19
19
* along with this program. If not, see
20
20
* <http://www.gnu.org/licenses/>.
22
* Contact the authors at <mandos@fukt.bsnet.se>.
22
* Contact the authors at <mandos@recompile.se>.
25
25
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), getline(),
26
asprintf(), O_CLOEXEC */
27
27
#include <stddef.h> /* size_t, NULL */
28
28
#include <stdlib.h> /* malloc(), exit(), EXIT_SUCCESS,
30
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
34
stat, waitpid(), WIFEXITED(),
35
WEXITSTATUS(), wait(), pid_t,
36
uid_t, gid_t, getuid(), getgid(),
31
#include <stdio.h> /* fileno(), fprintf(),
32
stderr, STDOUT_FILENO, fclose() */
33
#include <sys/types.h> /* fstat(), struct stat, waitpid(),
34
WIFEXITED(), WEXITSTATUS(), wait(),
35
pid_t, uid_t, gid_t, getuid(),
38
37
#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
39
38
FD_SET(), FD_ISSET(), FD_CLR */
40
39
#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),
41
40
WEXITSTATUS(), WTERMSIG(),
43
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
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(),
48
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,
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()
54
52
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
56
#include <string.h> /* strsep, strlen(), asprintf(),
53
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,
486
512
plugin *p = getplugin(arg);
488
514
p->disabled = false;
492
519
case 128: /* --plugin-dir */
494
521
plugindir = strdup(arg);
522
if(plugindir != NULL){
496
526
case 129: /* --config-file */
497
527
/* This is already done by parse_opt_config_file() */
499
529
case 130: /* --userid */
500
tmpmax = strtoimax(arg, &tmp, 10);
530
tmp_id = strtoimax(arg, &tmp, 10);
501
531
if(errno != 0 or tmp == arg or *tmp != '\0'
502
or tmpmax != (uid_t)tmpmax){
532
or tmp_id != (uid_t)tmp_id){
503
533
argp_error(state, "Bad user ID number: \"%s\", using %"
504
534
PRIdMAX, arg, (intmax_t)uid);
509
540
case 131: /* --groupid */
510
tmpmax = strtoimax(arg, &tmp, 10);
541
tmp_id = strtoimax(arg, &tmp, 10);
511
542
if(errno != 0 or tmp == arg or *tmp != '\0'
512
or tmpmax != (gid_t)tmpmax){
543
or tmp_id != (gid_t)tmp_id){
513
544
argp_error(state, "Bad group ID number: \"%s\", using %"
514
545
PRIdMAX, arg, (intmax_t)gid);
519
551
case 132: /* --debug */
554
case 133: /* --plugin-helper-dir */
555
free(pluginhelperdir);
556
pluginhelperdir = strdup(arg);
557
if(pluginhelperdir != NULL){
523
562
* These reproduce what we would get without ARGP_NO_HELP
743
/* Strip permissions down to nobody */
811
/* Work around Debian bug #633582:
812
<http://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");
830
TEMP_FAILURE_RETRY(close(plugindir_fd));
834
/* Lower permissions */
837
error(0, errno, "setgid");
748
839
ret = setuid(uid);
841
error(0, errno, "setuid");
753
844
/* Open plugin directory with close_on_exec flag */
756
if(plugindir == NULL){
757
dir_fd = open(PDIR, O_RDONLY |
760
#else /* not O_CLOEXEC */
762
#endif /* not O_CLOEXEC */
765
dir_fd = open(plugindir, O_RDONLY |
768
#else /* not O_CLOEXEC */
770
#endif /* not O_CLOEXEC */
846
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
849
#else /* not O_CLOEXEC */
851
#endif /* not O_CLOEXEC */
773
853
if(dir_fd == -1){
774
perror("Could not open plugin dir");
854
error(0, errno, "Could not open plugin dir");
775
855
exitstatus = EX_UNAVAILABLE;
780
860
/* Set the FD_CLOEXEC flag on the directory */
781
861
ret = set_cloexec_flag(dir_fd);
783
perror("set_cloexec_flag");
784
TEMP_FAILURE_RETRY(close(dir_fd));
863
error(0, errno, "set_cloexec_flag");
785
864
exitstatus = EX_OSERR;
788
867
#endif /* O_CLOEXEC */
790
dir = fdopendir(dir_fd);
792
perror("Could not open plugin dir");
793
TEMP_FAILURE_RETRY(close(dir_fd));
794
exitstatus = EX_OSERR;
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);
896
#if __GLIBC_PREREQ(2, 15)
897
int numplugins = scandirat(dir_fd, ".", &direntries, good_name,
899
#else /* not __GLIBC_PREREQ(2, 15) */
900
int numplugins = scandir(plugindir != NULL ? plugindir : PDIR,
901
&direntries, good_name, alphasort);
902
#endif /* not __GLIBC_PREREQ(2, 15) */
903
#else /* not __GLIBC__ */
904
int numplugins = scandir(plugindir != NULL ? plugindir : PDIR,
905
&direntries, good_name, alphasort);
906
#endif /* not __GLIBC__ */
907
if(numplugins == -1){
908
error(0, errno, "Could not scan plugin dir");
910
exitstatus = EX_OSERR;
799
914
FD_ZERO(&rfds_all);
801
916
/* Read and execute any executable in the plugin directory*/
804
dirst = readdir(dir);
805
} while(dirst == NULL and errno == EINTR);
807
/* All directory entries have been processed */
811
exitstatus = EX_IOERR;
817
d_name_len = strlen(dirst->d_name);
819
/* Ignore dotfiles, backup files and other junk */
821
bool bad_name = false;
823
const char const *bad_prefixes[] = { ".", "#", NULL };
825
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
828
".dpkg-divert", NULL };
829
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
830
size_t pre_len = strlen(*pre);
831
if((d_name_len >= pre_len)
832
and strncmp((dirst->d_name), *pre, pre_len) == 0){
834
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
835
" with bad prefix %s\n", dirst->d_name, *pre);
844
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
845
size_t suf_len = strlen(*suf);
846
if((d_name_len >= suf_len)
847
and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)
850
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
851
" with bad suffix %s\n", dirst->d_name, *suf);
864
if(plugindir == NULL){
865
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, PDIR "/%s",
868
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, "%s/%s",
917
for(int i = 0; i < numplugins; i++){
919
int plugin_fd = openat(dir_fd, direntries[i]->d_name, O_RDONLY);
921
error(0, errno, "Could not open plugin");
877
ret = (int)TEMP_FAILURE_RETRY(stat(filename, &st));
925
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
927
error(0, errno, "stat");
928
TEMP_FAILURE_RETRY(close(plugin_fd));
884
933
/* Ignore non-executable files */
885
934
if(not S_ISREG(st.st_mode)
886
or (TEMP_FAILURE_RETRY(access(filename, X_OK)) != 0)){
935
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, direntries[i]->d_name,
888
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
889
" with bad type or mode\n", filename);
938
fprintf(stderr, "Ignoring plugin dir entry \"%s/%s\""
939
" with bad type or mode\n",
940
plugindir != NULL ? plugindir : PDIR,
941
direntries[i]->d_name);
943
TEMP_FAILURE_RETRY(close(plugin_fd));
895
plugin *p = getplugin(dirst->d_name);
948
plugin *p = getplugin(direntries[i]->d_name);
950
error(0, errno, "getplugin");
951
TEMP_FAILURE_RETRY(close(plugin_fd));
903
957
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
958
direntries[i]->d_name);
960
TEMP_FAILURE_RETRY(close(plugin_fd));
913
968
for(char **a = g->argv + 1; *a != NULL; a++){
914
969
if(not add_argument(p, *a)){
915
perror("add_argument");
970
error(0, errno, "add_argument");
918
973
/* Add global environment variables */
919
974
for(char **e = g->environ; *e != NULL; e++){
920
975
if(not add_environment(p, *e, false)){
921
perror("add_environment");
976
error(0, errno, "add_environment");
926
/* If this plugin has any environment variables, we will call
927
using execve and need to duplicate the environment from this
981
/* If this plugin has any environment variables, we need to
982
duplicate the environment from this process, too. */
929
983
if(p->environ[0] != NULL){
930
984
for(char **e = environ; *e != NULL; e++){
931
985
if(not add_environment(p, *e, false)){
932
perror("add_environment");
986
error(0, errno, "add_environment");
938
993
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
994
#else /* O_CLOEXEC */
995
ret = (int)TEMP_FAILURE_RETRY(pipe2(pipefd, O_CLOEXEC));
996
#endif /* O_CLOEXEC */
941
exitstatus = EX_OSERR;
998
error(0, errno, "pipe");
999
exitstatus = EX_OSERR;
1000
free(direntries[i]);
1003
if(pipefd[0] >= FD_SETSIZE){
1004
fprintf(stderr, "pipe()[0] (%d) >= FD_SETSIZE (%d)", pipefd[0],
1006
TEMP_FAILURE_RETRY(close(pipefd[0]));
1007
TEMP_FAILURE_RETRY(close(pipefd[1]));
1008
exitstatus = EX_OSERR;
1009
free(direntries[i]);
944
1013
/* Ask OS to automatic close the pipe on exec */
945
1014
ret = set_cloexec_flag(pipefd[0]);
947
perror("set_cloexec_flag");
1016
error(0, errno, "set_cloexec_flag");
1017
TEMP_FAILURE_RETRY(close(pipefd[0]));
1018
TEMP_FAILURE_RETRY(close(pipefd[1]));
948
1019
exitstatus = EX_OSERR;
1020
free(direntries[i]);
951
1023
ret = set_cloexec_flag(pipefd[1]);
953
perror("set_cloexec_flag");
1025
error(0, errno, "set_cloexec_flag");
1026
TEMP_FAILURE_RETRY(close(pipefd[0]));
1027
TEMP_FAILURE_RETRY(close(pipefd[1]));
954
1028
exitstatus = EX_OSERR;
1029
free(direntries[i]);
1032
#endif /* not O_CLOEXEC */
957
1033
/* Block SIGCHLD until process is safely in process list */
958
1034
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
959
1035
&sigchld_action.sa_mask,
962
perror("sigprocmask");
1038
error(0, errno, "sigprocmask");
963
1039
exitstatus = EX_OSERR;
1040
free(direntries[i]);
966
1043
/* Starting a new process to be watched */
970
1047
} while(pid == -1 and errno == EINTR);
1049
error(0, errno, "fork");
1050
TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1051
&sigchld_action.sa_mask, NULL));
1052
TEMP_FAILURE_RETRY(close(pipefd[0]));
1053
TEMP_FAILURE_RETRY(close(pipefd[1]));
973
1054
exitstatus = EX_OSERR;
1055
free(direntries[i]);
977
1059
/* this is the child process */
978
1060
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1062
error(0, errno, "sigaction");
981
1063
_exit(EX_OSERR);
983
1065
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
985
perror("sigprocmask");
1067
error(0, errno, "sigprocmask");
986
1068
_exit(EX_OSERR);
989
1071
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1073
error(0, errno, "dup2");
992
1074
_exit(EX_OSERR);
996
/* If dir has no file descriptor, we could not set FD_CLOEXEC
997
above and must now close it manually here. */
1000
if(p->environ[0] == NULL){
1001
if(execv(filename, p->argv) < 0){
1006
if(execve(filename, p->argv, p->environ) < 0){
1077
if(fexecve(plugin_fd, p->argv,
1078
(p->environ[0] != NULL) ? p->environ : environ) < 0){
1079
error(0, errno, "fexecve for %s/%s",
1080
plugindir != NULL ? plugindir : PDIR,
1081
direntries[i]->d_name);
1011
1084
/* no return */
1013
1086
/* Parent process */
1014
1087
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
1017
plugin *new_plugin = getplugin(dirst->d_name);
1089
TEMP_FAILURE_RETRY(close(plugin_fd));
1090
plugin *new_plugin = getplugin(direntries[i]->d_name);
1018
1091
if(new_plugin == NULL){
1019
perror("getplugin");
1092
error(0, errno, "getplugin");
1020
1093
ret = (int)(TEMP_FAILURE_RETRY
1021
1094
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
1024
perror("sigprocmask");
1097
error(0, errno, "sigprocmask");
1026
1099
exitstatus = EX_OSERR;
1100
free(direntries[i]);
1103
free(direntries[i]);
1030
1105
new_plugin->pid = pid;
1031
1106
new_plugin->fd = pipefd[0];
1142
1243
bool bret = print_out_password(proc->buffer,
1143
1244
proc->buffer_length);
1145
perror("print_out_password");
1246
error(0, errno, "print_out_password");
1146
1247
exitstatus = EX_IOERR;
1151
1252
/* This process has not completed. Does it have any output? */
1253
#if defined (__GNUC__) and defined (__GLIBC__)
1254
#if not __GLIBC_PREREQ(2, 16)
1255
#pragma GCC diagnostic push
1256
#pragma GCC diagnostic ignored "-Wsign-conversion"
1152
1259
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){ /* Spurious
1265
#if defined (__GNUC__) and defined (__GLIBC__)
1266
#if not __GLIBC_PREREQ(2, 16)
1267
#pragma GCC diagnostic pop
1155
1270
/* This process had nothing to say at this time */
1156
1271
proc = proc->next;
1159
1274
/* Before reading, make the process' data buffer large enough */
1160
1275
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1161
proc->buffer = realloc(proc->buffer, proc->buffer_size
1162
+ (size_t) BUFFER_SIZE);
1163
if(proc->buffer == NULL){
1276
char *new_buffer = realloc(proc->buffer, proc->buffer_size
1277
+ (size_t) BUFFER_SIZE);
1278
if(new_buffer == NULL){
1279
error(0, errno, "malloc");
1165
1280
exitstatus = EX_OSERR;
1283
proc->buffer = new_buffer;
1168
1284
proc->buffer_size += BUFFER_SIZE;
1170
1286
/* Read from the process */