prison_check - determine if two credentials belong to the same jail
#include <sys/jail.h>
int
prison_check(struct ucred *cred1, struct ucred *cred2);
This function can be used to determine if the two credentials cred1 and
cred2 belong to the same jail.
The prison_check() function returns ESRCH if cred1 has been jailed, and
cred1 and cred2 do not belong to the same jail. In all other cases,
prison_check() returns zero.
jail(2)