xref: /netbsd-src/sys/compat/freebsd/freebsd_sysctl.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: freebsd_sysctl.c,v 1.10 2007/12/08 18:35:59 dsl Exp $	*/
2 
3 /*-
4  * Copyright (c) 2005 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by
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. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * FreeBSD compatibility module. Try to deal with various FreeBSD sysctl calls.
41  */
42 
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: freebsd_sysctl.c,v 1.10 2007/12/08 18:35:59 dsl Exp $");
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/proc.h>
49 #include <sys/mount.h>
50 #include <sys/signal.h>
51 #include <sys/signalvar.h>
52 #include <sys/malloc.h>
53 #include <sys/mman.h>
54 #include <sys/sysctl.h>
55 #include <sys/ktrace.h>
56 
57 #include <sys/syscallargs.h>
58 
59 #include <compat/freebsd/freebsd_syscallargs.h>
60 #include <compat/common/compat_util.h>
61 #include <compat/freebsd/freebsd_rtprio.h>
62 #include <compat/freebsd/freebsd_timex.h>
63 #include <compat/freebsd/freebsd_signal.h>
64 #include <compat/freebsd/freebsd_mman.h>
65 
66 static int freebsd_sysctl_name2oid(char *, int *, int *);
67 
68 SYSCTL_SETUP_PROTO(freebsd_sysctl_setup);
69 SYSCTL_SETUP(freebsd_sysctl_setup, "freebsd emulated sysctl setup")
70 {
71 	sysctl_createv(clog, 0, NULL, NULL,
72 			CTLFLAG_PERMANENT,
73 			CTLTYPE_NODE, "kern", NULL,
74 			NULL, 0, NULL, 0,
75 			CTL_KERN, CTL_EOL);
76         sysctl_createv(clog, 0, NULL, NULL,
77 			CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE,
78 			CTLTYPE_INT, "osreldate",
79 			SYSCTL_DESCR("Operating system revision"),
80 			NULL, __NetBSD_Version__, NULL, 0,
81 			CTL_KERN, CTL_CREATE, CTL_EOL);
82 }
83 
84 int
85 freebsd_sys_sysctl(struct lwp *l, void *v, register_t *retval)
86 {
87 	struct freebsd_sys_sysctl_args /* {
88 		syscallarg(int *) name;
89 		syscallarg(u_int) namelen;
90 		syscallarg(void *) old;
91 		syscallarg(size_t *) oldlenp;
92 		syscallarg(void *) new;
93 		syscallarg(size_t) newlen;
94 	} */ *uap = v;
95 	int error;
96 	int name[CTL_MAXNAME];
97 	size_t newlen, *oldlenp;
98 	u_int namelen;
99 	void *new, *old;
100 
101 	namelen = SCARG(uap, namelen);
102 
103 	if ((namelen > CTL_MAXNAME) || (namelen < 1))
104 		return EINVAL;
105 
106 	if ((error = copyin(SCARG(uap, name), name,
107 	    namelen * sizeof(*name))) != 0)
108 		return error;
109 
110 	if (namelen > 0 && name[0] != 0)
111 		return(sys___sysctl(l, v, retval));
112 
113 	ktrmib(name, namelen);
114 
115 	/*
116 	 * FreeBSD sysctl uses an undocumented set of special OIDs in it's
117 	 * sysctl MIB whose tree is rooted at oid 0.  These OIDs are
118 	 * interpretted by their sysctl to implement functions that NetBSD
119 	 * performs in libc, such as sysctlgetmibinfo.
120 	 *
121 	 * From the FreeBSD kern_sysctl.c, these OIDs are:
122 	 * {0,0}        printf the entire MIB-tree.
123 	 * {0,1,...}    return the name of the "..." OID.
124 	 * {0,2,...}    return the next OID.
125 	 * {0,3}        return the OID of the name in "new"
126 	 * {0,4,...}    return the kind & format info for the "..." OID.
127 	 * {0,5,...}    return the description the "..." OID.
128 	 *
129 	 * Only implement {0,3} for now.
130 	 */
131 
132 	if (namelen < 2 || namelen > CTL_MAXNAME)
133 		return(EINVAL);
134 
135 	if (name[1] == 3) {
136 		char *locnew;
137 		int oid[CTL_MAXNAME];
138 		u_int oidlen = CTL_MAXNAME;
139 
140 		new = SCARG(uap, new);
141 		newlen = SCARG(uap, newlen);
142 		if (new == NULL || newlen < 1 ||
143 		    newlen > (SYSCTL_NAMELEN * CTL_MAXNAME))
144 			return(EINVAL);
145 
146 		old = SCARG(uap, old);
147 		oldlenp = SCARG(uap, oldlenp);
148 		if (old == NULL || oldlenp == NULL || *oldlenp < sizeof(int))
149 			return(EINVAL);
150 
151 		if ((locnew =
152 		     (char *) malloc(newlen + 1, M_TEMP, M_WAITOK)) == NULL)
153 			return(ENOMEM);
154 
155 		if ((error = copyinstr(new, locnew, newlen + 1, NULL)) ||
156 		    (error = sysctl_lock(l, old, *oldlenp))) {
157 			free(locnew, M_TEMP);
158 			return(error);
159 		}
160 
161 		ktrmibio(-1, UIO_WRITE, new, newlen + 1, error);
162 		error = freebsd_sysctl_name2oid(locnew, oid, &oidlen);
163 		sysctl_unlock(l);
164 		free(locnew, M_TEMP);
165 		if (error)
166 			return(error);
167 
168 		oidlen *= sizeof(int);
169 		error = copyout(oid, SCARG(uap, old),
170 				MIN(oidlen, *SCARG(uap, oldlenp)));
171 		if (error)
172 			return(error);
173 		ktrmibio(-1, UIO_READ, SCARG(uap, old),
174 		    MIN(oidlen, *SCARG(uap, oldlenp)),  0);
175 
176 		error = copyout(&oidlen, SCARG(uap, oldlenp), sizeof(u_int));
177 
178 		return(error);
179 	}
180 
181 	return(EOPNOTSUPP);
182 }
183 
184 static int
185 freebsd_sysctl_name2oid(char *name, int *oid, int *oidlen)
186 {
187 	char *dot;
188 	int oi, ci;
189 	struct sysctlnode *node, *pnode;
190 
191 	pnode = &sysctl_root;
192 	node = sysctl_root.sysctl_child;
193 	oi = 0;
194 	if ((dot = strchr(name, (int)'.')) != NULL)
195 		*dot++ = '\0';
196 
197 next:
198 	while (*name != '\0' && node != NULL) {
199 		for (ci = 0; ci < pnode->sysctl_clen; ci++) {
200 			if (strcmp(name, node[ci].sysctl_name) == 0) {
201 				oid[oi++] = node[ci].sysctl_num;
202 				if ((name = dot) == NULL) {
203 					*oidlen = oi;
204 					return(0);
205 				}
206 				if ((dot = strchr(name, (int)'.')) != NULL)
207 					*dot++ = '\0';
208 
209 				if (SYSCTL_TYPE(node[ci].sysctl_flags) !=
210 				    CTLTYPE_NODE)
211 					return(ENOTDIR);
212 
213 				pnode = &node[ci];
214 				node = pnode->sysctl_child;
215 				goto next;
216 			}
217 		}
218 
219 		/* no more nodes, it must not exist */
220 		break;
221 	}
222 
223 	return(ENOENT);
224 }
225