/mandos/trunk : revision 678

23

*/

24

25

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

26

asprintf(), O_CLOEXEC */

26

O_CLOEXEC */

27

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

28

#include <stdlib.h> /* malloc(), exit(), EXIT_SUCCESS,

29

realloc() */

30

#include <stdbool.h> /* bool, true, false */

31

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

32

stderr, STDOUT_FILENO */

33

#include <sys/types.h> /* DIR, fdopendir(), stat(), struct

32

stderr, STDOUT_FILENO, fclose() */

33

#include <sys/types.h> /* DIR, fdopendir(), fstat(), struct

34

stat, waitpid(), WIFEXITED(),

35

WEXITSTATUS(), wait(), pid_t,

36

uid_t, gid_t, getuid(), getgid(),

40

#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),

41

WEXITSTATUS(), WTERMSIG(),

42

WCOREDUMP() */

43

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

43

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

44

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

45

#include <dirent.h> /* DIR, struct dirent, fdopendir(),

46

readdir(), closedir(), dirfd() */

47

#include <unistd.h> /* struct stat, stat(), S_ISREG(),

48

fcntl(), setuid(), setgid(),

49

F_GETFD, F_SETFD, FD_CLOEXEC,

50

access(), pipe(), fork(), close()

51

dup2(), STDOUT_FILENO, _exit(),

52

execv(), write(), read(),

53

close() */

47

#include <unistd.h> /* fcntl(), F_GETFD, F_SETFD,

48

FD_CLOEXEC, write(), STDOUT_FILENO,

49

struct stat, fstat(), close(),

50

setgid(), setuid(), S_ISREG(),

51

faccessat() pipe(), fork(),

52

_exit(), dup2(), fexecve(), read()

53

*/

54

#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,

55

FD_CLOEXEC */

56

#include <string.h> /* strsep, strlen(), asprintf(),

57

strsignal(), strcmp(), strncmp() */

55

FD_CLOEXEC, openat() */

56

#include <string.h> /* strsep, strlen(), strsignal(),

57

strcmp(), strncmp() */

58

#include <errno.h> /* errno */

59

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

60

argp_state, struct argp,

72

EX_CONFIG, EX_UNAVAILABLE, EX_OK */

73

#include <errno.h> /* errno */

74

#include <error.h> /* error() */

75

#include <fnmatch.h> /* fnmatch() */

75

76

77

#define BUFFER_SIZE 256

77

78

105

106

107

/* Gets an existing plugin based on name,

107

108

or if none is found, creates a new one */

109

__attribute__((warn_unused_result))

108

110

static plugin *getplugin(char *name){

109

111

/* Check for existing plugin with that name */

110

112

for(plugin *p = plugin_list; p != NULL; p = p->next){

171

173

}

172

174

173

175

/* Helper function for add_argument and add_environment */

174

__attribute__((nonnull))

176

__attribute__((nonnull, warn_unused_result))

175

177

static bool add_to_char_array(const char *new, char ***array,

176

178

int *len){

177

179

/* Resize the pointed-to array to hold one more pointer */

180

char **new_array = NULL;

178

181

do {

179

*array = realloc(*array, sizeof(char *)

180

* (size_t) ((*len) + 2));

181

} while(*array == NULL and errno == EINTR);

182

new_array = realloc(*array, sizeof(char *)

183

* (size_t) ((*len) + 2));

184

} while(new_array == NULL and errno == EINTR);

182

185

/* Malloc check */

183

if(*array == NULL){

186

if(new_array == NULL){

184

187

return false;

185

188

}

189

*array = new_array;

186

190

/* Make a copy of the new string */

187

191

char *copy;

188

192

do {

200

204

}

201

205

202

206

/* Add to a plugin's argument vector */

203

__attribute__((nonnull(2)))

207

__attribute__((nonnull(2), warn_unused_result))

204

208

static bool add_argument(plugin *p, const char *arg){

205

209

if(p == NULL){

206

210

return false;

209

213

}

210

214

211

215

/* Add to a plugin's environment */

212

__attribute__((nonnull(2)))

216

__attribute__((nonnull(2), warn_unused_result))

213

217

static bool add_environment(plugin *p, const char *def, bool replace){

214

218

if(p == NULL){

215

219

return false;

217

221

/* namelen = length of name of environment variable */

218

222

size_t namelen = (size_t)(strchrnul(def, '=') - def);

219

223

/* Search for this environment variable */

220

for(char **e = p->environ; *e != NULL; e++){

221

if(strncmp(*e, def, namelen + 1) == 0){

224

for(char **envdef = p->environ; *envdef != NULL; envdef++){

225

if(strncmp(*envdef, def, namelen + 1) == 0){

222

226

/* It already exists */

223

227

if(replace){

224

char *new;

228

char *new_envdef;

225

229

do {

226

new = realloc(*e, strlen(def) + 1);

227

} while(new == NULL and errno == EINTR);

228

if(new == NULL){

230

new_envdef = realloc(*envdef, strlen(def) + 1);

231

} while(new_envdef == NULL and errno == EINTR);

232

if(new_envdef == NULL){

229

233

return false;

230

234

}

231

*e = new;

232

strcpy(*e, def);

235

*envdef = new_envdef;

236

strcpy(*envdef, def);

233

237

}

234

238

return true;

235

239

}

242

246

* Descriptor Flags".

243

247

| [[info:libc:Descriptor%20Flags][File Descriptor Flags]] |

244

248

*/

249

__attribute__((warn_unused_result))

245

250

static int set_cloexec_flag(int fd){

246

251

int ret = (int)TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD, 0));

247

252

/* If reading the flags failed, return error indication now. */

289

294

}

290

295

291

296

/* Prints out a password to stdout */

292

__attribute__((nonnull))

297

__attribute__((nonnull, warn_unused_result))

293

298

static bool print_out_password(const char *buffer, size_t length){

294

299

ssize_t ret;

295

300

for(size_t written = 0; written < length; written += (size_t)ret){

343

348

char *plugindir = NULL;

344

349

char *argfile = NULL;

345

350

FILE *conffp;

346

size_t d_name_len;

347

351

DIR *dir = NULL;

348

352

struct dirent *dirst;

349

353

struct stat st;

359

363

.sa_flags = SA_NOCLDSTOP };

360

364

char **custom_argv = NULL;

361

365

int custom_argc = 0;

366

int dir_fd;

362

367

363

368

/* Establish a signal handler */

364

369

sigemptyset(&sigchld_action.sa_mask);

435

440

break;

436

441

}

437

442

}

443

errno = 0;

438

444

}

439

445

break;

440

446

case 'G': /* --global-env */

441

add_environment(getplugin(NULL), arg, true);

447

if(add_environment(getplugin(NULL), arg, true)){

448

errno = 0;

449

}

442

450

break;

443

451

case 'o': /* --options-for */

444

452

{

461

469

break;

462

470

}

463

471

}

472

errno = 0;

464

473

}

465

474

break;

466

475

case 'E': /* --env-for */

478

487

errno = EINVAL;

479

488

break;

480

489

}

481

add_environment(getplugin(arg), envdef, true);

490

if(add_environment(getplugin(arg), envdef, true)){

491

errno = 0;

492

}

482

493

}

483

494

break;

484

495

case 'd': /* --disable */

486

497

plugin *p = getplugin(arg);

487

498

if(p != NULL){

488

499

p->disabled = true;

500

errno = 0;

489

501

}

490

502

}

491

503

break;

494

506

plugin *p = getplugin(arg);

495

507

if(p != NULL){

496

508

p->disabled = false;

509

errno = 0;

497

510

}

498

511

}

499

512

break;

500

513

case 128: /* --plugin-dir */

501

514

free(plugindir);

502

515

plugindir = strdup(arg);

516

if(plugindir != NULL){

517

errno = 0;

518

}

503

519

break;

504

520

case 129: /* --config-file */

505

521

/* This is already done by parse_opt_config_file() */

513

529

break;

514

530

}

515

531

uid = (uid_t)tmp_id;

532

errno = 0;

516

533

break;

517

534

case 131: /* --groupid */

518

535

tmp_id = strtoimax(arg, &tmp, 10);

523

540

break;

524

541

}

525

542

gid = (gid_t)tmp_id;

543

errno = 0;

526

544

break;

527

545

case 132: /* --debug */

528

546

debug = true;

576

594

case 129: /* --config-file */

577

595

free(argfile);

578

596

argfile = strdup(arg);

597

if(argfile != NULL){

598

errno = 0;

599

}

579

600

break;

580

601

case 130: /* --userid */

581

602

case 131: /* --groupid */

664

685

}

665

686

666

687

custom_argc += 1;

667

custom_argv = realloc(custom_argv, sizeof(char *)

668

* ((unsigned int) custom_argc + 1));

669

if(custom_argv == NULL){

670

error(0, errno, "realloc");

671

exitstatus = EX_OSERR;

672

free(org_line);

673

goto fallback;

688

{

689

char **new_argv = realloc(custom_argv, sizeof(char *)

690

* ((unsigned int)

691

custom_argc + 1));

692

if(new_argv == NULL){

693

error(0, errno, "realloc");

694

exitstatus = EX_OSERR;

695

free(new_arg);

696

free(org_line);

697

goto fallback;

698

} else {

699

custom_argv = new_argv;

700

}

674

701

}

675

702

custom_argv[custom_argc-1] = new_arg;

676

703

custom_argv[custom_argc] = NULL;

753

780

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

754

781

int plugindir_fd = open(/* plugindir or */ PDIR, O_RDONLY);

755

782

if(plugindir_fd == -1){

756

error(0, errno, "open");

783

if(errno != ENOENT){

784

error(0, errno, "open(\"" PDIR "\")");

785

}

757

786

} else {

758

787

ret = (int)TEMP_FAILURE_RETRY(fstat(plugindir_fd, &st));

759

788

if(ret == -1){

782

811

783

812

/* Open plugin directory with close_on_exec flag */

784

813

{

785

int dir_fd = -1;

786

if(plugindir == NULL){

787

dir_fd = open(PDIR, O_RDONLY |

788

#ifdef O_CLOEXEC

789

O_CLOEXEC

790

#else /* not O_CLOEXEC */

791

0

792

#endif /* not O_CLOEXEC */

793

);

794

} else {

795

dir_fd = open(plugindir, O_RDONLY |

796

#ifdef O_CLOEXEC

797

O_CLOEXEC

798

#else /* not O_CLOEXEC */

799

0

800

#endif /* not O_CLOEXEC */

801

);

802

}

814

dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |

815

#ifdef O_CLOEXEC

816

O_CLOEXEC

817

#else /* not O_CLOEXEC */

818

0

819

#endif /* not O_CLOEXEC */

820

);

803

821

if(dir_fd == -1){

804

822

error(0, errno, "Could not open plugin dir");

805

823

exitstatus = EX_UNAVAILABLE;

844

862

break;

845

863

}

846

864

847

d_name_len = strlen(dirst->d_name);

848

849

865

/* Ignore dotfiles, backup files and other junk */

850

866

{

851

867

bool bad_name = false;

852

853

const char const *bad_prefixes[] = { ".", "#", NULL };

854

855

const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",

856

".dpkg-old",

857

".dpkg-bak",

858

".dpkg-divert", NULL };

859

for(const char **pre = bad_prefixes; *pre != NULL; pre++){

860

size_t pre_len = strlen(*pre);

861

if((d_name_len >= pre_len)

862

and strncmp((dirst->d_name), *pre, pre_len) == 0){

863

if(debug){

864

fprintf(stderr, "Ignoring plugin dir entry \"%s\""

865

" with bad prefix %s\n", dirst->d_name, *pre);

866

}

867

bad_name = true;

868

break;

869

}

870

}

871

if(bad_name){

872

continue;

873

}

874

for(const char **suf = bad_suffixes; *suf != NULL; suf++){

875

size_t suf_len = strlen(*suf);

876

if((d_name_len >= suf_len)

877

and (strcmp((dirst->d_name) + d_name_len-suf_len, *suf)

878

== 0)){

879

if(debug){

880

fprintf(stderr, "Ignoring plugin dir entry \"%s\""

881

" with bad suffix %s\n", dirst->d_name, *suf);

882

}

883

bad_name = true;

884

break;

885

}

886

}

887

868

const char * const patterns[] = { ".*", "#*#", "*~",

869

"*.dpkg-new", "*.dpkg-old",

870

"*.dpkg-bak", "*.dpkg-divert",

871

NULL };

872

#ifdef __GNUC__

873

#pragma GCC diagnostic push

874

#pragma GCC diagnostic ignored "-Wcast-qual"

875

#endif

876

for(const char **pat = (const char **)patterns;

877

*pat != NULL; pat++){

878

#ifdef __GNUC__

879

#pragma GCC diagnostic pop

880

#endif

881

if(fnmatch(*pat, dirst->d_name,

882

FNM_FILE_NAME | FNM_PERIOD) != FNM_NOMATCH){

883

if(debug){

884

fprintf(stderr, "Ignoring plugin dir entry \"%s\""

885

" matching pattern %s\n", dirst->d_name, *pat);

886

}

887

bad_name = true;

888

break;

889

}

890

}

888

891

if(bad_name){

889

892

continue;

890

893

}

891

894

}

892

895

893

char *filename;

894

if(plugindir == NULL){

895

ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, PDIR "/%s",

896

dirst->d_name));

897

} else {

898

ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, "%s/%s",

899

plugindir,

900

dirst->d_name));

896

int plugin_fd = openat(dir_fd, dirst->d_name, O_RDONLY |

897

#ifdef O_CLOEXEC

898

O_CLOEXEC

899

#else /* not O_CLOEXEC */

900

0

901

#endif /* not O_CLOEXEC */

902

);

903

if(plugin_fd == -1){

904

error(0, errno, "Could not open plugin");

905

continue;

901

906

}

907

#ifndef O_CLOEXEC

908

/* Set the FD_CLOEXEC flag on the plugin FD */

909

ret = set_cloexec_flag(plugin_fd);

902

910

if(ret < 0){

903

error(0, errno, "asprintf");

911

error(0, errno, "set_cloexec_flag");

912

TEMP_FAILURE_RETRY(close(plugin_fd));

904

913

continue;

905

914

}

906

907

ret = (int)TEMP_FAILURE_RETRY(stat(filename, &st));

915

#endif /* O_CLOEXEC */

916

ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));

908

917

if(ret == -1){

909

918

error(0, errno, "stat");

910

free(filename);

919

TEMP_FAILURE_RETRY(close(plugin_fd));

911

920

continue;

912

921

}

913

922

914

923

/* Ignore non-executable files */

915

924

if(not S_ISREG(st.st_mode)

916

or (TEMP_FAILURE_RETRY(access(filename, X_OK)) != 0)){

925

or (TEMP_FAILURE_RETRY(faccessat(dir_fd, dirst->d_name, X_OK,

926

0)) != 0)){

917

927

if(debug){

918

fprintf(stderr, "Ignoring plugin dir entry \"%s\""

919

" with bad type or mode\n", filename);

928

fprintf(stderr, "Ignoring plugin dir entry \"%s/%s\""

929

" with bad type or mode\n",

930

plugindir != NULL ? plugindir : PDIR, dirst->d_name);

920

931

}

921

free(filename);

932

TEMP_FAILURE_RETRY(close(plugin_fd));

922

933

continue;

923

934

}

924

935

925

936

plugin *p = getplugin(dirst->d_name);

926

937

if(p == NULL){

927

938

error(0, errno, "getplugin");

928

free(filename);

939

TEMP_FAILURE_RETRY(close(plugin_fd));

929

940

continue;

930

941

}

931

942

if(p->disabled){

933

944

fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",

934

945

dirst->d_name);

935

946

}

936

free(filename);

947

TEMP_FAILURE_RETRY(close(plugin_fd));

937

948

continue;

938

949

}

939

950

{

953

964

}

954

965

}

955

966

}

956

/* If this plugin has any environment variables, we will call

957

using execve and need to duplicate the environment from this

958

process, too. */

967

/* If this plugin has any environment variables, we need to

968

duplicate the environment from this process, too. */

959

969

if(p->environ[0] != NULL){

960

970

for(char **e = environ; *e != NULL; e++){

961

971

if(not add_environment(p, *e, false)){

1027

1037

above and must now close it manually here. */

1028

1038

closedir(dir);

1029

1039

}

1030

if(p->environ[0] == NULL){

1031

if(execv(filename, p->argv) < 0){

1032

error(0, errno, "execv for %s", filename);

1033

_exit(EX_OSERR);

1034

}

1035

} else {

1036

if(execve(filename, p->argv, p->environ) < 0){

1037

error(0, errno, "execve for %s", filename);

1038

_exit(EX_OSERR);

1039

}

1040

if(fexecve(plugin_fd, p->argv,

1041

(p->environ[0] != NULL) ? p->environ : environ) < 0){

1042

error(0, errno, "fexecve for %s/%s",

1043

plugindir != NULL ? plugindir : PDIR, dirst->d_name);

1044

_exit(EX_OSERR);

1040

1045

}

1041

1046

/* no return */

1042

1047

}

1043

1048

/* Parent process */

1044

1049

TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of

1045

1050

pipe */

1046

free(filename);

1051

TEMP_FAILURE_RETRY(close(plugin_fd));

1047

1052

plugin *new_plugin = getplugin(dirst->d_name);

1048

1053

if(new_plugin == NULL){

1049

1054

error(0, errno, "getplugin");

1226

1231

}

1227

1232

/* Before reading, make the process' data buffer large enough */

1228

1233

if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){

1229

proc->buffer = realloc(proc->buffer, proc->buffer_size

1230

+ (size_t) BUFFER_SIZE);

1231

if(proc->buffer == NULL){

1234

char *new_buffer = realloc(proc->buffer, proc->buffer_size

1235

+ (size_t) BUFFER_SIZE);

1236

if(new_buffer == NULL){

1232

1237

error(0, errno, "malloc");

1233

1238

exitstatus = EX_OSERR;

1234

1239

goto fallback;

1235

1240

}

1241

proc->buffer = new_buffer;

1236

1242

proc->buffer_size += BUFFER_SIZE;

1237

1243

}

1238

1244

/* Read from the process */