3
3
* Mandos plugin runner - Run Mandos plugins
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
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
14
16
* WITHOUT ANY WARRANTY; without even the implied warranty of
15
17
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16
18
* General Public License for more details.
18
20
* You should have received a copy of the GNU General Public License
19
* along with this program. If not, see
20
* <http://www.gnu.org/licenses/>.
21
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
22
* Contact the authors at <mandos@fukt.bsnet.se>.
23
* Contact the authors at <mandos@recompile.se>.
25
26
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), getline(),
26
asprintf(), O_CLOEXEC */
27
28
#include <stddef.h> /* size_t, NULL */
28
#include <stdlib.h> /* malloc(), exit(), EXIT_FAILURE,
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EXIT_SUCCESS, realloc() */
29
#include <stdlib.h> /* malloc(), exit(), EXIT_SUCCESS,
30
31
#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
34
stat, waitpid(), WIFEXITED(),
35
WEXITSTATUS(), wait(), pid_t,
36
uid_t, gid_t, getuid(), getgid(),
32
#include <stdio.h> /* fileno(), fprintf(),
33
stderr, STDOUT_FILENO, fclose() */
34
#include <sys/types.h> /* fstat(), struct stat, waitpid(),
35
WIFEXITED(), WEXITSTATUS(), wait(),
36
pid_t, uid_t, gid_t, getuid(),
38
38
#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
39
39
FD_SET(), FD_ISSET(), FD_CLR */
40
40
#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),
41
WEXITSTATUS(), WTERMSIG(),
43
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
41
WEXITSTATUS(), WTERMSIG() */
42
#include <sys/stat.h> /* struct stat, fstat(), S_ISREG() */
44
43
#include <iso646.h> /* and, or, not */
45
#include <dirent.h> /* DIR, struct dirent, fdopendir(),
46
readdir(), closedir(), dirfd() */
47
#include <unistd.h> /* struct stat, stat(), S_ISREG(),
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fcntl(), setuid(), setgid(),
49
F_GETFD, F_SETFD, FD_CLOEXEC,
50
access(), pipe(), fork(), close()
51
dup2(), STDOUT_FILENO, _exit(),
52
execv(), write(), read(),
44
#include <dirent.h> /* struct dirent, scandirat() */
45
#include <unistd.h> /* fcntl(), F_GETFD, F_SETFD,
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FD_CLOEXEC, write(), STDOUT_FILENO,
47
struct stat, fstat(), close(),
48
setgid(), setuid(), S_ISREG(),
49
faccessat() pipe2(), fork(),
50
_exit(), dup2(), fexecve(), read()
54
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#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
56
#include <string.h> /* strsep, strlen(), asprintf(),
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FD_CLOEXEC, openat(), scandirat(),
55
#include <string.h> /* strsep, strlen(), strsignal(),
56
strcmp(), strncmp() */
58
57
#include <errno.h> /* errno */
59
58
#include <argp.h> /* struct argp_option, struct
60
59
argp_state, struct argp,
394
417
.doc = "Group ID the plugins will run as", .group = 3 },
395
418
{ .name = "debug", .key = 132,
396
419
.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
427
{ .name = "help", .key = '?',
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.doc = "Give this help list", .group = -1 },
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{ .name = "usage", .key = -3,
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.doc = "Give a short usage message", .group = -1 },
431
{ .name = "version", .key = 'V',
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.doc = "Print program version", .group = -1 },
400
error_t parse_opt(int key, char *arg, __attribute__((unused))
401
struct argp_state *state){
436
__attribute__((nonnull(3)))
437
error_t parse_opt(int key, char *arg, struct argp_state *state){
405
442
case 'g': /* --global-options */
407
444
char *plugin_option;
408
445
while((plugin_option = strsep(&arg, ",")) != NULL){
409
if(plugin_option[0] == '\0'){
412
446
if(not add_argument(getplugin(NULL), plugin_option)){
413
perror("add_argument");
414
return ARGP_ERR_UNKNOWN;
419
453
case 'G': /* --global-env */
423
if(not add_environment(getplugin(NULL), arg, true)){
424
perror("add_environment");
454
if(add_environment(getplugin(NULL), arg, true)){
427
458
case 'o': /* --options-for */
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;
460
char *option_list = strchr(arg, ':');
461
if(option_list == NULL){
462
argp_error(state, "No colon in \"%s\"", arg);
469
argp_error(state, "Empty plugin name");
474
while((option = strsep(&option_list, ",")) != NULL){
475
if(not add_argument(getplugin(arg), option)){
442
482
case 'E': /* --env-for */
447
484
char *envdef = strchr(arg, ':');
448
485
if(envdef == NULL){
486
argp_error(state, "No colon in \"%s\"", arg);
452
if(not add_environment(getplugin(arg), envdef+1, true)){
453
perror("add_environment");
493
argp_error(state, "Empty plugin name");
497
if(add_environment(getplugin(arg), envdef, true)){
457
502
case 'd': /* --disable */
459
504
plugin *p = getplugin(arg);
461
return ARGP_ERR_UNKNOWN;
466
511
case 'e': /* --enable */
468
513
plugin *p = getplugin(arg);
470
return ARGP_ERR_UNKNOWN;
475
520
case 128: /* --plugin-dir */
477
522
plugindir = strdup(arg);
478
if(plugindir == NULL){
523
if(plugindir != NULL){
482
527
case 129: /* --config-file */
483
528
/* This is already done by parse_opt_config_file() */
485
530
case 130: /* --userid */
487
tmpmax = strtoimax(arg, &tmp, 10);
531
tmp_id = strtoimax(arg, &tmp, 10);
488
532
if(errno != 0 or tmp == arg or *tmp != '\0'
489
or tmpmax != (uid_t)tmpmax){
490
fprintf(stderr, "Bad user ID number: \"%s\", using %"
491
PRIdMAX "\n", arg, (intmax_t)uid);
533
or tmp_id != (uid_t)tmp_id){
534
argp_error(state, "Bad user ID number: \"%s\", using %"
535
PRIdMAX, arg, (intmax_t)uid);
496
541
case 131: /* --groupid */
498
tmpmax = strtoimax(arg, &tmp, 10);
542
tmp_id = strtoimax(arg, &tmp, 10);
499
543
if(errno != 0 or tmp == arg or *tmp != '\0'
500
or tmpmax != (gid_t)tmpmax){
501
fprintf(stderr, "Bad group ID number: \"%s\", using %"
502
PRIdMAX "\n", arg, (intmax_t)gid);
544
or tmp_id != (gid_t)tmp_id){
545
argp_error(state, "Bad group ID number: \"%s\", using %"
546
PRIdMAX, arg, (intmax_t)gid);
507
552
case 132: /* --debug */
555
case 133: /* --plugin-helper-dir */
556
free(pluginhelperdir);
557
pluginhelperdir = strdup(arg);
558
if(pluginhelperdir != NULL){
563
* These reproduce what we would get without ARGP_NO_HELP
565
case '?': /* --help */
566
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
567
argp_state_help(state, state->out_stream, ARGP_HELP_STD_HELP);
568
case -3: /* --usage */
569
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
570
argp_state_help(state, state->out_stream,
571
ARGP_HELP_USAGE | ARGP_HELP_EXIT_OK);
572
case 'V': /* --version */
573
fprintf(state->out_stream, "%s\n", argp_program_version);
511
577
* When adding more options before this line, remember to also add a
512
578
* "case" to the "parse_opt_config_file" function below.
648
730
/* Check for harmful errors and go to fallback. Other errors might
649
731
not affect opening plugins */
650
732
if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
652
exitstatus = EXIT_FAILURE;
733
error(0, errno, "fopen");
734
exitstatus = EX_OSERR;
656
/* If there was any arguments from configuration file,
657
pass them to parser as command arguments */
738
/* If there were any arguments from the configuration file, pass
739
them to parser as command line arguments */
658
740
if(custom_argv != NULL){
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;
741
ret = argp_parse(&argp, custom_argc, custom_argv,
742
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
750
error(0, errno, "argp_parse");
751
exitstatus = EX_OSERR;
754
exitstatus = EX_CONFIG;
668
759
/* Parse actual command line arguments, to let them override the
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;
761
ret = argp_parse(&argp, argc, argv,
762
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
770
error(0, errno, "argp_parse");
771
exitstatus = EX_OSERR;
774
exitstatus = EX_USAGE;
779
char *pluginhelperenv;
781
ret = asprintf(&pluginhelperenv, "MANDOSPLUGINHELPERDIR=%s",
782
pluginhelperdir != NULL ? pluginhelperdir : PHDIR);
784
bret = add_environment(getplugin(NULL), pluginhelperenv, true);
786
if(ret == -1 or not bret){
787
error(0, errno, "Failed to set MANDOSPLUGINHELPERDIR"
788
" environment variable to \"%s\" for all plugins\n",
789
pluginhelperdir != NULL ? pluginhelperdir : PHDIR);
792
free(pluginhelperenv);
678
for(plugin *p = plugin_list; p != NULL; p=p->next){
797
for(plugin *p = plugin_list; p != NULL; p = p->next){
679
798
fprintf(stderr, "Plugin: %s has %d arguments\n",
680
799
p->name ? p->name : "Global", p->argc - 1);
681
800
for(char **a = p->argv; *a != NULL; a++){
691
/* Strip permissions down to nobody */
811
/* Work around Debian bug #633582:
812
<https://bugs.debian.org/633582> */
813
int plugindir_fd = open(/* plugindir or */ PDIR, O_RDONLY);
814
if(plugindir_fd == -1){
816
error(0, errno, "open(\"" PDIR "\")");
819
ret = (int)TEMP_FAILURE_RETRY(fstat(plugindir_fd, &st));
821
error(0, errno, "fstat");
823
if(S_ISDIR(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
824
ret = fchown(plugindir_fd, uid, gid);
826
error(0, errno, "fchown");
834
/* Lower permissions */
837
error(0, errno, "setgid");
696
839
ret = setuid(uid);
841
error(0, errno, "setuid");
701
844
/* Open plugin directory with close_on_exec flag */
704
if(plugindir == NULL){
705
dir_fd = open(PDIR, O_RDONLY |
708
#else /* not O_CLOEXEC */
710
#endif /* not O_CLOEXEC */
713
dir_fd = open(plugindir, O_RDONLY |
716
#else /* not O_CLOEXEC */
718
#endif /* not O_CLOEXEC */
846
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
849
#else /* not O_CLOEXEC */
851
#endif /* not O_CLOEXEC */
721
853
if(dir_fd == -1){
722
perror("Could not open plugin dir");
723
exitstatus = EXIT_FAILURE;
854
error(0, errno, "Could not open plugin dir");
855
exitstatus = EX_UNAVAILABLE;
728
860
/* Set the FD_CLOEXEC flag on the directory */
729
861
ret = set_cloexec_flag(dir_fd);
731
perror("set_cloexec_flag");
732
TEMP_FAILURE_RETRY(close(dir_fd));
733
exitstatus = EXIT_FAILURE;
863
error(0, errno, "set_cloexec_flag");
864
exitstatus = EX_OSERR;
736
867
#endif /* O_CLOEXEC */
738
dir = fdopendir(dir_fd);
740
perror("Could not open plugin dir");
741
TEMP_FAILURE_RETRY(close(dir_fd));
742
exitstatus = EXIT_FAILURE;
870
int good_name(const struct dirent * const dirent){
871
const char * const patterns[] = { ".*", "#*#", "*~", "*.dpkg-new",
872
"*.dpkg-old", "*.dpkg-bak",
873
"*.dpkg-divert", NULL };
875
#pragma GCC diagnostic push
876
#pragma GCC diagnostic ignored "-Wcast-qual"
878
for(const char **pat = (const char **)patterns;
879
*pat != NULL; pat++){
881
#pragma GCC diagnostic pop
883
if(fnmatch(*pat, dirent->d_name, FNM_FILE_NAME | FNM_PERIOD)
886
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
887
" matching pattern %s\n", dirent->d_name, *pat);
895
int numplugins = scandirat(dir_fd, ".", &direntries, good_name,
897
if(numplugins == -1){
898
error(0, errno, "Could not scan plugin dir");
900
exitstatus = EX_OSERR;
747
904
FD_ZERO(&rfds_all);
749
906
/* Read and execute any executable in the plugin directory*/
752
dirst = readdir(dir);
753
} while(dirst == NULL and errno == EINTR);
755
/* All directory entries have been processed */
759
exitstatus = EXIT_FAILURE;
765
d_name_len = strlen(dirst->d_name);
767
/* Ignore dotfiles, backup files and other junk */
769
bool bad_name = false;
771
const char const *bad_prefixes[] = { ".", "#", NULL };
773
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
776
".dpkg-divert", NULL };
777
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
778
size_t pre_len = strlen(*pre);
779
if((d_name_len >= pre_len)
780
and strncmp((dirst->d_name), *pre, pre_len) == 0){
782
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
783
" with bad prefix %s\n", dirst->d_name, *pre);
792
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
793
size_t suf_len = strlen(*suf);
794
if((d_name_len >= suf_len)
795
and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)
798
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
799
" with bad suffix %s\n", dirst->d_name, *suf);
812
if(plugindir == NULL){
813
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, PDIR "/%s",
816
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, "%s/%s",
907
for(int i = 0; i < numplugins; i++){
909
int plugin_fd = openat(dir_fd, direntries[i]->d_name, O_RDONLY);
911
error(0, errno, "Could not open plugin");
825
ret = (int)TEMP_FAILURE_RETRY(stat(filename, &st));
915
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
917
error(0, errno, "stat");
832
923
/* Ignore non-executable files */
833
924
if(not S_ISREG(st.st_mode)
834
or (TEMP_FAILURE_RETRY(access(filename, X_OK)) != 0)){
925
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, direntries[i]->d_name,
836
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
837
" with bad type or mode\n", filename);
928
fprintf(stderr, "Ignoring plugin dir entry \"%s/%s\""
929
" with bad type or mode\n",
930
plugindir != NULL ? plugindir : PDIR,
931
direntries[i]->d_name);
843
plugin *p = getplugin(dirst->d_name);
938
plugin *p = getplugin(direntries[i]->d_name);
940
error(0, errno, "getplugin");
851
947
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
948
direntries[i]->d_name);
861
958
for(char **a = g->argv + 1; *a != NULL; a++){
862
959
if(not add_argument(p, *a)){
863
perror("add_argument");
960
error(0, errno, "add_argument");
866
963
/* Add global environment variables */
867
964
for(char **e = g->environ; *e != NULL; e++){
868
965
if(not add_environment(p, *e, false)){
869
perror("add_environment");
966
error(0, errno, "add_environment");
874
/* If this plugin has any environment variables, we will call
875
using execve and need to duplicate the environment from this
971
/* If this plugin has any environment variables, we need to
972
duplicate the environment from this process, too. */
877
973
if(p->environ[0] != NULL){
878
974
for(char **e = environ; *e != NULL; e++){
879
975
if(not add_environment(p, *e, false)){
880
perror("add_environment");
976
error(0, errno, "add_environment");
886
983
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
984
#else /* O_CLOEXEC */
985
ret = (int)TEMP_FAILURE_RETRY(pipe2(pipefd, O_CLOEXEC));
986
#endif /* O_CLOEXEC */
889
exitstatus = EXIT_FAILURE;
988
error(0, errno, "pipe");
989
exitstatus = EX_OSERR;
993
if(pipefd[0] >= FD_SETSIZE){
994
fprintf(stderr, "pipe()[0] (%d) >= FD_SETSIZE (%d)", pipefd[0],
998
exitstatus = EX_OSERR;
892
1003
/* Ask OS to automatic close the pipe on exec */
893
1004
ret = set_cloexec_flag(pipefd[0]);
895
perror("set_cloexec_flag");
896
exitstatus = EXIT_FAILURE;
1006
error(0, errno, "set_cloexec_flag");
1009
exitstatus = EX_OSERR;
1010
free(direntries[i]);
899
1013
ret = set_cloexec_flag(pipefd[1]);
901
perror("set_cloexec_flag");
902
exitstatus = EXIT_FAILURE;
1015
error(0, errno, "set_cloexec_flag");
1018
exitstatus = EX_OSERR;
1019
free(direntries[i]);
1022
#endif /* not O_CLOEXEC */
905
1023
/* Block SIGCHLD until process is safely in process list */
906
1024
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
907
1025
&sigchld_action.sa_mask,
910
perror("sigprocmask");
911
exitstatus = EXIT_FAILURE;
1028
error(0, errno, "sigprocmask");
1029
exitstatus = EX_OSERR;
1030
free(direntries[i]);
914
1033
/* Starting a new process to be watched */
918
1037
} while(pid == -1 and errno == EINTR);
921
exitstatus = EXIT_FAILURE;
1039
error(0, errno, "fork");
1040
TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1041
&sigchld_action.sa_mask, NULL));
1044
exitstatus = EX_OSERR;
1045
free(direntries[i]);
925
1049
/* this is the child process */
926
1050
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1052
error(0, errno, "sigaction");
931
1055
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
933
perror("sigprocmask");
1057
error(0, errno, "sigprocmask");
937
1061
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1063
error(0, errno, "dup2");
944
/* If dir has no file descriptor, we could not set FD_CLOEXEC
945
above and must now close it manually here. */
948
if(p->environ[0] == NULL){
949
if(execv(filename, p->argv) < 0){
954
if(execve(filename, p->argv, p->environ) < 0){
1067
if(fexecve(plugin_fd, p->argv,
1068
(p->environ[0] != NULL) ? p->environ : environ) < 0){
1069
error(0, errno, "fexecve for %s/%s",
1070
plugindir != NULL ? plugindir : PDIR,
1071
direntries[i]->d_name);
961
1076
/* Parent process */
962
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
965
plugin *new_plugin = getplugin(dirst->d_name);
1077
close(pipefd[1]); /* Close unused write end of pipe */
1079
plugin *new_plugin = getplugin(direntries[i]->d_name);
966
1080
if(new_plugin == NULL){
1081
error(0, errno, "getplugin");
968
1082
ret = (int)(TEMP_FAILURE_RETRY
969
1083
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
972
perror("sigprocmask");
1086
error(0, errno, "sigprocmask");
974
exitstatus = EXIT_FAILURE;
1088
exitstatus = EX_OSERR;
1089
free(direntries[i]);
1092
free(direntries[i]);
978
1094
new_plugin->pid = pid;
979
1095
new_plugin->fd = pipefd[0];
1090
1203
bool bret = print_out_password(proc->buffer,
1091
1204
proc->buffer_length);
1093
perror("print_out_password");
1094
exitstatus = EXIT_FAILURE;
1206
error(0, errno, "print_out_password");
1207
exitstatus = EX_IOERR;
1099
1212
/* This process has not completed. Does it have any output? */
1100
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){ /* Spurious
1213
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
1103
1214
/* This process had nothing to say at this time */
1104
1215
proc = proc->next;
1107
1218
/* Before reading, make the process' data buffer large enough */
1108
1219
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1109
proc->buffer = realloc(proc->buffer, proc->buffer_size
1110
+ (size_t) BUFFER_SIZE);
1111
if(proc->buffer == NULL){
1113
exitstatus = EXIT_FAILURE;
1220
char *new_buffer = realloc(proc->buffer, proc->buffer_size
1221
+ (size_t) BUFFER_SIZE);
1222
if(new_buffer == NULL){
1223
error(0, errno, "malloc");
1224
exitstatus = EX_OSERR;
1227
proc->buffer = new_buffer;
1116
1228
proc->buffer_size += BUFFER_SIZE;
1118
1230
/* Read from the process */