/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(),

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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

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.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);

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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

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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

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/*

228

208

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

229

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* 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 = 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 TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD, ret | FD_CLOEXEC));

219

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

240

220

}

241

221

242

222

299

279

}

300

280

free(plugin_node->environ);

301

281

free(plugin_node->buffer);

302

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303

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

304

284

if(plugin_node == plugin_list){

305

285

/* First one - simple */

332

312

struct dirent *dirst;

333

313

struct stat st;

334

314

fd_set rfds_all;

335

int ret, maxfd = 0;

315

int ret, numchars, maxfd = 0;

336

316

ssize_t sret;

317

intmax_t tmpmax;

337

318

uid_t uid = 65534;

338

319

gid_t gid = 65534;

339

320

bool debug = false;

399

380

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

400

381

struct argp_state *state){

401

382

switch(key){

402

char *tmp;

403

intmax_t tmpmax;

404

383

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

405

384

if(arg != NULL){

406

char *plugin_option;

407

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

408

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

385

char *p;

386

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

387

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

409

388

continue;

410

389

}

411

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

390

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

412

391

perror("add_argument");

413

392

return ARGP_ERR_UNKNOWN;

414

393

}

425

404

break;

426

405

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

427

406

if(arg != NULL){

428

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

429

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

430

break;

431

}

432

char *plugin_option;

433

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

434

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)){

435

421

perror("add_argument");

436

422

return ARGP_ERR_UNKNOWN;

437

423

}

476

462

plugindir = strdup(arg);

477

463

if(plugindir == NULL){

478

464

perror("strdup");

479

}

465

}

480

466

break;

481

467

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

482

468

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

483

469

break;

484

470

case 130: /* --userid */

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){

471

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

472

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

473

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

489

474

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

490

475

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

491

476

} else {

493

478

}

494

479

break;

495

480

case 131: /* --groupid */

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){

481

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

482

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

483

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

500

484

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

501

485

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

502

486

} else {

546

530

if(argfile == NULL){

547

531

perror("strdup");

548

532

}

549

break;

533

break;

550

534

case 130: /* --userid */

551

535

case 131: /* --groupid */

552

536

case 132: /* --debug */

581

565

conffp = fopen(AFILE, "r");

582

566

} else {

583

567

conffp = fopen(argfile, "r");

584

}

568

}

585

569

if(conffp != NULL){

586

570

char *org_line = NULL;

587

571

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

588

572

size_t size = 0;

589

573

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

590

574

const char comment_delim[] = "#";

591

575

592

576

custom_argc = 1;

593

577

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

594

578

if(custom_argv == NULL){

598

582

}

599

583

custom_argv[0] = argv[0];

600

584

custom_argv[1] = NULL;

601

585

602

586

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

603

587

commented text */

604

588

while(true){

606

590

if(sret == -1){

607

591

break;

608

592

}

609

593

610

594

line = org_line;

611

595

arg = strsep(&line, comment_delim);

612

596

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

631

615

goto fallback;

632

616

}

633

617

custom_argv[custom_argc-1] = new_arg;

634

custom_argv[custom_argc] = NULL;

618

custom_argv[custom_argc] = NULL;

635

619

}

636

620

}

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

}

645

621

free(org_line);

646

622

} else {

647

623

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

726

702

727

703

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

728

704

while(true){

729

do {

730

dirst = readdir(dir);

731

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

705

dirst = readdir(dir);

732

706

733

707

/* All directory entries have been processed */

734

708

if(dirst == NULL){

785

759

continue;

786

760

}

787

761

}

788

762

789

763

char *filename;

790

764

if(plugindir == NULL){

791

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

792

dirst->d_name));

765

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

793

766

} else {

794

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

795

dirst->d_name));

767

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

796

768

}

797

769

if(ret < 0){

798

770

perror("asprintf");

799

771

continue;

800

772

}

801

773

802

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

774

ret = stat(filename, &st);

803

775

if(ret == -1){

804

776

perror("stat");

805

777

free(filename);

806

778

continue;

807

779

}

808

780

809

781

/* Ignore non-executable files */

810

if(not S_ISREG(st.st_mode)

811

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

782

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

812

783

if(debug){

813

784

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

814

785

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

860

831

}

861

832

862

833

int pipefd[2];

863

ret = TEMP_FAILURE_RETRY(pipe(pipefd));

834

ret = pipe(pipefd);

864

835

if(ret == -1){

865

836

perror("pipe");

866

837

exitstatus = EXIT_FAILURE;

880

851

goto fallback;

881

852

}

882

853

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

883

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,

884

&sigchld_action.sa_mask,

885

NULL));

854

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

886

855

if(ret < 0){

887

856

perror("sigprocmask");

888

857

exitstatus = EXIT_FAILURE;

889

858

goto fallback;

890

859

}

891

860

/* Starting a new process to be watched */

892

pid_t pid;

893

do {

894

pid = fork();

895

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

861

pid_t pid = fork();

896

862

if(pid == -1){

897

863

perror("fork");

898

864

exitstatus = EXIT_FAILURE;

936

902

/* no return */

937

903

}

938

904

/* Parent process */

939

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

940

pipe */

905

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

941

906

free(filename);

942

907

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

943

908

if(new_plugin == NULL){

944

909

perror("getplugin");

945

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

946

&sigchld_action.sa_mask,

947

NULL));

910

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

948

911

if(ret < 0){

949

912

perror("sigprocmask");

950

913

}

957

920

958

921

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

959

922

has already completed */

960

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

961

&sigchld_action.sa_mask,

962

NULL));

923

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

963

924

if(ret < 0){

964

925

perror("sigprocmask");

965

926

exitstatus = EXIT_FAILURE;

973

934

}

974

935

}

975

936

976

TEMP_FAILURE_RETRY(closedir(dir));

937

closedir(dir);

977

938

dir = NULL;

978

free_plugin(getplugin(NULL));

979

939

980

940

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

981

941

if(p->pid != 0){

992

952

while(plugin_list){

993

953

fd_set rfds = rfds_all;

994

954

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

995

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

955

if(select_ret == -1){

996

956

perror("select");

997

957

exitstatus = EXIT_FAILURE;

998

958

goto fallback;

1006

966

if(not WIFEXITED(proc->status)

1007

967

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

1008

968

/* Bad exit by plugin */

1009

969

1010

970

if(debug){

1011

971

if(WIFEXITED(proc->status)){

1012

972

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

1015

975

WEXITSTATUS(proc->status));

1016

976

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

1017

977

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

1018

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

978

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

1019

979

(intmax_t) (proc->pid),

1020

WTERMSIG(proc->status),

1021

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

980

WTERMSIG(proc->status));

1022

981

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

1023

982

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

1024

983

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

1027

986

1028

987

/* Remove the plugin */

1029

988

FD_CLR(proc->fd, &rfds_all);

1030

989

1031

990

/* Block signal while modifying process_list */

1032

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,

1033

&sigchld_action.sa_mask,

1034

NULL));

991

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

1035

992

if(ret < 0){

1036

993

perror("sigprocmask");

1037

994

exitstatus = EXIT_FAILURE;

1043

1000

proc = next_plugin;

1044

1001

1045

1002

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

1046

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

1047

&sigchld_action.sa_mask,

1048

NULL));

1003

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

1004

NULL);

1049

1005

if(ret < 0){

1050

1006

perror("sigprocmask");

1051

1007

exitstatus = EXIT_FAILURE;

1088

1044

proc->buffer_size += BUFFER_SIZE;

1089

1045

}

1090

1046

/* Read from the process */

1091

sret = TEMP_FAILURE_RETRY(read(proc->fd,

1092

proc->buffer

1093

+ proc->buffer_length,

1094

BUFFER_SIZE));

1047

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

1048

BUFFER_SIZE);

1095

1049

if(sret < 0){

1096

1050

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

1097

1051

proc = proc->next;

1105

1059

}

1106

1060

}

1107

1061

}

1108

1109

1062

1063

1110

1064

fallback:

1111

1065

1112

1066

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

1159

1113

}

1160

1114

1161

1115

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

1162

do {

1116

do{

1163

1117

ret = wait(NULL);

1164

1118

} while(ret >= 0);

1165

1119

if(errno != ECHILD){