xref: /freebsd/usr.sbin/nvram/nvram.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1 /*
2  * Copyright (c) 2006 Maxim Sobolev <sobomax@FreeBSD.org>
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  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
18  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
20  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
23  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24  * POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/types.h>
30 #include <sys/uio.h>
31 #include <err.h>
32 #include <errno.h>
33 #include <fcntl.h>
34 #include <paths.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39 
40 #include <dev/powermac_nvram/powermac_nvramvar.h>
41 
42 #define	DEVICE_NAME	(_PATH_DEV "powermac_nvram")
43 
44 static void usage(void) __dead2;
45 static int remove_var(uint8_t *, int, const char *);
46 static int append_var(uint8_t *, int, const char *, const char *);
47 
48 struct deletelist {
49 	char *name;
50 	struct deletelist *next;
51 	struct deletelist *last;
52 };
53 
54 static union {
55 	uint8_t buf[sizeof(struct chrp_header)];
56 	struct chrp_header header;
57 } conv;
58 
59 int
60 main(int argc, char **argv)
61 {
62 	int opt, dump, fd, res, i, size;
63 	uint8_t buf[NVRAM_SIZE], *cp, *common;
64 	struct deletelist *dl;
65 
66 	dump = 0;
67 	dl = NULL;
68 
69 	while((opt = getopt(argc, argv, "d:p")) != -1) {
70 		switch(opt) {
71 		case 'p':
72 			dump = 1;
73 			break;
74 
75 		case 'd':
76 			if (dl == NULL) {
77 				dl = malloc(sizeof(*dl));
78 				if (dl == NULL)
79 					err(1, "malloc");
80 				bzero(dl, sizeof(*dl));
81 				dl->last = dl;
82 			} else {
83 				dl->last->next = malloc(sizeof(*dl));
84 				if (dl->last->next == NULL)
85 					err(1, "malloc");
86 				dl->last = dl->last->next;
87 				bzero(dl->last, sizeof(*dl));
88 			}
89 			dl->last->name = optarg;
90 			break;
91 
92 		default:
93 			usage();
94 			/* Not reached */
95 		}
96 	}
97 	argc -= optind;
98 	argv += optind;
99 
100 	if (argc == 0 && dump == 0 && dl == NULL) {
101 		usage();
102 		/* Not reached */
103 	}
104 
105 	fd = open(DEVICE_NAME, O_RDWR);
106 	if (fd == -1)
107 		err(1, DEVICE_NAME);
108 	for (i = 0; i < (int)sizeof(buf);) {
109 		res = read(fd, buf + i, sizeof(buf) - i);
110 		if (res == -1 && errno != EINTR)
111 			err(1, DEVICE_NAME);
112 		if (res == 0)
113 			break;
114 		if (res > 0)
115 			i += res;
116 	}
117 	if (i != sizeof(buf))
118 		errx(1, "%s: short read", DEVICE_NAME);
119 
120 	/* Locate common block */
121 	size = 0;
122 	for (cp = buf; cp < buf + sizeof(buf); cp += size) {
123 		memcpy(conv.buf, cp, sizeof(struct chrp_header));
124 		size = conv.header.length * 0x10;
125 		if (strncmp(conv.header.name, "common", 7) == 0)
126 			break;
127 	}
128 	if (cp >= buf + sizeof(buf) || size <= (int)sizeof(struct chrp_header))
129 		errx(1, "%s: no common block", DEVICE_NAME);
130 	common = cp + sizeof(struct chrp_header);
131 	size -= sizeof(struct chrp_header);
132 
133 	if (dump != 0) {
134 		while (size > 0) {
135 			i = strlen(common) + 1;
136 			if (i == 1)
137 				break;
138 			printf("%s\n", common);
139 			size -= i;
140 			common += i;
141 		}
142 		exit(0);
143 	}
144 
145 	for (;dl != NULL; dl = dl->next) {
146 		if (remove_var(common, size, dl->name) == 0)
147 			warnx("%s: no such variable", dl->name);
148 	}
149 
150 	for (; argc > 0; argc--, argv++) {
151 		cp = strchr(*argv, '=');
152 		if (cp == NULL)
153 			errx(1, "%s: invalid argument", *argv);
154 		cp[0] = '\0';
155 		cp++;
156 		remove_var(common, size, *argv);
157 		if (append_var(common, size, *argv, cp) == -1)
158 			errx(1, "%s: error setting variable", *argv);
159 	}
160 
161 	for (i = 0; i < (int)sizeof(buf);) {
162 		res = write(fd, buf + i, sizeof(buf) - i);
163 		if (res == -1 && errno != EINTR)
164 			err(1, DEVICE_NAME);
165 		if (res == 0)
166 			break;
167 		if (res > 0)
168 			i += res;
169 	}
170 	if (i != sizeof(buf))
171 		errx(1, "%s: short write", DEVICE_NAME);
172 	if (close(fd) == -1)
173 		err(1, DEVICE_NAME);
174 
175 	exit(0);
176 }
177 
178 static void
179 usage(void)
180 {
181 
182 	fprintf(stderr, "usage: nvram [-p] | [-d name ...] [name=value ...]\n");
183 	exit(1);
184 }
185 
186 static int
187 remove_var(uint8_t *buf, int len, const char *var_name)
188 {
189 	int nremoved, i, name_len;
190 
191 	nremoved = 0;
192 	name_len = strlen(var_name);
193 	while (len > 0) {
194 		i = strlen(buf) + 1;
195 		if (i == 1)
196 			break;
197 		if (strncmp(buf, var_name, name_len) == 0 && buf[name_len] == '=') {
198 			memmove(buf, buf + i, len - i);
199 			memset(buf + len - i, '\0', i);
200 			nremoved += 1;
201 			continue;
202 		}
203 		len -= i;
204 		buf += i;
205 	}
206 	return nremoved;
207 }
208 
209 static int
210 append_var(uint8_t *buf, int len, const char *var_name, const char *var_value)
211 {
212 	int i, append_len;
213 
214 	while (len > 0) {
215 		i = strlen(buf) + 1;
216 		if (i == 1)
217 			break;
218 		len -= i;
219 		buf += i;
220 	}
221 	append_len = strlen(var_name) + strlen(var_value) + 2;
222 	if (len < append_len)
223 		return -1;
224 	sprintf(buf, "%s=%s", var_name, var_value);
225 	return 0;
226 }
227