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(),
26
asprintf(), O_CLOEXEC */
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> /* DIR, fdopendir(), fstat(), struct
31
#include <stdio.h> /* perror, fileno(), fprintf(),
32
stderr, STDOUT_FILENO */
33
#include <sys/types.h> /* DIR, fdopendir(), stat(), 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, fstat(), S_ISREG() */
43
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
44
44
#include <iso646.h> /* and, or, not */
45
45
#include <dirent.h> /* DIR, struct dirent, fdopendir(),
46
46
readdir(), closedir(), dirfd() */
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()
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(),
54
54
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
55
FD_CLOEXEC, openat() */
56
#include <string.h> /* strsep, strlen(), strsignal(),
57
strcmp(), strncmp() */
56
#include <string.h> /* strsep, strlen(), asprintf(),
58
58
#include <errno.h> /* errno */
59
59
#include <argp.h> /* struct argp_option, struct
60
60
argp_state, struct argp,
175
170
/* Helper function for add_argument and add_environment */
176
__attribute__((nonnull, warn_unused_result))
177
171
static bool add_to_char_array(const char *new, char ***array,
179
173
/* Resize the pointed-to array to hold one more pointer */
180
char **new_array = NULL;
182
new_array = realloc(*array, sizeof(char *)
183
* (size_t) ((*len) + 2));
184
} while(new_array == NULL and errno == EINTR);
175
*array = realloc(*array, sizeof(char *)
176
* (size_t) ((*len) + 2));
177
} while(*array == NULL and errno == EINTR);
185
178
/* Malloc check */
186
if(new_array == NULL){
190
182
/* Make a copy of the new string */
221
211
/* namelen = length of name of environment variable */
222
212
size_t namelen = (size_t)(strchrnul(def, '=') - def);
223
213
/* Search for this environment variable */
224
for(char **envdef = p->environ; *envdef != NULL; envdef++){
225
if(strncmp(*envdef, def, namelen + 1) == 0){
214
for(char **e = p->environ; *e != NULL; e++){
215
if(strncmp(*e, def, namelen + 1) == 0){
226
216
/* It already exists */
230
new_envdef = realloc(*envdef, strlen(def) + 1);
231
} while(new_envdef == NULL and errno == EINTR);
232
if(new_envdef == NULL){
220
new = realloc(*e, strlen(def) + 1);
221
} while(new == NULL and errno == EINTR);
235
*envdef = new_envdef;
236
strcpy(*envdef, def);
363
351
.sa_flags = SA_NOCLDSTOP };
364
352
char **custom_argv = NULL;
365
353
int custom_argc = 0;
368
355
/* Establish a signal handler */
369
356
sigemptyset(&sigchld_action.sa_mask);
370
357
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
372
error(0, errno, "sigaddset");
373
exitstatus = EX_OSERR;
360
exitstatus = EXIT_FAILURE;
376
363
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
378
error(0, errno, "sigaction");
379
exitstatus = EX_OSERR;
366
exitstatus = EXIT_FAILURE;
506
485
plugin *p = getplugin(arg);
508
487
p->disabled = false;
513
491
case 128: /* --plugin-dir */
515
493
plugindir = strdup(arg);
516
if(plugindir != NULL){
520
495
case 129: /* --config-file */
521
496
/* This is already done by parse_opt_config_file() */
523
498
case 130: /* --userid */
524
tmp_id = strtoimax(arg, &tmp, 10);
499
tmpmax = strtoimax(arg, &tmp, 10);
525
500
if(errno != 0 or tmp == arg or *tmp != '\0'
526
or tmp_id != (uid_t)tmp_id){
501
or tmpmax != (uid_t)tmpmax){
527
502
argp_error(state, "Bad user ID number: \"%s\", using %"
528
503
PRIdMAX, arg, (intmax_t)uid);
534
508
case 131: /* --groupid */
535
tmp_id = strtoimax(arg, &tmp, 10);
509
tmpmax = strtoimax(arg, &tmp, 10);
536
510
if(errno != 0 or tmp == arg or *tmp != '\0'
537
or tmp_id != (gid_t)tmp_id){
511
or tmpmax != (gid_t)tmpmax){
538
512
argp_error(state, "Bad group ID number: \"%s\", using %"
539
513
PRIdMAX, arg, (intmax_t)gid);
545
518
case 132: /* --debug */
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 */
742
/* Strip permissions down to nobody */
805
error(0, errno, "setgid");
807
747
ret = setuid(uid);
809
error(0, errno, "setuid");
812
752
/* Open plugin directory with close_on_exec flag */
814
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
817
#else /* not O_CLOEXEC */
819
#endif /* not O_CLOEXEC */
755
if(plugindir == NULL){
756
dir_fd = open(PDIR, O_RDONLY |
759
#else /* not O_CLOEXEC */
761
#endif /* not O_CLOEXEC */
764
dir_fd = open(plugindir, O_RDONLY |
767
#else /* not O_CLOEXEC */
769
#endif /* not O_CLOEXEC */
821
772
if(dir_fd == -1){
822
error(0, errno, "Could not open plugin dir");
823
exitstatus = EX_UNAVAILABLE;
773
perror("Could not open plugin dir");
774
exitstatus = EXIT_FAILURE;
855
806
/* All directory entries have been processed */
856
807
if(dirst == NULL){
857
808
if(errno == EBADF){
858
error(0, errno, "readdir");
859
exitstatus = EX_IOERR;
810
exitstatus = EXIT_FAILURE;
816
d_name_len = strlen(dirst->d_name);
865
818
/* Ignore dotfiles, backup files and other junk */
867
820
bool bad_name = false;
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);
822
const char const *bad_prefixes[] = { ".", "#", NULL };
824
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
827
".dpkg-divert", NULL };
828
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
829
size_t pre_len = strlen(*pre);
830
if((d_name_len >= pre_len)
831
and strncmp((dirst->d_name), *pre, pre_len) == 0){
833
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
834
" with bad prefix %s\n", dirst->d_name, *pre);
843
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
844
size_t suf_len = strlen(*suf);
845
if((d_name_len >= suf_len)
846
and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)
849
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
850
" with bad suffix %s\n", dirst->d_name, *suf);
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");
863
if(plugindir == NULL){
864
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, PDIR "/%s",
867
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, "%s/%s",
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));
915
#endif /* O_CLOEXEC */
916
ret = (int)TEMP_FAILURE_RETRY(fstat(plugin_fd, &st));
876
ret = (int)TEMP_FAILURE_RETRY(stat(filename, &st));
918
error(0, errno, "stat");
919
TEMP_FAILURE_RETRY(close(plugin_fd));
923
883
/* Ignore non-executable files */
924
884
if(not S_ISREG(st.st_mode)
925
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, dirst->d_name, X_OK,
885
or (TEMP_FAILURE_RETRY(access(filename, X_OK)) != 0)){
928
fprintf(stderr, "Ignoring plugin dir entry \"%s/%s\""
929
" with bad type or mode\n",
930
plugindir != NULL ? plugindir : PDIR, dirst->d_name);
887
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
888
" with bad type or mode\n", filename);
932
TEMP_FAILURE_RETRY(close(plugin_fd));
936
894
plugin *p = getplugin(dirst->d_name);
938
error(0, errno, "getplugin");
939
TEMP_FAILURE_RETRY(close(plugin_fd));
954
912
for(char **a = g->argv + 1; *a != NULL; a++){
955
913
if(not add_argument(p, *a)){
956
error(0, errno, "add_argument");
914
perror("add_argument");
959
917
/* Add global environment variables */
960
918
for(char **e = g->environ; *e != NULL; e++){
961
919
if(not add_environment(p, *e, false)){
962
error(0, errno, "add_environment");
920
perror("add_environment");
967
/* If this plugin has any environment variables, we need to
968
duplicate the environment from this process, too. */
925
/* If this plugin has any environment variables, we will call
926
using execve and need to duplicate the environment from this
969
928
if(p->environ[0] != NULL){
970
929
for(char **e = environ; *e != NULL; e++){
971
930
if(not add_environment(p, *e, false)){
972
error(0, errno, "add_environment");
931
perror("add_environment");
978
937
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
980
error(0, errno, "pipe");
981
exitstatus = EX_OSERR;
984
if(pipefd[0] >= FD_SETSIZE){
985
fprintf(stderr, "pipe()[0] (%d) >= FD_SETSIZE (%d)", pipefd[0],
987
TEMP_FAILURE_RETRY(close(pipefd[0]));
988
TEMP_FAILURE_RETRY(close(pipefd[1]));
989
exitstatus = EX_OSERR;
940
exitstatus = EXIT_FAILURE;
992
943
/* Ask OS to automatic close the pipe on exec */
993
944
ret = set_cloexec_flag(pipefd[0]);
995
error(0, errno, "set_cloexec_flag");
996
TEMP_FAILURE_RETRY(close(pipefd[0]));
997
TEMP_FAILURE_RETRY(close(pipefd[1]));
998
exitstatus = EX_OSERR;
946
perror("set_cloexec_flag");
947
exitstatus = EXIT_FAILURE;
1001
950
ret = set_cloexec_flag(pipefd[1]);
1003
error(0, errno, "set_cloexec_flag");
1004
TEMP_FAILURE_RETRY(close(pipefd[0]));
1005
TEMP_FAILURE_RETRY(close(pipefd[1]));
1006
exitstatus = EX_OSERR;
952
perror("set_cloexec_flag");
953
exitstatus = EXIT_FAILURE;
1009
956
/* Block SIGCHLD until process is safely in process list */
1022
969
} while(pid == -1 and errno == EINTR);
1024
error(0, errno, "fork");
1025
TEMP_FAILURE_RETRY(sigprocmask(SIG_UNBLOCK,
1026
&sigchld_action.sa_mask, NULL));
1027
TEMP_FAILURE_RETRY(close(pipefd[0]));
1028
TEMP_FAILURE_RETRY(close(pipefd[1]));
1029
exitstatus = EX_OSERR;
972
exitstatus = EXIT_FAILURE;
1033
976
/* this is the child process */
1034
977
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
1036
error(0, errno, "sigaction");
1039
982
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
1041
error(0, errno, "sigprocmask");
984
perror("sigprocmask");
1045
988
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
1047
error(0, errno, "dup2");
1051
994
if(dirfd(dir) < 0){
1053
996
above and must now close it manually here. */
1056
if(fexecve(plugin_fd, p->argv,
1057
(p->environ[0] != NULL) ? p->environ : environ) < 0){
1058
error(0, errno, "fexecve for %s/%s",
1059
plugindir != NULL ? plugindir : PDIR, dirst->d_name);
999
if(p->environ[0] == NULL){
1000
if(execv(filename, p->argv) < 0){
1002
_exit(EXIT_FAILURE);
1005
if(execve(filename, p->argv, p->environ) < 0){
1007
_exit(EXIT_FAILURE);
1062
1010
/* no return */
1064
1012
/* Parent process */
1065
1013
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
1067
TEMP_FAILURE_RETRY(close(plugin_fd));
1068
1016
plugin *new_plugin = getplugin(dirst->d_name);
1069
1017
if(new_plugin == NULL){
1070
error(0, errno, "getplugin");
1018
perror("getplugin");
1071
1019
ret = (int)(TEMP_FAILURE_RETRY
1072
1020
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
1075
error(0, errno, "sigprocmask");
1023
perror("sigprocmask");
1077
exitstatus = EX_OSERR;
1025
exitstatus = EXIT_FAILURE;
1087
1035
&sigchld_action.sa_mask,
1090
error(0, errno, "sigprocmask");
1091
exitstatus = EX_OSERR;
1038
perror("sigprocmask");
1039
exitstatus = EXIT_FAILURE;
1095
#if defined (__GNUC__) and defined (__GLIBC__)
1096
#if not __GLIBC_PREREQ(2, 16)
1097
#pragma GCC diagnostic push
1098
#pragma GCC diagnostic ignored "-Wsign-conversion"
1101
1043
FD_SET(new_plugin->fd, &rfds_all); /* Spurious warning from
1102
-Wconversion in GNU libc
1104
#if defined (__GNUC__) and defined (__GLIBC__)
1105
#if not __GLIBC_PREREQ(2, 16)
1106
#pragma GCC diagnostic pop
1110
1046
if(maxfd < new_plugin->fd){
1111
1047
maxfd = new_plugin->fd;
1217
1141
bool bret = print_out_password(proc->buffer,
1218
1142
proc->buffer_length);
1220
error(0, errno, "print_out_password");
1221
exitstatus = EX_IOERR;
1144
perror("print_out_password");
1145
exitstatus = EXIT_FAILURE;
1226
1150
/* This process has not completed. Does it have any output? */
1227
#if defined (__GNUC__) and defined (__GLIBC__)
1228
#if not __GLIBC_PREREQ(2, 16)
1229
#pragma GCC diagnostic push
1230
#pragma GCC diagnostic ignored "-Wsign-conversion"
1233
1151
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){ /* Spurious
1239
#if defined (__GNUC__) and defined (__GLIBC__)
1240
#if not __GLIBC_PREREQ(2, 16)
1241
#pragma GCC diagnostic pop
1244
1154
/* This process had nothing to say at this time */
1245
1155
proc = proc->next;
1248
1158
/* Before reading, make the process' data buffer large enough */
1249
1159
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1250
char *new_buffer = realloc(proc->buffer, proc->buffer_size
1251
+ (size_t) BUFFER_SIZE);
1252
if(new_buffer == NULL){
1253
error(0, errno, "malloc");
1254
exitstatus = EX_OSERR;
1160
proc->buffer = realloc(proc->buffer, proc->buffer_size
1161
+ (size_t) BUFFER_SIZE);
1162
if(proc->buffer == NULL){
1164
exitstatus = EXIT_FAILURE;
1257
proc->buffer = new_buffer;
1258
1167
proc->buffer_size += BUFFER_SIZE;
1260
1169
/* Read from the process */