/mandos/trunk : revision 712

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

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

243

free(new_server->ip);

251

244

free(new_server);

252

245

return false;

253

246

}

650

643

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

651

644

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

652

645

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 remove_arg[] = "remove";

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 = 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

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

779

helper, O_RDONLY));

780

TEMP_FAILURE_RETRY(close(helperdir_fd));

781

#ifdef __GNUC__

782

#pragma GCC diagnostic push

783

#pragma GCC diagnostic ignored "-Wcast-qual"

784

#endif

785

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

786

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

787

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

788

#ifdef __GNUC__

789

#pragma GCC diagnostic pop

790

#endif

791

perror_plus("fexecve");

792

_exit(EXIT_FAILURE);

793

}

794

}

795

if(pid == -1){

796

perror_plus("fork");

797

return false;

798

}

799

int status;

800

pid_t pret = -1;

801

errno = 0;

802

do {

803

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

804

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

805

int errno_raising = 0;

806

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

807

errno_raising = errno;

808

perror_plus("Failed to raise privileges in order to"

809

" kill helper program");

810

}

811

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

812

perror_plus("kill");

813

}

814

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

815

perror_plus("Failed to lower privileges after killing"

816

" helper program");

817

}

818

return false;

819

}

820

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

821

if(pret == -1){

822

perror_plus("waitpid");

823

return false;

824

}

825

if(WIFEXITED(status)){

826

if(WEXITSTATUS(status) != 0){

827

fprintf_plus(stderr, "Error: iprouteadddel exited"

828

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

829

return false;

830

}

831

return true;

832

}

833

if(WIFSIGNALED(status)){

834

fprintf_plus(stderr, "Error: iprouteadddel died by"

835

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

836

return false;

837

}

838

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

839

return false;

840

}

841

842

__attribute__((nonnull, warn_unused_result))

843

static bool add_local_route(const char *address,

844

AvahiIfIndex if_index){

845

return add_remove_local_route(true, address, if_index);

846

}

847

848

__attribute__((nonnull, warn_unused_result))

849

static bool remove_local_route(const char *address,

850

AvahiIfIndex if_index){

851

return add_remove_local_route(false, address, if_index);

852

}

853

854

646

/* Called when a Mandos server is found */

855

647

__attribute__((nonnull, warn_unused_result))

856

648

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

867

659

int retval = -1;

868

660

gnutls_session_t session;

869

661

int pf; /* Protocol family */

870

bool route_added = false;

871

662

872

663

errno = 0;

873

664

931

722

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

932

723

}

933

724

934

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

725

tcp_sd = socket(pf, SOCK_STREAM, 0);

935

726

if(tcp_sd < 0){

936

727

int e = errno;

937

728

perror_plus("socket");

1026

817

goto mandos_end;

1027

818

}

1028

819

1029

while(true){

1030

if(af == AF_INET6){

1031

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

1032

sizeof(struct sockaddr_in6));

1033

} else {

1034

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

1035

sizeof(struct sockaddr_in));

1036

}

1037

if(ret < 0){

1038

if(errno == ENETUNREACH

1039

and if_index != AVAHI_IF_UNSPEC

1040

and connect_to == NULL

1041

and not route_added and

1042

((af == AF_INET6 and not

1043

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1044

&to)->sin6_addr)))

1045

or (af == AF_INET and

1046

/* Not a a IPv4LL address */

1047

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

1048

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

1049

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

1050

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

1051

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

1052

connect to a Mandos server announced by Avahi on a server

1053

host with a global address. Work around this by retrying

1054

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

1055

1056

Avahi bug reference:

1057

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

1058

https://bugs.debian.org/587961

1059

*/

1060

int e = errno;

1061

route_added = add_local_route(ip, if_index);

1062

if(route_added){

1063

continue;

1064

}

1065

errno = e;

1066

}

1067

if(errno != ECONNREFUSED or debug){

1068

int e = errno;

1069

perror_plus("connect");

1070

errno = e;

1071

}

1072

goto mandos_end;

1073

}

1074

1075

if(quit_now){

1076

errno = EINTR;

1077

goto mandos_end;

1078

}

1079

break;

820

if(af == AF_INET6){

821

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

822

sizeof(struct sockaddr_in6));

823

} else {

824

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

825

sizeof(struct sockaddr_in));

826

}

827

if(ret < 0){

828

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

829

int e = errno;

830

perror_plus("connect");

831

errno = e;

832

}

833

goto mandos_end;

834

}

835

836

if(quit_now){

837

errno = EINTR;

838

goto mandos_end;

1080

839

}

1081

840

1082

841

const char *out = mandos_protocol_version;

1265

1024

1266

1025

mandos_end:

1267

1026

{

1268

if(route_added){

1269

if(not remove_local_route(ip, if_index)){

1270

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

1271

" interface %d", ip, if_index);

1272

}

1273

}

1274

1027

int e = errno;

1275

1028

free(decrypted_buffer);

1276

1029

free(buffer);

1316

1069

timed out */

1317

1070

1318

1071

if(quit_now){

1319

avahi_s_service_resolver_free(r);

1320

1072

return;

1321

1073

}

1322

1074

1702

1454

}

1703

1455

}

1704

1456

1457

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

1458

__attribute__((warn_unused_result))

1459

error_t raise_privileges(void){

1460

error_t old_errno = errno;

1461

error_t ret_errno = 0;

1462

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

1463

ret_errno = errno;

1464

}

1465

errno = old_errno;

1466

return ret_errno;

1467

}

1468

1469

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

1470

__attribute__((warn_unused_result))

1471

error_t raise_privileges_permanently(void){

1472

error_t old_errno = errno;

1473

error_t ret_errno = raise_privileges();

1474

if(ret_errno != 0){

1475

errno = old_errno;

1476

return ret_errno;

1477

}

1478

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

1479

ret_errno = errno;

1480

}

1481

errno = old_errno;

1482

return ret_errno;

1483

}

1484

1485

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

1486

__attribute__((warn_unused_result))

1487

error_t lower_privileges(void){

1488

error_t old_errno = errno;

1489

error_t ret_errno = 0;

1490

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

1491

ret_errno = errno;

1492

}

1493

errno = old_errno;

1494

return ret_errno;

1495

}

1496

1497

/* Lower privileges permanently */

1498

__attribute__((warn_unused_result))

1499

error_t lower_privileges_permanently(void){

1500

error_t old_errno = errno;

1501

error_t ret_errno = 0;

1502

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

1503

ret_errno = errno;

1504

}

1505

errno = old_errno;

1506

return ret_errno;

1507

}

1508

1705

1509

__attribute__((nonnull))

1706

1510

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

1707

1511

const float delay){

1708

1512

struct dirent **direntries = NULL;

1709

1513

if(hookdir_fd == -1){

1710

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1711

| O_CLOEXEC);

1514

hookdir_fd = open(hookdir, O_RDONLY);

1712

1515

if(hookdir_fd == -1){

1713

1516

if(errno == ENOENT){

1714

1517

if(debug){

1739

1542

}

1740

1543

struct dirent *direntry;

1741

1544

int ret;

1742

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

1743

if(devnull == -1){

1744

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

1745

return;

1746

}

1545

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

1747

1546

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

1748

1547

direntry = direntries[i];

1749

1548

if(debug){

1773

1572

perror_plus("setgroups");

1774

1573

_exit(EX_NOPERM);

1775

1574

}

1575

ret = dup2(devnull, STDIN_FILENO);

1576

if(ret == -1){

1577

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

1578

_exit(EX_OSERR);

1579

}

1580

ret = close(devnull);

1581

if(ret == -1){

1582

perror_plus("close");

1583

_exit(EX_OSERR);

1584

}

1585

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1586

if(ret == -1){

1587

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

1588

_exit(EX_OSERR);

1589

}

1776

1590

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

1777

1591

if(ret == -1){

1778

1592

perror_plus("setenv");

1813

1627

_exit(EX_OSERR);

1814

1628

}

1815

1629

}

1816

int hook_fd = TEMP_FAILURE_RETRY(openat(hookdir_fd,

1817

direntry->d_name,

1818

O_RDONLY));

1630

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

1819

1631

if(hook_fd == -1){

1820

1632

perror_plus("openat");

1821

1633

_exit(EXIT_FAILURE);

1824

1636

perror_plus("close");

1825

1637

_exit(EXIT_FAILURE);

1826

1638

}

1827

ret = dup2(devnull, STDIN_FILENO);

1828

if(ret == -1){

1829

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

1830

_exit(EX_OSERR);

1831

}

1832

ret = close(devnull);

1833

if(ret == -1){

1834

perror_plus("close");

1835

_exit(EX_OSERR);

1836

}

1837

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1838

if(ret == -1){

1839

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

1840

_exit(EX_OSERR);

1841

}

1842

1639

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

1843

1640

environ) == -1){

1844

1641

perror_plus("fexecve");

1845

1642

_exit(EXIT_FAILURE);

1846

1643

}

1847

1644

} else {

1848

if(hook_pid == -1){

1849

perror_plus("fork");

1850

free(direntry);

1851

continue;

1852

}

1853

1645

int status;

1854

1646

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

1855

1647

perror_plus("waitpid");

1856

free(direntry);

1857

1648

continue;

1858

1649

}

1859

1650

if(WIFEXITED(status)){

1861

1652

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

1862

1653

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

1863

1654

WEXITSTATUS(status));

1864

free(direntry);

1865

1655

continue;

1866

1656

}

1867

1657

} else if(WIFSIGNALED(status)){

1868

1658

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

1869

1659

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

1870

1660

WTERMSIG(status));

1871

free(direntry);

1872

1661

continue;

1873

1662

} else {

1874

1663

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

1875

1664

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

1876

free(direntry);

1877

1665

continue;

1878

1666

}

1879

1667

}

1881

1669

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

1882

1670

direntry->d_name);

1883

1671

}

1884

free(direntry);

1885

1672

}

1886

1673

free(direntries);

1887

1674

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

2292

2079

goto end;

2293

2080

}

2294

2081

}

2295

2082

2296

2083

{

2297

2084

/* Work around Debian bug #633582:

2298

2085

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

2325

2112

TEMP_FAILURE_RETRY(close(seckey_fd));

2326

2113

}

2327

2114

}

2328

2115

2329

2116

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

2330

2117

int pubkey_fd = open(pubkey, O_RDONLY);

2331

2118

if(pubkey_fd == -1){

2346

2133

TEMP_FAILURE_RETRY(close(pubkey_fd));

2347

2134

}

2348

2135

}

2349

2136

2350

2137

/* Lower privileges */

2351

2138

ret_errno = lower_privileges();

2352

2139

if(ret_errno != 0){

2481

2268

if(ret_errno != 0){

2482

2269

errno = ret_errno;

2483

2270

perror_plus("argz_add");

2484

free(direntries[i]);

2485

2271

continue;

2486

2272

}

2487

2273

if(debug){

2488

2274

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

2489

2275

direntries[i]->d_name);

2490

2276

}

2491

free(direntries[i]);

2492

2277

}

2493

2278

free(direntries);

2494

2279

} else {

2764

2549

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

2765

2550

while(mc.current_server != NULL){

2766

2551

server *next = mc.current_server->next;

2767

#ifdef __GNUC__

2768

#pragma GCC diagnostic push

2769

#pragma GCC diagnostic ignored "-Wcast-qual"

2770

#endif

2771

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

2772

#ifdef __GNUC__

2773

#pragma GCC diagnostic pop

2774

#endif

2775

2552

free(mc.current_server);

2776

2553

mc.current_server = next;

2777

2554

}

2821

2598

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

2822

2599

if(tempdir != NULL){

2823

2600

struct dirent **direntries = NULL;

2824

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

2825

| O_NOFOLLOW

2826

| O_DIRECTORY

2827

| O_PATH));

2601

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

2602

O_NOFOLLOW));

2828

2603

if(tempdir_fd == -1){

2829

2604

perror_plus("open");

2830

2605

} else {

2848

2623

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

2849

2624

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

2850

2625

}

2851

free(direntries[i]);

2852

2626

}

2853

2627

2854

2628

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