xref: /freebsd/sbin/conscontrol/conscontrol.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2001 Jonathan Lemon <jlemon@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 #include <sys/types.h>
31 #include <sys/sysctl.h>
32 #include <sys/ioctl.h>
33 #include <sys/ttycom.h>
34 
35 #include <err.h>
36 #include <errno.h>
37 #include <fcntl.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 #define DEVDIR	"/dev/"
44 
45 static void __dead2
46 usage(void)
47 {
48 
49 	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
50 	    "usage: conscontrol [list]",
51 	    "       conscontrol mute on | off",
52 	    "       conscontrol add | delete console",
53 	    "       conscontrol set | unset console");
54 	exit(1);
55 }
56 
57 static void
58 consstatus(void)
59 {
60 	int mute;
61 	size_t len;
62 	char *buf, *p, *avail;
63 
64 	len = sizeof(mute);
65 	if (sysctlbyname("kern.consmute", &mute, &len, NULL, 0) == -1)
66 		err(1, "kern.consmute retrieval failed");
67 	if (sysctlbyname("kern.console", NULL, &len, NULL, 0) == -1)
68 		err(1, "kern.console estimate failed");
69 	if ((buf = malloc(len)) == NULL)
70 		errx(1, "kern.console malloc failed");
71 	if (sysctlbyname("kern.console", buf, &len, NULL, 0) == -1)
72 		err(1, "kern.console retrieval failed");
73 	if ((avail = strchr(buf, '/')) == NULL)
74 		errx(1, "kern.console format not understood");
75 	p = avail;
76 	*avail++ = '\0';
77 	if (p != buf)
78 		*--p = '\0';			/* remove trailing ',' */
79 	p = avail + strlen(avail);
80 	if (p != avail)
81 		*--p = '\0';			/* remove trailing ',' */
82 	printf("Configured: %s\n", buf);
83 	printf(" Available: %s\n", avail);
84 	printf("    Muting: %s\n", mute ? "on" : "off");
85 	free(buf);
86 }
87 
88 static void
89 consmute(const char *onoff)
90 {
91 	int mute;
92 	size_t len;
93 
94 	if (strcmp(onoff, "on") == 0)
95 		mute = 1;
96 	else if (strcmp(onoff, "off") == 0)
97 		mute = 0;
98 	else
99 		usage();
100 	len = sizeof(mute);
101 	if (sysctlbyname("kern.consmute", NULL, NULL, &mute, len) == -1)
102 		err(1, "could not change console muting");
103 }
104 
105 /*
106  * The name we supply to the sysctls should be an entry in /dev.  If
107  * the user has specified the full pathname in /dev, DTRT.  If he
108  * specifies a name in some other directory, it's an error.
109  */
110 
111 static char*
112 stripdev(char *devnam)
113 {
114 	if (memcmp (devnam, DEVDIR, strlen(DEVDIR)) == 0)
115 		return (&devnam[strlen(DEVDIR)]);	    /* remove /dev */
116 	else if (strchr (devnam, '/')) {
117 		fprintf(stderr, "Not a device in /dev: %s\n", devnam);
118 		return (NULL);				    /* end of string */
119 	} else
120 		return (devnam);			    /* passed */
121 }
122 
123 static void
124 consadd(char *devnam)
125 {
126 	size_t len;
127 
128 	devnam = stripdev(devnam);
129 	if (devnam == NULL)
130 		return;
131 	len = strlen(devnam);
132 	if (sysctlbyname("kern.console", NULL, NULL, devnam, len) == -1)
133 		err(1, "could not add %s as a console", devnam);
134 }
135 
136 static void
137 consdel(char *devnam)
138 {
139 	char *buf;
140 	size_t len;
141 
142 	devnam = stripdev(devnam);
143 	if (devnam == NULL)
144 		return;
145 	len = strlen(devnam) + sizeof("-");
146 	if ((buf = malloc(len)) == NULL)
147 		errx(1, "malloc failed");
148 	buf[0] = '-';
149 	strcpy(buf + 1, devnam);
150 	if (sysctlbyname("kern.console", NULL, NULL, buf, len) == -1)
151 		err(1, "could not remove %s as a console", devnam);
152 	free(buf);
153 }
154 
155 static void
156 consset(char *devnam, int flag)
157 {
158 	int ttyfd;
159 
160 	ttyfd = open(devnam, O_RDONLY);
161 	if (ttyfd == -1)
162 		err(1, "opening %s", devnam);
163 	if (ioctl(ttyfd, TIOCCONS, &flag) == -1)
164 		err(1, "could not %s %s as virtual console",
165 		    flag ? "set" : "unset", devnam);
166 	close(ttyfd);
167 }
168 
169 int
170 main(int argc, char **argv)
171 {
172 
173 	if (getopt(argc, argv, "") != -1)
174 		usage();
175 	argc -= optind;
176 	argv += optind;
177 
178 	if (argc > 0 && strcmp(argv[0], "list") != 0) {
179 		if (argc != 2)
180 			usage();
181 		else if (strcmp(argv[0], "mute") == 0)
182 			consmute(argv[1]);
183 		else if (strcmp(argv[0], "add") == 0)
184 			consadd(argv[1]);
185 		else if (strcmp(argv[0], "delete") == 0)
186 			consdel(argv[1]);
187 		else if (strcmp(argv[0], "set") == 0)
188 			consset(argv[1], 1);
189 		else if (strcmp(argv[0], "unset") == 0)
190 			consset(argv[1], 0);
191 		else
192 			usage();
193 	}
194 	consstatus();
195 	exit(0);
196 }
197