/mandos/trunk : revision 321

1

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

1

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

2

/*

3

* Mandos plugin runner - Run Mandos plugins

4

*

23

*/

24

25

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

26

asprintf(), O_CLOEXEC */

26

asprintf() */

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, fdopendir(), stat(), struct

33

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

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

44

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

46

45

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

47

46

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

48

47

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

53

52

close() */

54

53

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

55

54

FD_CLOEXEC */

56

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

57

strsignal() */

55

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

58

56

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

59

57

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

60

58

argp_state, struct argp,

110

108

}

111

109

}

112

110

/* 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));

117

112

if(new_plugin == NULL){

118

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);

117

copy_name = strdup(name);

125

118

if(copy_name == NULL){

126

119

free(new_plugin);

127

120

return NULL;

133

126

.disabled = false,

134

127

.next = plugin_list };

135

128

136

do {

137

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

130

if(new_plugin->argv == NULL){

140

131

free(copy_name);

141

132

free(new_plugin);

144

135

new_plugin->argv[0] = copy_name;

145

136

new_plugin->argv[1] = NULL;

146

137

147

do {

148

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

149

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

138

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

150

139

if(new_plugin->environ == NULL){

151

140

free(copy_name);

152

141

free(new_plugin->argv);

164

153

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

165

154

int *len){

166

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));

171

158

/* Malloc check */

172

159

if(*array == NULL){

173

160

return false;

174

161

}

175

162

/* Make a copy of the new string */

176

char *copy;

177

do {

178

copy = strdup(new);

179

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

163

char *copy = strdup(new);

180

164

if(copy == NULL){

181

165

return false;

182

166

}

208

192

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

208

/*

228

209

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

229

210

* Descriptor Flags".

230

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

211

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

231

212

*/

232

213

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

335

315

fd_set rfds_all;

336

316

int ret, maxfd = 0;

337

317

ssize_t sret;

318

intmax_t tmpmax;

338

319

uid_t uid = 65534;

339

320

gid_t gid = 65534;

340

321

bool debug = false;

399

380

400

381

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

401

382

struct argp_state *state){

383

char *tmp;

402

384

switch(key){

403

char *tmp;

404

intmax_t tmpmax;

405

385

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

406

386

if(arg != NULL){

407

387

char *plugin_option;

477

457

plugindir = strdup(arg);

478

458

if(plugindir == NULL){

479

459

perror("strdup");

480

}

460

}

481

461

break;

482

462

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

483

463

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

547

527

if(argfile == NULL){

548

528

perror("strdup");

549

529

}

550

break;

530

break;

551

531

case 130: /* --userid */

552

532

case 131: /* --groupid */

553

533

case 132: /* --debug */

582

562

conffp = fopen(AFILE, "r");

583

563

} else {

584

564

conffp = fopen(argfile, "r");

585

}

565

}

586

566

if(conffp != NULL){

587

567

char *org_line = NULL;

588

568

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

632

612

goto fallback;

633

613

}

634

614

custom_argv[custom_argc-1] = new_arg;

635

custom_argv[custom_argc] = NULL;

615

custom_argv[custom_argc] = NULL;

636

616

}

637

617

}

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

618

free(org_line);

647

619

} else {

648

620

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

698

670

perror("setuid");

699

671

}

700

672

701

/* Open plugin directory with close_on_exec flag */

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 */

702

686

{

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;

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

}

744

695

}

745

696

}

746

697

748

699

749

700

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

750

701

while(true){

751

do {

752

dirst = readdir(dir);

753

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

702

dirst = readdir(dir);

754

703

755

704

/* All directory entries have been processed */

756

705

if(dirst == NULL){

810

759

811

760

char *filename;

812

761

if(plugindir == NULL){

813

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

814

dirst->d_name));

762

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

815

763

} else {

816

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

817

plugindir,

818

dirst->d_name));

764

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

819

765

}

820

766

if(ret < 0){

821

767

perror("asprintf");

822

768

continue;

823

769

}

824

770

825

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

771

ret = stat(filename, &st);

826

772

if(ret == -1){

827

773

perror("stat");

828

774

free(filename);

830

776

}

831

777

832

778

/* Ignore non-executable files */

833

if(not S_ISREG(st.st_mode)

834

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

779

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

835

780

if(debug){

836

781

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

837

782

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

883

828

}

884

829

885

830

int pipefd[2];

886

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

831

ret = pipe(pipefd);

887

832

if(ret == -1){

888

833

perror("pipe");

889

834

exitstatus = EXIT_FAILURE;

903

848

goto fallback;

904

849

}

905

850

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

906

ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,

907

&sigchld_action.sa_mask,

908

NULL));

851

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

909

852

if(ret < 0){

910

853

perror("sigprocmask");

911

854

exitstatus = EXIT_FAILURE;

912

855

goto fallback;

913

856

}

914

857

/* Starting a new process to be watched */

915

pid_t pid;

916

do {

917

pid = fork();

918

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

858

pid_t pid = fork();

919

859

if(pid == -1){

920

860

perror("fork");

921

861

exitstatus = EXIT_FAILURE;

959

899

/* no return */

960

900

}

961

901

/* Parent process */

962

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

963

pipe */

902

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

964

903

free(filename);

965

904

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

966

905

if(new_plugin == NULL){

967

906

perror("getplugin");

968

ret = (int)(TEMP_FAILURE_RETRY

969

(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

970

NULL)));

907

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

971

908

if(ret < 0){

972

909

perror("sigprocmask");

973

910

}

980

917

981

918

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

982

919

has already completed */

983

ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

984

&sigchld_action.sa_mask,

985

NULL));

920

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

986

921

if(ret < 0){

987

922

perror("sigprocmask");

988

923

exitstatus = EXIT_FAILURE;

989

924

goto fallback;

990

925

}

991

926

992

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

993

-Wconversion */

927

FD_SET(new_plugin->fd, &rfds_all);

994

928

995

929

if(maxfd < new_plugin->fd){

996

930

maxfd = new_plugin->fd;

997

931

}

998

932

}

999

933

1000

TEMP_FAILURE_RETRY(closedir(dir));

934

closedir(dir);

1001

935

dir = NULL;

1002

936

free_plugin(getplugin(NULL));

1003

937

1016

950

while(plugin_list){

1017

951

fd_set rfds = rfds_all;

1018

952

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

1019

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

953

if(select_ret == -1){

1020

954

perror("select");

1021

955

exitstatus = EXIT_FAILURE;

1022

956

goto fallback;

1039

973

WEXITSTATUS(proc->status));

1040

974

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

1041

975

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

1042

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

976

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

1043

977

(intmax_t) (proc->pid),

1044

WTERMSIG(proc->status),

1045

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

978

WTERMSIG(proc->status));

1046

979

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

1047

980

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

1048

981

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

1050

983

}

1051

984

1052

985

/* Remove the plugin */

1053

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

1054

-Wconversion */

986

FD_CLR(proc->fd, &rfds_all);

1055

987

1056

988

/* Block signal while modifying process_list */

1057

ret = (int)TEMP_FAILURE_RETRY(sigprocmask

1058

(SIG_BLOCK,

1059

&sigchld_action.sa_mask,

1060

NULL));

989

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

1061

990

if(ret < 0){

1062

991

perror("sigprocmask");

1063

992

exitstatus = EXIT_FAILURE;

1069

998

proc = next_plugin;

1070

999

1071

1000

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

1072

ret = (int)(TEMP_FAILURE_RETRY

1073

(sigprocmask(SIG_UNBLOCK,

1074

&sigchld_action.sa_mask, NULL)));

1001

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

1002

NULL);

1075

1003

if(ret < 0){

1076

1004

perror("sigprocmask");

1077

1005

exitstatus = EXIT_FAILURE;

1097

1025

}

1098

1026

1099

1027

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

1100

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

1101

warning from

1102

-Wconversion */

1028

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

1103

1029

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

1104

1030

proc = proc->next;

1105

1031

continue;

1116

1042

proc->buffer_size += BUFFER_SIZE;

1117

1043

}

1118

1044

/* Read from the process */

1119

sret = TEMP_FAILURE_RETRY(read(proc->fd,

1120

proc->buffer

1121

+ proc->buffer_length,

1122

BUFFER_SIZE));

1045

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

1046

BUFFER_SIZE);

1123

1047

if(sret < 0){

1124

1048

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

1125

1049

proc = proc->next;

1187

1111

}

1188

1112

1189

1113

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

1190

do {

1114

do{

1191

1115

ret = wait(NULL);

1192

1116

} while(ret >= 0);

1193

1117

if(errno != ECHILD){