/mandos/release : revision 24.1.140

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,

65

67

SIG_UNBLOCK, kill(), sig_atomic_t

66

68

*/

67

69

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

68

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

70

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

69

71

70

72

#define BUFFER_SIZE 256

71

73

82

84

char **environ;

83

85

int envc;

84

86

bool disabled;

85

87

86

88

/* Variables used for running processes*/

87

89

pid_t pid;

88

90

int fd;

108

110

}

109

111

}

110

112

/* Create a new plugin */

111

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);

112

117

if(new_plugin == NULL){

113

118

return NULL;

114

119

}

115

120

char *copy_name = NULL;

116

121

if(name != NULL){

117

copy_name = strdup(name);

122

do {

123

copy_name = strdup(name);

124

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

118

125

if(copy_name == NULL){

119

126

free(new_plugin);

120

127

return NULL;

126

133

.disabled = false,

127

134

.next = plugin_list };

128

135

129

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);

130

139

if(new_plugin->argv == NULL){

131

140

free(copy_name);

132

141

free(new_plugin);

135

144

new_plugin->argv[0] = copy_name;

136

145

new_plugin->argv[1] = NULL;

137

146

138

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

147

do {

148

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

149

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

139

150

if(new_plugin->environ == NULL){

140

151

free(copy_name);

141

152

free(new_plugin->argv);

153

164

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

154

165

int *len){

155

166

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

156

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

157

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

167

do {

168

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

169

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

170

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

158

171

/* Malloc check */

159

172

if(*array == NULL){

160

173

return false;

161

174

}

162

175

/* Make a copy of the new string */

163

char *copy = strdup(new);

176

char *copy;

177

do {

178

copy = strdup(new);

179

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

164

180

if(copy == NULL){

165

181

return false;

166

182

}

192

208

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

193

209

/* It already exists */

194

210

if(replace){

195

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);

196

215

if(new == NULL){

197

216

return false;

198

217

}

208

227

/*

209

228

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

210

229

* Descriptor Flags".

211

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

230

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

212

231

*/

213

232

static int set_cloexec_flag(int fd){

214

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

233

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

215

234

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

216

235

if(ret < 0){

217

236

return ret;

218

237

}

219

238

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

220

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

239

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

221

240

}

222

241

223

242

280

299

}

281

300

free(plugin_node->environ);

282

301

free(plugin_node->buffer);

283

302

284

303

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

285

304

if(plugin_node == plugin_list){

286

305

/* First one - simple */

313

332

struct dirent *dirst;

314

333

struct stat st;

315

334

fd_set rfds_all;

316

int ret, numchars, maxfd = 0;

335

int ret, maxfd = 0;

317

336

ssize_t sret;

318

intmax_t tmpmax;

319

337

uid_t uid = 65534;

320

338

gid_t gid = 65534;

321

339

bool debug = false;

381

399

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

382

400

struct argp_state *state){

383

401

switch(key){

402

char *tmp;

403

intmax_t tmpmax;

384

404

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

385

405

if(arg != NULL){

386

406

char *plugin_option;

456

476

plugindir = strdup(arg);

457

477

if(plugindir == NULL){

458

478

perror("strdup");

459

}

479

}

460

480

break;

461

481

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

462

482

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

463

483

break;

464

484

case 130: /* --userid */

465

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

466

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

467

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){

468

489

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

469

490

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

470

491

} else {

472

493

}

473

494

break;

474

495

case 131: /* --groupid */

475

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

476

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

477

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){

478

500

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

479

501

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

480

502

} else {

524

546

if(argfile == NULL){

525

547

perror("strdup");

526

548

}

527

break;

549

break;

528

550

case 130: /* --userid */

529

551

case 131: /* --groupid */

530

552

case 132: /* --debug */

559

581

conffp = fopen(AFILE, "r");

560

582

} else {

561

583

conffp = fopen(argfile, "r");

562

}

584

}

563

585

if(conffp != NULL){

564

586

char *org_line = NULL;

565

587

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

566

588

size_t size = 0;

567

589

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

568

590

const char comment_delim[] = "#";

569

591

570

592

custom_argc = 1;

571

593

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

572

594

if(custom_argv == NULL){

576

598

}

577

599

custom_argv[0] = argv[0];

578

600

custom_argv[1] = NULL;

579

601

580

602

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

581

603

commented text */

582

604

while(true){

584

606

if(sret == -1){

585

607

break;

586

608

}

587

609

588

610

line = org_line;

589

611

arg = strsep(&line, comment_delim);

590

612

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

609

631

goto fallback;

610

632

}

611

633

custom_argv[custom_argc-1] = new_arg;

612

custom_argv[custom_argc] = NULL;

634

custom_argv[custom_argc] = NULL;

613

635

}

614

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

}

615

645

free(org_line);

616

646

} else {

617

647

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

696

726

697

727

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

698

728

while(true){

699

dirst = readdir(dir);

729

do {

730

dirst = readdir(dir);

731

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

700

732

701

733

/* All directory entries have been processed */

702

734

if(dirst == NULL){

753

785

continue;

754

786

}

755

787

}

756

788

757

789

char *filename;

758

790

if(plugindir == NULL){

759

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

791

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

792

dirst->d_name));

760

793

} else {

761

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

794

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

795

dirst->d_name));

762

796

}

763

797

if(ret < 0){

764

798

perror("asprintf");

765

799

continue;

766

800

}

767

801

768

ret = stat(filename, &st);

802

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

769

803

if(ret == -1){

770

804

perror("stat");

771

805

free(filename);

772

806

continue;

773

807

}

774

808

775

809

/* Ignore non-executable files */

776

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)){

777

812

if(debug){

778

813

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

779

814

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

825

860

}

826

861

827

862

int pipefd[2];

828

ret = pipe(pipefd);

863

ret = TEMP_FAILURE_RETRY(pipe(pipefd));

829

864

if(ret == -1){

830

865

perror("pipe");

831

866

exitstatus = EXIT_FAILURE;

845

880

goto fallback;

846

881

}

847

882

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

848

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

883

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,

884

&sigchld_action.sa_mask,

885

NULL));

849

886

if(ret < 0){

850

887

perror("sigprocmask");

851

888

exitstatus = EXIT_FAILURE;

852

889

goto fallback;

853

890

}

854

891

/* Starting a new process to be watched */

855

pid_t pid = fork();

892

pid_t pid;

893

do {

894

pid = fork();

895

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

856

896

if(pid == -1){

857

897

perror("fork");

858

898

exitstatus = EXIT_FAILURE;

896

936

/* no return */

897

937

}

898

938

/* Parent process */

899

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

939

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

940

pipe */

900

941

free(filename);

901

942

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

902

943

if(new_plugin == NULL){

903

944

perror("getplugin");

904

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

945

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

946

&sigchld_action.sa_mask,

947

NULL));

905

948

if(ret < 0){

906

949

perror("sigprocmask");

907

950

}

914

957

915

958

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

916

959

has already completed */

917

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

960

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

961

&sigchld_action.sa_mask,

962

NULL));

918

963

if(ret < 0){

919

964

perror("sigprocmask");

920

965

exitstatus = EXIT_FAILURE;

928

973

}

929

974

}

930

975

931

closedir(dir);

976

TEMP_FAILURE_RETRY(closedir(dir));

932

977

dir = NULL;

933

978

free_plugin(getplugin(NULL));

934

979

947

992

while(plugin_list){

948

993

fd_set rfds = rfds_all;

949

994

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

950

if(select_ret == -1){

995

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

951

996

perror("select");

952

997

exitstatus = EXIT_FAILURE;

953

998

goto fallback;

961

1006

if(not WIFEXITED(proc->status)

962

1007

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

963

1008

/* Bad exit by plugin */

964

1009

965

1010

if(debug){

966

1011

if(WIFEXITED(proc->status)){

967

1012

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

970

1015

WEXITSTATUS(proc->status));

971

1016

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

972

1017

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

973

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

1018

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

974

1019

(intmax_t) (proc->pid),

975

WTERMSIG(proc->status));

1020

WTERMSIG(proc->status),

1021

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

976

1022

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

977

1023

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

978

1024

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

981

1027

982

1028

/* Remove the plugin */

983

1029

FD_CLR(proc->fd, &rfds_all);

984

1030

985

1031

/* Block signal while modifying process_list */

986

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

1032

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,

1033

&sigchld_action.sa_mask,

1034

NULL));

987

1035

if(ret < 0){

988

1036

perror("sigprocmask");

989

1037

exitstatus = EXIT_FAILURE;

995

1043

proc = next_plugin;

996

1044

997

1045

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

998

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

999

NULL);

1046

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

1047

&sigchld_action.sa_mask,

1048

NULL));

1000

1049

if(ret < 0){

1001

1050

perror("sigprocmask");

1002

1051

exitstatus = EXIT_FAILURE;

1039

1088

proc->buffer_size += BUFFER_SIZE;

1040

1089

}

1041

1090

/* Read from the process */

1042

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

1043

BUFFER_SIZE);

1091

sret = TEMP_FAILURE_RETRY(read(proc->fd,

1092

proc->buffer

1093

+ proc->buffer_length,

1094

BUFFER_SIZE));

1044

1095

if(sret < 0){

1045

1096

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

1046

1097

proc = proc->next;

1054

1105

}

1055

1106

}

1056

1107

}

1057

1058

1108

1109

1059

1110

fallback:

1060

1111

1061

1112

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

1108

1159

}

1109

1160

1110

1161

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

1111

do{

1162

do {

1112

1163

ret = wait(NULL);

1113

1164

} while(ret >= 0);

1114

1165

if(errno != ECHILD){