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,
376
414
.doc = "Group ID the plugins will run as", .group = 3 },
377
415
{ .name = "debug", .key = 132,
378
416
.doc = "Debug mode", .group = 4 },
418
* These reproduce what we would get without ARGP_NO_HELP
420
{ .name = "help", .key = '?',
421
.doc = "Give this help list", .group = -1 },
422
{ .name = "usage", .key = -3,
423
.doc = "Give a short usage message", .group = -1 },
424
{ .name = "version", .key = 'V',
425
.doc = "Print program version", .group = -1 },
382
error_t parse_opt(int key, char *arg, __attribute__((unused))
383
struct argp_state *state){
429
__attribute__((nonnull(3)))
430
error_t parse_opt(int key, char *arg, struct argp_state *state){
387
435
case 'g': /* --global-options */
389
437
char *plugin_option;
390
438
while((plugin_option = strsep(&arg, ",")) != NULL){
391
if(plugin_option[0] == '\0'){
394
439
if(not add_argument(getplugin(NULL), plugin_option)){
395
perror("add_argument");
396
return ARGP_ERR_UNKNOWN;
401
446
case 'G': /* --global-env */
405
if(not add_environment(getplugin(NULL), arg, true)){
406
perror("add_environment");
447
if(add_environment(getplugin(NULL), arg, true)){
409
451
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;
453
char *option_list = strchr(arg, ':');
454
if(option_list == NULL){
455
argp_error(state, "No colon in \"%s\"", arg);
462
argp_error(state, "Empty plugin name");
467
while((option = strsep(&option_list, ",")) != NULL){
468
if(not add_argument(getplugin(arg), option)){
424
475
case 'E': /* --env-for */
429
477
char *envdef = strchr(arg, ':');
430
478
if(envdef == NULL){
479
argp_error(state, "No colon in \"%s\"", arg);
434
if(not add_environment(getplugin(arg), envdef+1, true)){
435
perror("add_environment");
486
argp_error(state, "Empty plugin name");
490
if(add_environment(getplugin(arg), envdef, true)){
439
495
case 'd': /* --disable */
441
497
plugin *p = getplugin(arg);
443
return ARGP_ERR_UNKNOWN;
448
504
case 'e': /* --enable */
450
506
plugin *p = getplugin(arg);
452
return ARGP_ERR_UNKNOWN;
457
513
case 128: /* --plugin-dir */
459
515
plugindir = strdup(arg);
460
if(plugindir == NULL){
516
if(plugindir != NULL){
464
520
case 129: /* --config-file */
465
521
/* This is already done by parse_opt_config_file() */
467
523
case 130: /* --userid */
469
tmpmax = strtoimax(arg, &tmp, 10);
524
tmp_id = strtoimax(arg, &tmp, 10);
470
525
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);
526
or tmp_id != (uid_t)tmp_id){
527
argp_error(state, "Bad user ID number: \"%s\", using %"
528
PRIdMAX, arg, (intmax_t)uid);
478
534
case 131: /* --groupid */
480
tmpmax = strtoimax(arg, &tmp, 10);
535
tmp_id = strtoimax(arg, &tmp, 10);
481
536
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);
537
or tmp_id != (gid_t)tmp_id){
538
argp_error(state, "Bad group ID number: \"%s\", using %"
539
PRIdMAX, arg, (intmax_t)gid);
489
545
case 132: /* --debug */
549
* These reproduce what we would get without ARGP_NO_HELP
551
case '?': /* --help */
552
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
553
argp_state_help(state, state->out_stream, ARGP_HELP_STD_HELP);
554
case -3: /* --usage */
555
state->flags &= ~(unsigned int)ARGP_NO_EXIT; /* force exit */
556
argp_state_help(state, state->out_stream,
557
ARGP_HELP_USAGE | ARGP_HELP_EXIT_OK);
558
case 'V': /* --version */
559
fprintf(state->out_stream, "%s\n", argp_program_version);
493
563
* When adding more options before this line, remember to also add a
494
564
* "case" to the "parse_opt_config_file" function below.
630
716
/* Check for harmful errors and go to fallback. Other errors might
631
717
not affect opening plugins */
632
718
if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
634
exitstatus = EXIT_FAILURE;
719
error(0, errno, "fopen");
720
exitstatus = EX_OSERR;
638
/* If there was any arguments from configuration file,
639
pass them to parser as command arguments */
724
/* If there were any arguments from the configuration file, pass
725
them to parser as command line arguments */
640
726
if(custom_argv != NULL){
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;
727
ret = argp_parse(&argp, custom_argc, custom_argv,
728
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
736
error(0, errno, "argp_parse");
737
exitstatus = EX_OSERR;
740
exitstatus = EX_CONFIG;
650
745
/* Parse actual command line arguments, to let them override the
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;
747
ret = argp_parse(&argp, argc, argv,
748
ARGP_IN_ORDER | ARGP_NO_EXIT | ARGP_NO_HELP,
756
error(0, errno, "argp_parse");
757
exitstatus = EX_OSERR;
760
exitstatus = EX_USAGE;
673
/* 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");
678
807
ret = setuid(uid);
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 */
809
error(0, errno, "setuid");
812
/* Open plugin directory with close_on_exec flag */
697
int dir_fd = dirfd(dir);
699
ret = set_cloexec_flag(dir_fd);
701
perror("set_cloexec_flag");
702
exitstatus = EXIT_FAILURE;
814
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
817
#else /* not O_CLOEXEC */
819
#endif /* not O_CLOEXEC */
822
error(0, errno, "Could not open plugin dir");
823
exitstatus = EX_UNAVAILABLE;
828
/* Set the FD_CLOEXEC flag on the directory */
829
ret = set_cloexec_flag(dir_fd);
831
error(0, errno, "set_cloexec_flag");
832
exitstatus = EX_OSERR;
835
#endif /* O_CLOEXEC */
838
int good_name(const struct dirent * const dirent){
839
const char * const patterns[] = { ".*", "#*#", "*~", "*.dpkg-new",
840
"*.dpkg-old", "*.dpkg-bak",
841
"*.dpkg-divert", NULL };
843
#pragma GCC diagnostic push
844
#pragma GCC diagnostic ignored "-Wcast-qual"
846
for(const char **pat = (const char **)patterns;
847
*pat != NULL; pat++){
849
#pragma GCC diagnostic pop
851
if(fnmatch(*pat, dirent->d_name, FNM_FILE_NAME | FNM_PERIOD)
854
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
855
" matching pattern %s\n", dirent->d_name, *pat);
864
#if __GLIBC_PREREQ(2, 15)
865
int numplugins = scandirat(dir_fd, ".", &direntries, good_name,
867
#else /* not __GLIBC_PREREQ(2, 15) */
868
int numplugins = scandir(plugindir != NULL ? plugindir : PDIR,
869
&direntries, good_name, alphasort);
870
#endif /* not __GLIBC_PREREQ(2, 15) */
871
#else /* not __GLIBC__ */
872
int numplugins = scandir(plugindir != NULL ? plugindir : PDIR,
873
&direntries, good_name, alphasort);
874
#endif /* not __GLIBC__ */
875
if(numplugins == -1){
876
error(0, errno, "Could not scan plugin dir");
878
exitstatus = EX_OSERR;
708
882
FD_ZERO(&rfds_all);
710
884
/* Read and execute any executable in the plugin directory*/
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);
885
for(int i = 0; i < numplugins; i++){
887
int plugin_fd = openat(dir_fd, direntries[i]->d_name, O_RDONLY);
889
error(0, errno, "Could not open plugin");
781
ret = stat(filename, &st);
892
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
894
error(0, errno, "stat");
895
TEMP_FAILURE_RETRY(close(plugin_fd));
788
899
/* Ignore non-executable files */
789
if(not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
900
if(not S_ISREG(st.st_mode)
901
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, direntries[i]->d_name,
791
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
792
" with bad type or mode\n", filename);
904
fprintf(stderr, "Ignoring plugin dir entry \"%s/%s\""
905
" with bad type or mode\n",
906
plugindir != NULL ? plugindir : PDIR,
907
direntries[i]->d_name);
909
TEMP_FAILURE_RETRY(close(plugin_fd));
798
plugin *p = getplugin(dirst->d_name);
913
plugin *p = getplugin(direntries[i]->d_name);
915
error(0, errno, "getplugin");
916
TEMP_FAILURE_RETRY(close(plugin_fd));
806
921
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
922
direntries[i]->d_name);
924
TEMP_FAILURE_RETRY(close(plugin_fd));
816
931
for(char **a = g->argv + 1; *a != NULL; a++){
817
932
if(not add_argument(p, *a)){
818
perror("add_argument");
933
error(0, errno, "add_argument");
821
936
/* Add global environment variables */
822
937
for(char **e = g->environ; *e != NULL; e++){
823
938
if(not add_environment(p, *e, false)){
824
perror("add_environment");
939
error(0, errno, "add_environment");
829
/* If this plugin has any environment variables, we will call
830
using execve and need to duplicate the environment from this
944
/* If this plugin has any environment variables, we need to
945
duplicate the environment from this process, too. */
832
946
if(p->environ[0] != NULL){
833
947
for(char **e = environ; *e != NULL; e++){
834
948
if(not add_environment(p, *e, false)){
835
perror("add_environment");
949
error(0, errno, "add_environment");
956
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
957
#else /* O_CLOEXEC */
958
ret = (int)TEMP_FAILURE_RETRY(pipe2(pipefd, O_CLOEXEC));
959
#endif /* O_CLOEXEC */
844
exitstatus = EXIT_FAILURE;
961
error(0, errno, "pipe");
962
exitstatus = EX_OSERR;
965
if(pipefd[0] >= FD_SETSIZE){
966
fprintf(stderr, "pipe()[0] (%d) >= FD_SETSIZE (%d)", pipefd[0],
968
TEMP_FAILURE_RETRY(close(pipefd[0]));
969
TEMP_FAILURE_RETRY(close(pipefd[1]));
970
exitstatus = EX_OSERR;
847
974
/* Ask OS to automatic close the pipe on exec */
848
975
ret = set_cloexec_flag(pipefd[0]);
850
perror("set_cloexec_flag");
851
exitstatus = EXIT_FAILURE;
977
error(0, errno, "set_cloexec_flag");
978
TEMP_FAILURE_RETRY(close(pipefd[0]));
979
TEMP_FAILURE_RETRY(close(pipefd[1]));
980
exitstatus = EX_OSERR;
854
983
ret = set_cloexec_flag(pipefd[1]);
856
perror("set_cloexec_flag");
857
exitstatus = EXIT_FAILURE;
985
error(0, errno, "set_cloexec_flag");
986
TEMP_FAILURE_RETRY(close(pipefd[0]));
987
TEMP_FAILURE_RETRY(close(pipefd[1]));
988
exitstatus = EX_OSERR;
991
#endif /* not O_CLOEXEC */
860
992
/* Block SIGCHLD until process is safely in process list */
861
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
993
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
994
&sigchld_action.sa_mask,
863
perror("sigprocmask");
864
exitstatus = EXIT_FAILURE;
997
error(0, errno, "sigprocmask");
998
exitstatus = EX_OSERR;
867
1001
/* Starting a new process to be watched */
1005
} while(pid == -1 and errno == EINTR);
871
exitstatus = EXIT_FAILURE;
1007
error(0, errno, "fork");
1008
TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1009
&sigchld_action.sa_mask, NULL));
1010
TEMP_FAILURE_RETRY(close(pipefd[0]));
1011
TEMP_FAILURE_RETRY(close(pipefd[1]));
1012
exitstatus = EX_OSERR;
875
1016
/* this is the child process */
876
1017
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1019
error(0, errno, "sigaction");
881
1022
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
883
perror("sigprocmask");
1024
error(0, errno, "sigprocmask");
887
1028
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1030
error(0, errno, "dup2");
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){
1034
if(fexecve(plugin_fd, p->argv,
1035
(p->environ[0] != NULL) ? p->environ : environ) < 0){
1036
error(0, errno, "fexecve for %s/%s",
1037
plugindir != NULL ? plugindir : PDIR,
1038
direntries[i]->d_name);
911
1043
/* Parent process */
912
close(pipefd[1]); /* Close unused write end of pipe */
914
plugin *new_plugin = getplugin(dirst->d_name);
1044
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
1046
TEMP_FAILURE_RETRY(close(plugin_fd));
1047
plugin *new_plugin = getplugin(direntries[i]->d_name);
915
1048
if(new_plugin == NULL){
917
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1049
error(0, errno, "getplugin");
1050
ret = (int)(TEMP_FAILURE_RETRY
1051
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
919
perror("sigprocmask");
1054
error(0, errno, "sigprocmask");
921
exitstatus = EXIT_FAILURE;
1056
exitstatus = EX_OSERR;
1029
1198
bool bret = print_out_password(proc->buffer,
1030
1199
proc->buffer_length);
1032
perror("print_out_password");
1033
exitstatus = EXIT_FAILURE;
1201
error(0, errno, "print_out_password");
1202
exitstatus = EX_IOERR;
1038
1207
/* This process has not completed. Does it have any output? */
1039
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
1208
#if defined (__GNUC__) and defined (__GLIBC__)
1209
#if not __GLIBC_PREREQ(2, 16)
1210
#pragma GCC diagnostic push
1211
#pragma GCC diagnostic ignored "-Wsign-conversion"
1214
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){ /* Spurious
1220
#if defined (__GNUC__) and defined (__GLIBC__)
1221
#if not __GLIBC_PREREQ(2, 16)
1222
#pragma GCC diagnostic pop
1040
1225
/* This process had nothing to say at this time */
1041
1226
proc = proc->next;
1044
1229
/* Before reading, make the process' data buffer large enough */
1045
1230
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1046
proc->buffer = realloc(proc->buffer, proc->buffer_size
1047
+ (size_t) BUFFER_SIZE);
1048
if(proc->buffer == NULL){
1050
exitstatus = EXIT_FAILURE;
1231
char *new_buffer = realloc(proc->buffer, proc->buffer_size
1232
+ (size_t) BUFFER_SIZE);
1233
if(new_buffer == NULL){
1234
error(0, errno, "malloc");
1235
exitstatus = EX_OSERR;
1238
proc->buffer = new_buffer;
1053
1239
proc->buffer_size += BUFFER_SIZE;
1055
1241
/* Read from the process */
1056
sret = read(proc->fd, proc->buffer + proc->buffer_length,
1242
sret = TEMP_FAILURE_RETRY(read(proc->fd,
1244
+ proc->buffer_length,
1059
1247
/* Read error from this process; ignore the error */
1060
1248
proc = proc->next;