/mandos/trunk : revision 308

1

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

1

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

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(), WTERMSIG(),

42

WCOREDUMP() */

41

WEXITSTATUS() */

43

42

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

44

43

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

45

44

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

53

52

close() */

54

53

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

55

54

FD_CLOEXEC */

56

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

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strsignal() */

55

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

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56

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

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57

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

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argp_state, struct argp,

67

65

SIG_UNBLOCK, kill(), sig_atomic_t

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66

*/

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67

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

70

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

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

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69

72

70

#define BUFFER_SIZE 256

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71

84

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char **environ;

85

83

int envc;

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bool disabled;

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/* Variables used for running processes*/

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pid_t pid;

90

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int fd;

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}

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}

112

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/* Create a new plugin */

113

plugin *new_plugin = NULL;

114

do {

115

new_plugin = malloc(sizeof(plugin));

116

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

111

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

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112

if(new_plugin == NULL){

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113

return NULL;

119

114

}

120

115

char *copy_name = NULL;

121

116

if(name != NULL){

122

do {

123

copy_name = strdup(name);

124

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

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copy_name = strdup(name);

125

118

if(copy_name == NULL){

126

119

free(new_plugin);

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return NULL;

133

126

.disabled = false,

134

127

.next = plugin_list };

135

128

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do {

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

138

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

129

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

139

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if(new_plugin->argv == NULL){

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free(copy_name);

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free(new_plugin);

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new_plugin->argv[0] = copy_name;

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136

new_plugin->argv[1] = NULL;

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137

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do {

148

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

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

138

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

150

139

if(new_plugin->environ == NULL){

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140

free(copy_name);

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free(new_plugin->argv);

164

153

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

165

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int *len){

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155

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

167

do {

168

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

169

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

170

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

156

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

157

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

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/* Malloc check */

172

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if(*array == NULL){

173

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return false;

174

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}

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/* Make a copy of the new string */

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char *copy;

177

do {

178

copy = strdup(new);

179

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

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char *copy = strdup(new);

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if(copy == NULL){

181

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return false;

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}

208

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

209

193

/* It already exists */

210

194

if(replace){

211

char *new;

212

do {

213

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

214

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

195

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

215

196

if(new == NULL){

216

197

return false;

217

198

}

227

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/*

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209

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

229

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* Descriptor Flags".

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

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

231

212

*/

232

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static int set_cloexec_flag(int fd){

233

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

214

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

234

215

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

235

216

if(ret < 0){

236

217

return ret;

237

218

}

238

219

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

239

return (int)TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD,

240

ret | FD_CLOEXEC));

220

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

241

221

}

242

222

243

223

300

280

}

301

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free(plugin_node->environ);

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free(plugin_node->buffer);

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

305

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if(plugin_node == plugin_list){

306

286

/* First one - simple */

333

313

struct dirent *dirst;

334

314

struct stat st;

335

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fd_set rfds_all;

336

int ret, maxfd = 0;

316

int ret, numchars, maxfd = 0;

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317

ssize_t sret;

318

intmax_t tmpmax;

338

319

uid_t uid = 65534;

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gid_t gid = 65534;

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321

bool debug = false;

400

381

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

401

382

struct argp_state *state){

402

383

switch(key){

403

char *tmp;

404

intmax_t tmpmax;

405

384

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

406

385

if(arg != NULL){

407

386

char *plugin_option;

477

456

plugindir = strdup(arg);

478

457

if(plugindir == NULL){

479

458

perror("strdup");

480

}

459

}

481

460

break;

482

461

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

483

462

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

484

463

break;

485

464

case 130: /* --userid */

486

errno = 0;

487

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

488

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

489

or tmpmax != (uid_t)tmpmax){

465

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

466

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

467

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

490

468

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

491

469

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

492

470

} else {

494

472

}

495

473

break;

496

474

case 131: /* --groupid */

497

errno = 0;

498

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

499

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

500

or tmpmax != (gid_t)tmpmax){

475

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

476

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

477

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

501

478

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

502

479

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

503

480

} else {

547

524

if(argfile == NULL){

548

525

perror("strdup");

549

526

}

550

break;

527

break;

551

528

case 130: /* --userid */

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529

case 131: /* --groupid */

553

530

case 132: /* --debug */

582

559

conffp = fopen(AFILE, "r");

583

560

} else {

584

561

conffp = fopen(argfile, "r");

585

}

562

}

586

563

if(conffp != NULL){

587

564

char *org_line = NULL;

588

565

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

589

566

size_t size = 0;

590

567

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

591

568

const char comment_delim[] = "#";

592

569

593

570

custom_argc = 1;

594

571

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

595

572

if(custom_argv == NULL){

599

576

}

600

577

custom_argv[0] = argv[0];

601

578

custom_argv[1] = NULL;

602

579

603

580

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

604

581

commented text */

605

582

while(true){

607

584

if(sret == -1){

608

585

break;

609

586

}

610

587

611

588

line = org_line;

612

589

arg = strsep(&line, comment_delim);

613

590

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

632

609

goto fallback;

633

610

}

634

611

custom_argv[custom_argc-1] = new_arg;

635

custom_argv[custom_argc] = NULL;

612

custom_argv[custom_argc] = NULL;

636

613

}

637

614

}

638

do {

639

ret = fclose(conffp);

640

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

641

if(ret == EOF){

642

perror("fclose");

643

exitstatus = EXIT_FAILURE;

644

goto fallback;

645

}

646

615

free(org_line);

647

616

} else {

648

617

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

727

696

728

697

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

729

698

while(true){

730

do {

731

dirst = readdir(dir);

732

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

699

dirst = readdir(dir);

733

700

734

701

/* All directory entries have been processed */

735

702

if(dirst == NULL){

786

753

continue;

787

754

}

788

755

}

789

756

790

757

char *filename;

791

758

if(plugindir == NULL){

792

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

793

dirst->d_name));

759

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

794

760

} else {

795

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

796

plugindir,

797

dirst->d_name));

761

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

798

762

}

799

763

if(ret < 0){

800

764

perror("asprintf");

801

765

continue;

802

766

}

803

767

804

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

768

ret = stat(filename, &st);

805

769

if(ret == -1){

806

770

perror("stat");

807

771

free(filename);

808

772

continue;

809

773

}

810

774

811

775

/* Ignore non-executable files */

812

if(not S_ISREG(st.st_mode)

813

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

776

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

814

777

if(debug){

815

778

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

816

779

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

862

825

}

863

826

864

827

int pipefd[2];

865

ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));

828

ret = pipe(pipefd);

866

829

if(ret == -1){

867

830

perror("pipe");

868

831

exitstatus = EXIT_FAILURE;

882

845

goto fallback;

883

846

}

884

847

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

885

ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,

886

&sigchld_action.sa_mask,

887

NULL));

848

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

888

849

if(ret < 0){

889

850

perror("sigprocmask");

890

851

exitstatus = EXIT_FAILURE;

891

852

goto fallback;

892

853

}

893

854

/* Starting a new process to be watched */

894

pid_t pid;

895

do {

896

pid = fork();

897

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

855

pid_t pid = fork();

898

856

if(pid == -1){

899

857

perror("fork");

900

858

exitstatus = EXIT_FAILURE;

938

896

/* no return */

939

897

}

940

898

/* Parent process */

941

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

942

pipe */

899

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

943

900

free(filename);

944

901

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

945

902

if(new_plugin == NULL){

946

903

perror("getplugin");

947

ret = (int)(TEMP_FAILURE_RETRY

948

(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

949

NULL)));

904

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

950

905

if(ret < 0){

951

906

perror("sigprocmask");

952

907

}

959

914

960

915

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

961

916

has already completed */

962

ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

963

&sigchld_action.sa_mask,

964

NULL));

917

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

965

918

if(ret < 0){

966

919

perror("sigprocmask");

967

920

exitstatus = EXIT_FAILURE;

975

928

}

976

929

}

977

930

978

TEMP_FAILURE_RETRY(closedir(dir));

931

closedir(dir);

979

932

dir = NULL;

980

933

free_plugin(getplugin(NULL));

981

934

994

947

while(plugin_list){

995

948

fd_set rfds = rfds_all;

996

949

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

997

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

950

if(select_ret == -1){

998

951

perror("select");

999

952

exitstatus = EXIT_FAILURE;

1000

953

goto fallback;

1008

961

if(not WIFEXITED(proc->status)

1009

962

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

1010

963

/* Bad exit by plugin */

1011

964

1012

965

if(debug){

1013

966

if(WIFEXITED(proc->status)){

1014

967

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

1017

970

WEXITSTATUS(proc->status));

1018

971

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

1019

972

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

1020

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

973

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

1021

974

(intmax_t) (proc->pid),

1022

WTERMSIG(proc->status),

1023

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

975

WTERMSIG(proc->status));

1024

976

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

1025

977

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

1026

978

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

1029

981

1030

982

/* Remove the plugin */

1031

983

FD_CLR(proc->fd, &rfds_all);

1032

984

1033

985

/* Block signal while modifying process_list */

1034

ret = (int)TEMP_FAILURE_RETRY(sigprocmask

1035

(SIG_BLOCK,

1036

&sigchld_action.sa_mask,

1037

NULL));

986

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

1038

987

if(ret < 0){

1039

988

perror("sigprocmask");

1040

989

exitstatus = EXIT_FAILURE;

1046

995

proc = next_plugin;

1047

996

1048

997

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

1049

ret = (int)(TEMP_FAILURE_RETRY

1050

(sigprocmask(SIG_UNBLOCK,

1051

&sigchld_action.sa_mask, NULL)));

998

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

999

NULL);

1052

1000

if(ret < 0){

1053

1001

perror("sigprocmask");

1054

1002

exitstatus = EXIT_FAILURE;

1091

1039

proc->buffer_size += BUFFER_SIZE;

1092

1040

}

1093

1041

/* Read from the process */

1094

sret = TEMP_FAILURE_RETRY(read(proc->fd,

1095

proc->buffer

1096

+ proc->buffer_length,

1097

BUFFER_SIZE));

1042

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

1043

BUFFER_SIZE);

1098

1044

if(sret < 0){

1099

1045

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

1100

1046

proc = proc->next;

1108

1054

}

1109

1055

}

1110

1056

}

1111

1112

1057

1058

1113

1059

fallback:

1114

1060

1115

1061

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

1162

1108

}

1163

1109

1164

1110

/* Wait for any remaining child processes to terminate */

1165

do {

1111

do{

1166

1112

ret = wait(NULL);

1167

1113

} while(ret >= 0);

1168

1114

if(errno != ECHILD){