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(),
38
38
#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
39
39
FD_SET(), FD_ISSET(), FD_CLR */
40
40
#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),
42
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
41
WEXITSTATUS(), WTERMSIG(),
43
#include <sys/stat.h> /* struct stat, fstat(), S_ISREG() */
43
44
#include <iso646.h> /* and, or, not */
44
#include <dirent.h> /* DIR, struct dirent, opendir(),
45
#include <dirent.h> /* DIR, struct dirent, fdopendir(),
45
46
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(),
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()
53
54
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
55
#include <string.h> /* strsep, strlen(), asprintf() */
55
FD_CLOEXEC, openat() */
56
#include <string.h> /* strsep, strlen(), strsignal(),
57
strcmp(), strncmp() */
56
58
#include <errno.h> /* errno */
57
59
#include <argp.h> /* struct argp_option, struct
58
60
argp_state, struct argp,
375
414
.doc = "Group ID the plugins will run as", .group = 3 },
376
415
{ .name = "debug", .key = 132,
377
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 },
381
error_t parse_opt(int key, char *arg, __attribute__((unused))
382
struct argp_state *state){
429
__attribute__((nonnull(3)))
430
error_t parse_opt(int key, char *arg, struct argp_state *state){
384
435
case 'g': /* --global-options */
386
437
char *plugin_option;
387
438
while((plugin_option = strsep(&arg, ",")) != NULL){
388
if(plugin_option[0] == '\0'){
391
439
if(not add_argument(getplugin(NULL), plugin_option)){
392
perror("add_argument");
393
return ARGP_ERR_UNKNOWN;
398
446
case 'G': /* --global-env */
402
if(not add_environment(getplugin(NULL), arg, true)){
403
perror("add_environment");
447
if(add_environment(getplugin(NULL), arg, true)){
406
451
case 'o': /* --options-for */
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;
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)){
421
475
case 'E': /* --env-for */
426
477
char *envdef = strchr(arg, ':');
427
478
if(envdef == NULL){
479
argp_error(state, "No colon in \"%s\"", arg);
431
if(not add_environment(getplugin(arg), envdef+1, true)){
432
perror("add_environment");
486
argp_error(state, "Empty plugin name");
490
if(add_environment(getplugin(arg), envdef, true)){
436
495
case 'd': /* --disable */
438
497
plugin *p = getplugin(arg);
440
return ARGP_ERR_UNKNOWN;
445
504
case 'e': /* --enable */
447
506
plugin *p = getplugin(arg);
449
return ARGP_ERR_UNKNOWN;
454
513
case 128: /* --plugin-dir */
456
515
plugindir = strdup(arg);
457
if(plugindir == NULL){
516
if(plugindir != NULL){
461
520
case 129: /* --config-file */
462
521
/* This is already done by parse_opt_config_file() */
464
523
case 130: /* --userid */
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);
524
tmp_id = strtoimax(arg, &tmp, 10);
525
if(errno != 0 or tmp == arg or *tmp != '\0'
526
or tmp_id != (uid_t)tmp_id){
527
argp_error(state, "Bad user ID number: \"%s\", using %"
528
PRIdMAX, arg, (intmax_t)uid);
474
534
case 131: /* --groupid */
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);
535
tmp_id = strtoimax(arg, &tmp, 10);
536
if(errno != 0 or tmp == arg or *tmp != '\0'
537
or tmp_id != (gid_t)tmp_id){
538
argp_error(state, "Bad group ID number: \"%s\", using %"
539
PRIdMAX, arg, (intmax_t)gid);
484
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);
488
563
* When adding more options before this line, remember to also add a
489
564
* "case" to the "parse_opt_config_file" function below.
594
679
new_arg = strdup(p);
595
680
if(new_arg == NULL){
597
exitstatus = EXIT_FAILURE;
681
error(0, errno, "strdup");
682
exitstatus = EX_OSERR;
602
687
custom_argc += 1;
603
custom_argv = realloc(custom_argv, sizeof(char *)
604
* ((unsigned int) custom_argc + 1));
605
if(custom_argv == NULL){
607
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;
611
702
custom_argv[custom_argc-1] = new_arg;
612
custom_argv[custom_argc] = NULL;
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;
617
716
/* Check for harmful errors and go to fallback. Other errors might
618
717
not affect opening plugins */
619
718
if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
621
exitstatus = EXIT_FAILURE;
719
error(0, errno, "fopen");
720
exitstatus = EX_OSERR;
625
/* If there was any arguments from configuration file,
626
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 */
627
726
if(custom_argv != NULL){
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;
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;
637
745
/* Parse actual command line arguments, to let them override the
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;
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;
660
/* 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");
665
807
ret = setuid(uid);
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 */
809
error(0, errno, "setuid");
812
/* Open plugin directory with close_on_exec flag */
684
int dir_fd = dirfd(dir);
686
ret = set_cloexec_flag(dir_fd);
688
perror("set_cloexec_flag");
689
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;
697
849
/* Read and execute any executable in the plugin directory*/
699
dirst = readdir(dir);
852
dirst = readdir(dir);
853
} while(dirst == NULL and errno == EINTR);
701
855
/* All directory entries have been processed */
702
856
if(dirst == NULL){
703
857
if(errno == EBADF){
705
exitstatus = EXIT_FAILURE;
858
error(0, errno, "readdir");
859
exitstatus = EX_IOERR;
711
d_name_len = strlen(dirst->d_name);
713
865
/* Ignore dotfiles, backup files and other junk */
715
867
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);
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);
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));
768
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));
775
923
/* Ignore non-executable files */
776
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,
778
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
779
" 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));
785
936
plugin *p = getplugin(dirst->d_name);
938
error(0, errno, "getplugin");
939
TEMP_FAILURE_RETRY(close(plugin_fd));
803
954
for(char **a = g->argv + 1; *a != NULL; a++){
804
955
if(not add_argument(p, *a)){
805
perror("add_argument");
956
error(0, errno, "add_argument");
808
959
/* Add global environment variables */
809
960
for(char **e = g->environ; *e != NULL; e++){
810
961
if(not add_environment(p, *e, false)){
811
perror("add_environment");
962
error(0, errno, "add_environment");
816
/* If this plugin has any environment variables, we will call
817
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. */
819
969
if(p->environ[0] != NULL){
820
970
for(char **e = environ; *e != NULL; e++){
821
971
if(not add_environment(p, *e, false)){
822
perror("add_environment");
972
error(0, errno, "add_environment");
978
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
831
exitstatus = EXIT_FAILURE;
980
error(0, errno, "pipe");
981
exitstatus = EX_OSERR;
834
984
/* Ask OS to automatic close the pipe on exec */
835
985
ret = set_cloexec_flag(pipefd[0]);
837
perror("set_cloexec_flag");
838
exitstatus = EXIT_FAILURE;
987
error(0, errno, "set_cloexec_flag");
988
exitstatus = EX_OSERR;
841
991
ret = set_cloexec_flag(pipefd[1]);
843
perror("set_cloexec_flag");
844
exitstatus = EXIT_FAILURE;
993
error(0, errno, "set_cloexec_flag");
994
exitstatus = EX_OSERR;
847
997
/* Block SIGCHLD until process is safely in process list */
848
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
998
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_BLOCK,
999
&sigchld_action.sa_mask,
850
perror("sigprocmask");
851
exitstatus = EXIT_FAILURE;
1002
error(0, errno, "sigprocmask");
1003
exitstatus = EX_OSERR;
854
1006
/* Starting a new process to be watched */
1010
} while(pid == -1 and errno == EINTR);
858
exitstatus = EXIT_FAILURE;
1012
error(0, errno, "fork");
1013
exitstatus = EX_OSERR;
862
1017
/* this is the child process */
863
1018
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1020
error(0, errno, "sigaction");
868
1023
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
870
perror("sigprocmask");
1025
error(0, errno, "sigprocmask");
874
1029
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1031
error(0, errno, "dup2");
880
1035
if(dirfd(dir) < 0){
882
1037
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){
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);
898
1048
/* Parent process */
899
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));
901
1052
plugin *new_plugin = getplugin(dirst->d_name);
902
1053
if(new_plugin == NULL){
904
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,
906
perror("sigprocmask");
1059
error(0, errno, "sigprocmask");
908
exitstatus = EXIT_FAILURE;
1061
exitstatus = EX_OSERR;
915
1068
/* Unblock SIGCHLD so signal handler can be run if this process
916
1069
has already completed */
917
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1070
ret = (int)TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1071
&sigchld_action.sa_mask,
919
perror("sigprocmask");
920
exitstatus = EXIT_FAILURE;
1074
error(0, errno, "sigprocmask");
1075
exitstatus = EX_OSERR;
924
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
926
1094
if(maxfd < new_plugin->fd){
927
1095
maxfd = new_plugin->fd;
1099
TEMP_FAILURE_RETRY(closedir(dir));
933
1101
free_plugin(getplugin(NULL));
1015
1201
bool bret = print_out_password(proc->buffer,
1016
1202
proc->buffer_length);
1018
perror("print_out_password");
1019
exitstatus = EXIT_FAILURE;
1204
error(0, errno, "print_out_password");
1205
exitstatus = EX_IOERR;
1024
1210
/* This process has not completed. Does it have any output? */
1025
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
1026
1228
/* This process had nothing to say at this time */
1027
1229
proc = proc->next;
1030
1232
/* Before reading, make the process' data buffer large enough */
1031
1233
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1032
proc->buffer = realloc(proc->buffer, proc->buffer_size
1033
+ (size_t) BUFFER_SIZE);
1034
if(proc->buffer == NULL){
1036
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;
1039
1242
proc->buffer_size += BUFFER_SIZE;
1041
1244
/* Read from the process */
1042
sret = read(proc->fd, proc->buffer + proc->buffer_length,
1245
sret = TEMP_FAILURE_RETRY(read(proc->fd,
1247
+ proc->buffer_length,
1045
1250
/* Read error from this process; ignore the error */
1046
1251
proc = proc->next;