platform_external_selinux/libselinux/utils/validatetrans.c
Joshua Brindle 25ce102907 Add security_validatetrans support
It seems validatetrans support was never added to libselinux, despite being added to
selinuxfs in kernel version 4.5

There is a utility to test, however the targeted policy has no validatetrans rules so some must be added:

$ cat validatetrans.cil
(mlsvalidatetrans db_table (and (or (or (or (eq l1 l2) (and (eq t3 unconfined_t) (domby l1 l2))) (and (eq t3 unconfined_t) (dom l1 l2))) (and (eq t3 unconfined_t) (incomp l1 l2))) (or (or (or (eq l1 h2) (and (eq t3 unconfined_t) (domby h1 h2))) (and (eq t3 unconfined_t) (dom h1 h2))) (and (eq t3 unconfined_t) (incomp h1 h2)))))

$ sudo semodule -i validatetrans.cil

$ ./validatetrans system_u:system_r:kernel_t:s0 system_u:system_r:init_t:s0:c0 db_table system_u:system_r: # invalid context here
opening /sys/fs/selinux/validatetrans
security_validatetrans returned -1 errno: Invalid argument

$ ./validatetrans system_u:system_r:kernel_t:s0 system_u:system_r:init_t:s0:c0 db_table system_u:system_r:init_t:s0
opening /sys/fs/selinux/validatetrans
security_validatetrans returned -1 errno: Operation not permitted

$ ./validatetrans system_u:system_r:kernel_t:s0 system_u:system_r:init_t:s0:c0 db_table system_u:system_r:unconfined_t:s0
opening /sys/fs/selinux/validatetrans
security_validatetrans returned 0 errno: Success

Signed-off-by: Joshua Brindle <joshua.brindle@crunchydata.com>
2019-04-09 06:51:02 -07:00

30 lines
643 B
C

#include <unistd.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <selinux/selinux.h>
int main(int argc, char **argv)
{
security_class_t tclass;
int ret;
if (argc != 5) {
fprintf(stderr, "usage: %s scontext tcontext tclass newcontext\n",
argv[0]);
exit(1);
}
tclass = string_to_security_class(argv[3]);
if (!tclass) {
fprintf(stderr, "%s: invalid class '%s'\n", argv[0], argv[3]);
exit(2);
}
ret = security_validatetrans(argv[1], argv[2], tclass, argv[4]);
printf("security_validatetrans returned %d errno: %s\n", ret, strerror(errno));
return ret;
}