xref: /freebsd/sys/compat/linux/linux_sysctl.c (revision 1d386b48a555f61cb7325543adbbb5c3f3407a66)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2001 Marcel Moolenaar
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 #include <sys/param.h>
31 #include <sys/lock.h>
32 #include <sys/malloc.h>
33 #include <sys/mutex.h>
34 #include <sys/sysctl.h>
35 #include <sys/sbuf.h>
36 #include <sys/vnode.h>
37 
38 #ifdef COMPAT_LINUX32
39 #include <machine/../linux32/linux.h>
40 #include <machine/../linux32/linux32_proto.h>
41 #else
42 #include <machine/../linux/linux.h>
43 #include <machine/../linux/linux_proto.h>
44 #endif
45 
46 #include <compat/linux/linux_dtrace.h>
47 #include <compat/linux/linux_misc.h>
48 #include <compat/linux/linux_util.h>
49 
50 #define	LINUX_CTL_KERN		1
51 #define	LINUX_CTL_VM		2
52 #define	LINUX_CTL_NET		3
53 #define	LINUX_CTL_PROC		4
54 #define	LINUX_CTL_FS		5
55 #define	LINUX_CTL_DEBUG		6
56 #define	LINUX_CTL_DEV		7
57 #define	LINUX_CTL_BUS		8
58 
59 /* CTL_KERN names */
60 #define	LINUX_KERN_OSTYPE	1
61 #define	LINUX_KERN_OSRELEASE	2
62 #define	LINUX_KERN_OSREV	3
63 #define	LINUX_KERN_VERSION	4
64 
65 /* DTrace init */
66 LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
67 
68 /**
69  * DTrace probes in this module.
70  */
71 LIN_SDT_PROBE_DEFINE1(sysctl, handle_string, copyout_error, "int");
72 LIN_SDT_PROBE_DEFINE1(sysctl, linux_sysctl, copyin_error, "int");
73 LIN_SDT_PROBE_DEFINE2(sysctl, linux_sysctl, wrong_length, "int", "int");
74 LIN_SDT_PROBE_DEFINE1(sysctl, linux_sysctl, unsupported_sysctl, "char *");
75 
76 #ifdef LINUX_LEGACY_SYSCALLS
77 static int
78 handle_string(struct l___sysctl_args *la, char *value)
79 {
80 	int error;
81 
82 	if (la->oldval != 0) {
83 		l_int len = strlen(value);
84 		error = copyout(value, PTRIN(la->oldval), len + 1);
85 		if (!error && la->oldlenp != 0)
86 			error = copyout(&len, PTRIN(la->oldlenp), sizeof(len));
87 		if (error) {
88 			LIN_SDT_PROBE1(sysctl, handle_string, copyout_error,
89 			    error);
90 			return (error);
91 		}
92 	}
93 
94 	if (la->newval != 0)
95 		return (ENOTDIR);
96 
97 	return (0);
98 }
99 
100 int
101 linux_sysctl(struct thread *td, struct linux_sysctl_args *args)
102 {
103 	struct l___sysctl_args la;
104 	struct sbuf *sb;
105 	l_int *mib;
106 	char *sysctl_string;
107 	int error, i;
108 
109 	error = copyin(args->args, &la, sizeof(la));
110 	if (error) {
111 		LIN_SDT_PROBE1(sysctl, linux_sysctl, copyin_error, error);
112 		return (error);
113 	}
114 
115 	if (la.nlen <= 0 || la.nlen > LINUX_CTL_MAXNAME) {
116 		LIN_SDT_PROBE2(sysctl, linux_sysctl, wrong_length, la.nlen,
117 		    LINUX_CTL_MAXNAME);
118 		return (ENOTDIR);
119 	}
120 
121 	mib = malloc(la.nlen * sizeof(l_int), M_LINUX, M_WAITOK);
122 	error = copyin(PTRIN(la.name), mib, la.nlen * sizeof(l_int));
123 	if (error) {
124 		LIN_SDT_PROBE1(sysctl, linux_sysctl, copyin_error, error);
125 		free(mib, M_LINUX);
126 		return (error);
127 	}
128 
129 	switch (mib[0]) {
130 	case LINUX_CTL_KERN:
131 		if (la.nlen < 2)
132 			break;
133 
134 		switch (mib[1]) {
135 		case LINUX_KERN_VERSION:
136 			error = handle_string(&la, version);
137 			free(mib, M_LINUX);
138 			return (error);
139 		default:
140 			break;
141 		}
142 		break;
143 	default:
144 		break;
145 	}
146 
147 	sb = sbuf_new(NULL, NULL, 20 + la.nlen * 5, SBUF_AUTOEXTEND);
148 	if (sb == NULL) {
149 		linux_msg(td, "sysctl is not implemented");
150 		LIN_SDT_PROBE1(sysctl, linux_sysctl, unsupported_sysctl,
151 		    "unknown sysctl, ENOMEM during lookup");
152 	} else {
153 		sbuf_printf(sb, "sysctl ");
154 		for (i = 0; i < la.nlen; i++)
155 			sbuf_printf(sb, "%c%d", (i) ? ',' : '{', mib[i]);
156 		sbuf_printf(sb, "} is not implemented");
157 		sbuf_finish(sb);
158 		sysctl_string = sbuf_data(sb);
159 		linux_msg(td, "%s", sysctl_string);
160 		LIN_SDT_PROBE1(sysctl, linux_sysctl, unsupported_sysctl,
161 		    sysctl_string);
162 		sbuf_delete(sb);
163 	}
164 
165 	free(mib, M_LINUX);
166 
167 	return (ENOTDIR);
168 }
169 #endif
170