NAME

cr_canseeotheruids — determine if subjects may see entities with differing user ID

SYNOPSIS

int
cr_canseeotheruids(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 the same real user ID.

This policy is active if and only if the sysctl(8) variable security.bsd.see_other_uids 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_canseeotheruids() function returns 0 if the policy is disabled, both credentials have the same real user ID, or if u1 has privilege exempting it from the policy. Otherwise, it returns ESRCH.

SEE ALSO

cr_bsd_visible(9), priv_check_cred(9)