107

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

1758

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

2108

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

2109

.interfaces = NULL, .interfaces_size = 0 };

1759

2110

AvahiSServiceBrowser *sb = NULL;

1760

2111

error_t ret_errno;

1761

2112

int ret;

1762

2113

intmax_t tmpmax;

1763

2114

char *tmp;

1764

2115

int exitcode = EXIT_SUCCESS;

1765

char *interfaces = NULL;

1766

size_t interfaces_size = 0;

1767

2116

char *interfaces_to_take_down = NULL;

1768

2117

size_t interfaces_to_take_down_size = 0;

1769

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

1770

bool tempdir_created = false;

2118

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

2119

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

2120

char *tempdir = NULL;

1771

2121

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1772

2122

const char *seckey = PATHDIR "/" SECKEY;

1773

2123

const char *pubkey = PATHDIR "/" PUBKEY;

1774

2124

char *interfaces_hooks = NULL;

1775

size_t interfaces_hooks_size = 0;

1776

2125

1777

2126

bool gnutls_initialized = false;

1778

2127

bool gpgme_initialized = false;

1869

2218

connect_to = arg;

1870

2219

break;

1871

2220

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

1872

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

1873

(int)',');

2221

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

2222

arg, (int)',');

1874

2223

if(ret_errno != 0){

1875

2224

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

1876

2225

}

1951

2300

goto end;

1952

2301

}

1953

2302

}

1954

2303

1955

2304

{

1956

2305

/* Work around Debian bug #633582:

1957

2306

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

1958

2307

1959

/* Re-raise priviliges */

1960

if(raise_privileges() == 0){

2308

/* Re-raise privileges */

2309

ret_errno = raise_privileges();

2310

if(ret_errno != 0){

2311

errno = ret_errno;

2312

perror_plus("Failed to raise privileges");

2313

} else {

1961

2314

struct stat st;

1962

2315

1963

2316

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

1980

2333

TEMP_FAILURE_RETRY(close(seckey_fd));

1981

2334

}

1982

2335

}

1983

2336

1984

2337

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

1985

2338

int pubkey_fd = open(pubkey, O_RDONLY);

1986

2339

if(pubkey_fd == -1){

2001

2354

TEMP_FAILURE_RETRY(close(pubkey_fd));

2002

2355

}

2003

2356

}

2004

2357

2005

2358

/* Lower privileges */

2006

errno = 0;

2007

ret = seteuid(uid);

2008

if(ret == -1){

2009

perror_plus("seteuid");

2359

ret_errno = lower_privileges();

2360

if(ret_errno != 0){

2361

errno = ret_errno;

2362

perror_plus("Failed to lower privileges");

2010

2363

}

2011

2364

}

2012

2365

}

2013

2366

2014

/* Remove empty interface names */

2367

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

2015

2368

{

2016

2369

char *interface = NULL;

2017

while((interface = argz_next(interfaces, interfaces_size,

2370

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

2018

2371

interface))){

2019

if(if_nametoindex(interface) == 0){

2020

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

2372

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

2373

and if_nametoindex(interface) == 0){

2374

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

2021

2375

fprintf_plus(stderr, "Not using nonexisting interface"

2022

2376

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

2023

2377

}

2024

argz_delete(&interfaces, &interfaces_size, interface);

2378

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

2025

2379

interface = NULL;

2026

2380

}

2027

2381

}

2029

2383

2030

2384

/* Run network hooks */

2031

2385

{

2032

2033

if(interfaces != NULL){

2034

interfaces_hooks = malloc(interfaces_size);

2386

if(mc.interfaces != NULL){

2387

interfaces_hooks = malloc(mc.interfaces_size);

2035

2388

if(interfaces_hooks == NULL){

2036

2389

perror_plus("malloc");

2037

2390

goto end;

2038

2391

}

2039

memcpy(interfaces_hooks, interfaces, interfaces_size);

2040

interfaces_hooks_size = interfaces_size;

2041

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2042

(int)',');

2043

}

2044

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

2045

interfaces_hooks : "", delay)){

2046

goto end;

2047

}

2392

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

2393

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

2394

}

2395

run_network_hooks("start", interfaces_hooks != NULL ?

2396

interfaces_hooks : "", delay);

2048

2397

}

2049

2398

2050

2399

if(not debug){

2127

2476

}

2128

2477

2129

2478

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

2130

if(interfaces == NULL){

2131

struct dirent **direntries;

2479

if(mc.interfaces == NULL){

2480

struct dirent **direntries = NULL;

2132

2481

/* Look for any good interfaces */

2133

2482

ret = scandir(sys_class_net, &direntries, good_interface,

2134

2483

alphasort);

2135

2484

if(ret >= 1){

2136

2485

/* Add all found interfaces to interfaces list */

2137

2486

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

2138

ret_errno = argz_add(&interfaces, &interfaces_size,

2487

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

2139

2488

direntries[i]->d_name);

2140

2489

if(ret_errno != 0){

2490

errno = ret_errno;

2141

2491

perror_plus("argz_add");

2492

free(direntries[i]);

2142

2493

continue;

2143

2494

}

2144

2495

if(debug){

2145

2496

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

2146

2497

direntries[i]->d_name);

2147

2498

}

2499

free(direntries[i]);

2148

2500

}

2149

2501

free(direntries);

2150

2502

} else {

2151

free(direntries);

2503

if(ret == 0){

2504

free(direntries);

2505

}

2152

2506

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

2153

2507

exitcode = EXIT_FAILURE;

2154

2508

goto end;

2155

2509

}

2156

2510

}

2157

2511

2158

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

2159

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

2160

if(debug){

2161

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

2162

interfaces);

2163

}

2164

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2165

}

2166

2167

/* Bring up interfaces which are down */

2168

if(not (argz_count(interfaces, interfaces_size) == 1

2169

and strcmp(interfaces, "none") == 0)){

2512

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

2513

{

2170

2514

char *interface = NULL;

2171

while((interface = argz_next(interfaces, interfaces_size,

2515

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

2172

2516

interface))){

2517

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

2518

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

2519

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

2520

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

2521

interface);

2522

interface = NULL;

2523

while((interface = argz_next(mc.interfaces,

2524

mc.interfaces_size, interface))){

2525

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

2526

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

2527

interface);

2528

interface = NULL;

2529

}

2530

}

2531

break;

2532

}

2173

2533

bool interface_was_up = interface_is_up(interface);

2174

ret = bring_up_interface(interface, delay);

2534

errno = bring_up_interface(interface, delay);

2175

2535

if(not interface_was_up){

2176

if(ret != 0){

2177

errno = ret;

2536

if(errno != 0){

2178

2537

perror_plus("Failed to bring up interface");

2179

2538

} else {

2180

ret_errno = argz_add(&interfaces_to_take_down,

2181

&interfaces_to_take_down_size,

2182

interface);

2539

errno = argz_add(&interfaces_to_take_down,

2540

&interfaces_to_take_down_size,

2541

interface);

2542

if(errno != 0){

2543

perror_plus("argz_add");

2544

}

2183

2545

}

2184

2546

}

2185

2547

}

2186

free(interfaces);

2187

interfaces = NULL;

2188

interfaces_size = 0;

2189

2548

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

2190

2549

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

2191

2550

}

2192

2551

}

2193

2552

2553

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

2554

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

2555

if(debug){

2556

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

2557

mc.interfaces);

2558

}

2559

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

2560

}

2561

2194

2562

if(quit_now){

2195

2563

goto end;

2196

2564

}

2208

2576

goto end;

2209

2577

}

2210

2578

2211

if(mkdtemp(tempdir) == NULL){

2579

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

2580

tempdir = mkdtemp(run_tempdir);

2581

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

2582

if(debug){

2583

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

2584

run_tempdir, old_tempdir);

2585

}

2586

tempdir = mkdtemp(old_tempdir);

2587

}

2588

if(tempdir == NULL){

2212

2589

perror_plus("mkdtemp");

2213

2590

goto end;

2214

2591

}

2215

tempdir_created = true;

2216

2592

2217

2593

if(quit_now){

2218

2594

goto end;

2254

2630

exitcode = EX_USAGE;

2255

2631

goto end;

2256

2632

}

2257

2633

2258

2634

if(quit_now){

2259

2635

goto end;

2260

2636

}

2290

2666

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

2291

2667

(int)retry_interval);

2292

2668

}

2293

sleep((int)retry_interval);

2669

sleep((unsigned int)retry_interval);

2294

2670

}

2295

2671

2296

if (not quit_now){

2672

if(not quit_now){

2297

2673

exitcode = EXIT_SUCCESS;

2298

2674

}

2299

2675

2354

2730

if(debug){

2355

2731

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

2356

2732

}

2357

2733

2358

2734

ret = avahi_loop_with_timeout(simple_poll,

2359

2735

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

2360

2736

if(debug){

2369

2745

}

2370

2746

2371

2747

/* Cleanup things */

2748

free(mc.interfaces);

2749

2372

2750

if(sb != NULL)

2373

2751

avahi_s_service_browser_free(sb);

2374

2752

2394

2772

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

2395

2773

while(mc.current_server != NULL){

2396

2774

server *next = mc.current_server->next;

2775

#ifdef __GNUC__

2776

#pragma GCC diagnostic push

2777

#pragma GCC diagnostic ignored "-Wcast-qual"

2778

#endif

2779

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

2780

#ifdef __GNUC__

2781

#pragma GCC diagnostic pop

2782

#endif

2397

2783

free(mc.current_server);

2398

2784

mc.current_server = next;

2399

2785

}

2400

2786

}

2401

2787

2402

/* Re-raise priviliges */

2788

/* Re-raise privileges */

2403

2789

{

2404

raise_privileges();

2405

2406

/* Run network hooks */

2407

run_network_hooks("stop", interfaces_hooks != NULL ?

2408

interfaces_hooks : "", delay);

2409

2410

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

2411

{

2412

char *interface = NULL;

2413

while((interface=argz_next(interfaces_to_take_down,

2414

interfaces_to_take_down_size,

2415

interface))){

2416

ret_errno = take_down_interface(interface);

2417

if(ret_errno != 0){

2418

errno = ret_errno;

2419

perror_plus("Failed to take down interface");

2420

}

2421

}

2422

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

2423

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

2424

" down\n");

2425

}

2426

}

2427

2428

lower_privileges_permanently();

2790

ret_errno = raise_privileges();

2791

if(ret_errno != 0){

2792

errno = ret_errno;

2793

perror_plus("Failed to raise privileges");

2794

} else {

2795

2796

/* Run network hooks */

2797

run_network_hooks("stop", interfaces_hooks != NULL ?

2798

interfaces_hooks : "", delay);

2799

2800

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

2801

{

2802

char *interface = NULL;

2803

while((interface=argz_next(interfaces_to_take_down,

2804

interfaces_to_take_down_size,

2805

interface))){

2806

ret_errno = take_down_interface(interface);

2807

if(ret_errno != 0){

2808

errno = ret_errno;

2809

perror_plus("Failed to take down interface");

2810

}

2811

}

2812

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

2813

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

2814

" down\n");

2815

}

2816

}

2817

}

2818

2819

ret_errno = lower_privileges_permanently();

2820

if(ret_errno != 0){

2821

errno = ret_errno;

2822

perror_plus("Failed to lower privileges permanently");

2823

}

2429

2824

}

2430

2825

2431

2826

free(interfaces_to_take_down);

2432

2827

free(interfaces_hooks);

2433

2828

2434

2829

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

2435

if(tempdir_created){

2830

if(tempdir != NULL){

2436

2831

struct dirent **direntries = NULL;

2437

struct dirent *direntry = NULL;

2438

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

2439

alphasort);

2440

if (numentries > 0){

2441

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

2442

direntry = direntries[i];

2443

char *fullname = NULL;

2444

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

2445

direntry->d_name);

2446

if(ret < 0){

2447

perror_plus("asprintf");

2448

continue;

2449

}

2450

ret = remove(fullname);

2451

if(ret == -1){

2452

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

2453

strerror(errno));

2454

}

2455

free(fullname);

2832

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

2833

| O_NOFOLLOW

2834

| O_DIRECTORY

2835

| O_PATH));

2836

if(tempdir_fd == -1){

2837

perror_plus("open");

2838

} else {

2839

#ifdef __GLIBC__

2840

#if __GLIBC_PREREQ(2, 15)

2841

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

2842

notdotentries, alphasort);

2843

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

2844

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

2845

alphasort);

2846

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

2847

#else /* not __GLIBC__ */

2848

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

2849

alphasort);

2850

#endif /* not __GLIBC__ */

2851

if(numentries >= 0){

2852

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

2853

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

2854

if(ret == -1){

2855

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

2856

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

2857

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

2858

}

2859

free(direntries[i]);

2860

}

2861

2862

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

2863

free(direntries);

2864

if(numentries == -1){

2865

perror_plus("scandir");

2866

}

2867

ret = rmdir(tempdir);

2868

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

2869

perror_plus("rmdir");

2870

}

2456

2871

}

2457

}

2458

2459

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

2460

free(direntries);

2461

if (numentries == -1){

2462

perror_plus("scandir");

2463

}

2464

ret = rmdir(tempdir);

2465

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

2466

perror_plus("rmdir");

2872

TEMP_FAILURE_RETRY(close(tempdir_fd));

2467

2873

}

2468

2874

}

2469

2875