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() */
41
#include <sys/stat.h> /* struct stat, fstat(), S_ISREG() */
41
WEXITSTATUS(), WTERMSIG(),
43
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
42
44
#include <iso646.h> /* and, or, not */
43
#include <dirent.h> /* struct dirent, scandirat() */
44
#include <unistd.h> /* fcntl(), F_GETFD, F_SETFD,
45
FD_CLOEXEC, write(), STDOUT_FILENO,
46
struct stat, fstat(), close(),
47
setgid(), setuid(), S_ISREG(),
48
faccessat() pipe2(), fork(),
49
_exit(), dup2(), fexecve(), read()
45
#include <dirent.h> /* DIR, struct dirent, opendir(),
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(),
51
54
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
52
FD_CLOEXEC, openat(), scandirat(),
54
#include <string.h> /* strsep, strlen(), strsignal(),
55
strcmp(), strncmp() */
56
#include <string.h> /* strsep, strlen(), asprintf(),
56
58
#include <errno.h> /* errno */
57
59
#include <argp.h> /* struct argp_option, struct
58
60
argp_state, struct argp,
415
376
.doc = "Group ID the plugins will run as", .group = 3 },
416
377
{ .name = "debug", .key = 132,
417
378
.doc = "Debug mode", .group = 4 },
418
{ .name = "plugin-helper-dir", .key = 133,
420
.doc = "Specify a different plugin helper directory",
423
* These reproduce what we would get without ARGP_NO_HELP
425
{ .name = "help", .key = '?',
426
.doc = "Give this help list", .group = -1 },
427
{ .name = "usage", .key = -3,
428
.doc = "Give a short usage message", .group = -1 },
429
{ .name = "version", .key = 'V',
430
.doc = "Print program version", .group = -1 },
434
__attribute__((nonnull(3)))
435
error_t parse_opt(int key, char *arg, struct argp_state *state){
382
error_t parse_opt(int key, char *arg, __attribute__((unused))
383
struct argp_state *state){
440
387
case 'g': /* --global-options */
442
389
char *plugin_option;
443
390
while((plugin_option = strsep(&arg, ",")) != NULL){
391
if(plugin_option[0] == '\0'){
444
394
if(not add_argument(getplugin(NULL), plugin_option)){
395
perror("add_argument");
396
return ARGP_ERR_UNKNOWN;
451
401
case 'G': /* --global-env */
452
if(add_environment(getplugin(NULL), arg, true)){
405
if(not add_environment(getplugin(NULL), arg, true)){
406
perror("add_environment");
456
409
case 'o': /* --options-for */
458
char *option_list = strchr(arg, ':');
459
if(option_list == NULL){
460
argp_error(state, "No colon in \"%s\"", arg);
467
argp_error(state, "Empty plugin name");
472
while((option = strsep(&option_list, ",")) != NULL){
473
if(not add_argument(getplugin(arg), option)){
411
char *plugin_name = strsep(&arg, ":");
412
if(plugin_name[0] == '\0'){
416
while((plugin_option = strsep(&arg, ",")) != NULL){
417
if(not add_argument(getplugin(plugin_name), plugin_option)){
418
perror("add_argument");
419
return ARGP_ERR_UNKNOWN;
480
424
case 'E': /* --env-for */
482
429
char *envdef = strchr(arg, ':');
483
430
if(envdef == NULL){
484
argp_error(state, "No colon in \"%s\"", arg);
491
argp_error(state, "Empty plugin name");
495
if(add_environment(getplugin(arg), envdef, true)){
434
if(not add_environment(getplugin(arg), envdef+1, true)){
435
perror("add_environment");
500
439
case 'd': /* --disable */
502
441
plugin *p = getplugin(arg);
443
return ARGP_ERR_UNKNOWN;
509
448
case 'e': /* --enable */
511
450
plugin *p = getplugin(arg);
452
return ARGP_ERR_UNKNOWN;
518
457
case 128: /* --plugin-dir */
520
459
plugindir = strdup(arg);
521
if(plugindir != NULL){
460
if(plugindir == NULL){
525
464
case 129: /* --config-file */
526
465
/* This is already done by parse_opt_config_file() */
528
467
case 130: /* --userid */
529
tmp_id = strtoimax(arg, &tmp, 10);
469
tmpmax = strtoimax(arg, &tmp, 10);
530
470
if(errno != 0 or tmp == arg or *tmp != '\0'
531
or tmp_id != (uid_t)tmp_id){
532
argp_error(state, "Bad user ID number: \"%s\", using %"
533
PRIdMAX, arg, (intmax_t)uid);
471
or tmpmax != (uid_t)tmpmax){
472
fprintf(stderr, "Bad user ID number: \"%s\", using %"
473
PRIdMAX "\n", arg, (intmax_t)uid);
539
478
case 131: /* --groupid */
540
tmp_id = strtoimax(arg, &tmp, 10);
480
tmpmax = strtoimax(arg, &tmp, 10);
541
481
if(errno != 0 or tmp == arg or *tmp != '\0'
542
or tmp_id != (gid_t)tmp_id){
543
argp_error(state, "Bad group ID number: \"%s\", using %"
544
PRIdMAX, arg, (intmax_t)gid);
482
or tmpmax != (gid_t)tmpmax){
483
fprintf(stderr, "Bad group ID number: \"%s\", using %"
484
PRIdMAX "\n", arg, (intmax_t)gid);
550
489
case 132: /* --debug */
553
case 133: /* --plugin-helper-dir */
554
free(pluginhelperdir);
555
pluginhelperdir = strdup(arg);
556
if(pluginhelperdir != NULL){
561
* These reproduce what we would get without ARGP_NO_HELP
563
case '?': /* --help */
564
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
565
argp_state_help(state, state->out_stream, ARGP_HELP_STD_HELP);
566
case -3: /* --usage */
567
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
568
argp_state_help(state, state->out_stream,
569
ARGP_HELP_USAGE | ARGP_HELP_EXIT_OK);
570
case 'V': /* --version */
571
fprintf(state->out_stream, "%s\n", argp_program_version);
575
493
* When adding more options before this line, remember to also add a
576
494
* "case" to the "parse_opt_config_file" function below.
728
630
/* Check for harmful errors and go to fallback. Other errors might
729
631
not affect opening plugins */
730
632
if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
731
error(0, errno, "fopen");
732
exitstatus = EX_OSERR;
634
exitstatus = EXIT_FAILURE;
736
/* If there were any arguments from the configuration file, pass
737
them to parser as command line arguments */
638
/* If there was any arguments from configuration file,
639
pass them to parser as command arguments */
738
640
if(custom_argv != NULL){
739
ret = argp_parse(&argp, custom_argc, custom_argv,
740
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
748
error(0, errno, "argp_parse");
749
exitstatus = EX_OSERR;
752
exitstatus = EX_CONFIG;
641
ret = argp_parse(&argp, custom_argc, custom_argv, ARGP_IN_ORDER,
643
if(ret == ARGP_ERR_UNKNOWN){
644
fprintf(stderr, "Unknown error while parsing arguments\n");
645
exitstatus = EXIT_FAILURE;
757
650
/* Parse actual command line arguments, to let them override the
759
ret = argp_parse(&argp, argc, argv,
760
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
768
error(0, errno, "argp_parse");
769
exitstatus = EX_OSERR;
772
exitstatus = EX_USAGE;
777
char *pluginhelperenv;
779
ret = asprintf(&pluginhelperenv, "MANDOSPLUGINHELPERDIR=%s",
780
pluginhelperdir != NULL ? pluginhelperdir : PHDIR);
782
bret = add_environment(getplugin(NULL), pluginhelperenv, true);
784
if(ret == -1 or not bret){
785
error(0, errno, "Failed to set MANDOSPLUGINHELPERDIR"
786
" environment variable to \"%s\" for all plugins\n",
787
pluginhelperdir != NULL ? pluginhelperdir : PHDIR);
790
free(pluginhelperenv);
652
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
653
if(ret == ARGP_ERR_UNKNOWN){
654
fprintf(stderr, "Unknown error while parsing arguments\n");
655
exitstatus = EXIT_FAILURE;
809
/* Work around Debian bug #633582:
810
<https://bugs.debian.org/633582> */
811
int plugindir_fd = open(/* plugindir or */ PDIR, O_RDONLY);
812
if(plugindir_fd == -1){
814
error(0, errno, "open(\"" PDIR "\")");
817
ret = (int)TEMP_FAILURE_RETRY(fstat(plugindir_fd, &st));
819
error(0, errno, "fstat");
821
if(S_ISDIR(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
822
ret = fchown(plugindir_fd, uid, gid);
824
error(0, errno, "fchown");
832
/* Lower permissions */
673
/* Strip permissions down to nobody */
835
error(0, errno, "setgid");
837
678
ret = setuid(uid);
839
error(0, errno, "setuid");
842
/* Open plugin directory with close_on_exec flag */
683
if(plugindir == NULL){
686
dir = opendir(plugindir);
690
perror("Could not open plugin dir");
691
exitstatus = EXIT_FAILURE;
695
/* Set the FD_CLOEXEC flag on the directory, if possible */
844
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
847
#else /* not O_CLOEXEC */
849
#endif /* not O_CLOEXEC */
852
error(0, errno, "Could not open plugin dir");
853
exitstatus = EX_UNAVAILABLE;
858
/* Set the FD_CLOEXEC flag on the directory */
859
ret = set_cloexec_flag(dir_fd);
861
error(0, errno, "set_cloexec_flag");
862
exitstatus = EX_OSERR;
865
#endif /* O_CLOEXEC */
868
int good_name(const struct dirent * const dirent){
869
const char * const patterns[] = { ".*", "#*#", "*~", "*.dpkg-new",
870
"*.dpkg-old", "*.dpkg-bak",
871
"*.dpkg-divert", NULL };
873
#pragma GCC diagnostic push
874
#pragma GCC diagnostic ignored "-Wcast-qual"
876
for(const char **pat = (const char **)patterns;
877
*pat != NULL; pat++){
879
#pragma GCC diagnostic pop
881
if(fnmatch(*pat, dirent->d_name, FNM_FILE_NAME | FNM_PERIOD)
884
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
885
" matching pattern %s\n", dirent->d_name, *pat);
697
int dir_fd = dirfd(dir);
699
ret = set_cloexec_flag(dir_fd);
701
perror("set_cloexec_flag");
702
exitstatus = EXIT_FAILURE;
893
int numplugins = scandirat(dir_fd, ".", &direntries, good_name,
895
if(numplugins == -1){
896
error(0, errno, "Could not scan plugin dir");
898
exitstatus = EX_OSERR;
902
708
FD_ZERO(&rfds_all);
904
710
/* Read and execute any executable in the plugin directory*/
905
for(int i = 0; i < numplugins; i++){
907
int plugin_fd = openat(dir_fd, direntries[i]->d_name, O_RDONLY);
909
error(0, errno, "Could not open plugin");
712
dirst = readdir(dir);
714
/* All directory entries have been processed */
718
exitstatus = EXIT_FAILURE;
724
d_name_len = strlen(dirst->d_name);
726
/* Ignore dotfiles, backup files and other junk */
728
bool bad_name = false;
730
const char const *bad_prefixes[] = { ".", "#", NULL };
732
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
735
".dpkg-divert", NULL };
736
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
737
size_t pre_len = strlen(*pre);
738
if((d_name_len >= pre_len)
739
and strncmp((dirst->d_name), *pre, pre_len) == 0){
741
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
742
" with bad prefix %s\n", dirst->d_name, *pre);
751
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
752
size_t suf_len = strlen(*suf);
753
if((d_name_len >= suf_len)
754
and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)
757
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
758
" with bad suffix %s\n", dirst->d_name, *suf);
771
if(plugindir == NULL){
772
ret = asprintf(&filename, PDIR "/%s", dirst->d_name);
774
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
913
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
781
ret = stat(filename, &st);
915
error(0, errno, "stat");
921
788
/* Ignore non-executable files */
922
if(not S_ISREG(st.st_mode)
923
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, direntries[i]->d_name,
789
if(not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
926
fprintf(stderr, "Ignoring plugin dir entry \"%s/%s\""
927
" with bad type or mode\n",
928
plugindir != NULL ? plugindir : PDIR,
929
direntries[i]->d_name);
791
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
792
" with bad type or mode\n", filename);
936
plugin *p = getplugin(direntries[i]->d_name);
798
plugin *p = getplugin(dirst->d_name);
938
error(0, errno, "getplugin");
945
806
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
946
direntries[i]->d_name);
956
816
for(char **a = g->argv + 1; *a != NULL; a++){
957
817
if(not add_argument(p, *a)){
958
error(0, errno, "add_argument");
818
perror("add_argument");
961
821
/* Add global environment variables */
962
822
for(char **e = g->environ; *e != NULL; e++){
963
823
if(not add_environment(p, *e, false)){
964
error(0, errno, "add_environment");
824
perror("add_environment");
969
/* If this plugin has any environment variables, we need to
970
duplicate the environment from this process, too. */
829
/* If this plugin has any environment variables, we will call
830
using execve and need to duplicate the environment from this
971
832
if(p->environ[0] != NULL){
972
833
for(char **e = environ; *e != NULL; e++){
973
834
if(not add_environment(p, *e, false)){
974
error(0, errno, "add_environment");
835
perror("add_environment");
981
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
982
#else /* O_CLOEXEC */
983
ret = (int)TEMP_FAILURE_RETRY(pipe2(pipefd, O_CLOEXEC));
984
#endif /* O_CLOEXEC */
986
error(0, errno, "pipe");
987
exitstatus = EX_OSERR;
991
if(pipefd[0] >= FD_SETSIZE){
992
fprintf(stderr, "pipe()[0] (%d) >= FD_SETSIZE (%d)", pipefd[0],
996
exitstatus = EX_OSERR;
844
exitstatus = EXIT_FAILURE;
1001
847
/* Ask OS to automatic close the pipe on exec */
1002
848
ret = set_cloexec_flag(pipefd[0]);
1004
error(0, errno, "set_cloexec_flag");
1007
exitstatus = EX_OSERR;
1008
free(direntries[i]);
850
perror("set_cloexec_flag");
851
exitstatus = EXIT_FAILURE;
1011
854
ret = set_cloexec_flag(pipefd[1]);
1013
error(0, errno, "set_cloexec_flag");
1016
exitstatus = EX_OSERR;
1017
free(direntries[i]);
856
perror("set_cloexec_flag");
857
exitstatus = EXIT_FAILURE;
1020
#endif /* not O_CLOEXEC */
1021
860
/* Block SIGCHLD until process is safely in process list */
1022
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
1023
&sigchld_action.sa_mask,
861
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
1026
error(0, errno, "sigprocmask");
1027
exitstatus = EX_OSERR;
1028
free(direntries[i]);
863
perror("sigprocmask");
864
exitstatus = EXIT_FAILURE;
1031
867
/* Starting a new process to be watched */
1035
} while(pid == -1 and errno == EINTR);
1037
error(0, errno, "fork");
1038
TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1039
&sigchld_action.sa_mask, NULL));
1042
exitstatus = EX_OSERR;
1043
free(direntries[i]);
871
exitstatus = EXIT_FAILURE;
1047
875
/* this is the child process */
1048
876
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1050
error(0, errno, "sigaction");
1053
881
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1055
error(0, errno, "sigprocmask");
883
perror("sigprocmask");
1059
887
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1061
error(0, errno, "dup2");
1065
if(fexecve(plugin_fd, p->argv,
1066
(p->environ[0] != NULL) ? p->environ : environ) < 0){
1067
error(0, errno, "fexecve for %s/%s",
1068
plugindir != NULL ? plugindir : PDIR,
1069
direntries[i]->d_name);
894
/* If dir has no file descriptor, we could not set FD_CLOEXEC
895
above and must now close it manually here. */
898
if(p->environ[0] == NULL){
899
if(execv(filename, p->argv) < 0){
904
if(execve(filename, p->argv, p->environ) < 0){
1074
911
/* Parent process */
1075
912
close(pipefd[1]); /* Close unused write end of pipe */
1077
plugin *new_plugin = getplugin(direntries[i]->d_name);
914
plugin *new_plugin = getplugin(dirst->d_name);
1078
915
if(new_plugin == NULL){
1079
error(0, errno, "getplugin");
1080
ret = (int)(TEMP_FAILURE_RETRY
1081
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
917
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1084
error(0, errno, "sigprocmask");
919
perror("sigprocmask");
1086
exitstatus = EX_OSERR;
1087
free(direntries[i]);
921
exitstatus = EXIT_FAILURE;
1090
free(direntries[i]);
1092
925
new_plugin->pid = pid;
1093
926
new_plugin->fd = pipefd[0];
1095
928
/* Unblock SIGCHLD so signal handler can be run if this process
1096
929
has already completed */
1097
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1098
&sigchld_action.sa_mask,
930
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1101
error(0, errno, "sigprocmask");
1102
exitstatus = EX_OSERR;
932
perror("sigprocmask");
933
exitstatus = EXIT_FAILURE;