/mandos/trunk : revision 24.1.134

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(),

57

strsignal(), strcmp(), strncmp() */

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,

64

62

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

65

63

sigaddset(), sigaction(),

66

64

sigprocmask(), SIG_BLOCK, SIGCHLD,

67

SIG_UNBLOCK, kill(), sig_atomic_t

68

*/

65

SIG_UNBLOCK, kill() */

69

66

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

70

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

67

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

71

68

72

69

#define BUFFER_SIZE 256

73

70

84

81

char **environ;

85

82

int envc;

86

83

bool disabled;

87

84

88

85

/* Variables used for running processes*/

89

86

pid_t pid;

90

87

int fd;

110

107

}

111

108

}

112

109

/* 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);

110

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

117

111

if(new_plugin == NULL){

118

112

return NULL;

119

113

}

120

114

char *copy_name = NULL;

121

115

if(name != NULL){

122

do {

123

copy_name = strdup(name);

124

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

116

copy_name = strdup(name);

125

117

if(copy_name == NULL){

126

118

free(new_plugin);

127

119

return NULL;

133

125

.disabled = false,

134

126

.next = plugin_list };

135

127

136

do {

137

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

138

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

128

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

139

129

if(new_plugin->argv == NULL){

140

130

free(copy_name);

141

131

free(new_plugin);

144

134

new_plugin->argv[0] = copy_name;

145

135

new_plugin->argv[1] = NULL;

146

136

147

do {

148

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

149

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

137

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

150

138

if(new_plugin->environ == NULL){

151

139

free(copy_name);

152

140

free(new_plugin->argv);

164

152

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

165

153

int *len){

166

154

/* 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);

155

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

156

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

171

157

/* Malloc check */

172

158

if(*array == NULL){

173

159

return false;

174

160

}

175

161

/* Make a copy of the new string */

176

char *copy;

177

do {

178

copy = strdup(new);

179

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

162

char *copy = strdup(new);

180

163

if(copy == NULL){

181

164

return false;

182

165

}

208

191

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

209

192

/* It already exists */

210

193

if(replace){

211

char *new;

212

do {

213

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

214

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

194

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

215

195

if(new == NULL){

216

196

return false;

217

197

}

227

207

/*

228

208

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

229

209

* Descriptor Flags".

230

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

210

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

231

211

*/

232

212

static int set_cloexec_flag(int fd){

233

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

213

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

234

214

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

235

215

if(ret < 0){

236

216

return ret;

237

217

}

238

218

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

239

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

240

ret | FD_CLOEXEC));

219

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

241

220

}

242

221

243

222

300

279

}

301

280

free(plugin_node->environ);

302

281

free(plugin_node->buffer);

303

282

304

283

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

305

284

if(plugin_node == plugin_list){

306

285

/* First one - simple */

333

312

struct dirent *dirst;

334

313

struct stat st;

335

314

fd_set rfds_all;

336

int ret, maxfd = 0;

315

int ret, numchars, maxfd = 0;

337

316

ssize_t sret;

317

intmax_t tmpmax;

338

318

uid_t uid = 65534;

339

319

gid_t gid = 65534;

340

320

bool debug = false;

400

380

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

401

381

struct argp_state *state){

402

382

switch(key){

403

char *tmp;

404

intmax_t tmpmax;

405

383

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

406

384

if(arg != NULL){

407

385

char *plugin_option;

477

455

plugindir = strdup(arg);

478

456

if(plugindir == NULL){

479

457

perror("strdup");

480

}

458

}

481

459

break;

482

460

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

483

461

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

484

462

break;

485

463

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){

464

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

465

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

466

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

490

467

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

491

468

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

492

469

} else {

494

471

}

495

472

break;

496

473

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){

474

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

475

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

476

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

501

477

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

502

478

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

503

479

} else {

547

523

if(argfile == NULL){

548

524

perror("strdup");

549

525

}

550

break;

526

break;

551

527

case 130: /* --userid */

552

528

case 131: /* --groupid */

553

529

case 132: /* --debug */

582

558

conffp = fopen(AFILE, "r");

583

559

} else {

584

560

conffp = fopen(argfile, "r");

585

}

561

}

586

562

if(conffp != NULL){

587

563

char *org_line = NULL;

588

564

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

589

565

size_t size = 0;

590

566

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

591

567

const char comment_delim[] = "#";

592

568

593

569

custom_argc = 1;

594

570

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

595

571

if(custom_argv == NULL){

599

575

}

600

576

custom_argv[0] = argv[0];

601

577

custom_argv[1] = NULL;

602

578

603

579

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

604

580

commented text */

605

581

while(true){

607

583

if(sret == -1){

608

584

break;

609

585

}

610

586

611

587

line = org_line;

612

588

arg = strsep(&line, comment_delim);

613

589

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

632

608

goto fallback;

633

609

}

634

610

custom_argv[custom_argc-1] = new_arg;

635

custom_argv[custom_argc] = NULL;

611

custom_argv[custom_argc] = NULL;

636

612

}

637

613

}

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

614

free(org_line);

647

615

} else {

648

616

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

727

695

728

696

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

729

697

while(true){

730

do {

731

dirst = readdir(dir);

732

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

698

dirst = readdir(dir);

733

699

734

700

/* All directory entries have been processed */

735

701

if(dirst == NULL){

771

737

for(const char **suf = bad_suffixes; *suf != NULL; suf++){

772

738

size_t suf_len = strlen(*suf);

773

739

if((d_name_len >= suf_len)

774

and (strcmp((dirst->d_name) + d_name_len-suf_len, *suf)

740

and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)

775

741

== 0)){

776

742

if(debug){

777

743

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

786

752

continue;

787

753

}

788

754

}

789

755

790

756

char *filename;

791

757

if(plugindir == NULL){

792

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

793

dirst->d_name));

758

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

794

759

} else {

795

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

796

plugindir,

797

dirst->d_name));

760

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

798

761

}

799

762

if(ret < 0){

800

763

perror("asprintf");

801

764

continue;

802

765

}

803

766

804

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

767

ret = stat(filename, &st);

805

768

if(ret == -1){

806

769

perror("stat");

807

770

free(filename);

808

771

continue;

809

772

}

810

773

811

774

/* Ignore non-executable files */

812

if(not S_ISREG(st.st_mode)

813

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

775

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

814

776

if(debug){

815

777

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

816

778

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

862

824

}

863

825

864

826

int pipefd[2];

865

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

827

ret = pipe(pipefd);

866

828

if(ret == -1){

867

829

perror("pipe");

868

830

exitstatus = EXIT_FAILURE;

882

844

goto fallback;

883

845

}

884

846

/* 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));

847

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

888

848

if(ret < 0){

889

849

perror("sigprocmask");

890

850

exitstatus = EXIT_FAILURE;

891

851

goto fallback;

892

852

}

893

853

/* Starting a new process to be watched */

894

pid_t pid;

895

do {

896

pid = fork();

897

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

854

pid_t pid = fork();

898

855

if(pid == -1){

899

856

perror("fork");

900

857

exitstatus = EXIT_FAILURE;

938

895

/* no return */

939

896

}

940

897

/* Parent process */

941

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

942

pipe */

898

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

943

899

free(filename);

944

900

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

945

901

if(new_plugin == NULL){

946

902

perror("getplugin");

947

ret = (int)(TEMP_FAILURE_RETRY

948

(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

949

NULL)));

903

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

950

904

if(ret < 0){

951

905

perror("sigprocmask");

952

906

}

959

913

960

914

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

961

915

has already completed */

962

ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

963

&sigchld_action.sa_mask,

964

NULL));

916

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

965

917

if(ret < 0){

966

918

perror("sigprocmask");

967

919

exitstatus = EXIT_FAILURE;

968

920

goto fallback;

969

921

}

970

922

971

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

972

-Wconversion */

923

FD_SET(new_plugin->fd, &rfds_all);

973

924

974

925

if(maxfd < new_plugin->fd){

975

926

maxfd = new_plugin->fd;

976

927

}

977

928

}

978

929

979

TEMP_FAILURE_RETRY(closedir(dir));

930

closedir(dir);

980

931

dir = NULL;

981

932

free_plugin(getplugin(NULL));

982

933

995

946

while(plugin_list){

996

947

fd_set rfds = rfds_all;

997

948

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

998

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

949

if(select_ret == -1){

999

950

perror("select");

1000

951

exitstatus = EXIT_FAILURE;

1001

952

goto fallback;

1009

960

if(not WIFEXITED(proc->status)

1010

961

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

1011

962

/* Bad exit by plugin */

1012

963

1013

964

if(debug){

1014

965

if(WIFEXITED(proc->status)){

1015

966

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

1018

969

WEXITSTATUS(proc->status));

1019

970

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

1020

971

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

1021

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

972

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

1022

973

(intmax_t) (proc->pid),

1023

WTERMSIG(proc->status),

1024

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

974

WTERMSIG(proc->status));

1025

975

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

1026

976

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

1027

977

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

1029

979

}

1030

980

1031

981

/* Remove the plugin */

1032

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

1033

-Wconversion */

1034

982

FD_CLR(proc->fd, &rfds_all);

983

1035

984

/* Block signal while modifying process_list */

1036

ret = (int)TEMP_FAILURE_RETRY(sigprocmask

1037

(SIG_BLOCK,

1038

&sigchld_action.sa_mask,

1039

NULL));

985

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

1040

986

if(ret < 0){

1041

987

perror("sigprocmask");

1042

988

exitstatus = EXIT_FAILURE;

1048

994

proc = next_plugin;

1049

995

1050

996

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

1051

ret = (int)(TEMP_FAILURE_RETRY

1052

(sigprocmask(SIG_UNBLOCK,

1053

&sigchld_action.sa_mask, NULL)));

997

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

998

NULL);

1054

999

if(ret < 0){

1055

1000

perror("sigprocmask");

1056

1001

exitstatus = EXIT_FAILURE;

1076

1021

}

1077

1022

1078

1023

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

1079

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

1080

warning from

1081

-Wconversion */

1024

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

1082

1025

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

1083

1026

proc = proc->next;

1084

1027

continue;

1095

1038

proc->buffer_size += BUFFER_SIZE;

1096

1039

}

1097

1040

/* Read from the process */

1098

sret = TEMP_FAILURE_RETRY(read(proc->fd,

1099

proc->buffer

1100

+ proc->buffer_length,

1101

BUFFER_SIZE));

1041

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

1042

BUFFER_SIZE);

1102

1043

if(sret < 0){

1103

1044

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

1104

1045

proc = proc->next;

1112

1053

}

1113

1054

}

1114

1055

}

1115

1116

1056

1057

1117

1058

fallback:

1118

1059

1119

1060

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

1166

1107

}

1167

1108

1168

1109

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

1169

do {

1110

do{

1170

1111

ret = wait(NULL);

1171

1112

} while(ret >= 0);

1172

1113

if(errno != ECHILD){