xref: /freebsd/usr.sbin/nvram/nvram.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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 
27 #include <sys/types.h>
28 #include <sys/uio.h>
29 #include <err.h>
30 #include <errno.h>
31 #include <fcntl.h>
32 #include <paths.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <unistd.h>
37 
38 #include <dev/powermac_nvram/powermac_nvramvar.h>
39 
40 #define	DEVICE_NAME	(_PATH_DEV "powermac_nvram")
41 
42 static void usage(void) __dead2;
43 static int remove_var(uint8_t *, int, const char *);
44 static int append_var(uint8_t *, int, const char *, const char *);
45 
46 struct deletelist {
47 	char *name;
48 	struct deletelist *next;
49 	struct deletelist *last;
50 };
51 
52 static union {
53 	uint8_t buf[sizeof(struct chrp_header)];
54 	struct chrp_header header;
55 } conv;
56 
57 int
58 main(int argc, char **argv)
59 {
60 	int opt, dump, fd, res, i, size;
61 	uint8_t buf[NVRAM_SIZE], *cp, *common;
62 	struct deletelist *dl;
63 
64 	dump = 0;
65 	dl = NULL;
66 
67 	while((opt = getopt(argc, argv, "d:p")) != -1) {
68 		switch(opt) {
69 		case 'p':
70 			dump = 1;
71 			break;
72 
73 		case 'd':
74 			if (dl == NULL) {
75 				dl = malloc(sizeof(*dl));
76 				if (dl == NULL)
77 					err(1, "malloc");
78 				bzero(dl, sizeof(*dl));
79 				dl->last = dl;
80 			} else {
81 				dl->last->next = malloc(sizeof(*dl));
82 				if (dl->last->next == NULL)
83 					err(1, "malloc");
84 				dl->last = dl->last->next;
85 				bzero(dl->last, sizeof(*dl));
86 			}
87 			dl->last->name = optarg;
88 			break;
89 
90 		default:
91 			usage();
92 			/* Not reached */
93 		}
94 	}
95 	argc -= optind;
96 	argv += optind;
97 
98 	if (argc == 0 && dump == 0 && dl == NULL) {
99 		usage();
100 		/* Not reached */
101 	}
102 
103 	fd = open(DEVICE_NAME, O_RDWR);
104 	if (fd == -1)
105 		err(1, DEVICE_NAME);
106 	for (i = 0; i < (int)sizeof(buf);) {
107 		res = read(fd, buf + i, sizeof(buf) - i);
108 		if (res == -1 && errno != EINTR)
109 			err(1, DEVICE_NAME);
110 		if (res == 0)
111 			break;
112 		if (res > 0)
113 			i += res;
114 	}
115 	if (i != sizeof(buf))
116 		errx(1, "%s: short read", DEVICE_NAME);
117 
118 	/* Locate common block */
119 	size = 0;
120 	for (cp = buf; cp < buf + sizeof(buf); cp += size) {
121 		memcpy(conv.buf, cp, sizeof(struct chrp_header));
122 		size = conv.header.length * 0x10;
123 		if (strncmp(conv.header.name, "common", 7) == 0)
124 			break;
125 	}
126 	if (cp >= buf + sizeof(buf) || size <= (int)sizeof(struct chrp_header))
127 		errx(1, "%s: no common block", DEVICE_NAME);
128 	common = cp + sizeof(struct chrp_header);
129 	size -= sizeof(struct chrp_header);
130 
131 	if (dump != 0) {
132 		while (size > 0) {
133 			i = strlen(common) + 1;
134 			if (i == 1)
135 				break;
136 			printf("%s\n", common);
137 			size -= i;
138 			common += i;
139 		}
140 		exit(0);
141 	}
142 
143 	for (;dl != NULL; dl = dl->next) {
144 		if (remove_var(common, size, dl->name) == 0)
145 			warnx("%s: no such variable", dl->name);
146 	}
147 
148 	for (; argc > 0; argc--, argv++) {
149 		cp = strchr(*argv, '=');
150 		if (cp == NULL)
151 			errx(1, "%s: invalid argument", *argv);
152 		cp[0] = '\0';
153 		cp++;
154 		remove_var(common, size, *argv);
155 		if (append_var(common, size, *argv, cp) == -1)
156 			errx(1, "%s: error setting variable", *argv);
157 	}
158 
159 	for (i = 0; i < (int)sizeof(buf);) {
160 		res = write(fd, buf + i, sizeof(buf) - i);
161 		if (res == -1 && errno != EINTR)
162 			err(1, DEVICE_NAME);
163 		if (res == 0)
164 			break;
165 		if (res > 0)
166 			i += res;
167 	}
168 	if (i != sizeof(buf))
169 		errx(1, "%s: short write", DEVICE_NAME);
170 	if (close(fd) == -1)
171 		err(1, DEVICE_NAME);
172 
173 	exit(0);
174 }
175 
176 static void
177 usage(void)
178 {
179 
180 	fprintf(stderr, "usage: nvram [-p] | [-d name ...] [name=value ...]\n");
181 	exit(1);
182 }
183 
184 static int
185 remove_var(uint8_t *buf, int len, const char *var_name)
186 {
187 	int nremoved, i, name_len;
188 
189 	nremoved = 0;
190 	name_len = strlen(var_name);
191 	while (len > 0) {
192 		i = strlen(buf) + 1;
193 		if (i == 1)
194 			break;
195 		if (strncmp(buf, var_name, name_len) == 0 && buf[name_len] == '=') {
196 			memmove(buf, buf + i, len - i);
197 			memset(buf + len - i, '\0', i);
198 			nremoved += 1;
199 			continue;
200 		}
201 		len -= i;
202 		buf += i;
203 	}
204 	return nremoved;
205 }
206 
207 static int
208 append_var(uint8_t *buf, int len, const char *var_name, const char *var_value)
209 {
210 	int i, append_len;
211 
212 	while (len > 0) {
213 		i = strlen(buf) + 1;
214 		if (i == 1)
215 			break;
216 		len -= i;
217 		buf += i;
218 	}
219 	append_len = strlen(var_name) + strlen(var_value) + 2;
220 	if (len < append_len)
221 		return -1;
222 	sprintf(buf, "%s=%s", var_name, var_value);
223 	return 0;
224 }
225