freebsd-skq/sys/nfs/nfs_nfssvc.c

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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.
 * 3. 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.
 *
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "opt_nfs.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/module.h>
#include <sys/sysent.h>
#include <sys/syscall.h>
#include <sys/sysproto.h>

#include <security/audit/audit.h>

#include <nfs/nfssvc.h>

static int nfssvc_offset = SYS_nfssvc;
static struct sysent nfssvc_prev_sysent;
MAKE_SYSENT(nfssvc);

/*
 * This tiny module simply handles the nfssvc() system call. The other
 * nfs modules that use the system call register themselves by setting
 * the nfsd_call_xxx function pointers non-NULL.
 */

int (*nfsd_call_nfsserver)(struct thread *, struct nfssvc_args *) = NULL;
int (*nfsd_call_nfscommon)(struct thread *, struct nfssvc_args *) = NULL;
int (*nfsd_call_nfscl)(struct thread *, struct nfssvc_args *) = NULL;
int (*nfsd_call_nfsd)(struct thread *, struct nfssvc_args *) = NULL;

/*
 * Nfs server pseudo system call for the nfsd's
 */
int
sys_nfssvc(struct thread *td, struct nfssvc_args *uap)
{
	int error;

	KASSERT(!mtx_owned(&Giant), ("nfssvc(): called with Giant"));

	AUDIT_ARG_CMD(uap->flag);

	/* Allow anyone to get the stats. */
	if ((uap->flag & ~NFSSVC_GETSTATS) != 0) {
		error = priv_check(td, PRIV_NFS_DAEMON);
		if (error != 0)
			return (error);
	}
	error = EINVAL;
	if ((uap->flag & (NFSSVC_ADDSOCK | NFSSVC_OLDNFSD | NFSSVC_NFSD)) &&
	    nfsd_call_nfsserver != NULL)
		error = (*nfsd_call_nfsserver)(td, uap);
	else if ((uap->flag & (NFSSVC_CBADDSOCK | NFSSVC_NFSCBD |
	    NFSSVC_DUMPMNTOPTS | NFSSVC_FORCEDISM)) && nfsd_call_nfscl != NULL)
		error = (*nfsd_call_nfscl)(td, uap);
	else if ((uap->flag & (NFSSVC_IDNAME | NFSSVC_GETSTATS |
	    NFSSVC_GSSDADDPORT | NFSSVC_GSSDADDFIRST | NFSSVC_GSSDDELETEALL |
	    NFSSVC_NFSUSERDPORT | NFSSVC_NFSUSERDDELPORT)) &&
	    nfsd_call_nfscommon != NULL)
		error = (*nfsd_call_nfscommon)(td, uap);
	else if ((uap->flag & (NFSSVC_NFSDNFSD | NFSSVC_NFSDADDSOCK |
	    NFSSVC_PUBLICFH | NFSSVC_V4ROOTEXPORT | NFSSVC_NOPUBLICFH |
	    NFSSVC_STABLERESTART | NFSSVC_ADMINREVOKE |
	    NFSSVC_DUMPCLIENTS | NFSSVC_DUMPLOCKS | NFSSVC_BACKUPSTABLE |
	    NFSSVC_SUSPENDNFSD | NFSSVC_RESUMENFSD)) &&
	    nfsd_call_nfsd != NULL)
		error = (*nfsd_call_nfsd)(td, uap);
	if (error == EINTR || error == ERESTART)
		error = 0;
	return (error);
}

/*
 * Called once to initialize data structures...
 */
static int
nfssvc_modevent(module_t mod, int type, void *data)
{
	static int registered;
	int error = 0;

	switch (type) {
	case MOD_LOAD:
		error = syscall_register(&nfssvc_offset, &nfssvc_sysent,
		    &nfssvc_prev_sysent, SY_THR_STATIC_KLD);
		if (error)
			break;
		registered = 1;
		break;

	case MOD_UNLOAD:
		if (nfsd_call_nfsserver != NULL || nfsd_call_nfscommon != NULL
		    || nfsd_call_nfscl != NULL || nfsd_call_nfsd != NULL) {
			error = EBUSY;
			break;
		}
		if (registered)
			syscall_deregister(&nfssvc_offset, &nfssvc_prev_sysent);
		registered = 0;
		break;
	default:
		error = EOPNOTSUPP;
		break;
	}
	return error;
}
static moduledata_t nfssvc_mod = {
	"nfssvc",
	nfssvc_modevent,
	NULL,
};
DECLARE_MODULE(nfssvc, nfssvc_mod, SI_SUB_VFS, SI_ORDER_ANY);

/* So that loader and kldload(2) can find us, wherever we are.. */
MODULE_VERSION(nfssvc, 1);