19
19
* along with this program. If not, see
20
20
* <http://www.gnu.org/licenses/>.
22
* Contact the authors at <mandos@recompile.se>.
22
* Contact the authors at <mandos@fukt.bsnet.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> /* 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(),
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(),
37
38
#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
38
39
FD_SET(), FD_ISSET(), FD_CLR */
39
40
#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),
40
41
WEXITSTATUS(), WTERMSIG(),
42
#include <sys/stat.h> /* struct stat, fstat(), S_ISREG() */
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, 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(),
52
54
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
53
FD_CLOEXEC, openat(), scandirat(),
55
#include <string.h> /* strsep, strlen(), strsignal(),
56
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,
69
70
#include <inttypes.h> /* intmax_t, PRIdMAX, strtoimax() */
70
71
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_IOERR,
71
72
EX_CONFIG, EX_UNAVAILABLE, EX_OK */
72
#include <errno.h> /* errno */
73
#include <error.h> /* error() */
74
#include <fnmatch.h> /* fnmatch() */
76
74
#define BUFFER_SIZE 256
78
76
#define PDIR "/lib/mandos/plugins.d"
79
#define PHDIR "/lib/mandos/plugin-helpers"
80
77
#define AFILE "/conf/conf.d/mandos/plugin-runner.conf"
82
79
const char *argp_program_version = "plugin-runner " VERSION;
83
const char *argp_program_bug_address = "<mandos@recompile.se>";
80
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
85
82
typedef struct plugin{
86
83
char *name; /* can be NULL or any plugin name */
512
486
plugin *p = getplugin(arg);
514
488
p->disabled = false;
519
492
case 128: /* --plugin-dir */
521
494
plugindir = strdup(arg);
522
if(plugindir != NULL){
526
496
case 129: /* --config-file */
527
497
/* This is already done by parse_opt_config_file() */
529
499
case 130: /* --userid */
530
tmp_id = strtoimax(arg, &tmp, 10);
500
tmpmax = strtoimax(arg, &tmp, 10);
531
501
if(errno != 0 or tmp == arg or *tmp != '\0'
532
or tmp_id != (uid_t)tmp_id){
502
or tmpmax != (uid_t)tmpmax){
533
503
argp_error(state, "Bad user ID number: \"%s\", using %"
534
504
PRIdMAX, arg, (intmax_t)uid);
540
509
case 131: /* --groupid */
541
tmp_id = strtoimax(arg, &tmp, 10);
510
tmpmax = strtoimax(arg, &tmp, 10);
542
511
if(errno != 0 or tmp == arg or *tmp != '\0'
543
or tmp_id != (gid_t)tmp_id){
512
or tmpmax != (gid_t)tmpmax){
544
513
argp_error(state, "Bad group ID number: \"%s\", using %"
545
514
PRIdMAX, arg, (intmax_t)gid);
551
519
case 132: /* --debug */
554
case 133: /* --plugin-helper-dir */
555
free(pluginhelperdir);
556
pluginhelperdir = strdup(arg);
557
if(pluginhelperdir != NULL){
562
523
* These reproduce what we would get without ARGP_NO_HELP
810
/* Work around Debian bug #633582:
811
<http://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 */
743
/* Strip permissions down to nobody */
836
error(0, errno, "setgid");
838
748
ret = setuid(uid);
840
error(0, errno, "setuid");
843
753
/* Open plugin directory with close_on_exec flag */
845
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
848
#else /* not O_CLOEXEC */
850
#endif /* not O_CLOEXEC */
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 */
852
773
if(dir_fd == -1){
853
error(0, errno, "Could not open plugin dir");
774
perror("Could not open plugin dir");
854
775
exitstatus = EX_UNAVAILABLE;
859
780
/* Set the FD_CLOEXEC flag on the directory */
860
781
ret = set_cloexec_flag(dir_fd);
862
error(0, errno, "set_cloexec_flag");
783
perror("set_cloexec_flag");
784
TEMP_FAILURE_RETRY(close(dir_fd));
863
785
exitstatus = EX_OSERR;
866
788
#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);
790
dir = fdopendir(dir_fd);
792
perror("Could not open plugin dir");
793
TEMP_FAILURE_RETRY(close(dir_fd));
794
exitstatus = EX_OSERR;
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
799
FD_ZERO(&rfds_all);
905
801
/* 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");
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",
914
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
877
ret = (int)TEMP_FAILURE_RETRY(stat(filename, &st));
916
error(0, errno, "stat");
922
884
/* Ignore non-executable files */
923
885
if(not S_ISREG(st.st_mode)
924
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, direntries[i]->d_name,
886
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);
888
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
889
" with bad type or mode\n", filename);
937
plugin *p = getplugin(direntries[i]->d_name);
895
plugin *p = getplugin(dirst->d_name);
939
error(0, errno, "getplugin");
946
903
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
947
direntries[i]->d_name);
957
913
for(char **a = g->argv + 1; *a != NULL; a++){
958
914
if(not add_argument(p, *a)){
959
error(0, errno, "add_argument");
915
perror("add_argument");
962
918
/* Add global environment variables */
963
919
for(char **e = g->environ; *e != NULL; e++){
964
920
if(not add_environment(p, *e, false)){
965
error(0, errno, "add_environment");
921
perror("add_environment");
970
/* If this plugin has any environment variables, we need to
971
duplicate the environment from this process, too. */
926
/* If this plugin has any environment variables, we will call
927
using execve and need to duplicate the environment from this
972
929
if(p->environ[0] != NULL){
973
930
for(char **e = environ; *e != NULL; e++){
974
931
if(not add_environment(p, *e, false)){
975
error(0, errno, "add_environment");
932
perror("add_environment");
982
938
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;
941
exitstatus = EX_OSERR;
1002
944
/* Ask OS to automatic close the pipe on exec */
1003
945
ret = set_cloexec_flag(pipefd[0]);
1005
error(0, errno, "set_cloexec_flag");
947
perror("set_cloexec_flag");
1008
948
exitstatus = EX_OSERR;
1009
free(direntries[i]);
1012
951
ret = set_cloexec_flag(pipefd[1]);
1014
error(0, errno, "set_cloexec_flag");
953
perror("set_cloexec_flag");
1017
954
exitstatus = EX_OSERR;
1018
free(direntries[i]);
1021
#endif /* not O_CLOEXEC */
1022
957
/* Block SIGCHLD until process is safely in process list */
1023
958
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
1024
959
&sigchld_action.sa_mask,
1027
error(0, errno, "sigprocmask");
962
perror("sigprocmask");
1028
963
exitstatus = EX_OSERR;
1029
free(direntries[i]);
1032
966
/* Starting a new process to be watched */
1036
970
} 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
973
exitstatus = EX_OSERR;
1044
free(direntries[i]);
1048
977
/* this is the child process */
1049
978
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1051
error(0, errno, "sigaction");
1052
981
_exit(EX_OSERR);
1054
983
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1056
error(0, errno, "sigprocmask");
985
perror("sigprocmask");
1057
986
_exit(EX_OSERR);
1060
989
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1062
error(0, errno, "dup2");
1063
992
_exit(EX_OSERR);
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);
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){
1073
1011
/* no return */
1075
1013
/* Parent process */
1076
close(pipefd[1]); /* Close unused write end of pipe */
1078
plugin *new_plugin = getplugin(direntries[i]->d_name);
1014
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
1017
plugin *new_plugin = getplugin(dirst->d_name);
1079
1018
if(new_plugin == NULL){
1080
error(0, errno, "getplugin");
1019
perror("getplugin");
1081
1020
ret = (int)(TEMP_FAILURE_RETRY
1082
1021
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
1085
error(0, errno, "sigprocmask");
1024
perror("sigprocmask");
1087
1026
exitstatus = EX_OSERR;
1088
free(direntries[i]);
1091
free(direntries[i]);
1093
1030
new_plugin->pid = pid;
1094
1031
new_plugin->fd = pipefd[0];
1205
1142
bool bret = print_out_password(proc->buffer,
1206
1143
proc->buffer_length);
1208
error(0, errno, "print_out_password");
1145
perror("print_out_password");
1209
1146
exitstatus = EX_IOERR;
1214
1151
/* This process has not completed. Does it have any output? */
1215
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
1152
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){ /* Spurious
1216
1155
/* This process had nothing to say at this time */
1217
1156
proc = proc->next;
1220
1159
/* Before reading, make the process' data buffer large enough */
1221
1160
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1222
char *new_buffer = realloc(proc->buffer, proc->buffer_size
1223
+ (size_t) BUFFER_SIZE);
1224
if(new_buffer == NULL){
1225
error(0, errno, "malloc");
1161
proc->buffer = realloc(proc->buffer, proc->buffer_size
1162
+ (size_t) BUFFER_SIZE);
1163
if(proc->buffer == NULL){
1226
1165
exitstatus = EX_OSERR;
1229
proc->buffer = new_buffer;
1230
1168
proc->buffer_size += BUFFER_SIZE;
1232
1170
/* Read from the process */