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linux_sysctl.c revision 1.44.4.1
      1 /*	$NetBSD: linux_sysctl.c,v 1.44.4.1 2020/04/08 14:08:00 martin Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2003, 2008 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Andrew Brown.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * sysctl system call.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 __KERNEL_RCSID(0, "$NetBSD: linux_sysctl.c,v 1.44.4.1 2020/04/08 14:08:00 martin Exp $");
     38 
     39 #include <sys/param.h>
     40 #include <sys/systm.h>
     41 #include <sys/errno.h>
     42 #include <sys/proc.h>
     43 #include <sys/mount.h>
     44 #include <sys/sysctl.h>
     45 #include <sys/sched.h>
     46 #include <sys/syscallargs.h>
     47 #include <sys/ktrace.h>
     48 
     49 #include <compat/linux/common/linux_types.h>
     50 #include <compat/linux/common/linux_signal.h>
     51 #include <compat/linux/common/linux_ipc.h>
     52 #include <compat/linux/common/linux_sem.h>
     53 
     54 #include <compat/linux/linux_syscallargs.h>
     55 #include <compat/linux/common/linux_sysctl.h>
     56 #include <compat/linux/common/linux_exec.h>
     57 #include <compat/linux/common/linux_machdep.h>
     58 
     59 char linux_sysname[128] = "Linux";
     60 char linux_release[128] = "3.11.6";
     61 char linux_version[128] = "#1 SMP PREEMPT Thu Oct 24 16:23:02 UTC 2013";
     62 
     63 struct sysctlnode linux_sysctl_root = {
     64 	.sysctl_flags = SYSCTL_VERSION|
     65 	    CTLFLAG_ROOT|CTLTYPE_NODE|CTLFLAG_READWRITE,
     66 	.sysctl_num = 0,
     67 	.sysctl_name = "(linux_root)",
     68 	.sysctl_size = sizeof(struct sysctlnode),
     69 };
     70 
     71 extern int linux_enabled;
     72 
     73 /*
     74  * We need an additional sysctllog here since each log can only
     75  * deal with a single root node.
     76  */
     77 
     78 static struct sysctllog *linux_clog;
     79 
     80 void
     81 linux_sysctl_fini(void)
     82 {
     83 
     84 	sysctl_teardown(&linux_clog);
     85 	sysctl_free(&linux_sysctl_root);
     86 }
     87 
     88 SYSCTL_SETUP(linux_sysctl_setup, "linux emulation sysctls")
     89 {
     90 	const struct sysctlnode *node = &linux_sysctl_root;
     91 
     92 	sysctl_createv(&linux_clog, 0, &node, &node,
     93 		       CTLFLAG_PERMANENT,
     94 		       CTLTYPE_NODE, "kern", NULL,
     95 		       NULL, 0, NULL, 0,
     96 		       LINUX_CTL_KERN, CTL_EOL);
     97 	sysctl_createv(&linux_clog, 0, &node, NULL,
     98 		       CTLFLAG_PERMANENT,
     99 		       CTLTYPE_STRING, "ostype", NULL,
    100 		       NULL, 0, linux_sysname, sizeof(linux_sysname),
    101 		       LINUX_KERN_OSTYPE, CTL_EOL);
    102 	sysctl_createv(&linux_clog, 0, &node, NULL,
    103 		       CTLFLAG_PERMANENT,
    104 		       CTLTYPE_STRING, "osrelease", NULL,
    105 		       NULL, 0, linux_release, sizeof(linux_release),
    106 		       LINUX_KERN_OSRELEASE, CTL_EOL);
    107 	sysctl_createv(&linux_clog, 0, &node, NULL,
    108 		       CTLFLAG_PERMANENT,
    109 		       CTLTYPE_STRING, "version", NULL,
    110 		       NULL, 0, linux_version, sizeof(linux_version),
    111 		       LINUX_KERN_VERSION, CTL_EOL);
    112 
    113 	sysctl_createv(clog, 0, NULL, NULL,
    114 		       CTLFLAG_PERMANENT,
    115 		       CTLTYPE_NODE, "linux",
    116 		       SYSCTL_DESCR("Linux emulation settings"),
    117 		       NULL, 0, NULL, 0,
    118 		       CTL_EMUL, EMUL_LINUX, CTL_EOL);
    119 
    120 	sysctl_createv(clog, 0, NULL, NULL,
    121 		       CTLFLAG_PERMANENT,
    122 		       CTLTYPE_NODE, "kern",
    123 		       SYSCTL_DESCR("Linux kernel emulation settings"),
    124 		       NULL, 0, NULL, 0,
    125 		       CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN, CTL_EOL);
    126 	sysctl_createv(clog, 0, NULL, NULL,
    127 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    128 		       CTLTYPE_STRING, "ostype",
    129 		       SYSCTL_DESCR("Linux operating system type"),
    130 		       NULL, 0, linux_sysname, sizeof(linux_sysname),
    131 		       CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN,
    132 		       EMUL_LINUX_KERN_OSTYPE, CTL_EOL);
    133 	sysctl_createv(clog, 0, NULL, NULL,
    134 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    135 		       CTLTYPE_STRING, "osrelease",
    136 		       SYSCTL_DESCR("Linux operating system release"),
    137 		       NULL, 0, linux_release, sizeof(linux_release),
    138 		       CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN,
    139 		       EMUL_LINUX_KERN_OSRELEASE, CTL_EOL);
    140 	sysctl_createv(clog, 0, NULL, NULL,
    141 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    142 		       CTLTYPE_STRING, "osversion",
    143 		       SYSCTL_DESCR("Linux operating system revision"),
    144 		       NULL, 0, linux_version, sizeof(linux_version),
    145 		       CTL_EMUL, EMUL_LINUX, EMUL_LINUX_KERN,
    146 		       EMUL_LINUX_KERN_VERSION, CTL_EOL);
    147 
    148 	sysctl_createv(clog, 0, NULL, NULL,
    149 		       CTLFLAG_READWRITE,
    150 		       CTLTYPE_INT, "enabled",
    151 		       SYSCTL_DESCR("Linux compat enabled."),
    152 		       linux_sysctl_enable, 0, &linux_enabled, 0,
    153 		       CTL_EMUL, EMUL_LINUX, CTL_CREATE, CTL_EOL);
    154 
    155 	linux_sysctl_root.sysctl_flags &= ~CTLFLAG_READWRITE;
    156 }
    157 
    158 /*
    159  * linux sysctl system call
    160  */
    161 int
    162 linux_sys___sysctl(struct lwp *l, const struct linux_sys___sysctl_args *uap, register_t *retval)
    163 {
    164 	struct linux___sysctl ls;
    165 	int error, nerror, name[CTL_MAXNAME];
    166 	size_t savelen = 0, oldlen = 0;
    167 
    168 	/*
    169 	 * get linux args structure
    170 	 */
    171 	if ((error = copyin(SCARG(uap, lsp), &ls, sizeof(ls))))
    172 		return error;
    173 
    174 	/*
    175 	 * get oldlen
    176 	 */
    177 	oldlen = 0;
    178 	if (ls.oldlenp != NULL) {
    179 		error = copyin(ls.oldlenp, &oldlen, sizeof(oldlen));
    180 		if (error)
    181 			return (error);
    182 	}
    183 	savelen = oldlen;
    184 
    185 	/*
    186 	 * top-level sysctl names may or may not be non-terminal, but
    187 	 * we don't care
    188 	 */
    189 	if (ls.nlen > CTL_MAXNAME || ls.nlen < 1)
    190 		return (ENOTDIR);
    191 	error = copyin(ls.name, &name, ls.nlen * sizeof(int));
    192 	if (error)
    193 		return (error);
    194 
    195 	ktrmib(name, ls.nlen);
    196 
    197 	/*
    198 	 * dispatch request into linux sysctl tree
    199 	 */
    200 	sysctl_lock(ls.newval != NULL);
    201 	error = sysctl_dispatch(&name[0], ls.nlen,
    202 				ls.oldval, &oldlen,
    203 				ls.newval, ls.newlen,
    204 				&name[0], l, &linux_sysctl_root);
    205 	sysctl_unlock();
    206 
    207 	/*
    208 	 * reset caller's oldlen, even if we got an error
    209 	 */
    210 	if (ls.oldlenp) {
    211 		nerror = copyout(&oldlen, ls.oldlenp, sizeof(oldlen));
    212 		if (error == 0)
    213 			error = nerror;
    214 	}
    215 
    216 	/*
    217 	 * if the only problem is that we weren't given enough space,
    218 	 * that's an ENOMEM error
    219 	 */
    220 	if (error == 0 && ls.oldval != NULL && savelen < oldlen)
    221 		error = ENOMEM;
    222 
    223 	return (error);
    224 }
    225