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(),
27
27
#include <stddef.h> /* size_t, NULL */
28
#include <stdlib.h> /* malloc(), exit(), EXIT_FAILURE,
29
EXIT_SUCCESS, realloc() */
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, opendir(), 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, 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(),
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,
207
241
return add_to_char_array(def, &(p->environ), &(p->envc));
211
246
* Based on the example in the GNU LibC manual chapter 13.13 "File
212
247
* Descriptor Flags".
213
* *Note File Descriptor Flags:(libc)Descriptor Flags.
248
| [[info:libc:Descriptor%20Flags][File Descriptor Flags]] |
250
__attribute__((warn_unused_result))
215
251
static int set_cloexec_flag(int fd){
216
int ret = fcntl(fd, F_GETFD, 0);
252
int ret = (int)TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD, 0));
217
253
/* If reading the flags failed, return error indication now. */
221
257
/* Store modified flag word in the descriptor. */
222
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
258
return (int)TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD,
261
#endif /* not O_CLOEXEC */
226
264
/* Mark processes as completed when they exit, and save their exit
377
416
.doc = "Group ID the plugins will run as", .group = 3 },
378
417
{ .name = "debug", .key = 132,
379
418
.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 },
383
error_t parse_opt(int key, char *arg, __attribute__((unused))
384
struct argp_state *state){
435
__attribute__((nonnull(3)))
436
error_t parse_opt(int key, char *arg, struct argp_state *state){
387
441
case 'g': /* --global-options */
389
443
char *plugin_option;
390
444
while((plugin_option = strsep(&arg, ",")) != NULL){
391
if(plugin_option[0] == '\0'){
394
445
if(not add_argument(getplugin(NULL), plugin_option)){
395
perror("add_argument");
396
return ARGP_ERR_UNKNOWN;
401
452
case 'G': /* --global-env */
405
if(not add_environment(getplugin(NULL), arg, true)){
406
perror("add_environment");
453
if(add_environment(getplugin(NULL), arg, true)){
409
457
case 'o': /* --options-for */
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;
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)){
424
481
case 'E': /* --env-for */
429
483
char *envdef = strchr(arg, ':');
430
484
if(envdef == NULL){
485
argp_error(state, "No colon in \"%s\"", arg);
434
if(not add_environment(getplugin(arg), envdef+1, true)){
435
perror("add_environment");
492
argp_error(state, "Empty plugin name");
496
if(add_environment(getplugin(arg), envdef, true)){
439
501
case 'd': /* --disable */
441
503
plugin *p = getplugin(arg);
443
return ARGP_ERR_UNKNOWN;
448
510
case 'e': /* --enable */
450
512
plugin *p = getplugin(arg);
452
return ARGP_ERR_UNKNOWN;
457
519
case 128: /* --plugin-dir */
459
521
plugindir = strdup(arg);
460
if(plugindir == NULL){
522
if(plugindir != NULL){
464
526
case 129: /* --config-file */
465
527
/* This is already done by parse_opt_config_file() */
467
529
case 130: /* --userid */
469
tmpmax = strtoimax(arg, &tmp, 10);
530
tmp_id = strtoimax(arg, &tmp, 10);
470
531
if(errno != 0 or tmp == arg or *tmp != '\0'
471
or tmpmax != (uid_t)tmpmax){
472
fprintf(stderr, "Bad user ID number: \"%s\", using %"
473
PRIdMAX "\n", arg, (intmax_t)uid);
532
or tmp_id != (uid_t)tmp_id){
533
argp_error(state, "Bad user ID number: \"%s\", using %"
534
PRIdMAX, arg, (intmax_t)uid);
478
540
case 131: /* --groupid */
480
tmpmax = strtoimax(arg, &tmp, 10);
541
tmp_id = strtoimax(arg, &tmp, 10);
481
542
if(errno != 0 or tmp == arg or *tmp != '\0'
482
or tmpmax != (gid_t)tmpmax){
483
fprintf(stderr, "Bad group ID number: \"%s\", using %"
484
PRIdMAX "\n", arg, (intmax_t)gid);
543
or tmp_id != (gid_t)tmp_id){
544
argp_error(state, "Bad group ID number: \"%s\", using %"
545
PRIdMAX, arg, (intmax_t)gid);
489
551
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);
493
576
* When adding more options before this line, remember to also add a
494
577
* "case" to the "parse_opt_config_file" function below.
599
693
new_arg = strdup(p);
600
694
if(new_arg == NULL){
602
exitstatus = EXIT_FAILURE;
695
error(0, errno, "strdup");
696
exitstatus = EX_OSERR;
607
701
custom_argc += 1;
608
custom_argv = realloc(custom_argv, sizeof(char *)
609
* ((unsigned int) custom_argc + 1));
610
if(custom_argv == NULL){
612
exitstatus = EXIT_FAILURE;
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;
616
715
custom_argv[custom_argc-1] = new_arg;
617
716
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;
622
729
/* Check for harmful errors and go to fallback. Other errors might
623
730
not affect opening plugins */
624
731
if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
626
exitstatus = EXIT_FAILURE;
732
error(0, errno, "fopen");
733
exitstatus = EX_OSERR;
630
/* If there was any arguments from configuration file,
631
pass them to parser as command arguments */
737
/* If there were any arguments from the configuration file, pass
738
them to parser as command line arguments */
632
739
if(custom_argv != NULL){
633
ret = argp_parse(&argp, custom_argc, custom_argv, ARGP_IN_ORDER,
635
if(ret == ARGP_ERR_UNKNOWN){
636
fprintf(stderr, "Unknown error while parsing arguments\n");
637
exitstatus = EXIT_FAILURE;
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;
642
758
/* Parse actual command line arguments, to let them override the
644
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
645
if(ret == ARGP_ERR_UNKNOWN){
646
fprintf(stderr, "Unknown error while parsing arguments\n");
647
exitstatus = EXIT_FAILURE;
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);
665
/* Strip permissions down to nobody */
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 */
836
error(0, errno, "setgid");
670
838
ret = setuid(uid);
675
if(plugindir == NULL){
678
dir = opendir(plugindir);
682
perror("Could not open plugin dir");
683
exitstatus = EXIT_FAILURE;
687
/* Set the FD_CLOEXEC flag on the directory, if possible */
840
error(0, errno, "setuid");
843
/* Open plugin directory with close_on_exec flag */
689
int dir_fd = dirfd(dir);
691
ret = set_cloexec_flag(dir_fd);
693
perror("set_cloexec_flag");
694
exitstatus = EXIT_FAILURE;
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);
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;
700
903
FD_ZERO(&rfds_all);
702
905
/* Read and execute any executable in the plugin directory*/
704
dirst = readdir(dir);
706
/* All directory entries have been processed */
710
exitstatus = EXIT_FAILURE;
716
d_name_len = strlen(dirst->d_name);
718
/* Ignore dotfiles, backup files and other junk */
720
bool bad_name = false;
722
const char const *bad_prefixes[] = { ".", "#", NULL };
724
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
727
".dpkg-divert", NULL };
728
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
729
size_t pre_len = strlen(*pre);
730
if((d_name_len >= pre_len)
731
and strncmp((dirst->d_name), *pre, pre_len) == 0){
733
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
734
" with bad prefix %s\n", dirst->d_name, *pre);
743
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
744
size_t suf_len = strlen(*suf);
745
if((d_name_len >= suf_len)
746
and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)
749
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
750
" with bad suffix %s\n", dirst->d_name, *suf);
763
if(plugindir == NULL){
764
ret = asprintf(&filename, PDIR "/%s", dirst->d_name);
766
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
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");
773
ret = stat(filename, &st);
914
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
916
error(0, errno, "stat");
780
922
/* Ignore non-executable files */
781
if(not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
923
if(not S_ISREG(st.st_mode)
924
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, direntries[i]->d_name,
783
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
784
" with bad type or mode\n", filename);
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);
790
plugin *p = getplugin(dirst->d_name);
937
plugin *p = getplugin(direntries[i]->d_name);
939
error(0, errno, "getplugin");
798
946
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
947
direntries[i]->d_name);
808
957
for(char **a = g->argv + 1; *a != NULL; a++){
809
958
if(not add_argument(p, *a)){
810
perror("add_argument");
959
error(0, errno, "add_argument");
813
962
/* Add global environment variables */
814
963
for(char **e = g->environ; *e != NULL; e++){
815
964
if(not add_environment(p, *e, false)){
816
perror("add_environment");
965
error(0, errno, "add_environment");
821
/* If this plugin has any environment variables, we will call
822
using execve and need to duplicate the environment from this
970
/* If this plugin has any environment variables, we need to
971
duplicate the environment from this process, too. */
824
972
if(p->environ[0] != NULL){
825
973
for(char **e = environ; *e != NULL; e++){
826
974
if(not add_environment(p, *e, false)){
827
perror("add_environment");
975
error(0, errno, "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 */
836
exitstatus = EXIT_FAILURE;
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;
839
1002
/* Ask OS to automatic close the pipe on exec */
840
1003
ret = set_cloexec_flag(pipefd[0]);
842
perror("set_cloexec_flag");
843
exitstatus = EXIT_FAILURE;
1005
error(0, errno, "set_cloexec_flag");
1008
exitstatus = EX_OSERR;
1009
free(direntries[i]);
846
1012
ret = set_cloexec_flag(pipefd[1]);
848
perror("set_cloexec_flag");
849
exitstatus = EXIT_FAILURE;
1014
error(0, errno, "set_cloexec_flag");
1017
exitstatus = EX_OSERR;
1018
free(direntries[i]);
1021
#endif /* not O_CLOEXEC */
852
1022
/* Block SIGCHLD until process is safely in process list */
853
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
1023
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
1024
&sigchld_action.sa_mask,
855
perror("sigprocmask");
856
exitstatus = EXIT_FAILURE;
1027
error(0, errno, "sigprocmask");
1028
exitstatus = EX_OSERR;
1029
free(direntries[i]);
859
1032
/* Starting a new process to be watched */
1036
} while(pid == -1 and errno == EINTR);
863
exitstatus = EXIT_FAILURE;
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]);
867
1048
/* this is the child process */
868
1049
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1051
error(0, errno, "sigaction");
873
1054
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
875
perror("sigprocmask");
1056
error(0, errno, "sigprocmask");
879
1060
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1062
error(0, errno, "dup2");
886
/* If dir has no file descriptor, we could not set FD_CLOEXEC
887
above and must now close it manually here. */
890
if(p->environ[0] == NULL){
891
if(execv(filename, p->argv) < 0){
896
if(execve(filename, p->argv, p->environ) < 0){
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);
903
1075
/* Parent process */
904
1076
close(pipefd[1]); /* Close unused write end of pipe */
906
plugin *new_plugin = getplugin(dirst->d_name);
1078
plugin *new_plugin = getplugin(direntries[i]->d_name);
907
1079
if(new_plugin == NULL){
909
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1080
error(0, errno, "getplugin");
1081
ret = (int)(TEMP_FAILURE_RETRY
1082
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
911
perror("sigprocmask");
1085
error(0, errno, "sigprocmask");
913
exitstatus = EXIT_FAILURE;
1087
exitstatus = EX_OSERR;
1088
free(direntries[i]);
1091
free(direntries[i]);
917
1093
new_plugin->pid = pid;
918
1094
new_plugin->fd = pipefd[0];
920
1096
/* Unblock SIGCHLD so signal handler can be run if this process
921
1097
has already completed */
922
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1098
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1099
&sigchld_action.sa_mask,
924
perror("sigprocmask");
925
exitstatus = EXIT_FAILURE;
1102
error(0, errno, "sigprocmask");
1103
exitstatus = EX_OSERR;