xref: /freebsd/sys/nfs/nfs_nfssvc.c (revision 5e53a4f90f82c4345f277dd87cc9292f26e04a29)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Rick Macklem at The University of Guelph.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  */
35 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include "opt_nfs.h"
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/sysproto.h>
44 #include <sys/kernel.h>
45 #include <sys/sysctl.h>
46 #include <sys/priv.h>
47 #include <sys/proc.h>
48 #include <sys/lock.h>
49 #include <sys/mutex.h>
50 #include <sys/module.h>
51 #include <sys/sysent.h>
52 #include <sys/syscall.h>
53 #include <sys/sysproto.h>
54 
55 #include <security/audit/audit.h>
56 
57 #include <nfs/nfssvc.h>
58 
59 static int nfssvc_offset = SYS_nfssvc;
60 static struct sysent nfssvc_prev_sysent;
61 MAKE_SYSENT(nfssvc);
62 
63 /*
64  * This tiny module simply handles the nfssvc() system call. The other
65  * nfs modules that use the system call register themselves by setting
66  * the nfsd_call_xxx function pointers non-NULL.
67  */
68 
69 int (*nfsd_call_nfsserver)(struct thread *, struct nfssvc_args *) = NULL;
70 int (*nfsd_call_nfscommon)(struct thread *, struct nfssvc_args *) = NULL;
71 int (*nfsd_call_nfscl)(struct thread *, struct nfssvc_args *) = NULL;
72 int (*nfsd_call_nfsd)(struct thread *, struct nfssvc_args *) = NULL;
73 
74 /*
75  * Nfs server pseudo system call for the nfsd's
76  */
77 int
78 sys_nfssvc(struct thread *td, struct nfssvc_args *uap)
79 {
80 	int error;
81 
82 	KASSERT(!mtx_owned(&Giant), ("nfssvc(): called with Giant"));
83 
84 	AUDIT_ARG_CMD(uap->flag);
85 
86 	/* Allow anyone to get the stats. */
87 	if ((uap->flag & ~NFSSVC_GETSTATS) != 0) {
88 		error = priv_check(td, PRIV_NFS_DAEMON);
89 		if (error != 0)
90 			return (error);
91 	}
92 	error = EINVAL;
93 	if ((uap->flag & (NFSSVC_ADDSOCK | NFSSVC_OLDNFSD | NFSSVC_NFSD)) &&
94 	    nfsd_call_nfsserver != NULL)
95 		error = (*nfsd_call_nfsserver)(td, uap);
96 	else if ((uap->flag & (NFSSVC_CBADDSOCK | NFSSVC_NFSCBD |
97 	    NFSSVC_DUMPMNTOPTS | NFSSVC_FORCEDISM)) && nfsd_call_nfscl != NULL)
98 		error = (*nfsd_call_nfscl)(td, uap);
99 	else if ((uap->flag & (NFSSVC_IDNAME | NFSSVC_GETSTATS |
100 	    NFSSVC_GSSDADDPORT | NFSSVC_GSSDADDFIRST | NFSSVC_GSSDDELETEALL |
101 	    NFSSVC_NFSUSERDPORT | NFSSVC_NFSUSERDDELPORT)) &&
102 	    nfsd_call_nfscommon != NULL)
103 		error = (*nfsd_call_nfscommon)(td, uap);
104 	else if ((uap->flag & (NFSSVC_NFSDNFSD | NFSSVC_NFSDADDSOCK |
105 	    NFSSVC_PUBLICFH | NFSSVC_V4ROOTEXPORT | NFSSVC_NOPUBLICFH |
106 	    NFSSVC_STABLERESTART | NFSSVC_ADMINREVOKE |
107 	    NFSSVC_DUMPCLIENTS | NFSSVC_DUMPLOCKS | NFSSVC_BACKUPSTABLE |
108 	    NFSSVC_SUSPENDNFSD | NFSSVC_RESUMENFSD)) &&
109 	    nfsd_call_nfsd != NULL)
110 		error = (*nfsd_call_nfsd)(td, uap);
111 	if (error == EINTR || error == ERESTART)
112 		error = 0;
113 	return (error);
114 }
115 
116 /*
117  * Called once to initialize data structures...
118  */
119 static int
120 nfssvc_modevent(module_t mod, int type, void *data)
121 {
122 	static int registered;
123 	int error = 0;
124 
125 	switch (type) {
126 	case MOD_LOAD:
127 		error = syscall_register(&nfssvc_offset, &nfssvc_sysent,
128 		    &nfssvc_prev_sysent, SY_THR_STATIC_KLD);
129 		if (error)
130 			break;
131 		registered = 1;
132 		break;
133 
134 	case MOD_UNLOAD:
135 		if (nfsd_call_nfsserver != NULL || nfsd_call_nfscommon != NULL
136 		    || nfsd_call_nfscl != NULL || nfsd_call_nfsd != NULL) {
137 			error = EBUSY;
138 			break;
139 		}
140 		if (registered)
141 			syscall_deregister(&nfssvc_offset, &nfssvc_prev_sysent);
142 		registered = 0;
143 		break;
144 	default:
145 		error = EOPNOTSUPP;
146 		break;
147 	}
148 	return error;
149 }
150 static moduledata_t nfssvc_mod = {
151 	"nfssvc",
152 	nfssvc_modevent,
153 	NULL,
154 };
155 DECLARE_MODULE(nfssvc, nfssvc_mod, SI_SUB_VFS, SI_ORDER_ANY);
156 
157 /* So that loader and kldload(2) can find us, wherever we are.. */
158 MODULE_VERSION(nfssvc, 1);
159 
160