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(),
27
27
#include <stddef.h> /* size_t, NULL */
28
#include <stdlib.h> /* malloc(), exit(), EXIT_SUCCESS,
28
#include <stdlib.h> /* malloc(), exit(), EXIT_FAILURE,
29
EXIT_SUCCESS, realloc() */
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, opendir(), 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
WEXITSTATUS(), WTERMSIG(),
42
#include <sys/stat.h> /* struct stat, fstat(), S_ISREG() */
42
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
43
43
#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()
44
#include <dirent.h> /* DIR, struct dirent, opendir(),
45
readdir(), closedir(), dirfd() */
46
#include <unistd.h> /* struct stat, stat(), S_ISREG(),
47
fcntl(), setuid(), setgid(),
48
F_GETFD, F_SETFD, FD_CLOEXEC,
49
access(), pipe(), fork(), close()
50
dup2(), STDOUT_FILENO, _exit(),
51
execv(), write(), read(),
52
53
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
53
FD_CLOEXEC, openat(), scandirat(),
55
#include <string.h> /* strsep, strlen(), strsignal(),
56
strcmp(), strncmp() */
55
#include <string.h> /* strsep, strlen(), asprintf() */
57
56
#include <errno.h> /* errno */
58
57
#include <argp.h> /* struct argp_option, struct
59
58
argp_state, struct argp,
66
65
SIG_UNBLOCK, kill(), sig_atomic_t
68
67
#include <errno.h> /* errno, EBADF */
69
#include <inttypes.h> /* intmax_t, PRIdMAX, strtoimax() */
70
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_IOERR,
71
EX_CONFIG, EX_UNAVAILABLE, EX_OK */
72
#include <errno.h> /* errno */
73
#include <error.h> /* error() */
74
#include <fnmatch.h> /* fnmatch() */
68
#include <inttypes.h> /* intmax_t, SCNdMAX, PRIdMAX, */
76
70
#define BUFFER_SIZE 256
78
72
#define PDIR "/lib/mandos/plugins.d"
79
#define PHDIR "/lib/mandos/plugin-helpers"
80
73
#define AFILE "/conf/conf.d/mandos/plugin-runner.conf"
82
75
const char *argp_program_version = "plugin-runner " VERSION;
83
const char *argp_program_bug_address = "<mandos@recompile.se>";
76
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
85
78
typedef struct plugin{
86
79
char *name; /* can be NULL or any plugin name */
416
375
.doc = "Group ID the plugins will run as", .group = 3 },
417
376
{ .name = "debug", .key = 132,
418
377
.doc = "Debug mode", .group = 4 },
419
{ .name = "plugin-helper-dir", .key = 133,
421
.doc = "Specify a different plugin helper directory",
424
* These reproduce what we would get without ARGP_NO_HELP
426
{ .name = "help", .key = '?',
427
.doc = "Give this help list", .group = -1 },
428
{ .name = "usage", .key = -3,
429
.doc = "Give a short usage message", .group = -1 },
430
{ .name = "version", .key = 'V',
431
.doc = "Print program version", .group = -1 },
435
__attribute__((nonnull(3)))
436
error_t parse_opt(int key, char *arg, struct argp_state *state){
381
error_t parse_opt(int key, char *arg, __attribute__((unused))
382
struct argp_state *state){
441
384
case 'g': /* --global-options */
443
386
char *plugin_option;
444
387
while((plugin_option = strsep(&arg, ",")) != NULL){
388
if(plugin_option[0] == '\0'){
445
391
if(not add_argument(getplugin(NULL), plugin_option)){
392
perror("add_argument");
393
return ARGP_ERR_UNKNOWN;
452
398
case 'G': /* --global-env */
453
if(add_environment(getplugin(NULL), arg, true)){
402
if(not add_environment(getplugin(NULL), arg, true)){
403
perror("add_environment");
457
406
case 'o': /* --options-for */
459
char *option_list = strchr(arg, ':');
460
if(option_list == NULL){
461
argp_error(state, "No colon in \"%s\"", arg);
468
argp_error(state, "Empty plugin name");
473
while((option = strsep(&option_list, ",")) != NULL){
474
if(not add_argument(getplugin(arg), option)){
408
char *plugin_name = strsep(&arg, ":");
409
if(plugin_name[0] == '\0'){
413
while((plugin_option = strsep(&arg, ",")) != NULL){
414
if(not add_argument(getplugin(plugin_name), plugin_option)){
415
perror("add_argument");
416
return ARGP_ERR_UNKNOWN;
481
421
case 'E': /* --env-for */
483
426
char *envdef = strchr(arg, ':');
484
427
if(envdef == NULL){
485
argp_error(state, "No colon in \"%s\"", arg);
492
argp_error(state, "Empty plugin name");
496
if(add_environment(getplugin(arg), envdef, true)){
431
if(not add_environment(getplugin(arg), envdef+1, true)){
432
perror("add_environment");
501
436
case 'd': /* --disable */
503
438
plugin *p = getplugin(arg);
440
return ARGP_ERR_UNKNOWN;
510
445
case 'e': /* --enable */
512
447
plugin *p = getplugin(arg);
449
return ARGP_ERR_UNKNOWN;
519
454
case 128: /* --plugin-dir */
521
456
plugindir = strdup(arg);
522
if(plugindir != NULL){
457
if(plugindir == NULL){
526
461
case 129: /* --config-file */
527
462
/* This is already done by parse_opt_config_file() */
529
464
case 130: /* --userid */
530
tmp_id = strtoimax(arg, &tmp, 10);
531
if(errno != 0 or tmp == arg or *tmp != '\0'
532
or tmp_id != (uid_t)tmp_id){
533
argp_error(state, "Bad user ID number: \"%s\", using %"
534
PRIdMAX, arg, (intmax_t)uid);
465
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
466
if(ret < 1 or tmpmax != (uid_t)tmpmax
467
or arg[numchars] != '\0'){
468
fprintf(stderr, "Bad user ID number: \"%s\", using %"
469
PRIdMAX "\n", arg, (intmax_t)uid);
540
474
case 131: /* --groupid */
541
tmp_id = strtoimax(arg, &tmp, 10);
542
if(errno != 0 or tmp == arg or *tmp != '\0'
543
or tmp_id != (gid_t)tmp_id){
544
argp_error(state, "Bad group ID number: \"%s\", using %"
545
PRIdMAX, arg, (intmax_t)gid);
475
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
476
if(ret < 1 or tmpmax != (gid_t)tmpmax
477
or arg[numchars] != '\0'){
478
fprintf(stderr, "Bad group ID number: \"%s\", using %"
479
PRIdMAX "\n", arg, (intmax_t)gid);
551
484
case 132: /* --debug */
554
case 133: /* --plugin-helper-dir */
555
free(pluginhelperdir);
556
pluginhelperdir = strdup(arg);
557
if(pluginhelperdir != NULL){
562
* These reproduce what we would get without ARGP_NO_HELP
564
case '?': /* --help */
565
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
566
argp_state_help(state, state->out_stream, ARGP_HELP_STD_HELP);
567
case -3: /* --usage */
568
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
569
argp_state_help(state, state->out_stream,
570
ARGP_HELP_USAGE | ARGP_HELP_EXIT_OK);
571
case 'V': /* --version */
572
fprintf(state->out_stream, "%s\n", argp_program_version);
576
488
* When adding more options before this line, remember to also add a
577
489
* "case" to the "parse_opt_config_file" function below.
693
594
new_arg = strdup(p);
694
595
if(new_arg == NULL){
695
error(0, errno, "strdup");
696
exitstatus = EX_OSERR;
597
exitstatus = EXIT_FAILURE;
701
602
custom_argc += 1;
703
char **new_argv = realloc(custom_argv, sizeof(char *)
704
* ((size_t)custom_argc + 1));
705
if(new_argv == NULL){
706
error(0, errno, "realloc");
707
exitstatus = EX_OSERR;
712
custom_argv = new_argv;
603
custom_argv = realloc(custom_argv, sizeof(char *)
604
* ((unsigned int) custom_argc + 1));
605
if(custom_argv == NULL){
607
exitstatus = EXIT_FAILURE;
715
611
custom_argv[custom_argc-1] = new_arg;
716
custom_argv[custom_argc] = NULL;
612
custom_argv[custom_argc] = NULL;
720
ret = fclose(conffp);
721
} while(ret == EOF and errno == EINTR);
723
error(0, errno, "fclose");
724
exitstatus = EX_IOERR;
729
617
/* Check for harmful errors and go to fallback. Other errors might
730
618
not affect opening plugins */
731
619
if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
732
error(0, errno, "fopen");
733
exitstatus = EX_OSERR;
621
exitstatus = EXIT_FAILURE;
737
/* If there were any arguments from the configuration file, pass
738
them to parser as command line arguments */
625
/* If there was any arguments from configuration file,
626
pass them to parser as command arguments */
739
627
if(custom_argv != NULL){
740
ret = argp_parse(&argp, custom_argc, custom_argv,
741
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
749
error(0, errno, "argp_parse");
750
exitstatus = EX_OSERR;
753
exitstatus = EX_CONFIG;
628
ret = argp_parse(&argp, custom_argc, custom_argv, ARGP_IN_ORDER,
630
if(ret == ARGP_ERR_UNKNOWN){
631
fprintf(stderr, "Unknown error while parsing arguments\n");
632
exitstatus = EXIT_FAILURE;
758
637
/* Parse actual command line arguments, to let them override the
760
ret = argp_parse(&argp, argc, argv,
761
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
769
error(0, errno, "argp_parse");
770
exitstatus = EX_OSERR;
773
exitstatus = EX_USAGE;
778
char *pluginhelperenv;
780
ret = asprintf(&pluginhelperenv, "MANDOSPLUGINHELPERDIR=%s",
781
pluginhelperdir != NULL ? pluginhelperdir : PHDIR);
783
bret = add_environment(getplugin(NULL), pluginhelperenv, true);
785
if(ret == -1 or not bret){
786
error(0, errno, "Failed to set MANDOSPLUGINHELPERDIR"
787
" environment variable to \"%s\" for all plugins\n",
788
pluginhelperdir != NULL ? pluginhelperdir : PHDIR);
791
free(pluginhelperenv);
639
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
640
if(ret == ARGP_ERR_UNKNOWN){
641
fprintf(stderr, "Unknown error while parsing arguments\n");
642
exitstatus = EXIT_FAILURE;
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 */
660
/* Strip permissions down to nobody */
836
error(0, errno, "setgid");
838
665
ret = setuid(uid);
840
error(0, errno, "setuid");
843
/* Open plugin directory with close_on_exec flag */
670
if(plugindir == NULL){
673
dir = opendir(plugindir);
677
perror("Could not open plugin dir");
678
exitstatus = EXIT_FAILURE;
682
/* Set the FD_CLOEXEC flag on the directory, if possible */
845
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
848
#else /* not O_CLOEXEC */
850
#endif /* not O_CLOEXEC */
853
error(0, errno, "Could not open plugin dir");
854
exitstatus = EX_UNAVAILABLE;
859
/* Set the FD_CLOEXEC flag on the directory */
860
ret = set_cloexec_flag(dir_fd);
862
error(0, errno, "set_cloexec_flag");
863
exitstatus = EX_OSERR;
866
#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);
684
int dir_fd = dirfd(dir);
686
ret = set_cloexec_flag(dir_fd);
688
perror("set_cloexec_flag");
689
exitstatus = EXIT_FAILURE;
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
695
FD_ZERO(&rfds_all);
905
697
/* 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");
699
dirst = readdir(dir);
701
/* All directory entries have been processed */
705
exitstatus = EXIT_FAILURE;
711
d_name_len = strlen(dirst->d_name);
713
/* Ignore dotfiles, backup files and other junk */
715
bool bad_name = false;
717
const char const *bad_prefixes[] = { ".", "#", NULL };
719
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
722
".dpkg-divert", NULL };
723
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
724
size_t pre_len = strlen(*pre);
725
if((d_name_len >= pre_len)
726
and strncmp((dirst->d_name), *pre, pre_len) == 0){
728
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
729
" with bad prefix %s\n", dirst->d_name, *pre);
738
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
739
size_t suf_len = strlen(*suf);
740
if((d_name_len >= suf_len)
741
and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)
744
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
745
" with bad suffix %s\n", dirst->d_name, *suf);
758
if(plugindir == NULL){
759
ret = asprintf(&filename, PDIR "/%s", dirst->d_name);
761
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
914
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
768
ret = stat(filename, &st);
916
error(0, errno, "stat");
922
775
/* Ignore non-executable files */
923
if(not S_ISREG(st.st_mode)
924
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, direntries[i]->d_name,
776
if(not S_ISREG(st.st_mode) or (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);
778
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
779
" with bad type or mode\n", filename);
937
plugin *p = getplugin(direntries[i]->d_name);
785
plugin *p = getplugin(dirst->d_name);
939
error(0, errno, "getplugin");
946
793
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
947
direntries[i]->d_name);
957
803
for(char **a = g->argv + 1; *a != NULL; a++){
958
804
if(not add_argument(p, *a)){
959
error(0, errno, "add_argument");
805
perror("add_argument");
962
808
/* Add global environment variables */
963
809
for(char **e = g->environ; *e != NULL; e++){
964
810
if(not add_environment(p, *e, false)){
965
error(0, errno, "add_environment");
811
perror("add_environment");
970
/* If this plugin has any environment variables, we need to
971
duplicate the environment from this process, too. */
816
/* If this plugin has any environment variables, we will call
817
using execve and need to duplicate the environment from this
972
819
if(p->environ[0] != NULL){
973
820
for(char **e = environ; *e != NULL; e++){
974
821
if(not add_environment(p, *e, false)){
975
error(0, errno, "add_environment");
822
perror("add_environment");
982
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;
831
exitstatus = EXIT_FAILURE;
1002
834
/* Ask OS to automatic close the pipe on exec */
1003
835
ret = set_cloexec_flag(pipefd[0]);
1005
error(0, errno, "set_cloexec_flag");
1008
exitstatus = EX_OSERR;
1009
free(direntries[i]);
837
perror("set_cloexec_flag");
838
exitstatus = EXIT_FAILURE;
1012
841
ret = set_cloexec_flag(pipefd[1]);
1014
error(0, errno, "set_cloexec_flag");
1017
exitstatus = EX_OSERR;
1018
free(direntries[i]);
843
perror("set_cloexec_flag");
844
exitstatus = EXIT_FAILURE;
1021
#endif /* not O_CLOEXEC */
1022
847
/* Block SIGCHLD until process is safely in process list */
1023
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
1024
&sigchld_action.sa_mask,
848
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
1027
error(0, errno, "sigprocmask");
1028
exitstatus = EX_OSERR;
1029
free(direntries[i]);
850
perror("sigprocmask");
851
exitstatus = EXIT_FAILURE;
1032
854
/* Starting a new process to be watched */
1036
} 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
exitstatus = EX_OSERR;
1044
free(direntries[i]);
858
exitstatus = EXIT_FAILURE;
1048
862
/* this is the child process */
1049
863
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1051
error(0, errno, "sigaction");
1054
868
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1056
error(0, errno, "sigprocmask");
870
perror("sigprocmask");
1060
874
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1062
error(0, errno, "dup2");
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);
881
/* If dir has no file descriptor, we could not set FD_CLOEXEC
882
above and must now close it manually here. */
885
if(p->environ[0] == NULL){
886
if(execv(filename, p->argv) < 0){
891
if(execve(filename, p->argv, p->environ) < 0){
1075
898
/* Parent process */
1076
899
close(pipefd[1]); /* Close unused write end of pipe */
1078
plugin *new_plugin = getplugin(direntries[i]->d_name);
901
plugin *new_plugin = getplugin(dirst->d_name);
1079
902
if(new_plugin == NULL){
1080
error(0, errno, "getplugin");
1081
ret = (int)(TEMP_FAILURE_RETRY
1082
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
904
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1085
error(0, errno, "sigprocmask");
906
perror("sigprocmask");
1087
exitstatus = EX_OSERR;
1088
free(direntries[i]);
908
exitstatus = EXIT_FAILURE;
1091
free(direntries[i]);
1093
912
new_plugin->pid = pid;
1094
913
new_plugin->fd = pipefd[0];
1096
915
/* Unblock SIGCHLD so signal handler can be run if this process
1097
916
has already completed */
1098
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1099
&sigchld_action.sa_mask,
917
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1102
error(0, errno, "sigprocmask");
1103
exitstatus = EX_OSERR;
919
perror("sigprocmask");
920
exitstatus = EXIT_FAILURE;