1.\" 2.\" Copyright (C) 2001 Chad David <davidc@acns.ab.ca>. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice(s), this list of conditions and the following disclaimer as 9.\" the first lines of this file unmodified other than the possible 10.\" addition of one or more copyright notices. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice(s), this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 16.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18.\" DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY 19.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 22.\" CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 25.\" DAMAGE. 26.\" 27.\" $FreeBSD$ 28.\" 29.Dd March 3, 2002 30.Dt UCRED 9 31.Os 32.Sh NAME 33.Nm ucred , 34.Nm crget , 35.Nm crhold , 36.Nm crfree , 37.Nm crshared , 38.Nm crcopy , 39.Nm crdup , 40.Nm cru2x , 41.NM cred_update_thread 42.Nd "functions related to user credentials" 43.Sh SYNOPSIS 44.In sys/param.h 45.In sys/ucred.h 46.Ft "struct ucred *" 47.Fn crget void 48.Ft "struct ucred *" 49.Fn crhold "struct ucred *cr" 50.Ft void 51.Fn crfree "struct ucred *cr" 52.Ft int 53.Fn crshared "struct ucred *cr" 54.Ft void 55.Fn crcopy "struct ucred *dest" "struct ucred *src" 56.Ft "struct ucred *" 57.Fn crdup "struct ucred *cr" 58.Ft void 59.Fn cru2x "struct ucred *cr" "struct xucred *xcr" 60.Ft void 61.Fn cred_update_thread "struct thread *td" 62.Sh DESCRIPTION 63The 64.Nm 65family of functions is used to manage user credential structures 66.Pq Vt "struct ucred" 67within the kernel. 68.Pp 69The 70.Fn crget 71function allocates memory 72for a new structure, sets its reference count to 1, and 73initializes its lock. 74.Pp 75The 76.Fn crhold 77function increases the reference count on the credential. 78.Pp 79The 80.Fn crfree 81function decreases the reference count on the credential. 82If the count drops to 0, the storage for the structure is freed. 83.Pp 84The 85.Fn crshared 86function returns true if the credential is shared. 87A credential is considered to be shared if its reference 88count is greater than one. 89.Pp 90The 91.Fn crcopy 92function copies the contents of the source (template) 93credential into the destination template. 94The 95.Vt uidinfo 96structure within the destination is referenced 97by calling 98.Xr uihold 9 . 99.Pp 100The 101.Fn crdup 102function allocates memory for a new structure and copies the 103contents of 104.Fa cr 105into it. 106The actual copying is performed by 107.Fn crcopy . 108.Pp 109The 110.Fn cru2x 111function converts a 112.Vt ucred 113structure to an 114.Vt xucred 115structure. 116That is, 117it copies data from 118.Fa cr 119to 120.Fa xcr ; 121it ignores fields in the former that are not present in the latter 122(e.g., 123.Va cr_uidinfo ) , 124and appropriately sets fields in the latter that are not present in 125the former 126(e.g., 127.Va cr_version ) . 128.Pp 129The 130.Fn cred_update_thread 131function sets the credentials of 132.Fa td 133to that of its process, freeing its old credential if required. 134.Sh RETURN VALUES 135.Fn crget , 136.Fn crhold 137and 138.Fn crdup 139all return a pointer to a 140.Vt ucred 141structure. 142.Pp 143.Fn crshared 144returns 0 if the credential has a reference count greater than 1; 145otherwise, 1 is returned. 146.Sh SEE ALSO 147.Xr uihold 9 148.Sh AUTHORS 149This man page was written by 150.An Chad David Aq davidc@acns.ab.ca . 151