xref: /NextBSD/lib/libcapsicum/libcapsicum_sysctl.c (revision 287e3b14e9552995def1802ec9c5034f4adf28ec)
1 /*-
2  * Copyright (c) 2013 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Pawel Jakub Dawidek under sponsorship from
6  * the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/nv.h>
34 
35 #include <errno.h>
36 #include <string.h>
37 
38 #include "libcapsicum.h"
39 #include "libcapsicum_sysctl.h"
40 
41 int
cap_sysctlbyname(cap_channel_t * chan,const char * name,void * oldp,size_t * oldlenp,const void * newp,size_t newlen)42 cap_sysctlbyname(cap_channel_t *chan, const char *name, void *oldp,
43     size_t *oldlenp, const void *newp, size_t newlen)
44 {
45 	nvlist_t *nvl;
46 	const uint8_t *retoldp;
47 	uint8_t operation;
48 	size_t oldlen;
49 
50 	operation = 0;
51 	if (oldp != NULL)
52 		operation |= CAP_SYSCTL_READ;
53 	if (newp != NULL)
54 		operation |= CAP_SYSCTL_WRITE;
55 
56 	nvl = nvlist_create(0);
57 	nvlist_add_string(nvl, "cmd", "sysctl");
58 	nvlist_add_string(nvl, "name", name);
59 	nvlist_add_number(nvl, "operation", (uint64_t)operation);
60 	if (oldp == NULL && oldlenp != NULL)
61 		nvlist_add_null(nvl, "justsize");
62 	else if (oldlenp != NULL)
63 		nvlist_add_number(nvl, "oldlen", (uint64_t)*oldlenp);
64 	if (newp != NULL)
65 		nvlist_add_binary(nvl, "newp", newp, newlen);
66 	nvl = cap_xfer_nvlist(chan, nvl, 0);
67 	if (nvl == NULL)
68 		return (-1);
69 	if (nvlist_get_number(nvl, "error") != 0) {
70 		errno = (int)nvlist_get_number(nvl, "error");
71 		nvlist_destroy(nvl);
72 		return (-1);
73 	}
74 
75 	if (oldp == NULL && oldlenp != NULL) {
76 		*oldlenp = (size_t)nvlist_get_number(nvl, "oldlen");
77 	} else if (oldp != NULL) {
78 		retoldp = nvlist_get_binary(nvl, "oldp", &oldlen);
79 		memcpy(oldp, retoldp, oldlen);
80 		if (oldlenp != NULL)
81 			*oldlenp = oldlen;
82 	}
83 	nvlist_destroy(nvl);
84 
85 	return (0);
86 }
87