target/linux/ar71xx/files/arch/mips/ath79/nvram.c

   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 #include <linux/etherdevice.h>
  17
  18 #include "nvram.h"
  19
  20 char *ath79_nvram_find_var(const char *name, const char *buf, unsigned buf_len)
  21 {
  22         unsigned len = strlen(name);
  23         char *cur, *last;
  24
  25         if (buf_len == 0 || len == 0)
  26                 return NULL;
  27
  28         if (buf_len < len)
  29                 return NULL;
  30
  31         if (len == 1)
  32                 return memchr(buf, (int) *name, buf_len);
  33
  34         last = (char *) buf + buf_len - len;
  35         for (cur = (char *) buf; cur <= last; cur++)
  36                 if (cur[0] == name[0] && memcmp(cur, name, len) == 0)
  37                         return cur + len;
  38
  39         return NULL;
  40 }
  41
  42 int ath79_nvram_parse_mac_addr(const char *nvram, unsigned nvram_len,
  43                                const char *name, char *mac)
  44 {
  45         char *buf;
  46         char *mac_str;
  47         int ret;
  48         int t;
  49
  50         buf = vmalloc(nvram_len);
  51         if (!buf)
  52                 return -ENOMEM;
  53
  54         memcpy(buf, nvram, nvram_len);
  55         buf[nvram_len - 1] = '\0';
  56
  57         mac_str = ath79_nvram_find_var(name, buf, nvram_len);
  58         if (!mac_str) {
  59                 ret = -EINVAL;
  60                 goto free;
  61         }
  62
  63         if (strlen(mac_str) == 19 && mac_str[0] == '"' && mac_str[18] == '"') {
  64                 mac_str[18] = 0;
  65                 mac_str++;
  66         }
  67
  68         t = sscanf(mac_str, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
  69                    &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5]);
  70
  71         if (t != ETH_ALEN)
  72                 t = sscanf(mac_str, "%02hhx-%02hhx-%02hhx-%02hhx-%02hhx-%02hhx",
  73                         &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5]);
  74
  75         if (t != ETH_ALEN) {
  76                 ret = -EINVAL;
  77                 goto free;
  78         }
  79
  80         ret = 0;
  81
  82 free:
  83         vfree(buf);
  84         return ret;
  85 }