1/*
2 *  Atheros AR71xx minimal nvram support
3 *
4 *  Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
5 *
6 *  This program is free software; you can redistribute it and/or modify it
7 *  under the terms of the GNU General Public License version 2 as published
8 *  by the Free Software Foundation.
9 */
10
11#include <linux/kernel.h>
12#include <linux/vmalloc.h>
13#include <linux/errno.h>
14#include <linux/init.h>
15#include <linux/string.h>
16
17#include "nvram.h"
18
19char *ath79_nvram_find_var(const char *name, const char *buf, unsigned buf_len)
20{
21	unsigned len = strlen(name);
22	char *cur, *last;
23
24	if (buf_len == 0 || len == 0)
25		return NULL;
26
27	if (buf_len < len)
28		return NULL;
29
30	if (len == 1)
31		return memchr(buf, (int) *name, buf_len);
32
33	last = (char *) buf + buf_len - len;
34	for (cur = (char *) buf; cur <= last; cur++)
35		if (cur[0] == name[0] && memcmp(cur, name, len) == 0)
36			return cur + len;
37
38	return NULL;
39}
40
41int ath79_nvram_parse_mac_addr(const char *nvram, unsigned nvram_len,
42			       const char *name, char *mac)
43{
44	char *buf;
45	char *mac_str;
46	int ret;
47	int t;
48
49	buf = vmalloc(nvram_len);
50	if (!buf)
51		return -ENOMEM;
52
53	memcpy(buf, nvram, nvram_len);
54	buf[nvram_len - 1] = '\0';
55
56	mac_str = ath79_nvram_find_var(name, buf, nvram_len);
57	if (!mac_str) {
58		ret = -EINVAL;
59		goto free;
60	}
61
62	t = sscanf(mac_str, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
63		   &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5]);
64
65	if (t != 6) {
66		ret = -EINVAL;
67		goto free;
68	}
69
70	ret = 0;
71
72free:
73	vfree(buf);
74	return ret;
75}
76