/mandos/trunk : revision 302

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() */

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(),

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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

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}

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

char *plugin_option;

408

while((plugin_option = strsep(&arg, ",")) != NULL){

409

if(plugin_option[0] == '\0'){

385

char *p;

386

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

387

if(p[0] == '\0'){

410

388

continue;

411

389

}

412

if(not add_argument(getplugin(NULL), plugin_option)){

390

if(not add_argument(getplugin(NULL), p)){

413

391

perror("add_argument");

414

392

return ARGP_ERR_UNKNOWN;

415

393

}

426

404

break;

427

405

case 'o': /* --options-for */

428

406

if(arg != NULL){

429

char *plugin_name = strsep(&arg, ":");

430

if(plugin_name[0] == '\0'){

431

break;

432

}

433

char *plugin_option;

434

while((plugin_option = strsep(&arg, ",")) != NULL){

435

if(not add_argument(getplugin(plugin_name), plugin_option)){

407

char *p_name = strsep(&arg, ":");

408

if(p_name[0] == '\0' or arg == NULL){

409

break;

410

}

411

char *opt = strsep(&arg, ":");

412

if(opt[0] == '\0' or opt == NULL){

413

break;

414

}

415

char *p;

416

while((p = strsep(&opt, ",")) != NULL){

417

if(p[0] == '\0'){

418

continue;

419

}

420

if(not add_argument(getplugin(p_name), p)){

436

421

perror("add_argument");

437

422

return ARGP_ERR_UNKNOWN;

438

423

}

477

462

plugindir = strdup(arg);

478

463

if(plugindir == NULL){

479

464

perror("strdup");

480

}

465

}

481

466

break;

482

467

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

483

468

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

484

469

break;

485

470

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){

471

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

472

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

473

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

490

474

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

491

475

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

492

476

} else {

494

478

}

495

479

break;

496

480

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){

481

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

482

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

483

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

501

484

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

502

485

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

503

486

} else {

547

530

if(argfile == NULL){

548

531

perror("strdup");

549

532

}

550

break;

533

break;

551

534

case 130: /* --userid */

552

535

case 131: /* --groupid */

553

536

case 132: /* --debug */

582

565

conffp = fopen(AFILE, "r");

583

566

} else {

584

567

conffp = fopen(argfile, "r");

585

}

568

}

586

569

if(conffp != NULL){

587

570

char *org_line = NULL;

588

571

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

589

572

size_t size = 0;

590

573

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

591

574

const char comment_delim[] = "#";

592

575

593

576

custom_argc = 1;

594

577

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

595

578

if(custom_argv == NULL){

599

582

}

600

583

custom_argv[0] = argv[0];

601

584

custom_argv[1] = NULL;

602

585

603

586

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

604

587

commented text */

605

588

while(true){

607

590

if(sret == -1){

608

591

break;

609

592

}

610

593

611

594

line = org_line;

612

595

arg = strsep(&line, comment_delim);

613

596

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

632

615

goto fallback;

633

616

}

634

617

custom_argv[custom_argc-1] = new_arg;

635

custom_argv[custom_argc] = NULL;

618

custom_argv[custom_argc] = NULL;

636

619

}

637

620

}

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

621

free(org_line);

647

622

} else {

648

623

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

727

702

728

703

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

729

704

while(true){

730

do {

731

dirst = readdir(dir);

732

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

705

dirst = readdir(dir);

733

706

734

707

/* All directory entries have been processed */

735

708

if(dirst == NULL){

786

759

continue;

787

760

}

788

761

}

789

762

790

763

char *filename;

791

764

if(plugindir == NULL){

792

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

793

dirst->d_name));

765

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

794

766

} else {

795

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

796

plugindir,

797

dirst->d_name));

767

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

798

768

}

799

769

if(ret < 0){

800

770

perror("asprintf");

801

771

continue;

802

772

}

803

773

804

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

774

ret = stat(filename, &st);

805

775

if(ret == -1){

806

776

perror("stat");

807

777

free(filename);

808

778

continue;

809

779

}

810

780

811

781

/* Ignore non-executable files */

812

if(not S_ISREG(st.st_mode)

813

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

782

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

814

783

if(debug){

815

784

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

816

785

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

862

831

}

863

832

864

833

int pipefd[2];

865

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

834

ret = pipe(pipefd);

866

835

if(ret == -1){

867

836

perror("pipe");

868

837

exitstatus = EXIT_FAILURE;

882

851

goto fallback;

883

852

}

884

853

/* 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));

854

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

888

855

if(ret < 0){

889

856

perror("sigprocmask");

890

857

exitstatus = EXIT_FAILURE;

891

858

goto fallback;

892

859

}

893

860

/* Starting a new process to be watched */

894

pid_t pid;

895

do {

896

pid = fork();

897

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

861

pid_t pid = fork();

898

862

if(pid == -1){

899

863

perror("fork");

900

864

exitstatus = EXIT_FAILURE;

938

902

/* no return */

939

903

}

940

904

/* Parent process */

941

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

942

pipe */

905

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

943

906

free(filename);

944

907

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

945

908

if(new_plugin == NULL){

946

909

perror("getplugin");

947

ret = (int)(TEMP_FAILURE_RETRY

948

(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

949

NULL)));

910

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

950

911

if(ret < 0){

951

912

perror("sigprocmask");

952

913

}

959

920

960

921

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

961

922

has already completed */

962

ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

963

&sigchld_action.sa_mask,

964

NULL));

923

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

965

924

if(ret < 0){

966

925

perror("sigprocmask");

967

926

exitstatus = EXIT_FAILURE;

975

934

}

976

935

}

977

936

978

TEMP_FAILURE_RETRY(closedir(dir));

937

closedir(dir);

979

938

dir = NULL;

980

free_plugin(getplugin(NULL));

981

939

982

940

for(plugin *p = plugin_list; p != NULL; p = p->next){

983

941

if(p->pid != 0){

994

952

while(plugin_list){

995

953

fd_set rfds = rfds_all;

996

954

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

997

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

955

if(select_ret == -1){

998

956

perror("select");

999

957

exitstatus = EXIT_FAILURE;

1000

958

goto fallback;

1008

966

if(not WIFEXITED(proc->status)

1009

967

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

1010

968

/* Bad exit by plugin */

1011

969

1012

970

if(debug){

1013

971

if(WIFEXITED(proc->status)){

1014

972

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

1017

975

WEXITSTATUS(proc->status));

1018

976

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

1019

977

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

1020

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

978

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

1021

979

(intmax_t) (proc->pid),

1022

WTERMSIG(proc->status),

1023

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

980

WTERMSIG(proc->status));

1024

981

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

1025

982

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

1026

983

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

1029

986

1030

987

/* Remove the plugin */

1031

988

FD_CLR(proc->fd, &rfds_all);

1032

989

1033

990

/* Block signal while modifying process_list */

1034

ret = (int)TEMP_FAILURE_RETRY(sigprocmask

1035

(SIG_BLOCK,

1036

&sigchld_action.sa_mask,

1037

NULL));

991

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

1038

992

if(ret < 0){

1039

993

perror("sigprocmask");

1040

994

exitstatus = EXIT_FAILURE;

1046

1000

proc = next_plugin;

1047

1001

1048

1002

/* 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)));

1003

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

1004

NULL);

1052

1005

if(ret < 0){

1053

1006

perror("sigprocmask");

1054

1007

exitstatus = EXIT_FAILURE;

1091

1044

proc->buffer_size += BUFFER_SIZE;

1092

1045

}

1093

1046

/* Read from the process */

1094

sret = TEMP_FAILURE_RETRY(read(proc->fd,

1095

proc->buffer

1096

+ proc->buffer_length,

1097

BUFFER_SIZE));

1047

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

1048

BUFFER_SIZE);

1098

1049

if(sret < 0){

1099

1050

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

1100

1051

proc = proc->next;

1108

1059

}

1109

1060

}

1110

1061

}

1111

1112

1062

1063

1113

1064

fallback:

1114

1065

1115

1066

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

1162

1113

}

1163

1114

1164

1115

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

1165

do {

1116

do{

1166

1117

ret = wait(NULL);

1167

1118

} while(ret >= 0);

1168

1119

if(errno != ECHILD){