1 /*	$NetBSD: linux32_sysctl.c,v 1.19 2020/03/21 16:28:56 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 1.19 2020/03/21 16:28:56 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 /*
74  * We need our own sysctllog here because we deal with two
75  * separate sysctl trees;  each clog is restricted to a
76  * single tree.
77  */
78 
79 static struct sysctllog *linux32_clog;
80 
81 void
linux32_sysctl_fini(void)82 linux32_sysctl_fini(void)
83 {
84 
85 	sysctl_teardown(&linux32_clog);
86 	sysctl_free(&linux32_sysctl_root);
87 }
88 
89 SYSCTL_SETUP(linux32_sysctl_init, "linux32 emulation sysctls")
90 {
91 	const struct sysctlnode *node = &linux32_sysctl_root;
92 
93 	sysctl_createv(clog, 0, NULL, NULL,
94 		       CTLFLAG_PERMANENT,
95 		       CTLTYPE_NODE, "linux32",
96 		       SYSCTL_DESCR("Linux 32 bit emulation settings"),
97 		       NULL, 0, NULL, 0,
98 		       CTL_EMUL, EMUL_LINUX32, CTL_EOL);
99 	sysctl_createv(clog, 0, NULL, NULL,
100 		       CTLFLAG_PERMANENT,
101 		       CTLTYPE_NODE, "kern",
102 		       SYSCTL_DESCR("Linux 32 bit kernel emulation settings"),
103 		       NULL, 0, NULL, 0,
104 		       CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN, CTL_EOL);
105 
106 	sysctl_createv(clog, 0, NULL, NULL,
107 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
108 		       CTLTYPE_STRING, "ostype",
109 		       SYSCTL_DESCR("Linux 32 bit operating system type"),
110 		       NULL, 0, linux32_sysname, sizeof(linux32_sysname),
111 		       CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN,
112 		       EMUL_LINUX32_KERN_OSTYPE, CTL_EOL);
113 	sysctl_createv(clog, 0, NULL, NULL,
114 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
115 		       CTLTYPE_STRING, "osrelease",
116 		       SYSCTL_DESCR("Linux 32 bit operating system release"),
117 		       NULL, 0, linux32_release, sizeof(linux32_release),
118 		       CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN,
119 		       EMUL_LINUX32_KERN_OSRELEASE, CTL_EOL);
120 	sysctl_createv(clog, 0, NULL, NULL,
121 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
122 		       CTLTYPE_STRING, "osversion",
123 		       SYSCTL_DESCR("Linux 32 bit operating system revision"),
124 		       NULL, 0, linux32_version, sizeof(linux32_version),
125 		       CTL_EMUL, EMUL_LINUX32, EMUL_LINUX32_KERN,
126 		       EMUL_LINUX32_KERN_VERSION, CTL_EOL);
127 	sysctl_createv(clog, 0, NULL, NULL,
128 		       CTLFLAG_READWRITE,
129 		       CTLTYPE_INT, "enabled",
130 		       SYSCTL_DESCR("Linux 32 bit compat enabled."),
131 		       linux32_sysctl_enable, 0, &linux32_enabled, 0,
132 		       CTL_EMUL, EMUL_LINUX32, CTL_CREATE, CTL_EOL);
133 
134 	sysctl_createv(&linux32_clog, 0, &node, &node,
135 		       CTLFLAG_PERMANENT,
136 		       CTLTYPE_NODE, "kern", NULL,
137 		       NULL, 0, NULL, 0,
138 		       LINUX_CTL_KERN, CTL_EOL);
139 
140 	sysctl_createv(&linux32_clog, 0, &node, NULL,
141 		       CTLFLAG_PERMANENT,
142 		       CTLTYPE_STRING, "ostype", NULL,
143 		       NULL, 0, linux32_sysname, sizeof(linux32_sysname),
144 		       LINUX_KERN_OSTYPE, CTL_EOL);
145 	sysctl_createv(&linux32_clog, 0, &node, NULL,
146 		       CTLFLAG_PERMANENT,
147 		       CTLTYPE_STRING, "osrelease", NULL,
148 		       NULL, 0, linux32_release, sizeof(linux32_release),
149 		       LINUX_KERN_OSRELEASE, CTL_EOL);
150 	sysctl_createv(&linux32_clog, 0, &node, NULL,
151 		       CTLFLAG_PERMANENT,
152 		       CTLTYPE_STRING, "version", NULL,
153 		       NULL, 0, linux32_version, sizeof(linux32_version),
154 		       LINUX_KERN_VERSION, CTL_EOL);
155 
156 	linux32_sysctl_root.sysctl_flags &= ~CTLFLAG_READWRITE;
157 }
158 
159 int
linux32_sys___sysctl(struct lwp * l,const struct linux32_sys___sysctl_args * uap,register_t * retval)160 linux32_sys___sysctl(struct lwp *l, const struct linux32_sys___sysctl_args *uap, register_t *retval)
161 {
162 	/* {
163 		syscallarg(linux32___sysctlp_t) lsp;
164 	} */
165 	struct linux32_sysctl ls32;
166 	int name[CTL_MAXNAME];
167 	size_t savelen;
168 	netbsd32_size_t oldlen32;
169 	size_t oldlen;
170 	int error;
171 
172 	/*
173 	 * Read sysctl arguments
174 	 */
175 	if ((error = copyin(SCARG_P32(uap, lsp), &ls32, sizeof(ls32))) != 0)
176 		return error;
177 
178 	/*
179 	 * Read oldlen
180 	 */
181 	if (NETBSD32PTR64(ls32.oldlenp) != NULL) {
182 		if ((error = copyin(NETBSD32PTR64(ls32.oldlenp),
183 		    &oldlen32, sizeof(oldlen32))) != 0)
184 			return error;
185 	} else {
186 		oldlen32 = 0;
187 	}
188 
189 	savelen = (size_t)oldlen32;
190 
191 	/*
192 	 * Sanity check nlen
193 	 */
194 	if ((ls32.nlen > CTL_MAXNAME) || (ls32.nlen < 1))
195 		return ENOTDIR;
196 
197 	/*
198 	 * Read the sysctl name
199 	 */
200 	if ((error = copyin(NETBSD32PTR64(ls32.name), &name,
201 	   ls32.nlen * sizeof(int))) != 0)
202 		return error;
203 
204 	ktrmib(name, ls32.nlen);
205 	/*
206 	 * First try linux32 tree, then linux tree
207 	 */
208 	oldlen = (size_t)oldlen32;
209 	sysctl_lock(NETBSD32PTR64(ls32.newval) != NULL);
210 	error = sysctl_dispatch(name, ls32.nlen,
211 				NETBSD32PTR64(ls32.oldval), &oldlen,
212 				NETBSD32PTR64(ls32.newval), ls32.newlen,
213 				name, l, &linux32_sysctl_root);
214 	oldlen32 = (netbsd32_size_t)oldlen;
215 	sysctl_unlock();
216 
217 	/*
218 	 * Check for oldlen overflow (not likely, but who knows...)
219 	 */
220 	if (oldlen != oldlen32) {
221 #ifdef DEBUG_LINUX
222 		printf("%s: oldlen32 = %d, oldlen = %ld\n",
223 		    __func__, oldlen32, oldlen);
224 #endif
225 		return EINVAL;
226 	}
227 
228 	/*
229 	 * set caller's oldlen, even if we got an error
230 	 */
231 	if (NETBSD32PTR64(ls32.oldlenp)) {
232 		int nerror;
233 
234 		nerror = copyout(&oldlen32,
235 		    NETBSD32PTR64(ls32.oldlenp), sizeof(oldlen32));
236 
237 		if (error == 0)
238 			error = nerror;
239 	}
240 
241 	/*
242 	 * oldlen was too short
243 	 */
244 	if ((error == 0) &&
245 	    (NETBSD32PTR64(ls32.oldval) != NULL) &&
246 	    (savelen < oldlen32))
247 		error = ENOMEM;
248 
249 	return error;
250 }
251