/mandos/trunk : revision 389

1

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

1

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

2

/*

3

* Mandos plugin runner - Run Mandos plugins

4

*

23

*/

24

25

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

26

asprintf() */

26

asprintf(), O_CLOEXEC */

27

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

28

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

29

EXIT_SUCCESS, realloc() */

30

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

31

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

32

stderr, STDOUT_FILENO */

33

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

33

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

34

stat, waitpid(), WIFEXITED(),

35

WEXITSTATUS(), wait(), pid_t,

36

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

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

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

45

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

45

46

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

46

47

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

47

48

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

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,

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

240

ret | FD_CLOEXEC));

221

241

}

222

242

223

243

315

335

fd_set rfds_all;

316

336

int ret, maxfd = 0;

317

337

ssize_t sret;

318

intmax_t tmpmax;

319

338

uid_t uid = 65534;

320

339

gid_t gid = 65534;

321

340

bool debug = false;

380

399

381

400

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

382

401

struct argp_state *state){

383

char *tmp;

384

402

switch(key){

403

char *tmp;

404

intmax_t tmpmax;

385

405

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

386

406

if(arg != NULL){

387

407

char *plugin_option;

457

477

plugindir = strdup(arg);

458

478

if(plugindir == NULL){

459

479

perror("strdup");

460

}

480

}

461

481

break;

462

482

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

463

483

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

527

547

if(argfile == NULL){

528

548

perror("strdup");

529

549

}

530

break;

550

break;

531

551

case 130: /* --userid */

532

552

case 131: /* --groupid */

533

553

case 132: /* --debug */

562

582

conffp = fopen(AFILE, "r");

563

583

} else {

564

584

conffp = fopen(argfile, "r");

565

}

585

}

566

586

if(conffp != NULL){

567

587

char *org_line = NULL;

568

588

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

612

632

goto fallback;

613

633

}

614

634

custom_argv[custom_argc-1] = new_arg;

615

custom_argv[custom_argc] = NULL;

635

custom_argv[custom_argc] = NULL;

616

636

}

617

637

}

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

}

618

646

free(org_line);

619

647

} else {

620

648

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

670

698

perror("setuid");

671

699

}

672

700

673

if(plugindir == NULL){

674

dir = opendir(PDIR);

675

} else {

676

dir = opendir(plugindir);

677

}

678

679

if(dir == NULL){

680

perror("Could not open plugin dir");

681

exitstatus = EXIT_FAILURE;

682

goto fallback;

683

}

684

685

/* Set the FD_CLOEXEC flag on the directory, if possible */

701

/* Open plugin directory with close_on_exec flag */

686

702

{

687

int dir_fd = dirfd(dir);

688

if(dir_fd >= 0){

689

ret = set_cloexec_flag(dir_fd);

690

if(ret < 0){

691

perror("set_cloexec_flag");

692

exitstatus = EXIT_FAILURE;

693

goto fallback;

694

}

703

int dir_fd = -1;

704

if(plugindir == NULL){

705

dir_fd = open(PDIR, O_RDONLY |

706

#ifdef O_CLOEXEC

707

O_CLOEXEC

708

#else /* not O_CLOEXEC */

709

0

710

#endif /* not O_CLOEXEC */

711

);

712

} else {

713

dir_fd = open(plugindir, O_RDONLY |

714

#ifdef O_CLOEXEC

715

O_CLOEXEC

716

#else /* not O_CLOEXEC */

717

0

718

#endif /* not O_CLOEXEC */

719

);

720

}

721

if(dir_fd == -1){

722

perror("Could not open plugin dir");

723

exitstatus = EXIT_FAILURE;

724

goto fallback;

725

}

726

727

#ifndef O_CLOEXEC

728

/* Set the FD_CLOEXEC flag on the directory */

729

ret = set_cloexec_flag(dir_fd);

730

if(ret < 0){

731

perror("set_cloexec_flag");

732

TEMP_FAILURE_RETRY(close(dir_fd));

733

exitstatus = EXIT_FAILURE;

734

goto fallback;

735

}

736

#endif /* O_CLOEXEC */

737

738

dir = fdopendir(dir_fd);

739

if(dir == NULL){

740

perror("Could not open plugin dir");

741

TEMP_FAILURE_RETRY(close(dir_fd));

742

exitstatus = EXIT_FAILURE;

743

goto fallback;

695

744

}

696

745

}

697

746

699

748

700

749

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

701

750

while(true){

702

dirst = readdir(dir);

751

do {

752

dirst = readdir(dir);

753

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

703

754

704

755

/* All directory entries have been processed */

705

756

if(dirst == NULL){

759

810

760

811

char *filename;

761

812

if(plugindir == NULL){

762

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

813

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

814

dirst->d_name));

763

815

} else {

764

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

816

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

817

plugindir,

818

dirst->d_name));

765

819

}

766

820

if(ret < 0){

767

821

perror("asprintf");

768

822

continue;

769

823

}

770

824

771

ret = stat(filename, &st);

825

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

772

826

if(ret == -1){

773

827

perror("stat");

774

828

free(filename);

776

830

}

777

831

778

832

/* Ignore non-executable files */

779

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

833

if(not S_ISREG(st.st_mode)

834

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

780

835

if(debug){

781

836

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

782

837

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

828

883

}

829

884

830

885

int pipefd[2];

831

ret = pipe(pipefd);

886

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

832

887

if(ret == -1){

833

888

perror("pipe");

834

889

exitstatus = EXIT_FAILURE;

848

903

goto fallback;

849

904

}

850

905

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

851

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

906

ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,

907

&sigchld_action.sa_mask,

908

NULL));

852

909

if(ret < 0){

853

910

perror("sigprocmask");

854

911

exitstatus = EXIT_FAILURE;

855

912

goto fallback;

856

913

}

857

914

/* Starting a new process to be watched */

858

pid_t pid = fork();

915

pid_t pid;

916

do {

917

pid = fork();

918

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

859

919

if(pid == -1){

860

920

perror("fork");

861

921

exitstatus = EXIT_FAILURE;

899

959

/* no return */

900

960

}

901

961

/* Parent process */

902

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

962

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

963

pipe */

903

964

free(filename);

904

965

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

905

966

if(new_plugin == NULL){

906

967

perror("getplugin");

907

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

968

ret = (int)(TEMP_FAILURE_RETRY

969

(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

970

NULL)));

908

971

if(ret < 0){

909

972

perror("sigprocmask");

910

973

}

917

980

918

981

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

919

982

has already completed */

920

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

983

ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

984

&sigchld_action.sa_mask,

985

NULL));

921

986

if(ret < 0){

922

987

perror("sigprocmask");

923

988

exitstatus = EXIT_FAILURE;

924

989

goto fallback;

925

990

}

926

991

927

FD_SET(new_plugin->fd, &rfds_all);

992

FD_SET(new_plugin->fd, &rfds_all); /* Spurious warning from

993

-Wconversion */

928

994

929

995

if(maxfd < new_plugin->fd){

930

996

maxfd = new_plugin->fd;

931

997

}

932

998

}

933

999

934

closedir(dir);

1000

TEMP_FAILURE_RETRY(closedir(dir));

935

1001

dir = NULL;

936

1002

free_plugin(getplugin(NULL));

937

1003

950

1016

while(plugin_list){

951

1017

fd_set rfds = rfds_all;

952

1018

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

953

if(select_ret == -1){

1019

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

954

1020

perror("select");

955

1021

exitstatus = EXIT_FAILURE;

956

1022

goto fallback;

973

1039

WEXITSTATUS(proc->status));

974

1040

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

975

1041

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

976

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

1042

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

977

1043

(intmax_t) (proc->pid),

978

WTERMSIG(proc->status));

1044

WTERMSIG(proc->status),

1045

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

979

1046

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

980

1047

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

981

1048

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

983

1050

}

984

1051

985

1052

/* Remove the plugin */

986

FD_CLR(proc->fd, &rfds_all);

1053

FD_CLR(proc->fd, &rfds_all); /* Spurious warning from

1054

-Wconversion */

987

1055

988

1056

/* Block signal while modifying process_list */

989

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

1057

ret = (int)TEMP_FAILURE_RETRY(sigprocmask

1058

(SIG_BLOCK,

1059

&sigchld_action.sa_mask,

1060

NULL));

990

1061

if(ret < 0){

991

1062

perror("sigprocmask");

992

1063

exitstatus = EXIT_FAILURE;

998

1069

proc = next_plugin;

999

1070

1000

1071

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

1001

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

1002

NULL);

1072

ret = (int)(TEMP_FAILURE_RETRY

1073

(sigprocmask(SIG_UNBLOCK,

1074

&sigchld_action.sa_mask, NULL)));

1003

1075

if(ret < 0){

1004

1076

perror("sigprocmask");

1005

1077

exitstatus = EXIT_FAILURE;

1025

1097

}

1026

1098

1027

1099

/* This process has not completed. Does it have any output? */

1028

if(proc->eof or not FD_ISSET(proc->fd, &rfds)){

1100

if(proc->eof or not FD_ISSET(proc->fd, &rfds)){ /* Spurious

1101

warning from

1102

-Wconversion */

1029

1103

/* This process had nothing to say at this time */

1030

1104

proc = proc->next;

1031

1105

continue;

1042

1116

proc->buffer_size += BUFFER_SIZE;

1043

1117

}

1044

1118

/* Read from the process */

1045

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

1046

BUFFER_SIZE);

1119

sret = TEMP_FAILURE_RETRY(read(proc->fd,

1120

proc->buffer

1121

+ proc->buffer_length,

1122

BUFFER_SIZE));

1047

1123

if(sret < 0){

1048

1124

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

1049

1125

proc = proc->next;

1111

1187

}

1112

1188

1113

1189

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

1114

do{

1190

do {

1115

1191

ret = wait(NULL);

1116

1192

} while(ret >= 0);

1117

1193

if(errno != ECHILD){