xref: /freebsd/sys/compat/linux/linux_sysctl.c (revision 67897cfb90605ac431a8d78beca50602708173a4)
1 /*-
2  * Copyright (c) 2001 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
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. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_compat.h"
33 #include "opt_kdtrace.h"
34 
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/malloc.h>
39 #include <sys/mutex.h>
40 #include <sys/proc.h>
41 #include <sys/sdt.h>
42 #include <sys/sysctl.h>
43 #include <sys/systm.h>
44 #include <sys/sbuf.h>
45 
46 #ifdef COMPAT_LINUX32
47 #include <machine/../linux32/linux.h>
48 #include <machine/../linux32/linux32_proto.h>
49 #else
50 #include <machine/../linux/linux.h>
51 #include <machine/../linux/linux_proto.h>
52 #endif
53 
54 #include <compat/linux/linux_dtrace.h>
55 #include <compat/linux/linux_util.h>
56 
57 #define	LINUX_CTL_KERN		1
58 #define	LINUX_CTL_VM		2
59 #define	LINUX_CTL_NET		3
60 #define	LINUX_CTL_PROC		4
61 #define	LINUX_CTL_FS		5
62 #define	LINUX_CTL_DEBUG		6
63 #define	LINUX_CTL_DEV		7
64 #define	LINUX_CTL_BUS		8
65 
66 /* CTL_KERN names */
67 #define	LINUX_KERN_OSTYPE	1
68 #define	LINUX_KERN_OSRELEASE	2
69 #define	LINUX_KERN_OSREV	3
70 #define	LINUX_KERN_VERSION	4
71 
72 /* DTrace init */
73 LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
74 
75 /**
76  * DTrace probes in this module.
77  */
78 LIN_SDT_PROBE_DEFINE2(sysctl, handle_string, entry, "struct l___sysctl_args *",
79     "char *");
80 LIN_SDT_PROBE_DEFINE1(sysctl, handle_string, copyout_error, "int");
81 LIN_SDT_PROBE_DEFINE1(sysctl, handle_string, return, "int");
82 LIN_SDT_PROBE_DEFINE2(sysctl, linux_sysctl, entry, "struct l___sysctl_args *",
83     "struct thread *");
84 LIN_SDT_PROBE_DEFINE1(sysctl, linux_sysctl, copyin_error, "int");
85 LIN_SDT_PROBE_DEFINE2(sysctl, linux_sysctl, wrong_length, "int", "int");
86 LIN_SDT_PROBE_DEFINE1(sysctl, linux_sysctl, unsupported_sysctl, "char *");
87 LIN_SDT_PROBE_DEFINE1(sysctl, linux_sysctl, return, "int");
88 
89 static int
90 handle_string(struct l___sysctl_args *la, char *value)
91 {
92 	int error;
93 
94 	LIN_SDT_PROBE2(sysctl, handle_string, entry, la, value);
95 
96 	if (la->oldval != 0) {
97 		l_int len = strlen(value);
98 		error = copyout(value, PTRIN(la->oldval), len + 1);
99 		if (!error && la->oldlenp != 0)
100 			error = copyout(&len, PTRIN(la->oldlenp), sizeof(len));
101 		if (error) {
102 			LIN_SDT_PROBE1(sysctl, handle_string, copyout_error,
103 			    error);
104 			LIN_SDT_PROBE1(sysctl, handle_string, return, error);
105 			return (error);
106 		}
107 	}
108 
109 	if (la->newval != 0) {
110 		LIN_SDT_PROBE1(sysctl, handle_string, return, ENOTDIR);
111 		return (ENOTDIR);
112 	}
113 
114 	LIN_SDT_PROBE1(sysctl, handle_string, return, 0);
115 	return (0);
116 }
117 
118 int
119 linux_sysctl(struct thread *td, struct linux_sysctl_args *args)
120 {
121 	struct l___sysctl_args la;
122 	struct sbuf *sb;
123 	l_int *mib;
124 	char *sysctl_string;
125 	int error, i;
126 
127 	LIN_SDT_PROBE2(sysctl, linux_sysctl, entry, td, args->args);
128 
129 	error = copyin(args->args, &la, sizeof(la));
130 	if (error) {
131 		LIN_SDT_PROBE1(sysctl, linux_sysctl, copyin_error, error);
132 		LIN_SDT_PROBE1(sysctl, linux_sysctl, return, error);
133 		return (error);
134 	}
135 
136 	if (la.nlen <= 0 || la.nlen > LINUX_CTL_MAXNAME) {
137 		LIN_SDT_PROBE2(sysctl, linux_sysctl, wrong_length, la.nlen,
138 		    LINUX_CTL_MAXNAME);
139 		LIN_SDT_PROBE1(sysctl, linux_sysctl, return, ENOTDIR);
140 		return (ENOTDIR);
141 	}
142 
143 	mib = malloc(la.nlen * sizeof(l_int), M_TEMP, M_WAITOK);
144 	error = copyin(PTRIN(la.name), mib, la.nlen * sizeof(l_int));
145 	if (error) {
146 		LIN_SDT_PROBE1(sysctl, linux_sysctl, copyin_error, error);
147 		LIN_SDT_PROBE1(sysctl, linux_sysctl, return, error);
148 		free(mib, M_TEMP);
149 		return (error);
150 	}
151 
152 	switch (mib[0]) {
153 	case LINUX_CTL_KERN:
154 		if (la.nlen < 2)
155 			break;
156 
157 		switch (mib[1]) {
158 		case LINUX_KERN_VERSION:
159 			error = handle_string(&la, version);
160 			free(mib, M_TEMP);
161 			LIN_SDT_PROBE1(sysctl, linux_sysctl, return, error);
162 			return (error);
163 		default:
164 			break;
165 		}
166 		break;
167 	default:
168 		break;
169 	}
170 
171 	sb = sbuf_new(NULL, NULL, 20 + la.nlen * 5, SBUF_AUTOEXTEND);
172 	if (sb == NULL) {
173 		linux_msg(td, "sysctl is not implemented");
174 		LIN_SDT_PROBE1(sysctl, linux_sysctl, unsupported_sysctl,
175 		    "unknown sysctl, ENOMEM during lookup");
176 	} else {
177 		sbuf_printf(sb, "sysctl ");
178 		for (i = 0; i < la.nlen; i++)
179 			sbuf_printf(sb, "%c%d", (i) ? ',' : '{', mib[i]);
180 		sbuf_printf(sb, "} is not implemented");
181 		sbuf_finish(sb);
182 		sysctl_string = sbuf_data(sb);
183 		linux_msg(td, "%s", sbuf_data(sb));
184 		LIN_SDT_PROBE1(sysctl, linux_sysctl, unsupported_sysctl,
185 		    sysctl_string);
186 		sbuf_delete(sb);
187 	}
188 
189 	free(mib, M_TEMP);
190 
191 	LIN_SDT_PROBE1(sysctl, linux_sysctl, return, ENOTDIR);
192 	return (ENOTDIR);
193 }
194