/mandos/trunk : revision 359

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(),

42

WCOREDUMP() */

43

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

44

#include <iso646.h> /* and, or, not */

45

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

45

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

46

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

47

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

48

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

110

}

111

}

112

/* 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);

113

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

117

114

if(new_plugin == NULL){

118

115

return NULL;

119

116

}

120

117

char *copy_name = NULL;

121

118

if(name != NULL){

122

do {

123

copy_name = strdup(name);

124

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

119

copy_name = strdup(name);

125

120

if(copy_name == NULL){

126

121

free(new_plugin);

127

122

return NULL;

133

128

.disabled = false,

134

129

.next = plugin_list };

135

130

136

do {

137

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

138

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

131

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

139

132

if(new_plugin->argv == NULL){

140

133

free(copy_name);

141

134

free(new_plugin);

144

137

new_plugin->argv[0] = copy_name;

145

138

new_plugin->argv[1] = NULL;

146

139

147

do {

148

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

149

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

140

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

150

141

if(new_plugin->environ == NULL){

151

142

free(copy_name);

152

143

free(new_plugin->argv);

164

155

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

165

156

int *len){

166

157

/* 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);

158

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

159

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

171

160

/* Malloc check */

172

161

if(*array == NULL){

173

162

return false;

174

163

}

175

164

/* Make a copy of the new string */

176

char *copy;

177

do {

178

copy = strdup(new);

179

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

165

char *copy = strdup(new);

180

166

if(copy == NULL){

181

167

return false;

182

168

}

208

194

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

209

195

/* It already exists */

210

196

if(replace){

211

char *new;

212

do {

213

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

214

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

197

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

215

198

if(new == NULL){

216

199

return false;

217

200

}

230

213

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

231

214

*/

232

215

static int set_cloexec_flag(int fd){

233

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

216

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

234

217

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

235

218

if(ret < 0){

236

219

return ret;

237

220

}

238

221

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

239

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

240

ret | FD_CLOEXEC));

222

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

241

223

}

242

224

243

225

335

317

fd_set rfds_all;

336

318

int ret, maxfd = 0;

337

319

ssize_t sret;

320

intmax_t tmpmax;

338

321

uid_t uid = 65534;

339

322

gid_t gid = 65534;

340

323

bool debug = false;

399

382

400

383

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

401

384

struct argp_state *state){

385

char *tmp;

402

386

switch(key){

403

char *tmp;

404

intmax_t tmpmax;

405

387

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

406

388

if(arg != NULL){

407

389

char *plugin_option;

635

617

custom_argv[custom_argc] = NULL;

636

618

}

637

619

}

638

do {

620

do{

639

621

ret = fclose(conffp);

640

} while(ret == EOF and errno == EINTR);

622

}while(ret == EOF and errno == EINTR);

641

623

if(ret == EOF){

642

624

perror("fclose");

643

625

exitstatus = EXIT_FAILURE;

698

680

perror("setuid");

699

681

}

700

682

701

/* Open plugin directory with close_on_exec flag */

683

if(plugindir == NULL){

684

dir = opendir(PDIR);

685

} else {

686

dir = opendir(plugindir);

687

}

688

689

if(dir == NULL){

690

perror("Could not open plugin dir");

691

exitstatus = EXIT_FAILURE;

692

goto fallback;

693

}

694

695

/* Set the FD_CLOEXEC flag on the directory, if possible */

702

696

{

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;

697

int dir_fd = dirfd(dir);

698

if(dir_fd >= 0){

699

ret = set_cloexec_flag(dir_fd);

700

if(ret < 0){

701

perror("set_cloexec_flag");

702

exitstatus = EXIT_FAILURE;

703

goto fallback;

704

}

744

705

}

745

706

}

746

707

748

709

749

710

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

750

711

while(true){

751

do {

752

dirst = readdir(dir);

753

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

712

dirst = readdir(dir);

754

713

755

714

/* All directory entries have been processed */

756

715

if(dirst == NULL){

810

769

811

770

char *filename;

812

771

if(plugindir == NULL){

813

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

814

dirst->d_name));

772

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

815

773

} else {

816

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

817

plugindir,

818

dirst->d_name));

774

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

819

775

}

820

776

if(ret < 0){

821

777

perror("asprintf");

822

778

continue;

823

779

}

824

780

825

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

781

ret = stat(filename, &st);

826

782

if(ret == -1){

827

783

perror("stat");

828

784

free(filename);

830

786

}

831

787

832

788

/* Ignore non-executable files */

833

if(not S_ISREG(st.st_mode)

834

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

789

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

835

790

if(debug){

836

791

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

837

792

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

883

838

}

884

839

885

840

int pipefd[2];

886

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

841

ret = pipe(pipefd);

887

842

if(ret == -1){

888

843

perror("pipe");

889

844

exitstatus = EXIT_FAILURE;

903

858

goto fallback;

904

859

}

905

860

/* 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));

861

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

909

862

if(ret < 0){

910

863

perror("sigprocmask");

911

864

exitstatus = EXIT_FAILURE;

912

865

goto fallback;

913

866

}

914

867

/* Starting a new process to be watched */

915

pid_t pid;

916

do {

917

pid = fork();

918

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

868

pid_t pid = fork();

919

869

if(pid == -1){

920

870

perror("fork");

921

871

exitstatus = EXIT_FAILURE;

959

909

/* no return */

960

910

}

961

911

/* Parent process */

962

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

963

pipe */

912

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

964

913

free(filename);

965

914

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

966

915

if(new_plugin == NULL){

967

916

perror("getplugin");

968

ret = (int)(TEMP_FAILURE_RETRY

969

(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

970

NULL)));

917

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

971

918

if(ret < 0){

972

919

perror("sigprocmask");

973

920

}

980

927

981

928

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

982

929

has already completed */

983

ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,

984

&sigchld_action.sa_mask,

985

NULL));

930

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

986

931

if(ret < 0){

987

932

perror("sigprocmask");

988

933

exitstatus = EXIT_FAILURE;

989

934

goto fallback;

990

935

}

991

936

992

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

993

-Wconversion */

937

FD_SET(new_plugin->fd, &rfds_all);

994

938

995

939

if(maxfd < new_plugin->fd){

996

940

maxfd = new_plugin->fd;

997

941

}

998

942

}

999

943

1000

TEMP_FAILURE_RETRY(closedir(dir));

944

closedir(dir);

1001

945

dir = NULL;

1002

946

free_plugin(getplugin(NULL));

1003

947

1016

960

while(plugin_list){

1017

961

fd_set rfds = rfds_all;

1018

962

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

1019

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

963

if(select_ret == -1){

1020

964

perror("select");

1021

965

exitstatus = EXIT_FAILURE;

1022

966

goto fallback;

1050

994

}

1051

995

1052

996

/* Remove the plugin */

1053

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

1054

-Wconversion */

997

FD_CLR(proc->fd, &rfds_all);

1055

998

1056

999

/* Block signal while modifying process_list */

1057

ret = (int)TEMP_FAILURE_RETRY(sigprocmask

1058

(SIG_BLOCK,

1059

&sigchld_action.sa_mask,

1060

NULL));

1000

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

1061

1001

if(ret < 0){

1062

1002

perror("sigprocmask");

1063

1003

exitstatus = EXIT_FAILURE;

1069

1009

proc = next_plugin;

1070

1010

1071

1011

/* 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)));

1012

ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,

1013

NULL);

1075

1014

if(ret < 0){

1076

1015

perror("sigprocmask");

1077

1016

exitstatus = EXIT_FAILURE;

1097

1036

}

1098

1037

1099

1038

/* 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 */

1039

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

1103

1040

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

1104

1041

proc = proc->next;

1105

1042

continue;

1116

1053

proc->buffer_size += BUFFER_SIZE;

1117

1054

}

1118

1055

/* Read from the process */

1119

sret = TEMP_FAILURE_RETRY(read(proc->fd,

1120

proc->buffer

1121

+ proc->buffer_length,

1122

BUFFER_SIZE));

1056

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

1057

BUFFER_SIZE);

1123

1058

if(sret < 0){

1124

1059

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

1125

1060

proc = proc->next;

1187

1122

}

1188

1123

1189

1124

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

1190

do {

1125

do{

1191

1126

ret = wait(NULL);

1192

1127

} while(ret >= 0);

1193

1128

if(errno != ECHILD){