Document a few kernel functions and the sysctl tunables that

affect their behaviour.

1 files changed, 81 insertions, 0 deletions

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+.\"
+.\" Copyright (c) 2003 Joseph Koshy <jkoshy@freebsd.org>
+.\"
+.\" All rights reserved.
+.\"
+.\" This program is free software.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
+.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.Dd November 11, 2003
+.Os
+.Dt cr_seeothergids 9
+.Sh NAME
+.Nm cr_seeothergids
+.Nd determine visibility of objects given their group memberships
+.Sh SYNOPSIS
+.Ft int
+.Fn cr_seeothergids "struct ucred *u1" "struct ucred *u2"
+.Sh DESCRIPTION
+This function determines the visibility of objects in the
+kernel based on the group ids in the credentials
+.Fa u1
+and
+.Fa u2
+associated with them.
+.Pp
+The visibility of objects is influenced by the
+.Xr sysctl 8
+tunable
+.Va security.bsd.see_other_gids .
+If this tunable is non-zero, then all objects in the kernel
+are visible to each othe irrespective of their group membership.
+If this tunable is zero, then the object with credentials
+.Fa u2
+is visible to the object with credentials
+.Fa u1
+if either
+.Fa u1
+is the super-user credential, or if at least one of
+.Fa u1 Ns 's
+group ids is present in
+.Fa u2 Ns 's
+group set.
+.Sh SYSCTL TUNABLES
+.Bl -tag -width indent
+.It Va security.bsd.see_other_gids
+must be non-zero if objects with unprivileged credentials are to be
+able to see each other.
+.El
+.Sh RETURN VALUES
+Ths function returns zero if the object with credential
+.Fa u1
+can
+.Dq see
+the object with credential
+.Fa u2 ,
+or
+.Er ESRCH
+otherwise.
+.Sh SEE ALSO
+.Xr cr_seeotheruids 9 ,
+.Xr p_candebug 9
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