3
3
* Mandos plugin runner - Run Mandos plugins
5
* Copyright © 2008-2017 Teddy Hogeborn
6
* Copyright © 2008-2017 Björn Påhlsson
8
* This file is part of Mandos.
10
* Mandos is free software: you can redistribute it and/or modify it
11
* under the terms of the GNU General Public License as published by
12
* the Free Software Foundation, either version 3 of the License, or
13
* (at your option) any later version.
15
* Mandos is distributed in the hope that it will be useful, but
5
* Copyright © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 Björn Påhlsson
8
* This program is free software: you can redistribute it and/or
9
* modify it under the terms of the GNU General Public License as
10
* published by the Free Software Foundation, either version 3 of the
11
* License, or (at your option) any later version.
13
* This program is distributed in the hope that it will be useful, but
16
14
* WITHOUT ANY WARRANTY; without even the implied warranty of
17
15
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18
16
* General Public License for more details.
20
18
* You should have received a copy of the GNU General Public License
21
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
19
* along with this program. If not, see
20
* <http://www.gnu.org/licenses/>.
23
* Contact the authors at <mandos@recompile.se>.
22
* Contact the authors at <mandos@fukt.bsnet.se>.
26
25
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), getline(),
28
27
#include <stddef.h> /* size_t, NULL */
29
#include <stdlib.h> /* malloc(), exit(), EXIT_SUCCESS,
28
#include <stdlib.h> /* malloc(), exit(), EXIT_FAILURE,
29
EXIT_SUCCESS, realloc() */
31
30
#include <stdbool.h> /* bool, true, false */
32
#include <stdio.h> /* fileno(), fprintf(),
33
stderr, STDOUT_FILENO, fclose() */
34
#include <sys/types.h> /* fstat(), struct stat, waitpid(),
35
WIFEXITED(), WEXITSTATUS(), wait(),
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pid_t, uid_t, gid_t, getuid(),
31
#include <stdio.h> /* perror, fileno(), fprintf(),
32
stderr, STDOUT_FILENO */
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(),
38
38
#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
39
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FD_SET(), FD_ISSET(), FD_CLR */
40
40
#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),
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WEXITSTATUS(), WTERMSIG() */
42
#include <sys/stat.h> /* struct stat, fstat(), S_ISREG() */
41
WEXITSTATUS(), WTERMSIG(),
43
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
43
44
#include <iso646.h> /* and, or, not */
44
#include <dirent.h> /* struct dirent, scandirat() */
45
#include <unistd.h> /* fcntl(), F_GETFD, F_SETFD,
46
FD_CLOEXEC, write(), STDOUT_FILENO,
47
struct stat, fstat(), close(),
48
setgid(), setuid(), S_ISREG(),
49
faccessat() pipe2(), fork(),
50
_exit(), dup2(), fexecve(), read()
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(),
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F_GETFD, F_SETFD, FD_CLOEXEC,
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access(), pipe(), fork(), close()
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dup2(), STDOUT_FILENO, _exit(),
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execv(), write(), read(),
52
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#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
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FD_CLOEXEC, openat(), scandirat(),
55
#include <string.h> /* strsep, strlen(), strsignal(),
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strcmp(), strncmp() */
56
#include <string.h> /* strsep, strlen(), asprintf(),
57
strsignal(), strcmp(), strncmp() */
57
58
#include <errno.h> /* errno */
58
59
#include <argp.h> /* struct argp_option, struct
59
60
argp_state, struct argp,
416
394
.doc = "Group ID the plugins will run as", .group = 3 },
417
395
{ .name = "debug", .key = 132,
418
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.doc = "Debug mode", .group = 4 },
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{ .name = "plugin-helper-dir", .key = 133,
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.doc = "Specify a different plugin helper directory",
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* These reproduce what we would get without ARGP_NO_HELP
426
{ .name = "help", .key = '?',
427
.doc = "Give this help list", .group = -1 },
428
{ .name = "usage", .key = -3,
429
.doc = "Give a short usage message", .group = -1 },
430
{ .name = "version", .key = 'V',
431
.doc = "Print program version", .group = -1 },
435
__attribute__((nonnull(3)))
436
error_t parse_opt(int key, char *arg, struct argp_state *state){
400
error_t parse_opt(int key, char *arg, __attribute__((unused))
401
struct argp_state *state){
441
405
case 'g': /* --global-options */
443
407
char *plugin_option;
444
408
while((plugin_option = strsep(&arg, ",")) != NULL){
409
if(plugin_option[0] == '\0'){
445
412
if(not add_argument(getplugin(NULL), plugin_option)){
413
perror("add_argument");
414
return ARGP_ERR_UNKNOWN;
452
419
case 'G': /* --global-env */
453
if(add_environment(getplugin(NULL), arg, true)){
423
if(not add_environment(getplugin(NULL), arg, true)){
424
perror("add_environment");
457
427
case 'o': /* --options-for */
459
char *option_list = strchr(arg, ':');
460
if(option_list == NULL){
461
argp_error(state, "No colon in \"%s\"", arg);
468
argp_error(state, "Empty plugin name");
473
while((option = strsep(&option_list, ",")) != NULL){
474
if(not add_argument(getplugin(arg), option)){
429
char *plugin_name = strsep(&arg, ":");
430
if(plugin_name[0] == '\0'){
434
while((plugin_option = strsep(&arg, ",")) != NULL){
435
if(not add_argument(getplugin(plugin_name), plugin_option)){
436
perror("add_argument");
437
return ARGP_ERR_UNKNOWN;
481
442
case 'E': /* --env-for */
483
447
char *envdef = strchr(arg, ':');
484
448
if(envdef == NULL){
485
argp_error(state, "No colon in \"%s\"", arg);
492
argp_error(state, "Empty plugin name");
496
if(add_environment(getplugin(arg), envdef, true)){
452
if(not add_environment(getplugin(arg), envdef+1, true)){
453
perror("add_environment");
501
457
case 'd': /* --disable */
503
459
plugin *p = getplugin(arg);
461
return ARGP_ERR_UNKNOWN;
510
466
case 'e': /* --enable */
512
468
plugin *p = getplugin(arg);
470
return ARGP_ERR_UNKNOWN;
519
475
case 128: /* --plugin-dir */
521
477
plugindir = strdup(arg);
522
if(plugindir != NULL){
478
if(plugindir == NULL){
526
482
case 129: /* --config-file */
527
483
/* This is already done by parse_opt_config_file() */
529
485
case 130: /* --userid */
530
tmp_id = strtoimax(arg, &tmp, 10);
487
tmpmax = strtoimax(arg, &tmp, 10);
531
488
if(errno != 0 or tmp == arg or *tmp != '\0'
532
or tmp_id != (uid_t)tmp_id){
533
argp_error(state, "Bad user ID number: \"%s\", using %"
534
PRIdMAX, arg, (intmax_t)uid);
489
or tmpmax != (uid_t)tmpmax){
490
fprintf(stderr, "Bad user ID number: \"%s\", using %"
491
PRIdMAX "\n", arg, (intmax_t)uid);
540
496
case 131: /* --groupid */
541
tmp_id = strtoimax(arg, &tmp, 10);
498
tmpmax = strtoimax(arg, &tmp, 10);
542
499
if(errno != 0 or tmp == arg or *tmp != '\0'
543
or tmp_id != (gid_t)tmp_id){
544
argp_error(state, "Bad group ID number: \"%s\", using %"
545
PRIdMAX, arg, (intmax_t)gid);
500
or tmpmax != (gid_t)tmpmax){
501
fprintf(stderr, "Bad group ID number: \"%s\", using %"
502
PRIdMAX "\n", arg, (intmax_t)gid);
551
507
case 132: /* --debug */
554
case 133: /* --plugin-helper-dir */
555
free(pluginhelperdir);
556
pluginhelperdir = strdup(arg);
557
if(pluginhelperdir != NULL){
562
* These reproduce what we would get without ARGP_NO_HELP
564
case '?': /* --help */
565
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
566
argp_state_help(state, state->out_stream, ARGP_HELP_STD_HELP);
567
case -3: /* --usage */
568
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
569
argp_state_help(state, state->out_stream,
570
ARGP_HELP_USAGE | ARGP_HELP_EXIT_OK);
571
case 'V': /* --version */
572
fprintf(state->out_stream, "%s\n", argp_program_version);
576
511
* When adding more options before this line, remember to also add a
577
512
* "case" to the "parse_opt_config_file" function below.
729
648
/* Check for harmful errors and go to fallback. Other errors might
730
649
not affect opening plugins */
731
650
if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
732
error(0, errno, "fopen");
733
exitstatus = EX_OSERR;
652
exitstatus = EXIT_FAILURE;
737
/* If there were any arguments from the configuration file, pass
738
them to parser as command line arguments */
656
/* If there was any arguments from configuration file,
657
pass them to parser as command arguments */
739
658
if(custom_argv != NULL){
740
ret = argp_parse(&argp, custom_argc, custom_argv,
741
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
749
error(0, errno, "argp_parse");
750
exitstatus = EX_OSERR;
753
exitstatus = EX_CONFIG;
659
ret = argp_parse(&argp, custom_argc, custom_argv, ARGP_IN_ORDER,
661
if(ret == ARGP_ERR_UNKNOWN){
662
fprintf(stderr, "Unknown error while parsing arguments\n");
663
exitstatus = EXIT_FAILURE;
758
668
/* Parse actual command line arguments, to let them override the
760
ret = argp_parse(&argp, argc, argv,
761
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
769
error(0, errno, "argp_parse");
770
exitstatus = EX_OSERR;
773
exitstatus = EX_USAGE;
778
char *pluginhelperenv;
780
ret = asprintf(&pluginhelperenv, "MANDOSPLUGINHELPERDIR=%s",
781
pluginhelperdir != NULL ? pluginhelperdir : PHDIR);
783
bret = add_environment(getplugin(NULL), pluginhelperenv, true);
785
if(ret == -1 or not bret){
786
error(0, errno, "Failed to set MANDOSPLUGINHELPERDIR"
787
" environment variable to \"%s\" for all plugins\n",
788
pluginhelperdir != NULL ? pluginhelperdir : PHDIR);
791
free(pluginhelperenv);
670
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
671
if(ret == ARGP_ERR_UNKNOWN){
672
fprintf(stderr, "Unknown error while parsing arguments\n");
673
exitstatus = EXIT_FAILURE;
796
for(plugin *p = plugin_list; p != NULL; p = p->next){
678
for(plugin *p = plugin_list; p != NULL; p=p->next){
797
679
fprintf(stderr, "Plugin: %s has %d arguments\n",
798
680
p->name ? p->name : "Global", p->argc - 1);
799
681
for(char **a = p->argv; *a != NULL; a++){
810
/* Work around Debian bug #633582:
811
<https://bugs.debian.org/633582> */
812
int plugindir_fd = open(/* plugindir or */ PDIR, O_RDONLY);
813
if(plugindir_fd == -1){
815
error(0, errno, "open(\"" PDIR "\")");
818
ret = (int)TEMP_FAILURE_RETRY(fstat(plugindir_fd, &st));
820
error(0, errno, "fstat");
822
if(S_ISDIR(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
823
ret = fchown(plugindir_fd, uid, gid);
825
error(0, errno, "fchown");
833
/* Lower permissions */
691
/* Strip permissions down to nobody */
836
error(0, errno, "setgid");
838
696
ret = setuid(uid);
840
error(0, errno, "setuid");
843
/* Open plugin directory with close_on_exec flag */
701
if(plugindir == NULL){
704
dir = opendir(plugindir);
708
perror("Could not open plugin dir");
709
exitstatus = EXIT_FAILURE;
713
/* Set the FD_CLOEXEC flag on the directory, if possible */
845
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
848
#else /* not O_CLOEXEC */
850
#endif /* not O_CLOEXEC */
853
error(0, errno, "Could not open plugin dir");
854
exitstatus = EX_UNAVAILABLE;
859
/* Set the FD_CLOEXEC flag on the directory */
860
ret = set_cloexec_flag(dir_fd);
862
error(0, errno, "set_cloexec_flag");
863
exitstatus = EX_OSERR;
866
#endif /* O_CLOEXEC */
869
int good_name(const struct dirent * const dirent){
870
const char * const patterns[] = { ".*", "#*#", "*~", "*.dpkg-new",
871
"*.dpkg-old", "*.dpkg-bak",
872
"*.dpkg-divert", NULL };
874
#pragma GCC diagnostic push
875
#pragma GCC diagnostic ignored "-Wcast-qual"
877
for(const char **pat = (const char **)patterns;
878
*pat != NULL; pat++){
880
#pragma GCC diagnostic pop
882
if(fnmatch(*pat, dirent->d_name, FNM_FILE_NAME | FNM_PERIOD)
885
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
886
" matching pattern %s\n", dirent->d_name, *pat);
715
int dir_fd = dirfd(dir);
717
ret = set_cloexec_flag(dir_fd);
719
perror("set_cloexec_flag");
720
exitstatus = EXIT_FAILURE;
894
int numplugins = scandirat(dir_fd, ".", &direntries, good_name,
896
if(numplugins == -1){
897
error(0, errno, "Could not scan plugin dir");
899
exitstatus = EX_OSERR;
903
726
FD_ZERO(&rfds_all);
905
728
/* Read and execute any executable in the plugin directory*/
906
for(int i = 0; i < numplugins; i++){
908
int plugin_fd = openat(dir_fd, direntries[i]->d_name, O_RDONLY);
910
error(0, errno, "Could not open plugin");
731
dirst = readdir(dir);
732
} while(dirst == NULL and errno == EINTR);
734
/* All directory entries have been processed */
738
exitstatus = EXIT_FAILURE;
744
d_name_len = strlen(dirst->d_name);
746
/* Ignore dotfiles, backup files and other junk */
748
bool bad_name = false;
750
const char const *bad_prefixes[] = { ".", "#", NULL };
752
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
755
".dpkg-divert", NULL };
756
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
757
size_t pre_len = strlen(*pre);
758
if((d_name_len >= pre_len)
759
and strncmp((dirst->d_name), *pre, pre_len) == 0){
761
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
762
" with bad prefix %s\n", dirst->d_name, *pre);
771
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
772
size_t suf_len = strlen(*suf);
773
if((d_name_len >= suf_len)
774
and (strcmp((dirst->d_name) + d_name_len-suf_len, *suf)
777
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
778
" with bad suffix %s\n", dirst->d_name, *suf);
791
if(plugindir == NULL){
792
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, PDIR "/%s",
795
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, "%s/%s",
914
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
804
ret = (int)TEMP_FAILURE_RETRY(stat(filename, &st));
916
error(0, errno, "stat");
922
811
/* Ignore non-executable files */
923
812
if(not S_ISREG(st.st_mode)
924
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, direntries[i]->d_name,
813
or (TEMP_FAILURE_RETRY(access(filename, X_OK)) != 0)){
927
fprintf(stderr, "Ignoring plugin dir entry \"%s/%s\""
928
" with bad type or mode\n",
929
plugindir != NULL ? plugindir : PDIR,
930
direntries[i]->d_name);
815
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
816
" with bad type or mode\n", filename);
937
plugin *p = getplugin(direntries[i]->d_name);
822
plugin *p = getplugin(dirst->d_name);
939
error(0, errno, "getplugin");
946
830
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
947
direntries[i]->d_name);
957
840
for(char **a = g->argv + 1; *a != NULL; a++){
958
841
if(not add_argument(p, *a)){
959
error(0, errno, "add_argument");
842
perror("add_argument");
962
845
/* Add global environment variables */
963
846
for(char **e = g->environ; *e != NULL; e++){
964
847
if(not add_environment(p, *e, false)){
965
error(0, errno, "add_environment");
848
perror("add_environment");
970
/* If this plugin has any environment variables, we need to
971
duplicate the environment from this process, too. */
853
/* If this plugin has any environment variables, we will call
854
using execve and need to duplicate the environment from this
972
856
if(p->environ[0] != NULL){
973
857
for(char **e = environ; *e != NULL; e++){
974
858
if(not add_environment(p, *e, false)){
975
error(0, errno, "add_environment");
859
perror("add_environment");
982
865
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
983
#else /* O_CLOEXEC */
984
ret = (int)TEMP_FAILURE_RETRY(pipe2(pipefd, O_CLOEXEC));
985
#endif /* O_CLOEXEC */
987
error(0, errno, "pipe");
988
exitstatus = EX_OSERR;
992
if(pipefd[0] >= FD_SETSIZE){
993
fprintf(stderr, "pipe()[0] (%d) >= FD_SETSIZE (%d)", pipefd[0],
997
exitstatus = EX_OSERR;
868
exitstatus = EXIT_FAILURE;
1002
871
/* Ask OS to automatic close the pipe on exec */
1003
872
ret = set_cloexec_flag(pipefd[0]);
1005
error(0, errno, "set_cloexec_flag");
1008
exitstatus = EX_OSERR;
1009
free(direntries[i]);
874
perror("set_cloexec_flag");
875
exitstatus = EXIT_FAILURE;
1012
878
ret = set_cloexec_flag(pipefd[1]);
1014
error(0, errno, "set_cloexec_flag");
1017
exitstatus = EX_OSERR;
1018
free(direntries[i]);
880
perror("set_cloexec_flag");
881
exitstatus = EXIT_FAILURE;
1021
#endif /* not O_CLOEXEC */
1022
884
/* Block SIGCHLD until process is safely in process list */
1023
885
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
1024
886
&sigchld_action.sa_mask,
1027
error(0, errno, "sigprocmask");
1028
exitstatus = EX_OSERR;
1029
free(direntries[i]);
889
perror("sigprocmask");
890
exitstatus = EXIT_FAILURE;
1032
893
/* Starting a new process to be watched */
1036
897
} while(pid == -1 and errno == EINTR);
1038
error(0, errno, "fork");
1039
TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1040
&sigchld_action.sa_mask, NULL));
1043
exitstatus = EX_OSERR;
1044
free(direntries[i]);
900
exitstatus = EXIT_FAILURE;
1048
904
/* this is the child process */
1049
905
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1051
error(0, errno, "sigaction");
1054
910
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1056
error(0, errno, "sigprocmask");
912
perror("sigprocmask");
1060
916
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1062
error(0, errno, "dup2");
1066
if(fexecve(plugin_fd, p->argv,
1067
(p->environ[0] != NULL) ? p->environ : environ) < 0){
1068
error(0, errno, "fexecve for %s/%s",
1069
plugindir != NULL ? plugindir : PDIR,
1070
direntries[i]->d_name);
923
/* If dir has no file descriptor, we could not set FD_CLOEXEC
924
above and must now close it manually here. */
927
if(p->environ[0] == NULL){
928
if(execv(filename, p->argv) < 0){
933
if(execve(filename, p->argv, p->environ) < 0){
1075
940
/* Parent process */
1076
close(pipefd[1]); /* Close unused write end of pipe */
1078
plugin *new_plugin = getplugin(direntries[i]->d_name);
941
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
944
plugin *new_plugin = getplugin(dirst->d_name);
1079
945
if(new_plugin == NULL){
1080
error(0, errno, "getplugin");
1081
947
ret = (int)(TEMP_FAILURE_RETRY
1082
948
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
1085
error(0, errno, "sigprocmask");
951
perror("sigprocmask");
1087
exitstatus = EX_OSERR;
1088
free(direntries[i]);
953
exitstatus = EXIT_FAILURE;
1091
free(direntries[i]);
1093
957
new_plugin->pid = pid;
1094
958
new_plugin->fd = pipefd[0];
1202
1069
bool bret = print_out_password(proc->buffer,
1203
1070
proc->buffer_length);
1205
error(0, errno, "print_out_password");
1206
exitstatus = EX_IOERR;
1072
perror("print_out_password");
1073
exitstatus = EXIT_FAILURE;
1211
1078
/* This process has not completed. Does it have any output? */
1212
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
1079
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){ /* Spurious
1213
1082
/* This process had nothing to say at this time */
1214
1083
proc = proc->next;
1217
1086
/* Before reading, make the process' data buffer large enough */
1218
1087
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1219
char *new_buffer = realloc(proc->buffer, proc->buffer_size
1220
+ (size_t) BUFFER_SIZE);
1221
if(new_buffer == NULL){
1222
error(0, errno, "malloc");
1223
exitstatus = EX_OSERR;
1088
proc->buffer = realloc(proc->buffer, proc->buffer_size
1089
+ (size_t) BUFFER_SIZE);
1090
if(proc->buffer == NULL){
1092
exitstatus = EXIT_FAILURE;
1226
proc->buffer = new_buffer;
1227
1095
proc->buffer_size += BUFFER_SIZE;
1229
1097
/* Read from the process */