xref: /netbsd-src/sys/compat/linux32/common/linux32_sysctl.c (revision 33881f779a77dce6440bdc44610d94de75bebefe)
1 /*	$NetBSD: linux32_sysctl.c,v 1.18 2020/03/16 21:20:09 pgoyette Exp $ */
2 
3 /*-
4  * Copyright (c) 2006 Emmanuel Dreyfus, all rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by Emmanuel Dreyfus
17  * 4. The name of the author may not be used to endorse or promote
18  *    products derived from this software without specific prior written
19  *    permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE THE AUTHOR AND CONTRIBUTORS ``AS IS''
22  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
23  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: linux32_sysctl.c,v 1.18 2020/03/16 21:20:09 pgoyette Exp $");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/errno.h>
39 #include <sys/proc.h>
40 #include <sys/mount.h>
41 #include <sys/sysctl.h>
42 #include <sys/syscallargs.h>
43 #include <sys/ktrace.h>
44 
45 #include <compat/netbsd32/netbsd32.h>
46 
47 #include <compat/linux/common/linux_types.h>
48 #include <compat/linux/common/linux_signal.h>
49 #include <compat/linux/common/linux_sysctl.h>
50 #include <compat/linux/common/linux_ipc.h>
51 #include <compat/linux/common/linux_sem.h>
52 #include <compat/linux/linux_syscallargs.h>
53 
54 #include <compat/linux32/common/linux32_types.h>
55 #include <compat/linux32/common/linux32_signal.h>
56 #include <compat/linux32/common/linux32_sysctl.h>
57 #include <compat/linux32/linux32_syscallargs.h>
58 
59 char linux32_sysname[128] = "Linux";
60 char linux32_release[128] = "3.11.6";
61 char linux32_version[128] = "#1 SMP PREEMPT Thu Oct 24 16:23:02 UTC 2013";
62 
63 struct sysctlnode linux32_sysctl_root = {
64 	.sysctl_flags = SYSCTL_VERSION|
65 	    CTLFLAG_ROOT|CTLTYPE_NODE|CTLFLAG_READWRITE,
66 	.sysctl_num = 0,
67 	.sysctl_name = "(linux32_root)",
68 	.sysctl_size = sizeof(struct sysctlnode),
69 };
70 
71 extern int linux32_enabled;
72 
73 SYSCTL_SETUP(linux32_sysctl_init, "linux32 emulation sysctls")
74 {
75 	const struct sysctlnode *node = &linux32_sysctl_root;
76 
77 	sysctl_createv(clog, 0, NULL, NULL,
78 		       CTLFLAG_PERMANENT,
79 		       CTLTYPE_NODE, "linux32",
80 		       SYSCTL_DESCR("Linux 32 bit emulation settings"),
81 		       NULL, 0, NULL, 0,
82 		       CTL_EMUL, EMUL_LINUX32, CTL_EOL);
83 	sysctl_createv(clog, 0, NULL, NULL,
84 		       CTLFLAG_PERMANENT,
85 		       CTLTYPE_NODE, "kern",
86 		       SYSCTL_DESCR("Linux 32 bit kernel emulation settings"),
87 		       NULL, 0, NULL, 0,
88 		       CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN, CTL_EOL);
89 
90 	sysctl_createv(clog, 0, NULL, NULL,
91 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
92 		       CTLTYPE_STRING, "ostype",
93 		       SYSCTL_DESCR("Linux 32 bit operating system type"),
94 		       NULL, 0, linux32_sysname, sizeof(linux32_sysname),
95 		       CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN,
96 		       EMUL_LINUX32_KERN_OSTYPE, CTL_EOL);
97 	sysctl_createv(clog, 0, NULL, NULL,
98 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
99 		       CTLTYPE_STRING, "osrelease",
100 		       SYSCTL_DESCR("Linux 32 bit operating system release"),
101 		       NULL, 0, linux32_release, sizeof(linux32_release),
102 		       CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN,
103 		       EMUL_LINUX32_KERN_OSRELEASE, CTL_EOL);
104 	sysctl_createv(clog, 0, NULL, NULL,
105 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
106 		       CTLTYPE_STRING, "osversion",
107 		       SYSCTL_DESCR("Linux 32 bit operating system revision"),
108 		       NULL, 0, linux32_version, sizeof(linux32_version),
109 		       CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN,
110 		       EMUL_LINUX32_KERN_VERSION, CTL_EOL);
111 	sysctl_createv(clog, 0, NULL, NULL,
112 		       CTLFLAG_READWRITE,
113 		       CTLTYPE_INT, "enabled",
114 		       SYSCTL_DESCR("Linux 32 bit compat enabled."),
115 		       linux32_sysctl_enable, 0, &linux32_enabled, 0,
116 		       CTL_EMUL, EMUL_LINUX32, CTL_CREATE, CTL_EOL);
117 
118 	sysctl_createv(clog, 0, &node, &node,
119 		       CTLFLAG_PERMANENT,
120 		       CTLTYPE_NODE, "kern", NULL,
121 		       NULL, 0, NULL, 0,
122 		       LINUX_CTL_KERN, CTL_EOL);
123 
124 	sysctl_createv(clog, 0, &node, NULL,
125 		       CTLFLAG_PERMANENT,
126 		       CTLTYPE_STRING, "ostype", NULL,
127 		       NULL, 0, linux32_sysname, sizeof(linux32_sysname),
128 		       LINUX_KERN_OSTYPE, CTL_EOL);
129 	sysctl_createv(clog, 0, &node, NULL,
130 		       CTLFLAG_PERMANENT,
131 		       CTLTYPE_STRING, "osrelease", NULL,
132 		       NULL, 0, linux32_release, sizeof(linux32_release),
133 		       LINUX_KERN_OSRELEASE, CTL_EOL);
134 	sysctl_createv(clog, 0, &node, NULL,
135 		       CTLFLAG_PERMANENT,
136 		       CTLTYPE_STRING, "version", NULL,
137 		       NULL, 0, linux32_version, sizeof(linux32_version),
138 		       LINUX_KERN_VERSION, CTL_EOL);
139 
140 	linux32_sysctl_root.sysctl_flags &= ~CTLFLAG_READWRITE;
141 }
142 
143 int
144 linux32_sys___sysctl(struct lwp *l, const struct linux32_sys___sysctl_args *uap, register_t *retval)
145 {
146 	/* {
147 		syscallarg(linux32___sysctlp_t) lsp;
148 	} */
149 	struct linux32_sysctl ls32;
150 	int name[CTL_MAXNAME];
151 	size_t savelen;
152 	netbsd32_size_t oldlen32;
153 	size_t oldlen;
154 	int error;
155 
156 	/*
157 	 * Read sysctl arguments
158 	 */
159 	if ((error = copyin(SCARG_P32(uap, lsp), &ls32, sizeof(ls32))) != 0)
160 		return error;
161 
162 	/*
163 	 * Read oldlen
164 	 */
165 	if (NETBSD32PTR64(ls32.oldlenp) != NULL) {
166 		if ((error = copyin(NETBSD32PTR64(ls32.oldlenp),
167 		    &oldlen32, sizeof(oldlen32))) != 0)
168 			return error;
169 	} else {
170 		oldlen32 = 0;
171 	}
172 
173 	savelen = (size_t)oldlen32;
174 
175 	/*
176 	 * Sanity check nlen
177 	 */
178 	if ((ls32.nlen > CTL_MAXNAME) || (ls32.nlen < 1))
179 		return ENOTDIR;
180 
181 	/*
182 	 * Read the sysctl name
183 	 */
184 	if ((error = copyin(NETBSD32PTR64(ls32.name), &name,
185 	   ls32.nlen * sizeof(int))) != 0)
186 		return error;
187 
188 	ktrmib(name, ls32.nlen);
189 	/*
190 	 * First try linux32 tree, then linux tree
191 	 */
192 	oldlen = (size_t)oldlen32;
193 	sysctl_lock(NETBSD32PTR64(ls32.newval) != NULL);
194 	error = sysctl_dispatch(name, ls32.nlen,
195 				NETBSD32PTR64(ls32.oldval), &oldlen,
196 				NETBSD32PTR64(ls32.newval), ls32.newlen,
197 				name, l, &linux32_sysctl_root);
198 	oldlen32 = (netbsd32_size_t)oldlen;
199 	sysctl_unlock();
200 
201 	/*
202 	 * Check for oldlen overflow (not likely, but who knows...)
203 	 */
204 	if (oldlen != oldlen32) {
205 #ifdef DEBUG_LINUX
206 		printf("%s: oldlen32 = %d, oldlen = %ld\n",
207 		    __func__, oldlen32, oldlen);
208 #endif
209 		return EINVAL;
210 	}
211 
212 	/*
213 	 * set caller's oldlen, even if we got an error
214 	 */
215 	if (NETBSD32PTR64(ls32.oldlenp)) {
216 		int nerror;
217 
218 		nerror = copyout(&oldlen32,
219 		    NETBSD32PTR64(ls32.oldlenp), sizeof(oldlen32));
220 
221 		if (error == 0)
222 			error = nerror;
223 	}
224 
225 	/*
226 	 * oldlen was too short
227 	 */
228 	if ((error == 0) &&
229 	    (NETBSD32PTR64(ls32.oldval) != NULL) &&
230 	    (savelen < oldlen32))
231 		error = ENOMEM;
232 
233 	return error;
234 }
235