xref: /freebsd/sys/kern/subr_boot.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
5  * All Rights Reserved.
6  * Copyright (c) 1998 Robert Nordier
7  * All Rights Reserved.
8  * Copyright (c) 2009, Oleksandr Tymoshenko <gonzo@FreeBSD.org>
9  * All rights reserved.
10  * Copyright (c) 2014 Roger Pau Monné <roger.pau@citrix.com>
11  * All Rights Reserved.
12  * Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org>
13  * Copyright (c) 2018 Netflix, Inc.
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer
20  *    in this position and unchanged.
21  * 2. Redistributions in binary form must reproduce the above copyright
22  *    notice, this list of conditions and the following disclaimer in the
23  *    documentation and/or other materials provided with the distribution.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 /* Note: This is compiled in both the kernel and boot loader contexts */
42 
43 #include <sys/param.h>
44 #ifdef _KERNEL
45 #include <sys/systm.h>
46 #else
47 #include <stand.h>
48 #endif
49 #include <sys/reboot.h>
50 #include <sys/boot.h>
51 
52 #ifdef _KERNEL
53 #define SETENV(k, v)	kern_setenv(k, v)
54 #define GETENV(k)	kern_getenv(k)
55 #define FREE(v)		freeenv(v)
56 #else	/* Boot loader */
57 #define SETENV(k, v)	setenv(k, v, 1)
58 #define GETENV(k)	getenv(k)
59 #define	FREE(v)
60 #endif
61 
62 static struct
63 {
64 	const char	*ev;
65 	int		mask;
66 } howto_names[] = {
67 	{ "boot_askname",	RB_ASKNAME},
68 	{ "boot_cdrom",		RB_CDROM},
69 	{ "boot_ddb",		RB_KDB},
70 	{ "boot_dfltroot",	RB_DFLTROOT},
71 	{ "boot_gdb",		RB_GDB},
72 	{ "boot_multicons",	RB_MULTIPLE},
73 	{ "boot_mute",		RB_MUTE},
74 	{ "boot_pause",		RB_PAUSE},
75 	{ "boot_serial",	RB_SERIAL},
76 	{ "boot_single",	RB_SINGLE},
77 	{ "boot_verbose",	RB_VERBOSE},
78 	{ NULL,	0}
79 };
80 
81 /*
82  * In the boot environment, we often parse a command line and have to throw away
83  * its contents. As we do so, we set environment variables that correspond to
84  * the flags we encounter. Later, to get a howto mask, we grovel through these
85  * to reconstruct it. This also allows users in their loader.conf to set them
86  * and have the kernel see them.
87  */
88 
89 /**
90  * @brief convert the env vars in howto_names into a howto mask
91  */
92 int
93 boot_env_to_howto(void)
94 {
95 	int i, howto;
96 	char *val;
97 
98 	for (howto = 0, i = 0; howto_names[i].ev != NULL; i++) {
99 		val = GETENV(howto_names[i].ev);
100 		if (val != NULL && strcasecmp(val, "no") != 0)
101 			howto |= howto_names[i].mask;
102 		FREE(val);
103 	}
104 	return (howto);
105 }
106 
107 /**
108  * @brief Set env vars from howto_names based on howto passed in
109  */
110 void
111 boot_howto_to_env(int howto)
112 {
113 	int i;
114 
115 	for (i = 0; howto_names[i].ev != NULL; i++)
116 		if (howto & howto_names[i].mask)
117 			SETENV(howto_names[i].ev, "YES");
118 }
119 
120 /**
121  * @brief Helper routine to parse a single arg and return its mask
122  *
123  * Parse all the - options to create a mask (or a serial speed in the
124  * case of -S). If the arg doesn't start with '-' assume it's an env
125  * variable and set that instead.
126  */
127 int
128 boot_parse_arg(char *v)
129 {
130 	char *n;
131 	int howto;
132 
133 #if 0
134 /* Need to see if this is better or worse than the meat of the #else */
135 static const char howto_switches[] = "aCdrgDmphsv";
136 static int howto_masks[] = {
137 	RB_ASKNAME, RB_CDROM, RB_KDB, RB_DFLTROOT, RB_GDB, RB_MULTIPLE,
138 	RB_MUTE, RB_PAUSE, RB_SERIAL, RB_SINGLE, RB_VERBOSE
139 };
140 
141 	opts = strchr(kargs, '-');
142 	while (opts != NULL) {
143 		while (*(++opts) != '\0') {
144 			sw = strchr(howto_switches, *opts);
145 			if (sw == NULL)
146 				break;
147 			howto |= howto_masks[sw - howto_switches];
148 		}
149 		opts = strchr(opts, '-');
150 	}
151 #else
152 	howto = 0;
153 	if (*v == '-') {
154 		while (*v != '\0') {
155 			v++;
156 			switch (*v) {
157 			case 'a': howto |= RB_ASKNAME; break;
158 			case 'C': howto |= RB_CDROM; break;
159 			case 'd': howto |= RB_KDB; break;
160 			case 'D': howto |= RB_MULTIPLE; break;
161 			case 'm': howto |= RB_MUTE; break;
162 			case 'g': howto |= RB_GDB; break;
163 			case 'h': howto |= RB_SERIAL; break;
164 			case 'p': howto |= RB_PAUSE; break;
165 			case 'P': howto |= RB_PROBE; break;
166 			case 'r': howto |= RB_DFLTROOT; break;
167 			case 's': howto |= RB_SINGLE; break;
168 			case 'S': SETENV("comconsole_speed", v + 1); v += strlen(v); break;
169 			case 'v': howto |= RB_VERBOSE; break;
170 			}
171 		}
172 	} else {
173 		n = strsep(&v, "=");
174 		if (v == NULL)
175 			SETENV(n, "1");
176 		else
177 			SETENV(n, v);
178 	}
179 #endif
180 	return (howto);
181 }
182 
183 /**
184  * @brief breakup the command line into args, and pass to boot_parse_arg
185  */
186 int
187 boot_parse_cmdline_delim(char *cmdline, const char *delim)
188 {
189 	char *v;
190 	int howto;
191 
192 	howto = 0;
193 	while ((v = strsep(&cmdline, delim)) != NULL) {
194 		if (*v == '\0')
195 			continue;
196 		howto |= boot_parse_arg(v);
197 	}
198 	return (howto);
199 }
200 
201 /**
202  * @brief Simplified interface for common 'space or tab separated' args
203  */
204 int
205 boot_parse_cmdline(char *cmdline)
206 {
207 
208 	return (boot_parse_cmdline_delim(cmdline, " \t\n"));
209 }
210 
211 /**
212  * @brief Pass a vector of strings to boot_parse_arg
213  */
214 int
215 boot_parse_args(int argc, char *argv[])
216 {
217         int i, howto;
218 
219 	howto = 0;
220         for (i = 1; i < argc; i++)
221                 howto |= boot_parse_arg(argv[i]);
222 	return (howto);
223 }
224