freebsd-src/sys/nfsserver/nfsm_subs.h
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

184 lines
5.4 KiB
C

/*-
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
* @(#)nfsm_subs.h 8.2 (Berkeley) 3/30/95
* $FreeBSD$
*/
#ifndef _NFSSERVER_NFSM_SUBS_H_
#define _NFSSERVER_NFSM_SUBS_H_
#include <nfs/nfs_common.h>
#define nfstov_mode(a) (fxdr_unsigned(u_int32_t, (a)) & ALLPERMS)
/*
* These macros do strange and peculiar things to mbuf chains for
* the assistance of the nfs code. To attempt to use them for any
* other purpose will be dangerous. (they make weird assumptions)
*/
/*
* First define what the actual subs. return
*/
#define M_HASCL(m) ((m)->m_flags & M_EXT)
#define NFSMSIZ(m) ((M_HASCL(m))?MCLBYTES: \
(((m)->m_flags & M_PKTHDR)?MHLEN:MLEN))
/*
* Now for the macros that do the simple stuff and call the functions
* for the hard stuff.
* These macros use several vars. declared in nfsm_reqhead and these
* vars. must not be used elsewhere unless you are careful not to corrupt
* them. The vars. starting with pN and tN (N=1,2,3,..) are temporaries
* that may be used so long as the value is not expected to retained
* after a macro.
* I know, this is kind of dorkey, but it makes the actual op functions
* fairly clean and deals with the mess caused by the xdr discriminating
* unions.
*/
/* ************************************* */
/* Dissection phase macros */
int nfsm_srvstrsiz_xx(int *s, int m, struct mbuf **md, caddr_t *dpos);
int nfsm_srvnamesiz_xx(int *s, int m, struct mbuf **md, caddr_t *dpos);
int nfsm_srvnamesiz0_xx(int *s, int m, struct mbuf **md, caddr_t *dpos);
int nfsm_srvmtofh_xx(fhandle_t *f, int v3, struct mbuf **md, caddr_t *dpos);
int nfsm_srvsattr_xx(struct vattr *a, struct mbuf **md, caddr_t *dpos);
#define nfsm_srvstrsiz(s, m) \
do { \
int t1; \
t1 = nfsm_srvstrsiz_xx(&(s), (m), &md, &dpos); \
if (t1) { \
error = t1; \
nfsm_reply(0); \
} \
} while (0)
#define nfsm_srvnamesiz(s) \
do { \
int t1; \
t1 = nfsm_srvnamesiz_xx(&(s), NFS_MAXNAMLEN, &md, &dpos); \
if (t1) { \
error = t1; \
nfsm_reply(0); \
} \
} while (0)
#define nfsm_srvpathsiz(s) \
do { \
int t1; \
t1 = nfsm_srvnamesiz0_xx(&(s), NFS_MAXPATHLEN, &md, &dpos); \
if (t1) { \
error = t1; \
nfsm_reply(0); \
} \
} while (0)
#define nfsm_srvmtofh(f) \
do { \
int t1; \
t1 = nfsm_srvmtofh_xx((f), nfsd->nd_flag & ND_NFSV3, &md, &dpos); \
if (t1) { \
error = t1; \
nfsm_reply(0); \
} \
} while (0)
/* XXX why is this different? */
#define nfsm_srvsattr(a) \
do { \
int t1; \
t1 = nfsm_srvsattr_xx((a), &md, &dpos); \
if (t1) { \
error = t1; \
m_freem(mrep); \
mrep = NULL; \
goto nfsmout; \
} \
} while (0)
/* ************************************* */
/* Prepare the reply */
#define nfsm_reply(s) \
do { \
if (mrep != NULL) { \
m_freem(mrep); \
mrep = NULL; \
} \
mreq = nfs_rephead((s), nfsd, error, &mb, &bpos); \
*mrq = mreq; \
if (error == EBADRPC) { \
error = 0; \
goto nfsmout; \
} \
} while (0)
#define nfsm_writereply(s) \
do { \
mreq = nfs_rephead((s), nfsd, error, &mb, &bpos); \
} while(0)
/* ************************************* */
/* Reply phase macros - add additional reply info */
void nfsm_srvfhtom_xx(fhandle_t *f, int v3, struct mbuf **mb,
caddr_t *bpos);
void nfsm_srvpostop_fh_xx(fhandle_t *f, struct mbuf **mb, caddr_t *bpos);
void nfsm_clget_xx(u_int32_t **tl, struct mbuf *mb, struct mbuf **mp,
char **bp, char **be, caddr_t bpos);
#define nfsm_srvfhtom(f, v3) \
nfsm_srvfhtom_xx((f), (v3), &mb, &bpos)
#define nfsm_srvpostop_fh(f) \
nfsm_srvpostop_fh_xx((f), &mb, &bpos)
#define nfsm_srvwcc_data(br, b, ar, a) \
nfsm_srvwcc(nfsd, (br), (b), (ar), (a), &mb, &bpos)
#define nfsm_srvpostop_attr(r, a) \
nfsm_srvpostopattr(nfsd, (r), (a), &mb, &bpos)
#define nfsm_srvfillattr(a, f) \
nfsm_srvfattr(nfsd, (a), (f))
#define nfsm_clget \
nfsm_clget_xx(&tl, mb, &mp, &bp, &be, bpos)
#endif