/mandos/trunk : revision 362

1

/* -*- coding: utf-8 -*- */

1

/* -*- coding: utf-8; mode: c; mode: orgtbl -*- */

2

/*

3

* Mandos plugin runner - Run Mandos plugins

4

*

38

#include <sys/select.h> /* fd_set, select(), FD_ZERO(),

39

FD_SET(), FD_ISSET(), FD_CLR */

40

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

41

WEXITSTATUS() */

41

WEXITSTATUS(), WTERMSIG(),

42

WCOREDUMP() */

42

43

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

43

44

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

44

45

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

52

53

close() */

53

54

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

54

55

FD_CLOEXEC */

55

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

56

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

57

strsignal() */

56

58

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

57

59

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

58

60

argp_state, struct argp,

62

64

#include <signal.h> /* struct sigaction, sigemptyset(),

63

65

sigaddset(), sigaction(),

64

66

sigprocmask(), SIG_BLOCK, SIGCHLD,

65

SIG_UNBLOCK, kill() */

67

SIG_UNBLOCK, kill(), sig_atomic_t

68

*/

66

69

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

67

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

70

#include <inttypes.h> /* intmax_t, PRIdMAX, strtoimax() */

68

71

69

72

#define BUFFER_SIZE 256

70

73

81

84

char **environ;

82

85

int envc;

83

86

bool disabled;

84

87

85

88

/* Variables used for running processes*/

86

89

pid_t pid;

87

90

int fd;

89

92

size_t buffer_size;

90

93

size_t buffer_length;

91

94

bool eof;

92

volatile bool completed;

93

volatile int status;

95

volatile sig_atomic_t completed;

96

int status;

94

97

struct plugin *next;

95

98

} plugin;

96

99

107

110

}

108

111

}

109

112

/* Create a new plugin */

110

plugin *new_plugin = malloc(sizeof(plugin));

113

plugin *new_plugin = NULL;

114

do{

115

new_plugin = malloc(sizeof(plugin));

116

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

111

117

if(new_plugin == NULL){

112

118

return NULL;

113

119

}

114

120

char *copy_name = NULL;

115

121

if(name != NULL){

116

copy_name = strdup(name);

122

do{

123

copy_name = strdup(name);

124

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

117

125

if(copy_name == NULL){

118

126

free(new_plugin);

119

127

return NULL;

120

128

}

121

129

}

122

130

123

*new_plugin = (plugin) { .name = copy_name,

124

.argc = 1,

125

.disabled = false,

126

.next = plugin_list };

131

*new_plugin = (plugin){ .name = copy_name,

132

.argc = 1,

133

.disabled = false,

134

.next = plugin_list };

127

135

128

new_plugin->argv = malloc(sizeof(char *) * 2);

136

do{

137

new_plugin->argv = malloc(sizeof(char *) * 2);

138

}while(new_plugin->argv == NULL and errno == EINTR);

129

139

if(new_plugin->argv == NULL){

130

140

free(copy_name);

131

141

free(new_plugin);

134

144

new_plugin->argv[0] = copy_name;

135

145

new_plugin->argv[1] = NULL;

136

146

137

new_plugin->environ = malloc(sizeof(char *));

147

do{

148

new_plugin->environ = malloc(sizeof(char *));

149

}while(new_plugin->environ == NULL and errno == EINTR);

138

150

if(new_plugin->environ == NULL){

139

151

free(copy_name);

140

152

free(new_plugin->argv);

152

164

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

153

165

int *len){

154

166

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

155

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

156

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

167

do{

168

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

169

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

170

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

157

171

/* Malloc check */

158

172

if(*array == NULL){

159

173

return false;

160

174

}

161

175

/* Make a copy of the new string */

162

char *copy = strdup(new);

176

char *copy;

177

do{

178

copy = strdup(new);

179

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

163

180

if(copy == NULL){

164

181

return false;

165

182

}

191

208

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

192

209

/* It already exists */

193

210

if(replace){

194

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

211

char *new;

212

do{

213

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

214

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

195

215

if(new == NULL){

196

216

return false;

197

217

}

207

227

/*

208

228

* Based on the example in the GNU LibC manual chapter 13.13 "File

209

229

* Descriptor Flags".

210

* *Note File Descriptor Flags:(libc)Descriptor Flags.

230

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

211

231

*/

212

232

static int set_cloexec_flag(int fd){

213

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

233

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

214

234

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

215

235

if(ret < 0){

216

236

return ret;

217

237

}

218

238

/* Store modified flag word in the descriptor. */

219

return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);

239

return TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD, ret | FD_CLOEXEC));

220

240

}

221

241

222

242

223

243

/* Mark processes as completed when they exit, and save their exit

224

244

status. */

225

245

static void handle_sigchld(__attribute__((unused)) int sig){

246

int old_errno = errno;

226

247

while(true){

227

248

plugin *proc = plugin_list;

228

249

int status;

232

253

break;

233

254

}

234

255

if(pid == -1){

235

if(errno != ECHILD){

236

perror("waitpid");

256

if(errno == ECHILD){

257

/* No child processes */

258

break;

237

259

}

238

/* No child processes */

239

break;

260

perror("waitpid");

240

261

}

241

262

242

263

/* A child exited, find it in process_list */

248

269

continue;

249

270

}

250

271

proc->status = status;

251

proc->completed = true;

272

proc->completed = 1;

252

273

}

274

errno = old_errno;

253

275

}

254

276

255

277

/* Prints out a password to stdout */

277

299

}

278

300

free(plugin_node->environ);

279

301

free(plugin_node->buffer);

280

302

281

303

/* Removes the plugin from the singly-linked list */

282

304

if(plugin_node == plugin_list){

283

305

/* First one - simple */

310

332

struct dirent *dirst;

311

333

struct stat st;

312

334

fd_set rfds_all;

313

int ret, numchars, maxfd = 0;

335

int ret, maxfd = 0;

314

336

ssize_t sret;

315

intmax_t tmpmax;

316

337

uid_t uid = 65534;

317

338

gid_t gid = 65534;

318

339

bool debug = false;

376

397

};

377

398

378

399

error_t parse_opt(int key, char *arg, __attribute__((unused))

379

struct argp_state *state) {

380

switch(key) {

400

struct argp_state *state){

401

switch(key){

402

char *tmp;

403

intmax_t tmpmax;

381

404

case 'g': /* --global-options */

382

405

if(arg != NULL){

383

char *p;

384

while((p = strsep(&arg, ",")) != NULL){

385

if(p[0] == '\0'){

406

char *plugin_option;

407

while((plugin_option = strsep(&arg, ",")) != NULL){

408

if(plugin_option[0] == '\0'){

386

409

continue;

387

410

}

388

if(not add_argument(getplugin(NULL), p)){

411

if(not add_argument(getplugin(NULL), plugin_option)){

389

412

perror("add_argument");

390

413

return ARGP_ERR_UNKNOWN;

391

414

}

402

425

break;

403

426

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

404

427

if(arg != NULL){

405

char *p_name = strsep(&arg, ":");

406

if(p_name[0] == '\0' or arg == NULL){

407

break;

408

}

409

char *opt = strsep(&arg, ":");

410

if(opt[0] == '\0' or opt == NULL){

411

break;

412

}

413

char *p;

414

while((p = strsep(&opt, ",")) != NULL){

415

if(p[0] == '\0'){

416

continue;

417

}

418

if(not add_argument(getplugin(p_name), p)){

428

char *plugin_name = strsep(&arg, ":");

429

if(plugin_name[0] == '\0'){

430

break;

431

}

432

char *plugin_option;

433

while((plugin_option = strsep(&arg, ",")) != NULL){

434

if(not add_argument(getplugin(plugin_name), plugin_option)){

419

435

perror("add_argument");

420

436

return ARGP_ERR_UNKNOWN;

421

437

}

460

476

plugindir = strdup(arg);

461

477

if(plugindir == NULL){

462

478

perror("strdup");

463

}

479

}

464

480

break;

465

481

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

466

482

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

467

483

break;

468

484

case 130: /* --userid */

469

ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);

470

if(ret < 1 or tmpmax != (uid_t)tmpmax

471

or arg[numchars] != '\0'){

485

errno = 0;

486

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

487

if(errno != 0 or tmp == arg or *tmp != '\0'

488

or tmpmax != (uid_t)tmpmax){

472

489

fprintf(stderr, "Bad user ID number: \"%s\", using %"

473

490

PRIdMAX "\n", arg, (intmax_t)uid);

474

491

} else {

476

493

}

477

494

break;

478

495

case 131: /* --groupid */

479

ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);

480

if(ret < 1 or tmpmax != (gid_t)tmpmax

481

or arg[numchars] != '\0'){

496

errno = 0;

497

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

498

if(errno != 0 or tmp == arg or *tmp != '\0'

499

or tmpmax != (gid_t)tmpmax){

482

500

fprintf(stderr, "Bad group ID number: \"%s\", using %"

483

501

PRIdMAX "\n", arg, (intmax_t)gid);

484

502

} else {

512

530

ignores everything but the --config-file option. */

513

531

error_t parse_opt_config_file(int key, char *arg,

514

532

__attribute__((unused))

515

struct argp_state *state) {

516

switch(key) {

533

struct argp_state *state){

534

switch(key){

517

535

case 'g': /* --global-options */

518

536

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

519

537

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

528

546

if(argfile == NULL){

529

547

perror("strdup");

530

548

}

531

break;

549

break;

532

550

case 130: /* --userid */

533

551

case 131: /* --groupid */

534

552

case 132: /* --debug */

563

581

conffp = fopen(AFILE, "r");

564

582

} else {

565

583

conffp = fopen(argfile, "r");

566

}

584

}

567

585

if(conffp != NULL){

568

586

char *org_line = NULL;

569

587

char *p, *arg, *new_arg, *line;

570

588

size_t size = 0;

571

589

const char whitespace_delims[] = " \r\t\f\v\n";

572

590

const char comment_delim[] = "#";

573

591

574

592

custom_argc = 1;

575

593

custom_argv = malloc(sizeof(char*) * 2);

576

594

if(custom_argv == NULL){

580

598

}

581

599

custom_argv[0] = argv[0];

582

600

custom_argv[1] = NULL;

583

601

584

602

/* for each line in the config file, strip whitespace and ignore

585

603

commented text */

586

604

while(true){

588

606

if(sret == -1){

589

607

break;

590

608

}

591

609

592

610

line = org_line;

593

611

arg = strsep(&line, comment_delim);

594

612

while((p = strsep(&arg, whitespace_delims)) != NULL){

613

631

goto fallback;

614

632

}

615

633

custom_argv[custom_argc-1] = new_arg;

616

custom_argv[custom_argc] = NULL;

634

custom_argv[custom_argc] = NULL;

617

635

}

618

636

}

637

do{

638

ret = fclose(conffp);

639

}while(ret == EOF and errno == EINTR);

640

if(ret == EOF){

641

perror("fclose");

642

exitstatus = EXIT_FAILURE;

643

goto fallback;

644

}

619

645

free(org_line);

620

646

} else {

621

647

/* Check for harmful errors and go to fallback. Other errors might

662

688

}

663

689

664

690

/* Strip permissions down to nobody */

691

setgid(gid);

692

if(ret == -1){

693

perror("setgid");

694

}

665

695

ret = setuid(uid);

666

696

if(ret == -1){

667

697

perror("setuid");

668

}

669

setgid(gid);

670

if(ret == -1){

671

perror("setgid");

672

698

}

673

699

674

700

if(plugindir == NULL){

700

726

701

727

/* Read and execute any executable in the plugin directory*/

702

728

while(true){

703

dirst = readdir(dir);

729

do{

730

dirst = readdir(dir);

731

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

704

732

705

733

/* All directory entries have been processed */

706

734

if(dirst == NULL){

757

785

continue;

758

786

}

759

787

}

760

788

761

789

char *filename;

762

790

if(plugindir == NULL){

763

ret = asprintf(&filename, PDIR "/%s", dirst->d_name);

791

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

792

dirst->d_name));

764

793

} else {

765

ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);

794

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

795

dirst->d_name));

766

796

}

767

797

if(ret < 0){

768

798

perror("asprintf");

769

799

continue;

770

800

}

771

801

772

ret = stat(filename, &st);

802

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

773

803

if(ret == -1){

774

804

perror("stat");

775

805

free(filename);

776

806

continue;

777

807

}

778

808

779

809

/* Ignore non-executable files */

780

if(not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){

810

if(not S_ISREG(st.st_mode)

811

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

781

812

if(debug){

782

813

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

783

814

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

829

860

}

830

861

831

862

int pipefd[2];

832

ret = pipe(pipefd);

863

ret = TEMP_FAILURE_RETRY(pipe(pipefd));

833

864

if(ret == -1){

834

865

perror("pipe");

835

866

exitstatus = EXIT_FAILURE;

849

880

goto fallback;

850

881

}

851

882

/* Block SIGCHLD until process is safely in process list */

852

ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);

883

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,

884

&sigchld_action.sa_mask,

885

NULL));

853

886

if(ret < 0){

854

887

perror("sigprocmask");

855

888

exitstatus = EXIT_FAILURE;

856

889

goto fallback;

857

890

}

858

891

/* Starting a new process to be watched */

859

pid_t pid = fork();

892

pid_t pid;

893

do{

894

pid = fork();

895

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

860

896

if(pid == -1){

861

897

perror("fork");

862

898

exitstatus = EXIT_FAILURE;

900

936

/* no return */

901

937

}

902

938

/* Parent process */

903

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

939

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

940

pipe */

904

941

free(filename);

905

942

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

906

943

if(new_plugin == NULL){

907

944

perror("getplugin");

908

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);

945

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

946

&sigchld_action.sa_mask,

947

NULL));

909

948

if(ret < 0){

910

949

perror("sigprocmask");

911

950

}

918

957

919

958

/* Unblock SIGCHLD so signal handler can be run if this process

920

959

has already completed */

921

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);

960

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

961

&sigchld_action.sa_mask,

962

NULL));

922

963

if(ret < 0){

923

964

perror("sigprocmask");

924

965

exitstatus = EXIT_FAILURE;

932

973

}

933

974

}

934

975

935

closedir(dir);

976

TEMP_FAILURE_RETRY(closedir(dir));

936

977

dir = NULL;

978

free_plugin(getplugin(NULL));

937

979

938

980

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

939

981

if(p->pid != 0){

950

992

while(plugin_list){

951

993

fd_set rfds = rfds_all;

952

994

int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);

953

if(select_ret == -1){

995

if(select_ret == -1 and errno != EINTR){

954

996

perror("select");

955

997

exitstatus = EXIT_FAILURE;

956

998

goto fallback;

959

1001

from one of them */

960

1002

for(plugin *proc = plugin_list; proc != NULL;){

961

1003

/* Is this process completely done? */

962

if(proc->eof and proc->completed){

1004

if(proc->completed and proc->eof){

963

1005

/* Only accept the plugin output if it exited cleanly */

964

1006

if(not WIFEXITED(proc->status)

965

1007

or WEXITSTATUS(proc->status) != 0){

966

1008

/* Bad exit by plugin */

967

1009

968

1010

if(debug){

969

1011

if(WIFEXITED(proc->status)){

970

fprintf(stderr, "Plugin %" PRIdMAX " exited with status"

971

" %d\n", (intmax_t) (proc->pid),

1012

fprintf(stderr, "Plugin %s [%" PRIdMAX "] exited with"

1013

" status %d\n", proc->name,

1014

(intmax_t) (proc->pid),

972

1015

WEXITSTATUS(proc->status));

973

} else if(WIFSIGNALED(proc->status)) {

974

fprintf(stderr, "Plugin %" PRIdMAX " killed by signal"

975

" %d\n", (intmax_t) (proc->pid),

976

WTERMSIG(proc->status));

1016

} else if(WIFSIGNALED(proc->status)){

1017

fprintf(stderr, "Plugin %s [%" PRIdMAX "] killed by"

1018

" signal %d: %s\n", proc->name,

1019

(intmax_t) (proc->pid),

1020

WTERMSIG(proc->status),

1021

strsignal(WTERMSIG(proc->status)));

977

1022

} else if(WCOREDUMP(proc->status)){

978

fprintf(stderr, "Plugin %" PRIdMAX " dumped core\n",

979

(intmax_t) (proc->pid));

1023

fprintf(stderr, "Plugin %s [%" PRIdMAX "] dumped"

1024

" core\n", proc->name, (intmax_t) (proc->pid));

980

1025

}

981

1026

}

982

1027

983

1028

/* Remove the plugin */

984

1029

FD_CLR(proc->fd, &rfds_all);

985

1030

986

1031

/* Block signal while modifying process_list */

987

ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);

1032

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,

1033

&sigchld_action.sa_mask,

1034

NULL));

988

1035

if(ret < 0){

989

1036

perror("sigprocmask");

990

1037

exitstatus = EXIT_FAILURE;

996

1043

proc = next_plugin;

997

1044

998

1045

/* We are done modifying process list, so unblock signal */

999

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

1000

NULL);

1046

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

1047

&sigchld_action.sa_mask,

1048

NULL));

1001

1049

if(ret < 0){

1002

1050

perror("sigprocmask");

1003

1051

exitstatus = EXIT_FAILURE;

1040

1088

proc->buffer_size += BUFFER_SIZE;

1041

1089

}

1042

1090

/* Read from the process */

1043

sret = read(proc->fd, proc->buffer + proc->buffer_length,

1044

BUFFER_SIZE);

1091

sret = TEMP_FAILURE_RETRY(read(proc->fd,

1092

proc->buffer

1093

+ proc->buffer_length,

1094

BUFFER_SIZE));

1045

1095

if(sret < 0){

1046

1096

/* Read error from this process; ignore the error */

1047

1097

proc = proc->next;

1055

1105

}

1056

1106

}

1057

1107

}

1058

1059

1108

1109

1060

1110

fallback:

1061

1111

1062

1112

if(plugin_list == NULL or exitstatus != EXIT_SUCCESS){