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(),
57
strsignal(), strcmp(), strncmp() */
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
506
plugin *p = getplugin(arg);
488
508
p->disabled = false;
492
513
case 128: /* --plugin-dir */
494
515
plugindir = strdup(arg);
516
if(plugindir != NULL){
496
520
case 129: /* --config-file */
497
521
/* This is already done by parse_opt_config_file() */
499
523
case 130: /* --userid */
500
tmpmax = strtoimax(arg, &tmp, 10);
524
tmp_id = strtoimax(arg, &tmp, 10);
501
525
if(errno != 0 or tmp == arg or *tmp != '\0'
502
or tmpmax != (uid_t)tmpmax){
526
or tmp_id != (uid_t)tmp_id){
503
527
argp_error(state, "Bad user ID number: \"%s\", using %"
504
528
PRIdMAX, arg, (intmax_t)uid);
509
534
case 131: /* --groupid */
510
tmpmax = strtoimax(arg, &tmp, 10);
535
tmp_id = strtoimax(arg, &tmp, 10);
511
536
if(errno != 0 or tmp == arg or *tmp != '\0'
512
or tmpmax != (gid_t)tmpmax){
537
or tmp_id != (gid_t)tmp_id){
513
538
argp_error(state, "Bad group ID number: \"%s\", using %"
514
539
PRIdMAX, arg, (intmax_t)gid);
519
545
case 132: /* --debug */
743
/* Strip permissions down to nobody */
779
/* Work around Debian bug #633582:
780
<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");
791
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");
748
807
ret = setuid(uid);
809
error(0, errno, "setuid");
753
812
/* 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 */
814
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
817
#else /* not O_CLOEXEC */
819
#endif /* not O_CLOEXEC */
773
821
if(dir_fd == -1){
774
perror("Could not open plugin dir");
822
error(0, errno, "Could not open plugin dir");
775
823
exitstatus = EX_UNAVAILABLE;
780
828
/* Set the FD_CLOEXEC flag on the directory */
781
829
ret = set_cloexec_flag(dir_fd);
783
perror("set_cloexec_flag");
831
error(0, errno, "set_cloexec_flag");
784
832
TEMP_FAILURE_RETRY(close(dir_fd));
785
833
exitstatus = EX_OSERR;
788
836
#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;
839
int good_name(const struct dirent * const dirent){
840
const char * const patterns[] = { ".*", "#*#", "*~", "*.dpkg-new",
841
"*.dpkg-old", "*.dpkg-bak",
842
"*.dpkg-divert", NULL };
844
#pragma GCC diagnostic push
845
#pragma GCC diagnostic ignored "-Wcast-qual"
847
for(const char **pat = (const char **)patterns;
848
*pat != NULL; pat++){
850
#pragma GCC diagnostic pop
852
if(fnmatch(*pat, dirent->d_name, FNM_FILE_NAME | FNM_PERIOD)
855
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
856
" matching pattern %s\n", dirent->d_name, *pat);
865
#if __GLIBC_PREREQ(2, 15)
866
int numplugins = scandirat(dir_fd, ".", &direntries, good_name,
868
#else /* not __GLIBC_PREREQ(2, 15) */
869
int numplugins = scandir(plugindir != NULL ? plugindir : PDIR,
870
&direntries, good_name, alphasort);
871
#endif /* not __GLIBC_PREREQ(2, 15) */
872
#else /* not __GLIBC__ */
873
int numplugins = scandir(plugindir != NULL ? plugindir : PDIR,
874
&direntries, good_name, alphasort);
875
#endif /* not __GLIBC__ */
876
if(numplugins == -1){
877
error(0, errno, "Could not scan plugin dir");
878
TEMP_FAILURE_RETRY(close(dir_fd));
879
exitstatus = EX_OSERR;
799
883
FD_ZERO(&rfds_all);
801
885
/* 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",
886
for(int i = 0; i < numplugins; i++){
888
int plugin_fd = openat(dir_fd, direntries[i]->d_name, O_RDONLY);
890
error(0, errno, "Could not open plugin");
877
ret = (int)TEMP_FAILURE_RETRY(stat(filename, &st));
893
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
895
error(0, errno, "stat");
896
TEMP_FAILURE_RETRY(close(plugin_fd));
884
900
/* Ignore non-executable files */
885
901
if(not S_ISREG(st.st_mode)
886
or (TEMP_FAILURE_RETRY(access(filename, X_OK)) != 0)){
902
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);
905
fprintf(stderr, "Ignoring plugin dir entry \"%s/%s\""
906
" with bad type or mode\n",
907
plugindir != NULL ? plugindir : PDIR,
908
direntries[i]->d_name);
910
TEMP_FAILURE_RETRY(close(plugin_fd));
895
plugin *p = getplugin(dirst->d_name);
914
plugin *p = getplugin(direntries[i]->d_name);
916
error(0, errno, "getplugin");
917
TEMP_FAILURE_RETRY(close(plugin_fd));
903
922
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
923
direntries[i]->d_name);
925
TEMP_FAILURE_RETRY(close(plugin_fd));
913
932
for(char **a = g->argv + 1; *a != NULL; a++){
914
933
if(not add_argument(p, *a)){
915
perror("add_argument");
934
error(0, errno, "add_argument");
918
937
/* Add global environment variables */
919
938
for(char **e = g->environ; *e != NULL; e++){
920
939
if(not add_environment(p, *e, false)){
921
perror("add_environment");
940
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
945
/* If this plugin has any environment variables, we need to
946
duplicate the environment from this process, too. */
929
947
if(p->environ[0] != NULL){
930
948
for(char **e = environ; *e != NULL; e++){
931
949
if(not add_environment(p, *e, false)){
932
perror("add_environment");
950
error(0, errno, "add_environment");
938
957
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
958
#else /* O_CLOEXEC */
959
ret = (int)TEMP_FAILURE_RETRY(pipe2(pipefd, O_CLOEXEC));
960
#endif /* O_CLOEXEC */
941
exitstatus = EX_OSERR;
962
error(0, errno, "pipe");
963
exitstatus = EX_OSERR;
966
if(pipefd[0] >= FD_SETSIZE){
967
fprintf(stderr, "pipe()[0] (%d) >= FD_SETSIZE (%d)", pipefd[0],
969
TEMP_FAILURE_RETRY(close(pipefd[0]));
970
TEMP_FAILURE_RETRY(close(pipefd[1]));
971
exitstatus = EX_OSERR;
944
975
/* Ask OS to automatic close the pipe on exec */
945
976
ret = set_cloexec_flag(pipefd[0]);
947
perror("set_cloexec_flag");
978
error(0, errno, "set_cloexec_flag");
979
TEMP_FAILURE_RETRY(close(pipefd[0]));
980
TEMP_FAILURE_RETRY(close(pipefd[1]));
948
981
exitstatus = EX_OSERR;
951
984
ret = set_cloexec_flag(pipefd[1]);
953
perror("set_cloexec_flag");
986
error(0, errno, "set_cloexec_flag");
987
TEMP_FAILURE_RETRY(close(pipefd[0]));
988
TEMP_FAILURE_RETRY(close(pipefd[1]));
954
989
exitstatus = EX_OSERR;
992
#endif /* not O_CLOEXEC */
957
993
/* Block SIGCHLD until process is safely in process list */
958
994
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
959
995
&sigchld_action.sa_mask,
962
perror("sigprocmask");
998
error(0, errno, "sigprocmask");
963
999
exitstatus = EX_OSERR;
977
1017
/* this is the child process */
978
1018
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1020
error(0, errno, "sigaction");
981
1021
_exit(EX_OSERR);
983
1023
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
985
perror("sigprocmask");
1025
error(0, errno, "sigprocmask");
986
1026
_exit(EX_OSERR);
989
1029
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1031
error(0, errno, "dup2");
992
1032
_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){
1035
if(fexecve(plugin_fd, p->argv,
1036
(p->environ[0] != NULL) ? p->environ : environ) < 0){
1037
error(0, errno, "fexecve for %s/%s",
1038
plugindir != NULL ? plugindir : PDIR,
1039
direntries[i]->d_name);
1011
1042
/* no return */
1013
1044
/* Parent process */
1014
1045
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
1017
plugin *new_plugin = getplugin(dirst->d_name);
1047
TEMP_FAILURE_RETRY(close(plugin_fd));
1048
plugin *new_plugin = getplugin(direntries[i]->d_name);
1018
1049
if(new_plugin == NULL){
1019
perror("getplugin");
1050
error(0, errno, "getplugin");
1020
1051
ret = (int)(TEMP_FAILURE_RETRY
1021
1052
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
1024
perror("sigprocmask");
1055
error(0, errno, "sigprocmask");
1026
1057
exitstatus = EX_OSERR;
1142
1196
bool bret = print_out_password(proc->buffer,
1143
1197
proc->buffer_length);
1145
perror("print_out_password");
1199
error(0, errno, "print_out_password");
1146
1200
exitstatus = EX_IOERR;
1151
1205
/* This process has not completed. Does it have any output? */
1206
#if defined (__GNUC__) and defined (__GLIBC__)
1207
#if not __GLIBC_PREREQ(2, 16)
1208
#pragma GCC diagnostic push
1209
#pragma GCC diagnostic ignored "-Wsign-conversion"
1152
1212
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){ /* Spurious
1218
#if defined (__GNUC__) and defined (__GLIBC__)
1219
#if not __GLIBC_PREREQ(2, 16)
1220
#pragma GCC diagnostic pop
1155
1223
/* This process had nothing to say at this time */
1156
1224
proc = proc->next;
1159
1227
/* Before reading, make the process' data buffer large enough */
1160
1228
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){
1229
char *new_buffer = realloc(proc->buffer, proc->buffer_size
1230
+ (size_t) BUFFER_SIZE);
1231
if(new_buffer == NULL){
1232
error(0, errno, "malloc");
1165
1233
exitstatus = EX_OSERR;
1236
proc->buffer = new_buffer;
1168
1237
proc->buffer_size += BUFFER_SIZE;
1170
1239
/* Read from the process */