NAME
cr_canseeothergids —
determine if subjects may see entities
in a disjoint group set
SYNOPSIS
int
cr_canseeothergids(struct
ucred *u1, struct ucred
*u2);
DESCRIPTION
This function checks if a subject associated to credentials u1 is denied seeing a subject or object associated to credentials u2 by a policy that requires both credentials to have at least one group in common. For this determination, the real and supplementary group IDs are used, but not the effective group IDs, as per realgroupmember(9).
This policy is active if and only if the sysctl(8) variable security.bsd.see_other_gids is set to zero.
As usual, the superuser (effective user ID 0) is exempt from this policy provided that the sysctl(8) variable security.bsd.suser_enabled is non-zero and no active MAC policy explicitly denies the exemption (see priv_check_cred(9)).
RETURN VALUES
The cr_canseeothergids() function returns
0 if the policy is disabled, the credentials share at least one common
group, or if u1 has privilege exempting it from the
policy. Otherwise, it returns ESRCH.