/mandos/trunk : revision 308

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(),

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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(),

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52

close() */

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53

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

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FD_CLOEXEC */

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

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strsignal() */

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

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56

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

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57

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

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argp_state, struct argp,

67

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SIG_UNBLOCK, kill(), sig_atomic_t

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66

*/

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67

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

70

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

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

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69

72

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#define BUFFER_SIZE 256

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71

84

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char **environ;

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int envc;

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bool disabled;

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/* Variables used for running processes*/

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pid_t pid;

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int fd;

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}

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}

112

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/* Create a new plugin */

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plugin *new_plugin = NULL;

114

do {

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new_plugin = malloc(sizeof(plugin));

116

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

111

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

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112

if(new_plugin == NULL){

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113

return NULL;

119

114

}

120

115

char *copy_name = NULL;

121

116

if(name != NULL){

122

do {

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copy_name = strdup(name);

124

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

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copy_name = strdup(name);

125

118

if(copy_name == NULL){

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119

free(new_plugin);

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return NULL;

133

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.disabled = false,

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127

.next = plugin_list };

135

128

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do {

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

138

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

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

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if(new_plugin->argv == NULL){

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free(copy_name);

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free(new_plugin);

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new_plugin->argv[0] = copy_name;

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new_plugin->argv[1] = NULL;

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137

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do {

148

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

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

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

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if(new_plugin->environ == NULL){

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free(copy_name);

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free(new_plugin->argv);

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

165

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int *len){

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/* 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 *)

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

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/* Malloc check */

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if(*array == NULL){

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return false;

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}

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/* Make a copy of the new string */

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char *copy;

177

do {

178

copy = strdup(new);

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

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char *copy = strdup(new);

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if(copy == NULL){

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return false;

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}

208

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

209

193

/* It already exists */

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if(replace){

211

char *new;

212

do {

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

214

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

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

215

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if(new == NULL){

216

197

return false;

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198

}

227

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/*

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

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* Descriptor Flags".

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

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

231

212

*/

232

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static int set_cloexec_flag(int fd){

233

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

220

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

240

221

}

241

222

242

223

299

280

}

300

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free(plugin_node->environ);

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free(plugin_node->buffer);

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

304

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if(plugin_node == plugin_list){

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/* First one - simple */

332

313

struct dirent *dirst;

333

314

struct stat st;

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315

fd_set rfds_all;

335

int ret, maxfd = 0;

316

int ret, numchars, maxfd = 0;

336

317

ssize_t sret;

318

intmax_t tmpmax;

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uid_t uid = 65534;

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gid_t gid = 65534;

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321

bool debug = false;

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381

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

400

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struct argp_state *state){

401

383

switch(key){

402

char *tmp;

403

intmax_t tmpmax;

404

384

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

405

385

if(arg != NULL){

406

386

char *plugin_option;

476

456

plugindir = strdup(arg);

477

457

if(plugindir == NULL){

478

458

perror("strdup");

479

}

459

}

480

460

break;

481

461

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

482

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

483

463

break;

484

464

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){

465

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

466

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

467

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

489

468

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

490

469

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

491

470

} else {

493

472

}

494

473

break;

495

474

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){

475

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

476

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

477

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

500

478

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

501

479

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

502

480

} else {

546

524

if(argfile == NULL){

547

525

perror("strdup");

548

526

}

549

break;

527

break;

550

528

case 130: /* --userid */

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529

case 131: /* --groupid */

552

530

case 132: /* --debug */

581

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conffp = fopen(AFILE, "r");

582

560

} else {

583

561

conffp = fopen(argfile, "r");

584

}

562

}

585

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if(conffp != NULL){

586

564

char *org_line = NULL;

587

565

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

588

566

size_t size = 0;

589

567

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

590

568

const char comment_delim[] = "#";

591

569

592

570

custom_argc = 1;

593

571

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

594

572

if(custom_argv == NULL){

598

576

}

599

577

custom_argv[0] = argv[0];

600

578

custom_argv[1] = NULL;

601

579

602

580

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

603

581

commented text */

604

582

while(true){

606

584

if(sret == -1){

607

585

break;

608

586

}

609

587

610

588

line = org_line;

611

589

arg = strsep(&line, comment_delim);

612

590

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

631

609

goto fallback;

632

610

}

633

611

custom_argv[custom_argc-1] = new_arg;

634

custom_argv[custom_argc] = NULL;

612

custom_argv[custom_argc] = NULL;

635

613

}

636

614

}

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

615

free(org_line);

646

616

} else {

647

617

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

726

696

727

697

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

728

698

while(true){

729

do {

730

dirst = readdir(dir);

731

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

699

dirst = readdir(dir);

732

700

733

701

/* All directory entries have been processed */

734

702

if(dirst == NULL){

785

753

continue;

786

754

}

787

755

}

788

756

789

757

char *filename;

790

758

if(plugindir == NULL){

791

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

792

dirst->d_name));

759

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

793

760

} else {

794

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

795

dirst->d_name));

761

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

796

762

}

797

763

if(ret < 0){

798

764

perror("asprintf");

799

765

continue;

800

766

}

801

767

802

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

768

ret = stat(filename, &st);

803

769

if(ret == -1){

804

770

perror("stat");

805

771

free(filename);

806

772

continue;

807

773

}

808

774

809

775

/* Ignore non-executable files */

810

if(not S_ISREG(st.st_mode)

811

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

776

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

812

777

if(debug){

813

778

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

814

779

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

860

825

}

861

826

862

827

int pipefd[2];

863

ret = TEMP_FAILURE_RETRY(pipe(pipefd));

828

ret = pipe(pipefd);

864

829

if(ret == -1){

865

830

perror("pipe");

866

831

exitstatus = EXIT_FAILURE;

880

845

goto fallback;

881

846

}

882

847

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

883

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,

884

&sigchld_action.sa_mask,

885

NULL));

848

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

886

849

if(ret < 0){

887

850

perror("sigprocmask");

888

851

exitstatus = EXIT_FAILURE;

889

852

goto fallback;

890

853

}

891

854

/* Starting a new process to be watched */

892

pid_t pid;

893

do {

894

pid = fork();

895

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

855

pid_t pid = fork();

896

856

if(pid == -1){

897

857

perror("fork");

898

858

exitstatus = EXIT_FAILURE;

936

896

/* no return */

937

897

}

938

898

/* Parent process */

939

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

940

pipe */

899

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

941

900

free(filename);

942

901

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

943

902

if(new_plugin == NULL){

944

903

perror("getplugin");

945

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

946

&sigchld_action.sa_mask,

947

NULL));

904

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

948

905

if(ret < 0){

949

906

perror("sigprocmask");

950

907

}

957

914

958

915

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

959

916

has already completed */

960

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

961

&sigchld_action.sa_mask,

962

NULL));

917

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

963

918

if(ret < 0){

964

919

perror("sigprocmask");

965

920

exitstatus = EXIT_FAILURE;

973

928

}

974

929

}

975

930

976

TEMP_FAILURE_RETRY(closedir(dir));

931

closedir(dir);

977

932

dir = NULL;

978

933

free_plugin(getplugin(NULL));

979

934

992

947

while(plugin_list){

993

948

fd_set rfds = rfds_all;

994

949

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

995

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

950

if(select_ret == -1){

996

951

perror("select");

997

952

exitstatus = EXIT_FAILURE;

998

953

goto fallback;

1006

961

if(not WIFEXITED(proc->status)

1007

962

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

1008

963

/* Bad exit by plugin */

1009

964

1010

965

if(debug){

1011

966

if(WIFEXITED(proc->status)){

1012

967

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

1015

970

WEXITSTATUS(proc->status));

1016

971

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

1017

972

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

1018

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

973

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

1019

974

(intmax_t) (proc->pid),

1020

WTERMSIG(proc->status),

1021

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

975

WTERMSIG(proc->status));

1022

976

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

1023

977

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

1024

978

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

1027

981

1028

982

/* Remove the plugin */

1029

983

FD_CLR(proc->fd, &rfds_all);

1030

984

1031

985

/* Block signal while modifying process_list */

1032

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,

1033

&sigchld_action.sa_mask,

1034

NULL));

986

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

1035

987

if(ret < 0){

1036

988

perror("sigprocmask");

1037

989

exitstatus = EXIT_FAILURE;

1043

995

proc = next_plugin;

1044

996

1045

997

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

1046

ret = TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

1047

&sigchld_action.sa_mask,

1048

NULL));

998

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

999

NULL);

1049

1000

if(ret < 0){

1050

1001

perror("sigprocmask");

1051

1002

exitstatus = EXIT_FAILURE;

1088

1039

proc->buffer_size += BUFFER_SIZE;

1089

1040

}

1090

1041

/* Read from the process */

1091

sret = TEMP_FAILURE_RETRY(read(proc->fd,

1092

proc->buffer

1093

+ proc->buffer_length,

1094

BUFFER_SIZE));

1042

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

1043

BUFFER_SIZE);

1095

1044

if(sret < 0){

1096

1045

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

1097

1046

proc = proc->next;

1105

1054

}

1106

1055

}

1107

1056

}

1108

1109

1057

1058

1110

1059

fallback:

1111

1060

1112

1061

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

1159

1108

}

1160

1109

1161

1110

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

1162

do {

1111

do{

1163

1112

ret = wait(NULL);

1164

1113

} while(ret >= 0);

1165

1114

if(errno != ECHILD){