lib/net_utils.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/string.h>
   3 #include <linux/if_ether.h>
   4 #include <linux/ctype.h>
   5 #include <linux/export.h>
   6 #include <linux/hex.h>
   7
   8 bool mac_pton(const char *s, u8 *mac)
   9 {
  10         size_t maxlen = 3 * ETH_ALEN - 1;
  11         int i;
  12
  13         /* XX:XX:XX:XX:XX:XX */
  14         if (strnlen(s, maxlen) < maxlen)
  15                 return false;
  16
  17         /* Don't dirty result unless string is valid MAC. */
  18         for (i = 0; i < ETH_ALEN; i++) {
  19                 if (!isxdigit(s[i * 3]) || !isxdigit(s[i * 3 + 1]))
  20                         return false;
  21                 if (i != ETH_ALEN - 1 && s[i * 3 + 2] != ':')
  22                         return false;
  23         }
  24         for (i = 0; i < ETH_ALEN; i++) {
  25                 mac[i] = (hex_to_bin(s[i * 3]) << 4) | hex_to_bin(s[i * 3 + 1]);
  26         }
  27         return true;
  28 }
  29 EXPORT_SYMBOL(mac_pton);