3
3
* Mandos plugin runner - Run Mandos plugins
5
* Copyright © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 Björn Påhlsson
5
* Copyright © 2008-2013 Teddy Hogeborn
6
* Copyright © 2008-2013 Björn Påhlsson
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* This program is free software: you can redistribute it and/or
9
9
* modify it under the terms of the GNU General Public License as
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* along with this program. If not, see
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* <http://www.gnu.org/licenses/>.
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* Contact the authors at <mandos@fukt.bsnet.se>.
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* Contact the authors at <mandos@recompile.se>.
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#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), getline(),
26
asprintf(), O_CLOEXEC */
27
27
#include <stddef.h> /* size_t, NULL */
28
#include <stdlib.h> /* malloc(), exit(), EXIT_FAILURE,
29
EXIT_SUCCESS, realloc() */
28
#include <stdlib.h> /* malloc(), exit(), EXIT_SUCCESS,
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#include <stdbool.h> /* bool, true, false */
31
#include <stdio.h> /* perror, fileno(), fprintf(),
32
stderr, STDOUT_FILENO */
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#include <sys/types.h> /* DIR, fdopendir(), stat(), struct
31
#include <stdio.h> /* fileno(), fprintf(),
32
stderr, STDOUT_FILENO, fclose() */
33
#include <sys/types.h> /* DIR, fdopendir(), fstat(), struct
34
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stat, waitpid(), WIFEXITED(),
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WEXITSTATUS(), wait(), pid_t,
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uid_t, gid_t, getuid(), getgid(),
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#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),
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WEXITSTATUS(), WTERMSIG(),
43
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
43
#include <sys/stat.h> /* struct stat, fstat(), S_ISREG() */
44
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#include <iso646.h> /* and, or, not */
45
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#include <dirent.h> /* DIR, struct dirent, fdopendir(),
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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()
51
dup2(), STDOUT_FILENO, _exit(),
52
execv(), write(), read(),
47
#include <unistd.h> /* fcntl(), F_GETFD, F_SETFD,
48
FD_CLOEXEC, write(), STDOUT_FILENO,
49
struct stat, fstat(), close(),
50
setgid(), setuid(), S_ISREG(),
51
faccessat() pipe(), fork(),
52
_exit(), dup2(), fexecve(), read()
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#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
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#include <string.h> /* strsep, strlen(), asprintf(),
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FD_CLOEXEC, openat() */
56
#include <string.h> /* strsep, strlen(), strsignal(),
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strcmp(), strncmp() */
58
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#include <errno.h> /* errno */
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#include <argp.h> /* struct argp_option, struct
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argp_state, struct argp,
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#include <errno.h> /* errno, EBADF */
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#include <inttypes.h> /* intmax_t, PRIdMAX, strtoimax() */
71
#include <sysexits.h> /* EX_OSERR, EX_USAGE */
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#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_IOERR,
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EX_CONFIG, EX_UNAVAILABLE, EX_OK */
73
#include <errno.h> /* errno */
74
#include <error.h> /* error() */
73
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#define BUFFER_SIZE 256
103
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/* Gets an existing plugin based on name,
104
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or if none is found, creates a new one */
108
__attribute__((warn_unused_result))
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static plugin *getplugin(char *name){
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/* Check for existing plugin with that name */
107
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for(plugin *p = plugin_list; p != NULL; p = p->next){
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/* Helper function for add_argument and add_environment */
175
__attribute__((nonnull, warn_unused_result))
171
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static bool add_to_char_array(const char *new, char ***array,
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/* Resize the pointed-to array to hold one more pointer */
179
char **new_array = NULL;
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*array = realloc(*array, sizeof(char *)
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* (size_t) ((*len) + 2));
177
} while(*array == NULL and errno == EINTR);
181
new_array = realloc(*array, sizeof(char *)
182
* (size_t) ((*len) + 2));
183
} while(new_array == NULL and errno == EINTR);
178
184
/* Malloc check */
185
if(new_array == NULL){
182
189
/* Make a copy of the new string */
211
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/* namelen = length of name of environment variable */
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size_t namelen = (size_t)(strchrnul(def, '=') - def);
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/* Search for this environment variable */
214
for(char **e = p->environ; *e != NULL; e++){
215
if(strncmp(*e, def, namelen + 1) == 0){
223
for(char **envdef = p->environ; *envdef != NULL; envdef++){
224
if(strncmp(*envdef, def, namelen + 1) == 0){
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/* It already exists */
220
new = realloc(*e, strlen(def) + 1);
221
} while(new == NULL and errno == EINTR);
229
new_envdef = realloc(*envdef, strlen(def) + 1);
230
} while(new_envdef == NULL and errno == EINTR);
231
if(new_envdef == NULL){
234
*envdef = new_envdef;
235
strcpy(*envdef, def);
351
363
.sa_flags = SA_NOCLDSTOP };
352
364
char **custom_argv = NULL;
353
365
int custom_argc = 0;
355
368
/* Establish a signal handler */
356
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sigemptyset(&sigchld_action.sa_mask);
357
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ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
360
exitstatus = EXIT_FAILURE;
372
error(0, errno, "sigaddset");
373
exitstatus = EX_OSERR;
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ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
366
exitstatus = EXIT_FAILURE;
378
error(0, errno, "sigaction");
379
exitstatus = EX_OSERR;
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plugin *p = getplugin(arg);
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p->disabled = false;
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case 128: /* --plugin-dir */
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plugindir = strdup(arg);
516
if(plugindir != NULL){
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case 129: /* --config-file */
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/* This is already done by parse_opt_config_file() */
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case 130: /* --userid */
499
tmpmax = strtoimax(arg, &tmp, 10);
524
tmp_id = strtoimax(arg, &tmp, 10);
500
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if(errno != 0 or tmp == arg or *tmp != '\0'
501
or tmpmax != (uid_t)tmpmax){
526
or tmp_id != (uid_t)tmp_id){
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argp_error(state, "Bad user ID number: \"%s\", using %"
503
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PRIdMAX, arg, (intmax_t)uid);
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case 131: /* --groupid */
509
tmpmax = strtoimax(arg, &tmp, 10);
535
tmp_id = strtoimax(arg, &tmp, 10);
510
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if(errno != 0 or tmp == arg or *tmp != '\0'
511
or tmpmax != (gid_t)tmpmax){
537
or tmp_id != (gid_t)tmp_id){
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argp_error(state, "Bad group ID number: \"%s\", using %"
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PRIdMAX, arg, (intmax_t)gid);
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case 132: /* --debug */
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new_arg = strdup(p);
650
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if(new_arg == NULL){
652
exitstatus = EXIT_FAILURE;
681
error(0, errno, "strdup");
682
exitstatus = EX_OSERR;
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custom_argc += 1;
658
custom_argv = realloc(custom_argv, sizeof(char *)
659
* ((unsigned int) custom_argc + 1));
660
if(custom_argv == NULL){
662
exitstatus = EXIT_FAILURE;
689
char **new_argv = realloc(custom_argv, sizeof(char *)
692
if(new_argv == NULL){
693
error(0, errno, "realloc");
694
exitstatus = EX_OSERR;
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custom_argv = new_argv;
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custom_argv[custom_argc-1] = new_arg;
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custom_argv[custom_argc] = NULL;
742
/* Strip permissions down to nobody */
779
/* Work around Debian bug #633582:
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<http://bugs.debian.org/633582> */
781
int plugindir_fd = open(/* plugindir or */ PDIR, O_RDONLY);
782
if(plugindir_fd == -1){
784
error(0, errno, "open(\"" PDIR "\")");
787
ret = (int)TEMP_FAILURE_RETRY(fstat(plugindir_fd, &st));
789
error(0, errno, "fstat");
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if(S_ISDIR(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
792
ret = fchown(plugindir_fd, uid, gid);
794
error(0, errno, "fchown");
798
TEMP_FAILURE_RETRY(close(plugindir_fd));
802
/* Lower permissions */
805
error(0, errno, "setgid");
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ret = setuid(uid);
809
error(0, errno, "setuid");
752
812
/* Open plugin directory with close_on_exec flag */
755
if(plugindir == NULL){
756
dir_fd = open(PDIR, O_RDONLY |
759
#else /* not O_CLOEXEC */
761
#endif /* not O_CLOEXEC */
764
dir_fd = open(plugindir, O_RDONLY |
767
#else /* not O_CLOEXEC */
769
#endif /* not O_CLOEXEC */
814
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
817
#else /* not O_CLOEXEC */
819
#endif /* not O_CLOEXEC */
772
821
if(dir_fd == -1){
773
perror("Could not open plugin dir");
774
exitstatus = EXIT_FAILURE;
822
error(0, errno, "Could not open plugin dir");
823
exitstatus = EX_UNAVAILABLE;
779
828
/* Set the FD_CLOEXEC flag on the directory */
780
829
ret = set_cloexec_flag(dir_fd);
782
perror("set_cloexec_flag");
831
error(0, errno, "set_cloexec_flag");
783
832
TEMP_FAILURE_RETRY(close(dir_fd));
784
exitstatus = EXIT_FAILURE;
833
exitstatus = EX_OSERR;
787
836
#endif /* O_CLOEXEC */
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dir = fdopendir(dir_fd);
791
perror("Could not open plugin dir");
840
error(0, errno, "Could not open plugin dir");
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TEMP_FAILURE_RETRY(close(dir_fd));
793
exitstatus = EXIT_FAILURE;
842
exitstatus = EX_OSERR;
820
869
bool bad_name = false;
822
const char const *bad_prefixes[] = { ".", "#", NULL };
871
const char * const bad_prefixes[] = { ".", "#", NULL };
824
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
873
const char * const bad_suffixes[] = { "~", "#", ".dpkg-new",
827
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".dpkg-divert", NULL };
828
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
878
#pragma GCC diagnostic push
879
#pragma GCC diagnostic ignored "-Wcast-qual"
881
for(const char **pre = (const char **)bad_prefixes;
882
*pre != NULL; pre++){
884
#pragma GCC diagnostic pop
829
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size_t pre_len = strlen(*pre);
830
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if((d_name_len >= pre_len)
831
888
and strncmp((dirst->d_name), *pre, pre_len) == 0){
843
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
901
#pragma GCC diagnostic push
902
#pragma GCC diagnostic ignored "-Wcast-qual"
904
for(const char **suf = (const char **)bad_suffixes;
905
*suf != NULL; suf++){
907
#pragma GCC diagnostic pop
844
909
size_t suf_len = strlen(*suf);
845
910
if((d_name_len >= suf_len)
846
and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)
911
and (strcmp((dirst->d_name) + d_name_len-suf_len, *suf)
849
914
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
863
if(plugindir == NULL){
864
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, PDIR "/%s",
867
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, "%s/%s",
927
int plugin_fd = openat(dir_fd, dirst->d_name, O_RDONLY |
930
#else /* not O_CLOEXEC */
932
#endif /* not O_CLOEXEC */
935
error(0, errno, "Could not open plugin");
939
/* Set the FD_CLOEXEC flag on the plugin FD */
940
ret = set_cloexec_flag(plugin_fd);
942
error(0, errno, "set_cloexec_flag");
943
TEMP_FAILURE_RETRY(close(plugin_fd));
876
ret = (int)TEMP_FAILURE_RETRY(stat(filename, &st));
946
#endif /* O_CLOEXEC */
947
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
949
error(0, errno, "stat");
950
TEMP_FAILURE_RETRY(close(plugin_fd));
883
954
/* Ignore non-executable files */
884
955
if(not S_ISREG(st.st_mode)
885
or (TEMP_FAILURE_RETRY(access(filename, X_OK)) != 0)){
956
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, dirst->d_name, X_OK,
887
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
888
" with bad type or mode\n", filename);
959
fprintf(stderr, "Ignoring plugin dir entry \"%s/%s\""
960
" with bad type or mode\n",
961
plugindir != NULL ? plugindir : PDIR, dirst->d_name);
963
TEMP_FAILURE_RETRY(close(plugin_fd));
894
967
plugin *p = getplugin(dirst->d_name);
969
error(0, errno, "getplugin");
970
TEMP_FAILURE_RETRY(close(plugin_fd));
912
985
for(char **a = g->argv + 1; *a != NULL; a++){
913
986
if(not add_argument(p, *a)){
914
perror("add_argument");
987
error(0, errno, "add_argument");
917
990
/* Add global environment variables */
918
991
for(char **e = g->environ; *e != NULL; e++){
919
992
if(not add_environment(p, *e, false)){
920
perror("add_environment");
993
error(0, errno, "add_environment");
925
/* If this plugin has any environment variables, we will call
926
using execve and need to duplicate the environment from this
998
/* If this plugin has any environment variables, we need to
999
duplicate the environment from this process, too. */
928
1000
if(p->environ[0] != NULL){
929
1001
for(char **e = environ; *e != NULL; e++){
930
1002
if(not add_environment(p, *e, false)){
931
perror("add_environment");
1003
error(0, errno, "add_environment");
937
1009
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
940
exitstatus = EXIT_FAILURE;
1011
error(0, errno, "pipe");
1012
exitstatus = EX_OSERR;
943
1015
/* Ask OS to automatic close the pipe on exec */
944
1016
ret = set_cloexec_flag(pipefd[0]);
946
perror("set_cloexec_flag");
947
exitstatus = EXIT_FAILURE;
1018
error(0, errno, "set_cloexec_flag");
1019
exitstatus = EX_OSERR;
950
1022
ret = set_cloexec_flag(pipefd[1]);
952
perror("set_cloexec_flag");
953
exitstatus = EXIT_FAILURE;
1024
error(0, errno, "set_cloexec_flag");
1025
exitstatus = EX_OSERR;
956
1028
/* Block SIGCHLD until process is safely in process list */
969
1041
} while(pid == -1 and errno == EINTR);
972
exitstatus = EXIT_FAILURE;
1043
error(0, errno, "fork");
1044
exitstatus = EX_OSERR;
976
1048
/* this is the child process */
977
1049
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1051
error(0, errno, "sigaction");
982
1054
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
984
perror("sigprocmask");
1056
error(0, errno, "sigprocmask");
988
1060
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1062
error(0, errno, "dup2");
994
1066
if(dirfd(dir) < 0){
996
1068
above and must now close it manually here. */
999
if(p->environ[0] == NULL){
1000
if(execv(filename, p->argv) < 0){
1002
_exit(EXIT_FAILURE);
1005
if(execve(filename, p->argv, p->environ) < 0){
1007
_exit(EXIT_FAILURE);
1071
if(fexecve(plugin_fd, p->argv,
1072
(p->environ[0] != NULL) ? p->environ : environ) < 0){
1073
error(0, errno, "fexecve for %s/%s",
1074
plugindir != NULL ? plugindir : PDIR, dirst->d_name);
1010
1077
/* no return */
1012
1079
/* Parent process */
1013
1080
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
1082
TEMP_FAILURE_RETRY(close(plugin_fd));
1016
1083
plugin *new_plugin = getplugin(dirst->d_name);
1017
1084
if(new_plugin == NULL){
1018
perror("getplugin");
1085
error(0, errno, "getplugin");
1019
1086
ret = (int)(TEMP_FAILURE_RETRY
1020
1087
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
1023
perror("sigprocmask");
1090
error(0, errno, "sigprocmask");
1025
exitstatus = EXIT_FAILURE;
1092
exitstatus = EX_OSERR;
1035
1102
&sigchld_action.sa_mask,
1038
perror("sigprocmask");
1039
exitstatus = EXIT_FAILURE;
1105
error(0, errno, "sigprocmask");
1106
exitstatus = EX_OSERR;
1110
#if defined (__GNUC__) and defined (__GLIBC__)
1111
#if not __GLIBC_PREREQ(2, 16)
1112
#pragma GCC diagnostic push
1113
#pragma GCC diagnostic ignored "-Wsign-conversion"
1043
1116
FD_SET(new_plugin->fd, &rfds_all); /* Spurious warning from
1117
-Wconversion in GNU libc
1119
#if defined (__GNUC__) and defined (__GLIBC__)
1120
#if not __GLIBC_PREREQ(2, 16)
1121
#pragma GCC diagnostic pop
1046
1125
if(maxfd < new_plugin->fd){
1047
1126
maxfd = new_plugin->fd;
1068
1147
fd_set rfds = rfds_all;
1069
1148
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
1070
1149
if(select_ret == -1 and errno != EINTR){
1072
exitstatus = EXIT_FAILURE;
1150
error(0, errno, "select");
1151
exitstatus = EX_OSERR;
1075
1154
/* OK, now either a process completed, or something can be read
1103
1182
/* Remove the plugin */
1183
#if defined (__GNUC__) and defined (__GLIBC__)
1184
#if not __GLIBC_PREREQ(2, 16)
1185
#pragma GCC diagnostic push
1186
#pragma GCC diagnostic ignored "-Wsign-conversion"
1104
1189
FD_CLR(proc->fd, &rfds_all); /* Spurious warning from
1190
-Wconversion in GNU libc
1192
#if defined (__GNUC__) and defined (__GLIBC__)
1193
#if not __GLIBC_PREREQ(2, 16)
1194
#pragma GCC diagnostic pop
1107
1198
/* Block signal while modifying process_list */
1108
1199
ret = (int)TEMP_FAILURE_RETRY(sigprocmask
1141
1232
bool bret = print_out_password(proc->buffer,
1142
1233
proc->buffer_length);
1144
perror("print_out_password");
1145
exitstatus = EXIT_FAILURE;
1235
error(0, errno, "print_out_password");
1236
exitstatus = EX_IOERR;
1150
1241
/* This process has not completed. Does it have any output? */
1242
#if defined (__GNUC__) and defined (__GLIBC__)
1243
#if not __GLIBC_PREREQ(2, 16)
1244
#pragma GCC diagnostic push
1245
#pragma GCC diagnostic ignored "-Wsign-conversion"
1151
1248
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){ /* Spurious
1254
#if defined (__GNUC__) and defined (__GLIBC__)
1255
#if not __GLIBC_PREREQ(2, 16)
1256
#pragma GCC diagnostic pop
1154
1259
/* This process had nothing to say at this time */
1155
1260
proc = proc->next;
1158
1263
/* Before reading, make the process' data buffer large enough */
1159
1264
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1160
proc->buffer = realloc(proc->buffer, proc->buffer_size
1161
+ (size_t) BUFFER_SIZE);
1162
if(proc->buffer == NULL){
1164
exitstatus = EXIT_FAILURE;
1265
char *new_buffer = realloc(proc->buffer, proc->buffer_size
1266
+ (size_t) BUFFER_SIZE);
1267
if(new_buffer == NULL){
1268
error(0, errno, "malloc");
1269
exitstatus = EX_OSERR;
1272
proc->buffer = new_buffer;
1167
1273
proc->buffer_size += BUFFER_SIZE;
1169
1275
/* Read from the process */
1203
1310
bret = print_out_password(passwordbuffer, len);
1205
perror("print_out_password");
1206
exitstatus = EXIT_FAILURE;
1312
error(0, errno, "print_out_password");
1313
exitstatus = EX_IOERR;
1210
1317
/* Restore old signal handler */
1211
1318
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1213
perror("sigaction");
1214
exitstatus = EXIT_FAILURE;
1320
error(0, errno, "sigaction");
1321
exitstatus = EX_OSERR;
1217
1324
if(custom_argv != NULL){