DOKK / manpages / debian 10 / freebsd-manpages / cr_cansee.9freebsd.en
CR_CANSEE(9) Kernel Developer's Manual CR_CANSEE(9)

cr_canseedetermine visibility of objects given their user credentials

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ucred.h>

int
cr_cansee(struct ucred *u1, struct ucred *u2);

This function determines the visibility of objects in the kernel based on the real user IDs and group IDs in the credentials u1 and u2 associated with them.

The visibility of objects is influenced by the sysctl(8) variables security.bsd.see_other_gids and security.bsd.see_other_uids, as per the description in cr_seeothergids(9) and cr_seeotheruids(9) respectively.

This function returns zero if the object with credential u1 can “see” the object with credential u2, or ESRCH otherwise.

[]
The object with credential u1 cannot “see” the object with credential u2.
[]
The object with credential u1 has been jailed and the object with credential u2 does not belong to the same jail as u1.
[]
The MAC subsystem denied visibility.

cr_seeothergids(9), cr_seeotheruids(9), mac(9), p_cansee(9)

November 19, 2006 Debian