xref: /netbsd-src/sys/compat/linux/common/linux_sysctl.c (revision 33881f779a77dce6440bdc44610d94de75bebefe)
1 /*	$NetBSD: linux_sysctl.c,v 1.45 2020/03/16 21:20:09 pgoyette Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Brown.
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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * sysctl system call.
34  */
35 
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: linux_sysctl.c,v 1.45 2020/03/16 21:20:09 pgoyette Exp $");
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/errno.h>
42 #include <sys/proc.h>
43 #include <sys/mount.h>
44 #include <sys/sysctl.h>
45 #include <sys/sched.h>
46 #include <sys/syscallargs.h>
47 #include <sys/ktrace.h>
48 
49 #include <compat/linux/common/linux_types.h>
50 #include <compat/linux/common/linux_signal.h>
51 #include <compat/linux/common/linux_ipc.h>
52 #include <compat/linux/common/linux_sem.h>
53 
54 #include <compat/linux/linux_syscallargs.h>
55 #include <compat/linux/common/linux_sysctl.h>
56 #include <compat/linux/common/linux_exec.h>
57 #include <compat/linux/common/linux_machdep.h>
58 
59 char linux_sysname[128] = "Linux";
60 char linux_release[128] = "3.11.6";
61 char linux_version[128] = "#1 SMP PREEMPT Thu Oct 24 16:23:02 UTC 2013";
62 
63 struct sysctlnode linux_sysctl_root = {
64 	.sysctl_flags = SYSCTL_VERSION|
65 	    CTLFLAG_ROOT|CTLTYPE_NODE|CTLFLAG_READWRITE,
66 	.sysctl_num = 0,
67 	.sysctl_name = "(linux_root)",
68 	.sysctl_size = sizeof(struct sysctlnode),
69 };
70 
71 extern int linux_enabled;
72 
73 SYSCTL_SETUP(linux_sysctl_setup, "linux emulation sysctls")
74 {
75 	const struct sysctlnode *node = &linux_sysctl_root;
76 
77 	sysctl_createv(clog, 0, &node, &node,
78 		       CTLFLAG_PERMANENT,
79 		       CTLTYPE_NODE, "kern", NULL,
80 		       NULL, 0, NULL, 0,
81 		       LINUX_CTL_KERN, CTL_EOL);
82 	sysctl_createv(clog, 0, &node, NULL,
83 		       CTLFLAG_PERMANENT,
84 		       CTLTYPE_STRING, "ostype", NULL,
85 		       NULL, 0, linux_sysname, sizeof(linux_sysname),
86 		       LINUX_KERN_OSTYPE, CTL_EOL);
87 	sysctl_createv(clog, 0, &node, NULL,
88 		       CTLFLAG_PERMANENT,
89 		       CTLTYPE_STRING, "osrelease", NULL,
90 		       NULL, 0, linux_release, sizeof(linux_release),
91 		       LINUX_KERN_OSRELEASE, CTL_EOL);
92 	sysctl_createv(clog, 0, &node, NULL,
93 		       CTLFLAG_PERMANENT,
94 		       CTLTYPE_STRING, "version", NULL,
95 		       NULL, 0, linux_version, sizeof(linux_version),
96 		       LINUX_KERN_VERSION, CTL_EOL);
97 
98 	sysctl_createv(clog, 0, NULL, NULL,
99 		       CTLFLAG_PERMANENT,
100 		       CTLTYPE_NODE, "linux",
101 		       SYSCTL_DESCR("Linux emulation settings"),
102 		       NULL, 0, NULL, 0,
103 		       CTL_EMUL, EMUL_LINUX, CTL_EOL);
104 
105 	sysctl_createv(clog, 0, NULL, NULL,
106 		       CTLFLAG_PERMANENT,
107 		       CTLTYPE_NODE, "kern",
108 		       SYSCTL_DESCR("Linux kernel emulation settings"),
109 		       NULL, 0, NULL, 0,
110 		       CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN, CTL_EOL);
111 	sysctl_createv(clog, 0, NULL, NULL,
112 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
113 		       CTLTYPE_STRING, "ostype",
114 		       SYSCTL_DESCR("Linux operating system type"),
115 		       NULL, 0, linux_sysname, sizeof(linux_sysname),
116 		       CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN,
117 		       EMUL_LINUX_KERN_OSTYPE, CTL_EOL);
118 	sysctl_createv(clog, 0, NULL, NULL,
119 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
120 		       CTLTYPE_STRING, "osrelease",
121 		       SYSCTL_DESCR("Linux operating system release"),
122 		       NULL, 0, linux_release, sizeof(linux_release),
123 		       CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN,
124 		       EMUL_LINUX_KERN_OSRELEASE, CTL_EOL);
125 	sysctl_createv(clog, 0, NULL, NULL,
126 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
127 		       CTLTYPE_STRING, "osversion",
128 		       SYSCTL_DESCR("Linux operating system revision"),
129 		       NULL, 0, linux_version, sizeof(linux_version),
130 		       CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN,
131 		       EMUL_LINUX_KERN_VERSION, CTL_EOL);
132 
133 	sysctl_createv(clog, 0, NULL, NULL,
134 		       CTLFLAG_READWRITE,
135 		       CTLTYPE_INT, "enabled",
136 		       SYSCTL_DESCR("Linux compat enabled."),
137 		       linux_sysctl_enable, 0, &linux_enabled, 0,
138 		       CTL_EMUL, EMUL_LINUX, CTL_CREATE, CTL_EOL);
139 
140 	linux_sysctl_root.sysctl_flags &= ~CTLFLAG_READWRITE;
141 }
142 
143 /*
144  * linux sysctl system call
145  */
146 int
147 linux_sys___sysctl(struct lwp *l, const struct linux_sys___sysctl_args *uap, register_t *retval)
148 {
149 	struct linux___sysctl ls;
150 	int error, nerror, name[CTL_MAXNAME];
151 	size_t savelen = 0, oldlen = 0;
152 
153 	/*
154 	 * get linux args structure
155 	 */
156 	if ((error = copyin(SCARG(uap, lsp), &ls, sizeof(ls))))
157 		return error;
158 
159 	/*
160 	 * get oldlen
161 	 */
162 	oldlen = 0;
163 	if (ls.oldlenp != NULL) {
164 		error = copyin(ls.oldlenp, &oldlen, sizeof(oldlen));
165 		if (error)
166 			return (error);
167 	}
168 	savelen = oldlen;
169 
170 	/*
171 	 * top-level sysctl names may or may not be non-terminal, but
172 	 * we don't care
173 	 */
174 	if (ls.nlen > CTL_MAXNAME || ls.nlen < 1)
175 		return (ENOTDIR);
176 	error = copyin(ls.name, &name, ls.nlen * sizeof(int));
177 	if (error)
178 		return (error);
179 
180 	ktrmib(name, ls.nlen);
181 
182 	/*
183 	 * dispatch request into linux sysctl tree
184 	 */
185 	sysctl_lock(ls.newval != NULL);
186 	error = sysctl_dispatch(&name[0], ls.nlen,
187 				ls.oldval, &oldlen,
188 				ls.newval, ls.newlen,
189 				&name[0], l, &linux_sysctl_root);
190 	sysctl_unlock();
191 
192 	/*
193 	 * reset caller's oldlen, even if we got an error
194 	 */
195 	if (ls.oldlenp) {
196 		nerror = copyout(&oldlen, ls.oldlenp, sizeof(oldlen));
197 		if (error == 0)
198 			error = nerror;
199 	}
200 
201 	/*
202 	 * if the only problem is that we weren't given enough space,
203 	 * that's an ENOMEM error
204 	 */
205 	if (error == 0 && ls.oldval != NULL && savelen < oldlen)
206 		error = ENOMEM;
207 
208 	return (error);
209 }
210