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freebsd/sys/rpc/svc_auth.c
Doug Rabson a9148abd9d Implement support for RPCSEC_GSS authentication to both the NFS client
and server. This replaces the RPC implementation of the NFS client and
server with the newer RPC implementation originally developed
(actually ported from the userland sunrpc code) to support the NFS
Lock Manager.  I have tested this code extensively and I believe it is
stable and that performance is at least equal to the legacy RPC
implementation.

The NFS code currently contains support for both the new RPC
implementation and the older legacy implementation inherited from the
original NFS codebase. The default is to use the new implementation -
add the NFS_LEGACYRPC option to fall back to the old code. When I
merge this support back to RELENG_7, I will probably change this so
that users have to 'opt in' to get the new code.

To use RPCSEC_GSS on either client or server, you must build a kernel
which includes the KGSSAPI option and the crypto device. On the
userland side, you must build at least a new libc, mountd, mount_nfs
and gssd. You must install new versions of /etc/rc.d/gssd and
/etc/rc.d/nfsd and add 'gssd_enable=YES' to /etc/rc.conf.

As long as gssd is running, you should be able to mount an NFS
filesystem from a server that requires RPCSEC_GSS authentication. The
mount itself can happen without any kerberos credentials but all
access to the filesystem will be denied unless the accessing user has
a valid ticket file in the standard place (/tmp/krb5cc_<uid>). There
is currently no support for situations where the ticket file is in a
different place, such as when the user logged in via SSH and has
delegated credentials from that login. This restriction is also
present in Solaris and Linux. In theory, we could improve this in
future, possibly using Brooks Davis' implementation of variant
symlinks.

Supporting RPCSEC_GSS on a server is nearly as simple. You must create
service creds for the server in the form 'nfs/<fqdn>@<REALM>' and
install them in /etc/krb5.keytab. The standard heimdal utility ktutil
makes this fairly easy. After the service creds have been created, you
can add a '-sec=krb5' option to /etc/exports and restart both mountd
and nfsd.

The only other difference an administrator should notice is that nfsd
doesn't fork to create service threads any more. In normal operation,
there will be two nfsd processes, one in userland waiting for TCP
connections and one in the kernel handling requests. The latter
process will create as many kthreads as required - these should be
visible via 'top -H'. The code has some support for varying the number
of service threads according to load but initially at least, nfsd uses
a fixed number of threads according to the value supplied to its '-n'
option.

Sponsored by:	Isilon Systems
MFC after:	1 month
2008-11-03 10:38:00 +00:00

197 lines
5.0 KiB
C

/* $NetBSD: svc_auth.c,v 1.12 2000/07/06 03:10:35 christos Exp $ */
/*
* Sun RPC is a product of Sun Microsystems, Inc. and is provided for
* unrestricted use provided that this legend is included on all tape
* media and as a part of the software program in whole or part. Users
* may copy or modify Sun RPC without charge, but are not authorized
* to license or distribute it to anyone else except as part of a product or
* program developed by the user.
*
* SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
* WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
*
* Sun RPC is provided with no support and without any obligation on the
* part of Sun Microsystems, Inc. to assist in its use, correction,
* modification or enhancement.
*
* SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
* INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
* OR ANY PART THEREOF.
*
* In no event will Sun Microsystems, Inc. be liable for any lost revenue
* or profits or other special, indirect and consequential damages, even if
* Sun has been advised of the possibility of such damages.
*
* Sun Microsystems, Inc.
* 2550 Garcia Avenue
* Mountain View, California 94043
*/
/*
* Copyright (c) 1986-1991 by Sun Microsystems Inc.
*/
#if defined(LIBC_SCCS) && !defined(lint)
#ident "@(#)svc_auth.c 1.16 94/04/24 SMI"
static char sccsid[] = "@(#)svc_auth.c 1.26 89/02/07 Copyr 1984 Sun Micro";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* svc_auth.c, Server-side rpc authenticator interface.
*
*/
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/systm.h>
#include <sys/ucred.h>
#include <rpc/rpc.h>
static enum auth_stat (*_svcauth_rpcsec_gss)(struct svc_req *,
struct rpc_msg *) = NULL;
static int (*_svcauth_rpcsec_gss_getcred)(struct svc_req *,
struct ucred **, int *);
static struct svc_auth_ops svc_auth_null_ops;
/*
* The call rpc message, msg has been obtained from the wire. The msg contains
* the raw form of credentials and verifiers. authenticate returns AUTH_OK
* if the msg is successfully authenticated. If AUTH_OK then the routine also
* does the following things:
* set rqst->rq_xprt->verf to the appropriate response verifier;
* sets rqst->rq_client_cred to the "cooked" form of the credentials.
*
* NB: rqst->rq_cxprt->verf must be pre-alloctaed;
* its length is set appropriately.
*
* The caller still owns and is responsible for msg->u.cmb.cred and
* msg->u.cmb.verf. The authentication system retains ownership of
* rqst->rq_client_cred, the cooked credentials.
*
* There is an assumption that any flavour less than AUTH_NULL is
* invalid.
*/
enum auth_stat
_authenticate(struct svc_req *rqst, struct rpc_msg *msg)
{
int cred_flavor;
enum auth_stat dummy;
rqst->rq_cred = msg->rm_call.cb_cred;
rqst->rq_auth.svc_ah_ops = &svc_auth_null_ops;
rqst->rq_auth.svc_ah_private = NULL;
cred_flavor = rqst->rq_cred.oa_flavor;
switch (cred_flavor) {
case AUTH_NULL:
dummy = _svcauth_null(rqst, msg);
return (dummy);
case AUTH_SYS:
dummy = _svcauth_unix(rqst, msg);
return (dummy);
case AUTH_SHORT:
dummy = _svcauth_short(rqst, msg);
return (dummy);
case RPCSEC_GSS:
if (!_svcauth_rpcsec_gss)
return (AUTH_REJECTEDCRED);
dummy = _svcauth_rpcsec_gss(rqst, msg);
return (dummy);
default:
break;
}
return (AUTH_REJECTEDCRED);
}
/*
* A set of null auth methods used by any authentication protocols
* that don't need to inspect or modify the message body.
*/
static bool_t
svcauth_null_wrap(SVCAUTH *auth, struct mbuf **mp)
{
return (TRUE);
}
static bool_t
svcauth_null_unwrap(SVCAUTH *auth, struct mbuf **mp)
{
return (TRUE);
}
static void
svcauth_null_release(SVCAUTH *auth)
{
}
static struct svc_auth_ops svc_auth_null_ops = {
svcauth_null_wrap,
svcauth_null_unwrap,
svcauth_null_release,
};
/*ARGSUSED*/
enum auth_stat
_svcauth_null(struct svc_req *rqst, struct rpc_msg *msg)
{
rqst->rq_verf = _null_auth;
return (AUTH_OK);
}
int
svc_auth_reg(int flavor,
enum auth_stat (*svcauth)(struct svc_req *, struct rpc_msg *),
int (*getcred)(struct svc_req *, struct ucred **, int *))
{
if (flavor == RPCSEC_GSS) {
_svcauth_rpcsec_gss = svcauth;
_svcauth_rpcsec_gss_getcred = getcred;
}
return (TRUE);
}
int
svc_getcred(struct svc_req *rqst, struct ucred **crp, int *flavorp)
{
struct ucred *cr = NULL;
int flavor, i;
struct xucred *xcr;
flavor = rqst->rq_cred.oa_flavor;
if (flavorp)
*flavorp = flavor;
switch (flavor) {
case AUTH_UNIX:
xcr = (struct xucred *) rqst->rq_clntcred;
cr = crget();
cr->cr_uid = cr->cr_ruid = cr->cr_svuid = xcr->cr_uid;
cr->cr_ngroups = xcr->cr_ngroups;
for (i = 0; i < xcr->cr_ngroups; i++)
cr->cr_groups[i] = xcr->cr_groups[i];
cr->cr_rgid = cr->cr_svgid = cr->cr_groups[0];
*crp = cr;
return (TRUE);
case RPCSEC_GSS:
if (!_svcauth_rpcsec_gss_getcred)
return (FALSE);
return (_svcauth_rpcsec_gss_getcred(rqst, crp, flavorp));
default:
return (FALSE);
}
}