linux_sysctl.c revision 293532 
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: stable/10/sys/compat/linux/linux_sysctl.c 293532 2016-01-09 16:20:29Z dchagin $");
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_misc.h>
56#include <compat/linux/linux_util.h>
57
58#define	LINUX_CTL_KERN		1
59#define	LINUX_CTL_VM		2
60#define	LINUX_CTL_NET		3
61#define	LINUX_CTL_PROC		4
62#define	LINUX_CTL_FS		5
63#define	LINUX_CTL_DEBUG		6
64#define	LINUX_CTL_DEV		7
65#define	LINUX_CTL_BUS		8
66
67/* CTL_KERN names */
68#define	LINUX_KERN_OSTYPE	1
69#define	LINUX_KERN_OSRELEASE	2
70#define	LINUX_KERN_OSREV	3
71#define	LINUX_KERN_VERSION	4
72
73/* DTrace init */
74LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
75
76/**
77 * DTrace probes in this module.
78 */
79LIN_SDT_PROBE_DEFINE2(sysctl, handle_string, entry, "struct l___sysctl_args *",
80    "char *");
81LIN_SDT_PROBE_DEFINE1(sysctl, handle_string, copyout_error, "int");
82LIN_SDT_PROBE_DEFINE1(sysctl, handle_string, return, "int");
83LIN_SDT_PROBE_DEFINE2(sysctl, linux_sysctl, entry, "struct l___sysctl_args *",
84    "struct thread *");
85LIN_SDT_PROBE_DEFINE1(sysctl, linux_sysctl, copyin_error, "int");
86LIN_SDT_PROBE_DEFINE2(sysctl, linux_sysctl, wrong_length, "int", "int");
87LIN_SDT_PROBE_DEFINE1(sysctl, linux_sysctl, unsupported_sysctl, "char *");
88LIN_SDT_PROBE_DEFINE1(sysctl, linux_sysctl, return, "int");
89
90static int
91handle_string(struct l___sysctl_args *la, char *value)
92{
93	int error;
94
95	LIN_SDT_PROBE2(sysctl, handle_string, entry, la, value);
96
97	if (la->oldval != 0) {
98		l_int len = strlen(value);
99		error = copyout(value, PTRIN(la->oldval), len + 1);
100		if (!error && la->oldlenp != 0)
101			error = copyout(&len, PTRIN(la->oldlenp), sizeof(len));
102		if (error) {
103			LIN_SDT_PROBE1(sysctl, handle_string, copyout_error,
104			    error);
105			LIN_SDT_PROBE1(sysctl, handle_string, return, error);
106			return (error);
107		}
108	}
109
110	if (la->newval != 0) {
111		LIN_SDT_PROBE1(sysctl, handle_string, return, ENOTDIR);
112		return (ENOTDIR);
113	}
114
115	LIN_SDT_PROBE1(sysctl, handle_string, return, 0);
116	return (0);
117}
118
119int
120linux_sysctl(struct thread *td, struct linux_sysctl_args *args)
121{
122	struct l___sysctl_args la;
123	struct sbuf *sb;
124	l_int *mib;
125	char *sysctl_string;
126	int error, i;
127
128	LIN_SDT_PROBE2(sysctl, linux_sysctl, entry, td, args->args);
129
130	error = copyin(args->args, &la, sizeof(la));
131	if (error) {
132		LIN_SDT_PROBE1(sysctl, linux_sysctl, copyin_error, error);
133		LIN_SDT_PROBE1(sysctl, linux_sysctl, return, error);
134		return (error);
135	}
136
137	if (la.nlen <= 0 || la.nlen > LINUX_CTL_MAXNAME) {
138		LIN_SDT_PROBE2(sysctl, linux_sysctl, wrong_length, la.nlen,
139		    LINUX_CTL_MAXNAME);
140		LIN_SDT_PROBE1(sysctl, linux_sysctl, return, ENOTDIR);
141		return (ENOTDIR);
142	}
143
144	mib = malloc(la.nlen * sizeof(l_int), M_LINUX, M_WAITOK);
145	error = copyin(PTRIN(la.name), mib, la.nlen * sizeof(l_int));
146	if (error) {
147		LIN_SDT_PROBE1(sysctl, linux_sysctl, copyin_error, error);
148		LIN_SDT_PROBE1(sysctl, linux_sysctl, return, error);
149		free(mib, M_LINUX);
150		return (error);
151	}
152
153	switch (mib[0]) {
154	case LINUX_CTL_KERN:
155		if (la.nlen < 2)
156			break;
157
158		switch (mib[1]) {
159		case LINUX_KERN_VERSION:
160			error = handle_string(&la, version);
161			free(mib, M_LINUX);
162			LIN_SDT_PROBE1(sysctl, linux_sysctl, return, error);
163			return (error);
164		default:
165			break;
166		}
167		break;
168	default:
169		break;
170	}
171
172	sb = sbuf_new(NULL, NULL, 20 + la.nlen * 5, SBUF_AUTOEXTEND);
173	if (sb == NULL) {
174		linux_msg(td, "sysctl is not implemented");
175		LIN_SDT_PROBE1(sysctl, linux_sysctl, unsupported_sysctl,
176		    "unknown sysctl, ENOMEM during lookup");
177	} else {
178		sbuf_printf(sb, "sysctl ");
179		for (i = 0; i < la.nlen; i++)
180			sbuf_printf(sb, "%c%d", (i) ? ',' : '{', mib[i]);
181		sbuf_printf(sb, "} is not implemented");
182		sbuf_finish(sb);
183		sysctl_string = sbuf_data(sb);
184		linux_msg(td, "%s", sbuf_data(sb));
185		LIN_SDT_PROBE1(sysctl, linux_sysctl, unsupported_sysctl,
186		    sysctl_string);
187		sbuf_delete(sb);
188	}
189
190	free(mib, M_LINUX);
191
192	LIN_SDT_PROBE1(sysctl, linux_sysctl, return, ENOTDIR);
193	return (ENOTDIR);
194}
195