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: releng/11.0/sys/compat/linux/linux_sysctl.c 283427 2015-05-24 16:14:41Z dchagin $");
31
32#include "opt_compat.h"
33
34#include <sys/param.h>
35#include <sys/kernel.h>
36#include <sys/lock.h>
37#include <sys/malloc.h>
38#include <sys/mutex.h>
39#include <sys/proc.h>
40#include <sys/sdt.h>
41#include <sys/sysctl.h>
42#include <sys/systm.h>
43#include <sys/sbuf.h>
44
45#ifdef COMPAT_LINUX32
46#include <machine/../linux32/linux.h>
47#include <machine/../linux32/linux32_proto.h>
48#else
49#include <machine/../linux/linux.h>
50#include <machine/../linux/linux_proto.h>
51#endif
52
53#include <compat/linux/linux_dtrace.h>
54#include <compat/linux/linux_misc.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 */
73LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
74
75/**
76 * DTrace probes in this module.
77 */
78LIN_SDT_PROBE_DEFINE2(sysctl, handle_string, entry, "struct l___sysctl_args *",
79    "char *");
80LIN_SDT_PROBE_DEFINE1(sysctl, handle_string, copyout_error, "int");
81LIN_SDT_PROBE_DEFINE1(sysctl, handle_string, return, "int");
82LIN_SDT_PROBE_DEFINE2(sysctl, linux_sysctl, entry, "struct l___sysctl_args *",
83    "struct thread *");
84LIN_SDT_PROBE_DEFINE1(sysctl, linux_sysctl, copyin_error, "int");
85LIN_SDT_PROBE_DEFINE2(sysctl, linux_sysctl, wrong_length, "int", "int");
86LIN_SDT_PROBE_DEFINE1(sysctl, linux_sysctl, unsupported_sysctl, "char *");
87LIN_SDT_PROBE_DEFINE1(sysctl, linux_sysctl, return, "int");
88
89static int
90handle_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
118int
119linux_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_LINUX, 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_LINUX);
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_LINUX);
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_LINUX);
190
191	LIN_SDT_PROBE1(sysctl, linux_sysctl, return, ENOTDIR);
192	return (ENOTDIR);
193}
194