nvram.c revision 160892 
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: head/usr.sbin/nvram/nvram.c 160892 2006-08-01 22:19:01Z sobomax $
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
44static void usage(void);
45static int remove_var(uint8_t *, int, const char *);
46static int append_var(uint8_t *, int, const char *, const char *);
47
48struct deletelist {
49	char *name;
50	struct deletelist *next;
51	struct deletelist *last;
52};
53
54int
55main(int argc, char **argv)
56{
57	int opt, dump, fd, res, i, size;
58	uint8_t buf[NVRAM_SIZE], *cp, *common;
59	struct chrp_header *header;
60	struct deletelist *dl;
61
62	dump = 0;
63	dl = NULL;
64
65	while((opt = getopt(argc, argv, "d:p")) != -1) {
66		switch(opt) {
67		case 'p':
68			dump = 1;
69			break;
70
71		case 'd':
72			if (dl == NULL) {
73				dl = malloc(sizeof(*dl));
74				if (dl == NULL)
75					err(1, "malloc");
76				bzero(dl, sizeof(*dl));
77				dl->last = dl;
78			} else {
79				dl->last->next = malloc(sizeof(*dl));
80				if (dl->last->next == NULL)
81					err(1, "malloc");
82				dl->last = dl->last->next;
83				bzero(dl->last, sizeof(*dl));
84			}
85			dl->last->name = optarg;
86			break;
87
88		default:
89			usage();
90			/* Not reached */
91		}
92	}
93	argc -= optind;
94	argv += optind;
95
96	if (argc == 0 && dump == 0 && dl == NULL) {
97		usage();
98		/* Not reached */
99	}
100
101	fd = open(DEVICE_NAME, O_RDWR);
102	if (fd == -1)
103		err(1, DEVICE_NAME);
104	for (i = 0; i < (int)sizeof(buf);) {
105		res = read(fd, buf + i, sizeof(buf) - i);
106		if (res == -1 && errno != EINTR)
107			err(1, DEVICE_NAME);
108		if (res == 0)
109			break;
110		if (res > 0)
111			i += res;
112	}
113	if (i != sizeof(buf))
114		errx(1, "%s: short read", DEVICE_NAME);
115
116	/* Locate common block */
117	size = 0;
118	for (cp = buf; cp < buf + sizeof(buf); cp += size) {
119		header = (struct chrp_header *)cp;
120		size = header->length * 0x10;
121		if (strncmp(header->name, "common", 7) == 0)
122			break;
123	}
124	if (cp >= buf + sizeof(buf) || size <= (int)sizeof(struct chrp_header))
125		errx(1, "%s: no common block", DEVICE_NAME);
126	common = cp + sizeof(struct chrp_header);
127	size -= sizeof(struct chrp_header);
128
129	if (dump != 0) {
130		while (size > 0) {
131			i = strlen(common) + 1;
132			if (i == 1)
133				break;
134			printf("%s\n", common);
135			size -= i;
136			common += i;
137		}
138		exit(0);
139	}
140
141	for (;dl != NULL; dl = dl->next) {
142		if (remove_var(common, size, dl->name) == 0)
143			warnx("%s: no such variable", dl->name);
144	}
145
146	for (; argc > 0; argc--, argv++) {
147		cp = strchr(*argv, '=');
148		if (cp == NULL)
149			errx(1, "%s: invalid argument", *argv);
150		cp[0] = '\0';
151		cp++;
152		remove_var(common, size, *argv);
153		if (append_var(common, size, *argv, cp) == -1)
154			errx(1, "%s: error setting variable", *argv);
155	}
156
157	for (i = 0; i < (int)sizeof(buf);) {
158		res = write(fd, buf + i, sizeof(buf) - i);
159		if (res == -1 && errno != EINTR)
160			err(1, DEVICE_NAME);
161		if (res == 0)
162			break;
163		if (res > 0)
164			i += res;
165	}
166	if (i != sizeof(buf))
167		errx(1, "%s: short write", DEVICE_NAME);
168	if (close(fd) == -1)
169		err(1, DEVICE_NAME);
170
171	exit(0);
172}
173
174static void
175usage(void)
176{
177
178	fprintf(stderr, "usage: nvram [-p] | [-d name ...] [name=value ...]\n");
179	exit(1);
180}
181
182static int
183remove_var(uint8_t *buf, int len, const char *var_name)
184{
185	int nremoved, i, name_len;
186
187	nremoved = 0;
188	name_len = strlen(var_name);
189	while (len > 0) {
190		i = strlen(buf) + 1;
191		if (i == 1)
192			break;
193		if (strncmp(buf, var_name, name_len) == 0 && buf[name_len] == '=') {
194			memmove(buf, buf + i, len - i);
195			memset(buf + len - i, '\0', i);
196			nremoved += 1;
197			continue;
198		}
199		len -= i;
200		buf += i;
201	}
202	return nremoved;
203}
204
205static int
206append_var(uint8_t *buf, int len, const char *var_name, const char *var_value)
207{
208	int i, append_len;
209
210	while (len > 0) {
211		i = strlen(buf) + 1;
212		if (i == 1)
213			break;
214		len -= i;
215		buf += i;
216	}
217	append_len = strlen(var_name) + strlen(var_value) + 2;
218	if (len < append_len)
219		return -1;
220	sprintf(buf, "%s=%s", var_name, var_value);
221	return 0;
222}
223