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
31
#include <stdio.h> /* fileno(), fprintf(),
32
stderr, STDOUT_FILENO, fclose() */
33
#include <sys/types.h> /* DIR, fdopendir(), fstat(), struct
34
34
stat, waitpid(), WIFEXITED(),
35
35
WEXITSTATUS(), wait(), pid_t,
36
36
uid_t, gid_t, getuid(), getgid(),
40
40
#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),
41
41
WEXITSTATUS(), WTERMSIG(),
43
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
43
#include <sys/stat.h> /* struct stat, fstat(), S_ISREG() */
44
44
#include <iso646.h> /* and, or, not */
45
#include <dirent.h> /* DIR, struct dirent, opendir(),
45
#include <dirent.h> /* DIR, struct dirent, fdopendir(),
46
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(),
47
#include <unistd.h> /* fcntl(), F_GETFD, F_SETFD,
48
FD_CLOEXEC, write(), STDOUT_FILENO,
49
struct stat, fstat(), close(),
50
setgid(), setuid(), S_ISREG(),
51
faccessat() pipe(), fork(),
52
_exit(), dup2(), fexecve(), read()
54
54
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
56
#include <string.h> /* strsep, strlen(), asprintf(),
55
FD_CLOEXEC, openat() */
56
#include <string.h> /* strsep, strlen(), strsignal(),
57
strcmp(), strncmp() */
58
58
#include <errno.h> /* errno */
59
59
#include <argp.h> /* struct argp_option, struct
60
60
argp_state, struct argp,
377
414
.doc = "Group ID the plugins will run as", .group = 3 },
378
415
{ .name = "debug", .key = 132,
379
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 },
383
error_t parse_opt(int key, char *arg, __attribute__((unused))
384
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.
599
679
new_arg = strdup(p);
600
680
if(new_arg == NULL){
602
exitstatus = EXIT_FAILURE;
681
error(0, errno, "strdup");
682
exitstatus = EX_OSERR;
607
687
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;
689
char **new_argv = realloc(custom_argv, sizeof(char *)
692
if(new_argv == NULL){
693
error(0, errno, "realloc");
694
exitstatus = EX_OSERR;
699
custom_argv = new_argv;
616
702
custom_argv[custom_argc-1] = new_arg;
617
703
custom_argv[custom_argc] = NULL;
707
ret = fclose(conffp);
708
} while(ret == EOF and errno == EINTR);
710
error(0, errno, "fclose");
711
exitstatus = EX_IOERR;
622
716
/* Check for harmful errors and go to fallback. Other errors might
623
717
not affect opening plugins */
624
718
if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
626
exitstatus = EXIT_FAILURE;
719
error(0, errno, "fopen");
720
exitstatus = EX_OSERR;
630
/* If there was any arguments from configuration file,
631
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 */
632
726
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;
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;
642
745
/* 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;
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;
665
/* 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");
670
807
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 */
809
error(0, errno, "setuid");
812
/* 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;
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
TEMP_FAILURE_RETRY(close(dir_fd));
833
exitstatus = EX_OSERR;
836
#endif /* O_CLOEXEC */
838
dir = fdopendir(dir_fd);
840
error(0, errno, "Could not open plugin dir");
841
TEMP_FAILURE_RETRY(close(dir_fd));
842
exitstatus = EX_OSERR;
702
849
/* Read and execute any executable in the plugin directory*/
704
dirst = readdir(dir);
852
dirst = readdir(dir);
853
} while(dirst == NULL and errno == EINTR);
706
855
/* All directory entries have been processed */
707
856
if(dirst == NULL){
708
857
if(errno == EBADF){
710
exitstatus = EXIT_FAILURE;
858
error(0, errno, "readdir");
859
exitstatus = EX_IOERR;
716
d_name_len = strlen(dirst->d_name);
718
865
/* Ignore dotfiles, backup files and other junk */
720
867
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);
868
const char * const patterns[] = { ".*", "#*#", "*~",
869
"*.dpkg-new", "*.dpkg-old",
870
"*.dpkg-bak", "*.dpkg-divert",
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, dirst->d_name,
882
FNM_FILE_NAME | FNM_PERIOD) != FNM_NOMATCH){
884
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
885
" matching pattern %s\n", dirst->d_name, *pat);
763
if(plugindir == NULL){
764
ret = asprintf(&filename, PDIR "/%s", dirst->d_name);
766
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
896
int plugin_fd = openat(dir_fd, dirst->d_name, O_RDONLY |
899
#else /* not O_CLOEXEC */
901
#endif /* not O_CLOEXEC */
904
error(0, errno, "Could not open plugin");
908
/* Set the FD_CLOEXEC flag on the plugin FD */
909
ret = set_cloexec_flag(plugin_fd);
911
error(0, errno, "set_cloexec_flag");
912
TEMP_FAILURE_RETRY(close(plugin_fd));
773
ret = stat(filename, &st);
915
#endif /* O_CLOEXEC */
916
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
918
error(0, errno, "stat");
919
TEMP_FAILURE_RETRY(close(plugin_fd));
780
923
/* Ignore non-executable files */
781
if(not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
924
if(not S_ISREG(st.st_mode)
925
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, dirst->d_name, X_OK,
783
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
784
" with bad type or mode\n", filename);
928
fprintf(stderr, "Ignoring plugin dir entry \"%s/%s\""
929
" with bad type or mode\n",
930
plugindir != NULL ? plugindir : PDIR, dirst->d_name);
932
TEMP_FAILURE_RETRY(close(plugin_fd));
790
936
plugin *p = getplugin(dirst->d_name);
938
error(0, errno, "getplugin");
939
TEMP_FAILURE_RETRY(close(plugin_fd));
808
954
for(char **a = g->argv + 1; *a != NULL; a++){
809
955
if(not add_argument(p, *a)){
810
perror("add_argument");
956
error(0, errno, "add_argument");
813
959
/* Add global environment variables */
814
960
for(char **e = g->environ; *e != NULL; e++){
815
961
if(not add_environment(p, *e, false)){
816
perror("add_environment");
962
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
967
/* If this plugin has any environment variables, we need to
968
duplicate the environment from this process, too. */
824
969
if(p->environ[0] != NULL){
825
970
for(char **e = environ; *e != NULL; e++){
826
971
if(not add_environment(p, *e, false)){
827
perror("add_environment");
972
error(0, errno, "add_environment");
978
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
836
exitstatus = EXIT_FAILURE;
980
error(0, errno, "pipe");
981
exitstatus = EX_OSERR;
839
984
/* Ask OS to automatic close the pipe on exec */
840
985
ret = set_cloexec_flag(pipefd[0]);
842
perror("set_cloexec_flag");
843
exitstatus = EXIT_FAILURE;
987
error(0, errno, "set_cloexec_flag");
988
exitstatus = EX_OSERR;
846
991
ret = set_cloexec_flag(pipefd[1]);
848
perror("set_cloexec_flag");
849
exitstatus = EXIT_FAILURE;
993
error(0, errno, "set_cloexec_flag");
994
exitstatus = EX_OSERR;
852
997
/* Block SIGCHLD until process is safely in process list */
853
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
998
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
999
&sigchld_action.sa_mask,
855
perror("sigprocmask");
856
exitstatus = EXIT_FAILURE;
1002
error(0, errno, "sigprocmask");
1003
exitstatus = EX_OSERR;
859
1006
/* Starting a new process to be watched */
1010
} while(pid == -1 and errno == EINTR);
863
exitstatus = EXIT_FAILURE;
1012
error(0, errno, "fork");
1013
exitstatus = EX_OSERR;
867
1017
/* this is the child process */
868
1018
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1020
error(0, errno, "sigaction");
873
1023
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
875
perror("sigprocmask");
1025
error(0, errno, "sigprocmask");
879
1029
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1031
error(0, errno, "dup2");
885
1035
if(dirfd(dir) < 0){
887
1037
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){
1040
if(fexecve(plugin_fd, p->argv,
1041
(p->environ[0] != NULL) ? p->environ : environ) < 0){
1042
error(0, errno, "fexecve for %s/%s",
1043
plugindir != NULL ? plugindir : PDIR, dirst->d_name);
903
1048
/* Parent process */
904
close(pipefd[1]); /* Close unused write end of pipe */
1049
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
1051
TEMP_FAILURE_RETRY(close(plugin_fd));
906
1052
plugin *new_plugin = getplugin(dirst->d_name);
907
1053
if(new_plugin == NULL){
909
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1054
error(0, errno, "getplugin");
1055
ret = (int)(TEMP_FAILURE_RETRY
1056
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
911
perror("sigprocmask");
1059
error(0, errno, "sigprocmask");
913
exitstatus = EXIT_FAILURE;
1061
exitstatus = EX_OSERR;
920
1068
/* Unblock SIGCHLD so signal handler can be run if this process
921
1069
has already completed */
922
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1070
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1071
&sigchld_action.sa_mask,
924
perror("sigprocmask");
925
exitstatus = EXIT_FAILURE;
1074
error(0, errno, "sigprocmask");
1075
exitstatus = EX_OSERR;
929
FD_SET(new_plugin->fd, &rfds_all);
1079
#if defined (__GNUC__) and defined (__GLIBC__)
1080
#if not __GLIBC_PREREQ(2, 16)
1081
#pragma GCC diagnostic push
1082
#pragma GCC diagnostic ignored "-Wsign-conversion"
1085
FD_SET(new_plugin->fd, &rfds_all); /* Spurious warning from
1086
-Wconversion in GNU libc
1088
#if defined (__GNUC__) and defined (__GLIBC__)
1089
#if not __GLIBC_PREREQ(2, 16)
1090
#pragma GCC diagnostic pop
931
1094
if(maxfd < new_plugin->fd){
932
1095
maxfd = new_plugin->fd;
1099
TEMP_FAILURE_RETRY(closedir(dir));
938
1101
free_plugin(getplugin(NULL));
1021
1201
bool bret = print_out_password(proc->buffer,
1022
1202
proc->buffer_length);
1024
perror("print_out_password");
1025
exitstatus = EXIT_FAILURE;
1204
error(0, errno, "print_out_password");
1205
exitstatus = EX_IOERR;
1030
1210
/* This process has not completed. Does it have any output? */
1031
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
1211
#if defined (__GNUC__) and defined (__GLIBC__)
1212
#if not __GLIBC_PREREQ(2, 16)
1213
#pragma GCC diagnostic push
1214
#pragma GCC diagnostic ignored "-Wsign-conversion"
1217
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){ /* Spurious
1223
#if defined (__GNUC__) and defined (__GLIBC__)
1224
#if not __GLIBC_PREREQ(2, 16)
1225
#pragma GCC diagnostic pop
1032
1228
/* This process had nothing to say at this time */
1033
1229
proc = proc->next;
1036
1232
/* Before reading, make the process' data buffer large enough */
1037
1233
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1038
proc->buffer = realloc(proc->buffer, proc->buffer_size
1039
+ (size_t) BUFFER_SIZE);
1040
if(proc->buffer == NULL){
1042
exitstatus = EXIT_FAILURE;
1234
char *new_buffer = realloc(proc->buffer, proc->buffer_size
1235
+ (size_t) BUFFER_SIZE);
1236
if(new_buffer == NULL){
1237
error(0, errno, "malloc");
1238
exitstatus = EX_OSERR;
1241
proc->buffer = new_buffer;
1045
1242
proc->buffer_size += BUFFER_SIZE;
1047
1244
/* Read from the process */
1048
sret = read(proc->fd, proc->buffer + proc->buffer_length,
1245
sret = TEMP_FAILURE_RETRY(read(proc->fd,
1247
+ proc->buffer_length,
1051
1250
/* Read error from this process; ignore the error */
1052
1251
proc = proc->next;