/mandos/trunk : revision 738.1.6

9

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

10

*

11

* Everything else is

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13

12

13

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*

15

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

16

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

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() */

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

43

stdout, ferror(), remove() */

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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() */

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

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inet_pton(), connect(),

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getnameinfo() */

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

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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(),

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

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

76

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

76

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

77

unlinkat() */

78

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

77

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

78

80

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

79

81

argp_state, struct argp,

91

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argz_delete(), argz_append(),

92

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argz_stringify(), argz_add(),

93

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

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98

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99

#ifdef __linux__

96

100

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

138

142

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

139

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char *connect_to = NULL;

140

144

const char *hookdir = HOOKDIR;

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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

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

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va_list ap;

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va_start (ap, format);

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192

186

193

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

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194

program_invocation_short_name));

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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

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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 delete_local_route() */

706

__attribute__((nonnull, warn_unused_result))

707

static bool add_delete_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 debug_flag[] = "--debug";

715

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

716

if(pluginhelperdir == NULL){

717

if(debug){

718

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

719

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

720

}

721

return false;

722

}

723

724

char interface[IF_NAMESIZE];

725

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

726

perror_plus("if_indextoname");

727

return false;

728

}

729

730

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

731

if(devnull == -1){

732

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

733

return false;

734

}

735

pid_t pid = fork();

736

if(pid == 0){

737

/* Child */

738

/* Raise privileges */

739

errno = raise_privileges_permanently();

740

if(errno != 0){

741

perror_plus("Failed to raise privileges");

742

/* _exit(EX_NOPERM); */

743

} else {

744

/* Set group */

745

errno = 0;

746

ret = setgid(0);

747

if(ret == -1){

748

perror_plus("setgid");

749

_exit(EX_NOPERM);

750

}

751

/* Reset supplementary groups */

752

errno = 0;

753

ret = setgroups(0, NULL);

754

if(ret == -1){

755

perror_plus("setgroups");

756

_exit(EX_NOPERM);

757

}

758

}

759

ret = dup2(devnull, STDIN_FILENO);

760

if(ret == -1){

761

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

762

_exit(EX_OSERR);

763

}

764

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

765

if(ret == -1){

766

perror_plus("close");

767

_exit(EX_OSERR);

768

}

769

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

770

if(ret == -1){

771

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

772

_exit(EX_OSERR);

773

}

774

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

775

O_RDONLY

776

| O_DIRECTORY

777

| O_PATH

778

| O_CLOEXEC));

779

if(helperdir_fd == -1){

780

perror_plus("open");

781

_exit(EX_UNAVAILABLE);

782

}

783

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

784

helper, O_RDONLY));

785

if(helper_fd == -1){

786

perror_plus("openat");

787

_exit(EX_UNAVAILABLE);

788

}

789

TEMP_FAILURE_RETRY(close(helperdir_fd));

790

#ifdef __GNUC__

791

#pragma GCC diagnostic push

792

#pragma GCC diagnostic ignored "-Wcast-qual"

793

#endif

794

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

795

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

796

interface, debug ? debug_flag : NULL, NULL },

797

environ) == -1){

798

#ifdef __GNUC__

799

#pragma GCC diagnostic pop

800

#endif

801

perror_plus("fexecve");

802

_exit(EXIT_FAILURE);

803

}

804

}

805

if(pid == -1){

806

perror_plus("fork");

807

return false;

808

}

809

int status;

810

pid_t pret = -1;

811

errno = 0;

812

do {

813

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

814

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

815

int errno_raising = 0;

816

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

817

errno_raising = errno;

818

perror_plus("Failed to raise privileges in order to"

819

" kill helper program");

820

}

821

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

822

perror_plus("kill");

823

}

824

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

825

perror_plus("Failed to lower privileges after killing"

826

" helper program");

827

}

828

return false;

829

}

830

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

831

if(pret == -1){

832

perror_plus("waitpid");

833

return false;

834

}

835

if(WIFEXITED(status)){

836

if(WEXITSTATUS(status) != 0){

837

fprintf_plus(stderr, "Error: iprouteadddel exited"

838

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

839

return false;

840

}

841

return true;

842

}

843

if(WIFSIGNALED(status)){

844

fprintf_plus(stderr, "Error: iprouteadddel died by"

845

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

846

return false;

847

}

848

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

849

return false;

850

}

851

852

__attribute__((nonnull, warn_unused_result))

853

static bool add_local_route(const char *address,

854

AvahiIfIndex if_index){

855

if(debug){

856

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

857

}

858

return add_delete_local_route(true, address, if_index);

859

}

860

861

__attribute__((nonnull, warn_unused_result))

862

static bool delete_local_route(const char *address,

863

AvahiIfIndex if_index){

864

if(debug){

865

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

866

}

867

return add_delete_local_route(false, address, if_index);

868

}

869

621

870

/* Called when a Mandos server is found */

871

__attribute__((nonnull, warn_unused_result))

622

872

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

623

873

AvahiIfIndex if_index,

624

874

int af, mandos_context *mc){

625

875

int ret, tcp_sd = -1;

626

876

ssize_t sret;

627

union {

628

struct sockaddr_in in;

629

struct sockaddr_in6 in6;

630

} to;

877

struct sockaddr_storage to;

631

878

char *buffer = NULL;

632

879

char *decrypted_buffer = NULL;

633

880

size_t buffer_length = 0;

636

883

int retval = -1;

637

884

gnutls_session_t session;

638

885

int pf; /* Protocol family */

886

bool route_added = false;

639

887

640

888

errno = 0;

641

889

657

905

return -1;

658

906

}

659

907

908

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

909

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

910

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

911

bool match = false;

912

{

913

char *interface = NULL;

914

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

915

interface))){

916

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

917

match = true;

918

break;

919

}

920

}

921

}

922

if(not match){

923

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

924

connect to the server */

925

if(debug){

926

char interface[IF_NAMESIZE];

927

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

928

perror_plus("if_indextoname");

929

} else {

930

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

931

" \"%s\"\n",

932

if_indextoname((unsigned int)if_index,

933

interface));

934

}

935

}

936

return -1;

937

}

938

}

939

660

940

ret = init_gnutls_session(&session, mc);

661

941

if(ret != 0){

662

942

return -1;

667

947

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

668

948

}

669

949

670

tcp_sd = socket(pf, SOCK_STREAM, 0);

950

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

671

951

if(tcp_sd < 0){

672

952

int e = errno;

673

953

perror_plus("socket");

682

962

683

963

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

684

964

if(af == AF_INET6){

685

to.in6.sin6_family = (sa_family_t)af;

686

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

965

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

966

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

687

967

} else { /* IPv4 */

688

to.in.sin_family = (sa_family_t)af;

689

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

968

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

969

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

690

970

}

691

971

if(ret < 0 ){

692

972

int e = errno;

701

981

goto mandos_end;

702

982

}

703

983

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*/

984

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

985

if(IN6_IS_ADDR_LINKLOCAL

986

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

708

987

if(if_index == AVAHI_IF_UNSPEC){

709

988

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

710

989

" incomplete without a network interface\n");

712

991

goto mandos_end;

713

992

}

714

993

/* Set the network interface number as scope */

715

to.in6.sin6_scope_id = (uint32_t)if_index;

994

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

716

995

}

717

996

} else {

718

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

719

-Wconversion and

720

-Wunreachable-code */

997

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

721

998

}

722

999

723

1000

if(quit_now){

740

1017

}

741

1018

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

742

1019

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;

1020

if(af == AF_INET6){

1021

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

1022

sizeof(struct sockaddr_in6),

1023

addrstr, sizeof(addrstr), NULL, 0,

1024

NI_NUMERICHOST);

1025

} else {

1026

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

1027

sizeof(struct sockaddr_in),

1028

addrstr, sizeof(addrstr), NULL, 0,

1029

NI_NUMERICHOST);

1030

}

1031

if(ret == EAI_SYSTEM){

1032

perror_plus("getnameinfo");

1033

} else if(ret != 0) {

1034

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

1035

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

1036

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

1037

}

1038

}

1039

1040

if(quit_now){

1041

errno = EINTR;

1042

goto mandos_end;

1043

}

1044

1045

while(true){

1046

if(af == AF_INET6){

1047

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

1048

sizeof(struct sockaddr_in6));

1049

} else {

1050

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

1051

sizeof(struct sockaddr_in));

1052

}

1053

if(ret < 0){

1054

if(errno == ENETUNREACH

1055

and if_index != AVAHI_IF_UNSPEC

1056

and connect_to == NULL

1057

and not route_added and

1058

((af == AF_INET6 and not

1059

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1060

&to)->sin6_addr)))

1061

or (af == AF_INET and

1062

/* Not a a IPv4LL address */

1063

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

1064

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

1065

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

1066

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

1067

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

1068

connect to a Mandos server announced by Avahi on a server

1069

host with a global address. Work around this by retrying

1070

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

1071

1072

Avahi bug reference:

1073

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

1074

https://bugs.debian.org/587961

1075

*/

1076

if(debug){

1077

fprintf_plus(stderr, "Mandos server unreachable, trying"

1078

" direct route\n");

1079

}

1080

int e = errno;

1081

route_added = add_local_route(ip, if_index);

1082

if(route_added){

1083

continue;

1084

}

1085

errno = e;

1086

}

1087

if(errno != ECONNREFUSED or debug){

1088

int e = errno;

1089

perror_plus("connect");

1090

errno = e;

1091

}

1092

goto mandos_end;

1093

}

1094

1095

if(quit_now){

1096

errno = EINTR;

1097

goto mandos_end;

1098

}

1099

break;

782

1100

}

783

1101

784

1102

const char *out = mandos_protocol_version;

967

1285

968

1286

mandos_end:

969

1287

{

1288

if(route_added){

1289

if(not delete_local_route(ip, if_index)){

1290

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

1291

" interface %d", ip, if_index);

1292

}

1293

}

970

1294

int e = errno;

971

1295

free(decrypted_buffer);

972

1296

free(buffer);

989

1313

return retval;

990

1314

}

991

1315

1316

__attribute__((nonnull))

992

1317

static void resolve_callback(AvahiSServiceResolver *r,

993

1318

AvahiIfIndex interface,

994

1319

AvahiProtocol proto,

1002

1327

AVAHI_GCC_UNUSED AvahiStringList *txt,

1003

1328

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1004

1329

flags,

1005

void* mc){

1330

void *mc){

1006

1331

if(r == NULL){

1007

1332

return;

1008

1333

}

1011

1336

timed out */

1012

1337

1013

1338

if(quit_now){

1339

avahi_s_service_resolver_free(r);

1014

1340

return;

1015

1341

}

1016

1342

1061

1387

const char *domain,

1062

1388

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1063

1389

flags,

1064

void* mc){

1390

void *mc){

1065

1391

if(b == NULL){

1066

1392

return;

1067

1393

}

1127

1453

errno = old_errno;

1128

1454

}

1129

1455

1456

__attribute__((nonnull, warn_unused_result))

1130

1457

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

1131

1458

int ret;

1132

1459

error_t ret_errno;

1151

1478

return true;

1152

1479

}

1153

1480

1481

__attribute__((nonnull, warn_unused_result))

1154

1482

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

1155

1483

1156

1484

/* Reject the loopback device */

1198

1526

* corresponds to an acceptable network device.

1199

1527

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

1200

1528

*/

1529

__attribute__((nonnull, warn_unused_result))

1201

1530

int good_interface(const struct dirent *if_entry){

1202

1531

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

1203

1532

return 0;

1221

1550

/*

1222

1551

* This function determines if a network interface is up.

1223

1552

*/

1553

__attribute__((nonnull, warn_unused_result))

1224

1554

bool interface_is_up(const char *interface){

1225

1555

struct ifreq ifr;

1226

1556

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

1237

1567

/*

1238

1568

* This function determines if a network interface is running

1239

1569

*/

1570

__attribute__((nonnull, warn_unused_result))

1240

1571

bool interface_is_running(const char *interface){

1241

1572

struct ifreq ifr;

1242

1573

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

1250

1581

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

1251

1582

}

1252

1583

1584

__attribute__((nonnull, pure, warn_unused_result))

1253

1585

int notdotentries(const struct dirent *direntry){

1254

1586

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

1255

1587

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

1262

1594

}

1263

1595

1264

1596

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

1597

__attribute__((nonnull, warn_unused_result))

1265

1598

int runnable_hook(const struct dirent *direntry){

1266

1599

int ret;

1267

1600

size_t sret;

1275

1608

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

1276

1609

"abcdefghijklmnopqrstuvwxyz"

1277

1610

"0123456789"

1278

"_-");

1611

"_.-");

1279

1612

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

1280

1613

/* Contains non-allowed characters */

1281

1614

if(debug){

1285

1618

return 0;

1286

1619

}

1287

1620

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);

1621

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

1296

1622

if(ret == -1){

1297

1623

if(debug){

1298

1624

perror_plus("Could not stat hook");

1322

1648

return 1;

1323

1649

}

1324

1650

1651

__attribute__((nonnull, warn_unused_result))

1325

1652

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1326

1653

mandos_context *mc){

1327

1654

int ret;

1331

1658

1332

1659

while(true){

1333

1660

if(mc->current_server == NULL){

1334

if (debug){

1661

if(debug){

1335

1662

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

1336

1663

" No timeout!\n");

1337

1664

}

1338

1665

ret = avahi_simple_poll_iterate(s, -1);

1339

1666

} else {

1340

if (debug){

1667

if(debug){

1341

1668

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

1342

1669

" it, or wait\n");

1343

1670

}

1360

1687

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

1361

1688

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

1362

1689

1363

if (debug){

1690

if(debug){

1364

1691

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

1365

1692

block_time);

1366

1693

}

1388

1715

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

1389

1716

}

1390

1717

if(ret != 0){

1391

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

1718

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

1392

1719

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

1393

1720

}

1394

1721

}

1395

1722

}

1396

1723

}

1397

1724

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,

1725

__attribute__((nonnull))

1726

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

1451

1727

const float delay){

1452

struct dirent **direntries;

1728

struct dirent **direntries = NULL;

1729

if(hookdir_fd == -1){

1730

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1731

| O_CLOEXEC);

1732

if(hookdir_fd == -1){

1733

if(errno == ENOENT){

1734

if(debug){

1735

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

1736

" found\n", hookdir);

1737

}

1738

} else {

1739

perror_plus("open");

1740

}

1741

return;

1742

}

1743

}

1744

#ifdef __GLIBC__

1745

#if __GLIBC_PREREQ(2, 15)

1746

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

1747

runnable_hook, alphasort);

1748

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

1749

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

1750

alphasort);

1751

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

1752

#else /* not __GLIBC__ */

1753

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

1754

alphasort);

1755

#endif /* not __GLIBC__ */

1756

if(numhooks == -1){

1757

perror_plus("scandir");

1758

return;

1759

}

1453

1760

struct dirent *direntry;

1454

1761

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");

1762

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

1763

if(devnull == -1){

1764

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

1765

return;

1766

}

1767

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

1768

direntry = direntries[i];

1769

if(debug){

1770

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

1771

direntry->d_name);

1465

1772

}

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){

1773

pid_t hook_pid = fork();

1774

if(hook_pid == 0){

1775

/* Child */

1776

/* Raise privileges */

1777

errno = raise_privileges_permanently();

1778

if(errno != 0){

1779

perror_plus("Failed to raise privileges");

1780

_exit(EX_NOPERM);

1781

}

1782

/* Set group */

1783

errno = 0;

1784

ret = setgid(0);

1785

if(ret == -1){

1786

perror_plus("setgid");

1787

_exit(EX_NOPERM);

1788

}

1789

/* Reset supplementary groups */

1790

errno = 0;

1791

ret = setgroups(0, NULL);

1792

if(ret == -1){

1793

perror_plus("setgroups");

1794

_exit(EX_NOPERM);

1795

}

1796

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

1797

if(ret == -1){

1798

perror_plus("setenv");

1799

_exit(EX_OSERR);

1800

}

1801

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

1802

if(ret == -1){

1803

perror_plus("setenv");

1804

_exit(EX_OSERR);

1805

}

1806

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

1807

if(ret == -1){

1808

perror_plus("setenv");

1809

_exit(EX_OSERR);

1810

}

1811

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

1812

if(ret == -1){

1813

perror_plus("setenv");

1814

_exit(EX_OSERR);

1815

}

1816

char *delaystring;

1817

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

1818

if(ret == -1){

1473

1819

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

}

1820

_exit(EX_OSERR);

1821

}

1822

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

1823

if(ret == -1){

1532

1824

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

}

1825

perror_plus("setenv");

1826

_exit(EX_OSERR);

1827

}

1828

free(delaystring);

1829

if(connect_to != NULL){

1830

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

1831

if(ret == -1){

1832

perror_plus("setenv");

1833

_exit(EX_OSERR);

1834

}

1835

}

1836

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

1837

direntry->d_name,

1838

O_RDONLY));

1839

if(hook_fd == -1){

1840

perror_plus("openat");

1841

_exit(EXIT_FAILURE);

1842

}

1843

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

1844

perror_plus("close");

1845

_exit(EXIT_FAILURE);

1846

}

1847

ret = dup2(devnull, STDIN_FILENO);

1848

if(ret == -1){

1849

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

1850

_exit(EX_OSERR);

1851

}

1852

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

1853

if(ret == -1){

1854

perror_plus("close");

1855

_exit(EX_OSERR);

1856

}

1857

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1858

if(ret == -1){

1859

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

1860

_exit(EX_OSERR);

1861

}

1862

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

1863

environ) == -1){

1864

perror_plus("fexecve");

1865

_exit(EXIT_FAILURE);

1866

}

1867

} else {

1868

if(hook_pid == -1){

1869

perror_plus("fork");

1870

free(direntry);

1871

continue;

1872

}

1873

int status;

1874

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

1875

perror_plus("waitpid");

1876

free(direntry);

1877

continue;

1878

}

1879

if(WIFEXITED(status)){

1880

if(WEXITSTATUS(status) != 0){

1881

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

1882

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

1883

WEXITSTATUS(status));

1884

free(direntry);

1885

continue;

1886

}

1887

} else if(WIFSIGNALED(status)){

1888

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

1889

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

1890

WTERMSIG(status));

1891

free(direntry);

1892

continue;

1544

1893

} 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;

1894

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

1895

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

1896

free(direntry);

1897

continue;

1898

}

1899

}

1900

if(debug){

1901

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

1902

direntry->d_name);

1903

}

1904

free(direntry);

1905

}

1906

free(direntries);

1907

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

1908

perror_plus("close");

1909

} else {

1910

hookdir_fd = -1;

1911

}

1912

close(devnull);

1581

1913

}

1582

1914

1915

__attribute__((nonnull, warn_unused_result))

1583

1916

error_t bring_up_interface(const char *const interface,

1584

1917

const float delay){

1585

int sd = -1;

1586

1918

error_t old_errno = errno;

1587

error_t ret_errno = 0;

1588

int ret, ret_setflags;

1919

int ret;

1589

1920

struct ifreq network;

1590

1921

unsigned int if_index = if_nametoindex(interface);

1591

1922

if(if_index == 0){

1600

1931

}

1601

1932

1602

1933

if(not interface_is_up(interface)){

1603

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

1934

error_t ret_errno = 0, ioctl_errno = 0;

1935

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

1604

1936

ret_errno = errno;

1605

1937

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

1606

1938

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

1939

errno = old_errno;

1607

1940

return ret_errno;

1608

1941

}

1609

network.ifr_flags |= IFF_UP;

1942

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

1610

1943

1611

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1612

if(sd < 0){

1944

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

1945

if(sd == -1){

1613

1946

ret_errno = errno;

1614

1947

perror_plus("socket");

1615

1948

errno = old_errno;

1616

1949

return ret_errno;

1617

1950

}

1618

1951

1619

1952

if(quit_now){

1620

close(sd);

1953

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

1954

if(ret == -1){

1955

perror_plus("close");

1956

}

1621

1957

errno = old_errno;

1622

1958

return EINTR;

1623

1959

}

1627

1963

interface);

1628

1964

}

1629

1965

1630

/* Raise priviliges */

1631

raise_privileges();

1966

/* Raise privileges */

1967

ret_errno = raise_privileges();

1968

if(ret_errno != 0){

1969

errno = ret_errno;

1970

perror_plus("Failed to raise privileges");

1971

}

1632

1972

1633

1973

#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");

1974

int ret_linux;

1975

bool restore_loglevel = false;

1976

if(ret_errno == 0){

1977

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1978

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

1979

ret_linux = klogctl(8, NULL, 5);

1980

if(ret_linux == -1){

1981

perror_plus("klogctl");

1982

} else {

1983

restore_loglevel = true;

1984

}

1641

1985

}

1642

1986

#endif /* __linux__ */

1643

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

1644

ret_errno = errno;

1987

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

1988

ioctl_errno = errno;

1645

1989

#ifdef __linux__

1646

1990

if(restore_loglevel){

1647

1991

ret_linux = klogctl(7, NULL, 0);

1651

1995

}

1652

1996

#endif /* __linux__ */

1653

1997

1654

/* Lower privileges */

1655

lower_privileges();

1998

/* If raise_privileges() succeeded above */

1999

if(ret_errno == 0){

2000

/* Lower privileges */

2001

ret_errno = lower_privileges();

2002

if(ret_errno != 0){

2003

errno = ret_errno;

2004

perror_plus("Failed to lower privileges");

2005

}

2006

}

1656

2007

1657

2008

/* Close the socket */

1658

2009

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

1661

2012

}

1662

2013

1663

2014

if(ret_setflags == -1){

1664

errno = ret_errno;

2015

errno = ioctl_errno;

1665

2016

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1666

2017

errno = old_errno;

1667

return ret_errno;

2018

return ioctl_errno;

1668

2019

}

1669

2020

} else if(debug){

1670

2021

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

1688

2039

return 0;

1689

2040

}

1690

2041

2042

__attribute__((nonnull, warn_unused_result))

1691

2043

error_t take_down_interface(const char *const interface){

1692

int sd = -1;

1693

2044

error_t old_errno = errno;

1694

error_t ret_errno = 0;

1695

int ret, ret_setflags;

1696

2045

struct ifreq network;

1697

2046

unsigned int if_index = if_nametoindex(interface);

1698

2047

if(if_index == 0){

1701

2050

return ENXIO;

1702

2051

}

1703

2052

if(interface_is_up(interface)){

2053

error_t ret_errno = 0, ioctl_errno = 0;

1704

2054

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

1705

2055

ret_errno = errno;

1706

2056

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

1707

2057

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

2058

errno = old_errno;

1708

2059

return ret_errno;

1709

2060

}

1710

2061

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

1711

2062

1712

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1713

if(sd < 0){

2063

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

2064

if(sd == -1){

1714

2065

ret_errno = errno;

1715

2066

perror_plus("socket");

1716

2067

errno = old_errno;

1722

2073

interface);

1723

2074

}

1724

2075

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();

2076

/* Raise privileges */

2077

ret_errno = raise_privileges();

2078

if(ret_errno != 0){

2079

errno = ret_errno;

2080

perror_plus("Failed to raise privileges");

2081

}

2082

2083

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

2084

ioctl_errno = errno;

2085

2086

/* If raise_privileges() succeeded above */

2087

if(ret_errno == 0){

2088

/* Lower privileges */

2089

ret_errno = lower_privileges();

2090

if(ret_errno != 0){

2091

errno = ret_errno;

2092

perror_plus("Failed to lower privileges");

2093

}

2094

}

1733

2095

1734

2096

/* Close the socket */

1735

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

2097

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

1736

2098

if(ret == -1){

1737

2099

perror_plus("close");

1738

2100

}

1739

2101

1740

2102

if(ret_setflags == -1){

1741

errno = ret_errno;

2103

errno = ioctl_errno;

1742

2104

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1743

2105

errno = old_errno;

1744

return ret_errno;

2106

return ioctl_errno;

1745

2107

}

1746

2108

} else if(debug){

1747

2109

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

1755

2117

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

1756

2118

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

1757

2119

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

1758

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

2120

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

2121

.interfaces = NULL, .interfaces_size = 0 };

1759

2122

AvahiSServiceBrowser *sb = NULL;

1760

2123

error_t ret_errno;

1761

2124

int ret;

1762

2125

intmax_t tmpmax;

1763

2126

char *tmp;

1764

2127

int exitcode = EXIT_SUCCESS;

1765

char *interfaces = NULL;

1766

size_t interfaces_size = 0;

1767

2128

char *interfaces_to_take_down = NULL;

1768

2129

size_t interfaces_to_take_down_size = 0;

1769

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

1770

bool tempdir_created = false;

2130

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

2131

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

2132

char *tempdir = NULL;

1771

2133

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1772

2134

const char *seckey = PATHDIR "/" SECKEY;

1773

2135

const char *pubkey = PATHDIR "/" PUBKEY;

1774

2136

char *interfaces_hooks = NULL;

1775

size_t interfaces_hooks_size = 0;

1776

2137

1777

2138

bool gnutls_initialized = false;

1778

2139

bool gpgme_initialized = false;

1869

2230

connect_to = arg;

1870

2231

break;

1871

2232

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

1872

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

1873

(int)',');

2233

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

2234

arg, (int)',');

1874

2235

if(ret_errno != 0){

1875

2236

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

1876

2237

}

1951

2312

goto end;

1952

2313

}

1953

2314

}

1954

2315

1955

2316

{

1956

2317

/* Work around Debian bug #633582:

1957

2318

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

1958

2319

1959

/* Re-raise priviliges */

1960

if(raise_privileges() == 0){

2320

/* Re-raise privileges */

2321

ret_errno = raise_privileges();

2322

if(ret_errno != 0){

2323

errno = ret_errno;

2324

perror_plus("Failed to raise privileges");

2325

} else {

1961

2326

struct stat st;

1962

2327

1963

2328

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

1980

2345

TEMP_FAILURE_RETRY(close(seckey_fd));

1981

2346

}

1982

2347

}

1983

2348

1984

2349

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

1985

2350

int pubkey_fd = open(pubkey, O_RDONLY);

1986

2351

if(pubkey_fd == -1){

2001

2366

TEMP_FAILURE_RETRY(close(pubkey_fd));

2002

2367

}

2003

2368

}

2004

2369

2005

2370

/* Lower privileges */

2006

errno = 0;

2007

ret = seteuid(uid);

2008

if(ret == -1){

2009

perror_plus("seteuid");

2371

ret_errno = lower_privileges();

2372

if(ret_errno != 0){

2373

errno = ret_errno;

2374

perror_plus("Failed to lower privileges");

2010

2375

}

2011

2376

}

2012

2377

}

2013

2378

2014

/* Remove empty interface names */

2379

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

2015

2380

{

2016

2381

char *interface = NULL;

2017

while((interface = argz_next(interfaces, interfaces_size,

2382

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

2018

2383

interface))){

2019

if(if_nametoindex(interface) == 0){

2020

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

2384

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

2385

and if_nametoindex(interface) == 0){

2386

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

2021

2387

fprintf_plus(stderr, "Not using nonexisting interface"

2022

2388

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

2023

2389

}

2024

argz_delete(&interfaces, &interfaces_size, interface);

2390

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

2025

2391

interface = NULL;

2026

2392

}

2027

2393

}

2029

2395

2030

2396

/* Run network hooks */

2031

2397

{

2032

2033

if(interfaces != NULL){

2034

interfaces_hooks = malloc(interfaces_size);

2398

if(mc.interfaces != NULL){

2399

interfaces_hooks = malloc(mc.interfaces_size);

2035

2400

if(interfaces_hooks == NULL){

2036

2401

perror_plus("malloc");

2037

2402

goto end;

2038

2403

}

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

}

2404

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

2405

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

2406

}

2407

run_network_hooks("start", interfaces_hooks != NULL ?

2408

interfaces_hooks : "", delay);

2048

2409

}

2049

2410

2050

2411

if(not debug){

2127

2488

}

2128

2489

2129

2490

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

2130

if(interfaces == NULL){

2131

struct dirent **direntries;

2491

if(mc.interfaces == NULL){

2492

struct dirent **direntries = NULL;

2132

2493

/* Look for any good interfaces */

2133

2494

ret = scandir(sys_class_net, &direntries, good_interface,

2134

2495

alphasort);

2135

2496

if(ret >= 1){

2136

2497

/* Add all found interfaces to interfaces list */

2137

2498

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

2138

ret_errno = argz_add(&interfaces, &interfaces_size,

2499

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

2139

2500

direntries[i]->d_name);

2140

2501

if(ret_errno != 0){

2502

errno = ret_errno;

2141

2503

perror_plus("argz_add");

2504

free(direntries[i]);

2142

2505

continue;

2143

2506

}

2144

2507

if(debug){

2145

2508

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

2146

2509

direntries[i]->d_name);

2147

2510

}

2511

free(direntries[i]);

2148

2512

}

2149

2513

free(direntries);

2150

2514

} else {

2151

free(direntries);

2515

if(ret == 0){

2516

free(direntries);

2517

}

2152

2518

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

2153

2519

exitcode = EXIT_FAILURE;

2154

2520

goto end;

2155

2521

}

2156

2522

}

2157

2523

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)){

2524

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

2525

{

2170

2526

char *interface = NULL;

2171

while((interface = argz_next(interfaces, interfaces_size,

2527

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

2172

2528

interface))){

2529

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

2530

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

2531

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

2532

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

2533

interface);

2534

interface = NULL;

2535

while((interface = argz_next(mc.interfaces,

2536

mc.interfaces_size, interface))){

2537

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

2538

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

2539

interface);

2540

interface = NULL;

2541

}

2542

}

2543

break;

2544

}

2173

2545

bool interface_was_up = interface_is_up(interface);

2174

ret = bring_up_interface(interface, delay);

2546

errno = bring_up_interface(interface, delay);

2175

2547

if(not interface_was_up){

2176

if(ret != 0){

2177

errno = ret;

2548

if(errno != 0){

2178

2549

perror_plus("Failed to bring up interface");

2179

2550

} else {

2180

ret_errno = argz_add(&interfaces_to_take_down,

2181

&interfaces_to_take_down_size,

2182

interface);

2551

errno = argz_add(&interfaces_to_take_down,

2552

&interfaces_to_take_down_size,

2553

interface);

2554

if(errno != 0){

2555

perror_plus("argz_add");

2556

}

2183

2557

}

2184

2558

}

2185

2559

}

2186

free(interfaces);

2187

interfaces = NULL;

2188

interfaces_size = 0;

2189

2560

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

2190

2561

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

2191

2562

}

2192

2563

}

2193

2564

2565

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

2566

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

2567

if(debug){

2568

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

2569

mc.interfaces);

2570

}

2571

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

2572

}

2573

2194

2574

if(quit_now){

2195

2575

goto end;

2196

2576

}

2208

2588

goto end;

2209

2589

}

2210

2590

2211

if(mkdtemp(tempdir) == NULL){

2591

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

2592

tempdir = mkdtemp(run_tempdir);

2593

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

2594

if(debug){

2595

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

2596

run_tempdir, old_tempdir);

2597

}

2598

tempdir = mkdtemp(old_tempdir);

2599

}

2600

if(tempdir == NULL){

2212

2601

perror_plus("mkdtemp");

2213

2602

goto end;

2214

2603

}

2215

tempdir_created = true;

2216

2604

2217

2605

if(quit_now){

2218

2606

goto end;

2254

2642

exitcode = EX_USAGE;

2255

2643

goto end;

2256

2644

}

2257

2645

2258

2646

if(quit_now){

2259

2647

goto end;

2260

2648

}

2290

2678

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

2291

2679

(int)retry_interval);

2292

2680

}

2293

sleep((int)retry_interval);

2681

sleep((unsigned int)retry_interval);

2294

2682

}

2295

2683

2296

if (not quit_now){

2684

if(not quit_now){

2297

2685

exitcode = EXIT_SUCCESS;

2298

2686

}

2299

2687

2354

2742

if(debug){

2355

2743

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

2356

2744

}

2357

2745

2358

2746

ret = avahi_loop_with_timeout(simple_poll,

2359

2747

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

2360

2748

if(debug){

2369

2757

}

2370

2758

2371

2759

/* Cleanup things */

2760

free(mc.interfaces);

2761

2372

2762

if(sb != NULL)

2373

2763

avahi_s_service_browser_free(sb);

2374

2764

2394

2784

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

2395

2785

while(mc.current_server != NULL){

2396

2786

server *next = mc.current_server->next;

2787

#ifdef __GNUC__

2788

#pragma GCC diagnostic push

2789

#pragma GCC diagnostic ignored "-Wcast-qual"

2790

#endif

2791

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

2792

#ifdef __GNUC__

2793

#pragma GCC diagnostic pop

2794

#endif

2397

2795

free(mc.current_server);

2398

2796

mc.current_server = next;

2399

2797

}

2400

2798

}

2401

2799

2402

/* Re-raise priviliges */

2800

/* Re-raise privileges */

2403

2801

{

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();

2802

ret_errno = raise_privileges();

2803

if(ret_errno != 0){

2804

errno = ret_errno;

2805

perror_plus("Failed to raise privileges");

2806

} else {

2807

2808

/* Run network hooks */

2809

run_network_hooks("stop", interfaces_hooks != NULL ?

2810

interfaces_hooks : "", delay);

2811

2812

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

2813

{

2814

char *interface = NULL;

2815

while((interface=argz_next(interfaces_to_take_down,

2816

interfaces_to_take_down_size,

2817

interface))){

2818

ret_errno = take_down_interface(interface);

2819

if(ret_errno != 0){

2820

errno = ret_errno;

2821

perror_plus("Failed to take down interface");

2822

}

2823

}

2824

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

2825

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

2826

" down\n");

2827

}

2828

}

2829

}

2830

2831

ret_errno = lower_privileges_permanently();

2832

if(ret_errno != 0){

2833

errno = ret_errno;

2834

perror_plus("Failed to lower privileges permanently");

2835

}

2429

2836

}

2430

2837

2431

2838

free(interfaces_to_take_down);

2432

2839

free(interfaces_hooks);

2433

2840

2434

2841

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

2435

if(tempdir_created){

2842

if(tempdir != NULL){

2436

2843

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);

2844

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

2845

| O_NOFOLLOW

2846

| O_DIRECTORY

2847

| O_PATH));

2848

if(tempdir_fd == -1){

2849

perror_plus("open");

2850

} else {

2851

#ifdef __GLIBC__

2852

#if __GLIBC_PREREQ(2, 15)

2853

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

2854

notdotentries, alphasort);

2855

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

2856

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

2857

alphasort);

2858

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

2859

#else /* not __GLIBC__ */

2860

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

2861

alphasort);

2862

#endif /* not __GLIBC__ */

2863

if(numentries >= 0){

2864

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

2865

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

2866

if(ret == -1){

2867

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

2868

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

2869

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

2870

}

2871

free(direntries[i]);

2872

}

2873

2874

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

2875

free(direntries);

2876

if(numentries == -1){

2877

perror_plus("scandir");

2878

}

2879

ret = rmdir(tempdir);

2880

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

2881

perror_plus("rmdir");

2882

}

2456

2883

}

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");

2884

TEMP_FAILURE_RETRY(close(tempdir_fd));

2467

2885

}

2468

2886

}

2469

2887