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(),
26
asprintf(), O_CLOEXEC */
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, fdopendir(), 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
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,
170
175
/* Helper function for add_argument and add_environment */
176
__attribute__((nonnull, warn_unused_result))
171
177
static bool add_to_char_array(const char *new, char ***array,
173
179
/* Resize the pointed-to array to hold one more pointer */
180
char **new_array = NULL;
175
*array = realloc(*array, sizeof(char *)
176
* (size_t) ((*len) + 2));
177
} while(*array == NULL and errno == EINTR);
182
new_array = realloc(*array, sizeof(char *)
183
* (size_t) ((*len) + 2));
184
} while(new_array == NULL and errno == EINTR);
178
185
/* Malloc check */
186
if(new_array == NULL){
182
190
/* Make a copy of the new string */
211
221
/* namelen = length of name of environment variable */
212
222
size_t namelen = (size_t)(strchrnul(def, '=') - def);
213
223
/* Search for this environment variable */
214
for(char **e = p->environ; *e != NULL; e++){
215
if(strncmp(*e, def, namelen + 1) == 0){
224
for(char **envdef = p->environ; *envdef != NULL; envdef++){
225
if(strncmp(*envdef, def, namelen + 1) == 0){
216
226
/* It already exists */
220
new = realloc(*e, strlen(def) + 1);
221
} while(new == NULL and errno == EINTR);
230
new_envdef = realloc(*envdef, strlen(def) + 1);
231
} while(new_envdef == NULL and errno == EINTR);
232
if(new_envdef == NULL){
235
*envdef = new_envdef;
236
strcpy(*envdef, def);
351
363
.sa_flags = SA_NOCLDSTOP };
352
364
char **custom_argv = NULL;
353
365
int custom_argc = 0;
355
368
/* Establish a signal handler */
356
369
sigemptyset(&sigchld_action.sa_mask);
357
370
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
360
exitstatus = EXIT_FAILURE;
372
error(0, errno, "sigaddset");
373
exitstatus = EX_OSERR;
363
376
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
366
exitstatus = EXIT_FAILURE;
378
error(0, errno, "sigaction");
379
exitstatus = EX_OSERR;
485
506
plugin *p = getplugin(arg);
487
508
p->disabled = false;
491
513
case 128: /* --plugin-dir */
493
515
plugindir = strdup(arg);
516
if(plugindir != NULL){
495
520
case 129: /* --config-file */
496
521
/* This is already done by parse_opt_config_file() */
498
523
case 130: /* --userid */
499
tmpmax = strtoimax(arg, &tmp, 10);
524
tmp_id = strtoimax(arg, &tmp, 10);
500
525
if(errno != 0 or tmp == arg or *tmp != '\0'
501
or tmpmax != (uid_t)tmpmax){
526
or tmp_id != (uid_t)tmp_id){
502
527
argp_error(state, "Bad user ID number: \"%s\", using %"
503
528
PRIdMAX, arg, (intmax_t)uid);
508
534
case 131: /* --groupid */
509
tmpmax = strtoimax(arg, &tmp, 10);
535
tmp_id = strtoimax(arg, &tmp, 10);
510
536
if(errno != 0 or tmp == arg or *tmp != '\0'
511
or tmpmax != (gid_t)tmpmax){
537
or tmp_id != (gid_t)tmp_id){
512
538
argp_error(state, "Bad group ID number: \"%s\", using %"
513
539
PRIdMAX, arg, (intmax_t)gid);
518
545
case 132: /* --debug */
742
/* 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");
747
807
ret = setuid(uid);
809
error(0, errno, "setuid");
752
812
/* Open plugin directory with close_on_exec flag */
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 */
814
dir_fd = open(plugindir != NULL ? plugindir : PDIR, O_RDONLY |
817
#else /* not O_CLOEXEC */
819
#endif /* not O_CLOEXEC */
772
821
if(dir_fd == -1){
773
perror("Could not open plugin dir");
774
exitstatus = EXIT_FAILURE;
822
error(0, errno, "Could not open plugin dir");
823
exitstatus = EX_UNAVAILABLE;
806
855
/* All directory entries have been processed */
807
856
if(dirst == NULL){
808
857
if(errno == EBADF){
810
exitstatus = EXIT_FAILURE;
858
error(0, errno, "readdir");
859
exitstatus = EX_IOERR;
816
d_name_len = strlen(dirst->d_name);
818
865
/* Ignore dotfiles, backup files and other junk */
820
867
bool bad_name = false;
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);
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);
863
if(plugindir == NULL){
864
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, PDIR "/%s",
867
ret = (int)TEMP_FAILURE_RETRY(asprintf(&filename, "%s/%s",
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));
876
ret = (int)TEMP_FAILURE_RETRY(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));
883
923
/* Ignore non-executable files */
884
924
if(not S_ISREG(st.st_mode)
885
or (TEMP_FAILURE_RETRY(access(filename, X_OK)) != 0)){
925
or (TEMP_FAILURE_RETRY(faccessat(dir_fd, dirst->d_name, X_OK,
887
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
888
" 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));
894
936
plugin *p = getplugin(dirst->d_name);
938
error(0, errno, "getplugin");
939
TEMP_FAILURE_RETRY(close(plugin_fd));
912
954
for(char **a = g->argv + 1; *a != NULL; a++){
913
955
if(not add_argument(p, *a)){
914
perror("add_argument");
956
error(0, errno, "add_argument");
917
959
/* Add global environment variables */
918
960
for(char **e = g->environ; *e != NULL; e++){
919
961
if(not add_environment(p, *e, false)){
920
perror("add_environment");
962
error(0, errno, "add_environment");
925
/* If this plugin has any environment variables, we will call
926
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. */
928
969
if(p->environ[0] != NULL){
929
970
for(char **e = environ; *e != NULL; e++){
930
971
if(not add_environment(p, *e, false)){
931
perror("add_environment");
972
error(0, errno, "add_environment");
937
978
ret = (int)TEMP_FAILURE_RETRY(pipe(pipefd));
940
exitstatus = EXIT_FAILURE;
980
error(0, errno, "pipe");
981
exitstatus = EX_OSERR;
943
984
/* Ask OS to automatic close the pipe on exec */
944
985
ret = set_cloexec_flag(pipefd[0]);
946
perror("set_cloexec_flag");
947
exitstatus = EXIT_FAILURE;
987
error(0, errno, "set_cloexec_flag");
988
exitstatus = EX_OSERR;
950
991
ret = set_cloexec_flag(pipefd[1]);
952
perror("set_cloexec_flag");
953
exitstatus = EXIT_FAILURE;
993
error(0, errno, "set_cloexec_flag");
994
exitstatus = EX_OSERR;
956
997
/* Block SIGCHLD until process is safely in process list */
996
1037
above and must now close it manually here. */
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);
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);
1010
1046
/* no return */
1012
1048
/* Parent process */
1013
1049
TEMP_FAILURE_RETRY(close(pipefd[1])); /* Close unused write end of
1051
TEMP_FAILURE_RETRY(close(plugin_fd));
1016
1052
plugin *new_plugin = getplugin(dirst->d_name);
1017
1053
if(new_plugin == NULL){
1018
perror("getplugin");
1054
error(0, errno, "getplugin");
1019
1055
ret = (int)(TEMP_FAILURE_RETRY
1020
1056
(sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
1023
perror("sigprocmask");
1059
error(0, errno, "sigprocmask");
1025
exitstatus = EXIT_FAILURE;
1061
exitstatus = EX_OSERR;
1035
1071
&sigchld_action.sa_mask,
1038
perror("sigprocmask");
1039
exitstatus = EXIT_FAILURE;
1074
error(0, errno, "sigprocmask");
1075
exitstatus = EX_OSERR;
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"
1043
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
1046
1094
if(maxfd < new_plugin->fd){
1047
1095
maxfd = new_plugin->fd;
1141
1201
bool bret = print_out_password(proc->buffer,
1142
1202
proc->buffer_length);
1144
perror("print_out_password");
1145
exitstatus = EXIT_FAILURE;
1204
error(0, errno, "print_out_password");
1205
exitstatus = EX_IOERR;
1150
1210
/* This process has not completed. Does it have any output? */
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"
1151
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
1154
1228
/* This process had nothing to say at this time */
1155
1229
proc = proc->next;
1158
1232
/* Before reading, make the process' data buffer large enough */
1159
1233
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
1160
proc->buffer = realloc(proc->buffer, proc->buffer_size
1161
+ (size_t) BUFFER_SIZE);
1162
if(proc->buffer == NULL){
1164
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;
1167
1242
proc->buffer_size += BUFFER_SIZE;
1169
1244
/* Read from the process */