/mandos/trunk : revision 706

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Viewing changes to plugins.d/mandos-client.c

Committer: Teddy Hogeborn
Date: 2014-06-15 01:01:14 UTC
Revision ID: teddy@recompile.se-20140615010114-fzz32p5naoo8nket

mandos-client: Better error messages.

* Makefile (run-client): Update message to match current messages.
                         Also set GNOME_KEYRING_CONTROL to empty
                         string to block pam_gnome_keyring.
* plugins.d/mandos-client (raise_privileges): Do not print errors.
  (raise_privileges_permanently): - '' -
  (lower_privileges): - '' -
  (lower_privileges_permanently): - '' -
  (run_network_hooks): Print errors from above functions correctly.
  (bring_up_interface, take_down_interface, main): - '' -

Show diffs side-by-side

added added

removed removed

plugins.d/mandos-client.c

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

* Everything else is

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

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

234

.af = af };

235

if(new_server->ip == NULL){

236

perror_plus("strdup");

237

free(new_server);

238

237

return false;

239

238

}

240

239

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

241

240

if(ret == -1){

242

241

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

252

242

return false;

253

243

}

254

244

/* Special case of first server */

650

640

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

651

641

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

652

642

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

862

643

/* Called when a Mandos server is found */

863

644

__attribute__((nonnull, warn_unused_result))

864

645

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

875

656

int retval = -1;

876

657

gnutls_session_t session;

877

658

int pf; /* Protocol family */

878

bool route_added = false;

879

659

880

660

errno = 0;

881

661

939

719

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

940

720

}

941

721

942

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

722

tcp_sd = socket(pf, SOCK_STREAM, 0);

943

723

if(tcp_sd < 0){

944

724

int e = errno;

945

725

perror_plus("socket");

1034

814

goto mandos_end;

1035

815

}

1036

816

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;

817

if(af == AF_INET6){

818

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

819

sizeof(struct sockaddr_in6));

820

} else {

821

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

822

sizeof(struct sockaddr_in));

823

}

824

if(ret < 0){

825

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

826

int e = errno;

827

perror_plus("connect");

828

errno = e;

829

}

830

goto mandos_end;

831

}

832

833

if(quit_now){

834

errno = EINTR;

835

goto mandos_end;

1088

836

}

1089

837

1090

838

const char *out = mandos_protocol_version;

1273

1021

1274

1022

mandos_end:

1275

1023

{

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

}

1282

1024

int e = errno;

1283

1025

free(decrypted_buffer);

1284

1026

free(buffer);

1324

1066

timed out */

1325

1067

1326

1068

if(quit_now){

1327

avahi_s_service_resolver_free(r);

1328

1069

return;

1329

1070

}

1330

1071

1710

1451

}

1711

1452

}

1712

1453

1454

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

1455

__attribute__((warn_unused_result))

1456

error_t raise_privileges(void){

1457

error_t old_errno = errno;

1458

error_t ret_errno = 0;

1459

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

1460

ret_errno = errno;

1461

}

1462

errno = old_errno;

1463

return ret_errno;

1464

}

1465

1466

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

1467

__attribute__((warn_unused_result))

1468

error_t raise_privileges_permanently(void){

1469

error_t old_errno = errno;

1470

error_t ret_errno = raise_privileges();

1471

if(ret_errno != 0){

1472

errno = old_errno;

1473

return ret_errno;

1474

}

1475

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

1476

ret_errno = errno;

1477

}

1478

errno = old_errno;

1479

return ret_errno;

1480

}

1481

1482

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

1483

__attribute__((warn_unused_result))

1484

error_t lower_privileges(void){

1485

error_t old_errno = errno;

1486

error_t ret_errno = 0;

1487

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

1488

ret_errno = errno;

1489

}

1490

errno = old_errno;

1491

return ret_errno;

1492

}

1493

1494

/* Lower privileges permanently */

1495

__attribute__((warn_unused_result))

1496

error_t lower_privileges_permanently(void){

1497

error_t old_errno = errno;

1498

error_t ret_errno = 0;

1499

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

1500

ret_errno = errno;

1501

}

1502

errno = old_errno;

1503

return ret_errno;

1504

}

1505

1713

1506

__attribute__((nonnull))

1714

1507

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

1715

1508

const float delay){

1716

1509

struct dirent **direntries = NULL;

1717

1510

if(hookdir_fd == -1){

1718

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1719

| O_CLOEXEC);

1511

hookdir_fd = open(hookdir, O_RDONLY);

1720

1512

if(hookdir_fd == -1){

1721

1513

if(errno == ENOENT){

1722

1514

if(debug){

1747

1539

}

1748

1540

struct dirent *direntry;

1749

1541

int ret;

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

}

1542

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

1755

1543

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

1756

1544

direntry = direntries[i];

1757

1545

if(debug){

1781

1569

perror_plus("setgroups");

1782

1570

_exit(EX_NOPERM);

1783

1571

}

1572

ret = dup2(devnull, STDIN_FILENO);

1573

if(ret == -1){

1574

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

1575

_exit(EX_OSERR);

1576

}

1577

ret = close(devnull);

1578

if(ret == -1){

1579

perror_plus("close");

1580

_exit(EX_OSERR);

1581

}

1582

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1583

if(ret == -1){

1584

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

1585

_exit(EX_OSERR);

1586

}

1784

1587

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

1785

1588

if(ret == -1){

1786

1589

perror_plus("setenv");

1821

1624

_exit(EX_OSERR);

1822

1625

}

1823

1626

}

1824

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

1825

direntry->d_name,

1826

O_RDONLY));

1627

int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);

1827

1628

if(hook_fd == -1){

1828

1629

perror_plus("openat");

1829

1630

_exit(EXIT_FAILURE);

1832

1633

perror_plus("close");

1833

1634

_exit(EXIT_FAILURE);

1834

1635

}

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

1636

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

1851

1637

environ) == -1){

1852

1638

perror_plus("fexecve");

1853

1639

_exit(EXIT_FAILURE);

1854

1640

}

1855

1641

} else {

1856

if(hook_pid == -1){

1857

perror_plus("fork");

1858

free(direntry);

1859

continue;

1860

}

1861

1642

int status;

1862

1643

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

1863

1644

perror_plus("waitpid");

1864

free(direntry);

1865

1645

continue;

1866

1646

}

1867

1647

if(WIFEXITED(status)){

1869

1649

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

1870

1650

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

1871

1651

WEXITSTATUS(status));

1872

free(direntry);

1873

1652

continue;

1874

1653

}

1875

1654

} else if(WIFSIGNALED(status)){

1876

1655

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

1877

1656

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

1878

1657

WTERMSIG(status));

1879

free(direntry);

1880

1658

continue;

1881

1659

} else {

1882

1660

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

1883

1661

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

1884

free(direntry);

1885

1662

continue;

1886

1663

}

1887

1664

}

1889

1666

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

1890

1667

direntry->d_name);

1891

1668

}

1892

free(direntry);

1893

1669

}

1894

1670

free(direntries);

1895

1671

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

2300

2076

goto end;

2301

2077

}

2302

2078

}

2303

2079

2304

2080

{

2305

2081

/* Work around Debian bug #633582:

2306

2082

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

2333

2109

TEMP_FAILURE_RETRY(close(seckey_fd));

2334

2110

}

2335

2111

}

2336

2112

2337

2113

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

2338

2114

int pubkey_fd = open(pubkey, O_RDONLY);

2339

2115

if(pubkey_fd == -1){

2354

2130

TEMP_FAILURE_RETRY(close(pubkey_fd));

2355

2131

}

2356

2132

}

2357

2133

2358

2134

/* Lower privileges */

2359

2135

ret_errno = lower_privileges();

2360

2136

if(ret_errno != 0){

2489

2265

if(ret_errno != 0){

2490

2266

errno = ret_errno;

2491

2267

perror_plus("argz_add");

2492

free(direntries[i]);

2493

2268

continue;

2494

2269

}

2495

2270

if(debug){

2496

2271

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

2497

2272

direntries[i]->d_name);

2498

2273

}

2499

free(direntries[i]);

2500

2274

}

2501

2275

free(direntries);

2502

2276

} else {

2772

2546

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

2773

2547

while(mc.current_server != NULL){

2774

2548

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

2783

2549

free(mc.current_server);

2784

2550

mc.current_server = next;

2785

2551

}

2829

2595

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

2830

2596

if(tempdir != NULL){

2831

2597

struct dirent **direntries = NULL;

2832

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

2833

| O_NOFOLLOW

2834

| O_DIRECTORY

2835

| O_PATH));

2598

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

2599

O_NOFOLLOW));

2836

2600

if(tempdir_fd == -1){

2837

2601

perror_plus("open");

2838

2602

} else {

2856

2620

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

2857

2621

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

2858

2622

}

2859

free(direntries[i]);

2860

2623

}

2861

2624

2862

2625

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

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