libbb/in_ether.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  */
   5 //kbuild:lib-$(CONFIG_ARP) += in_ether.o
   6 //kbuild:lib-$(CONFIG_IFCONFIG) += in_ether.o
   7 //kbuild:lib-$(CONFIG_IFENSLAVE) += in_ether.o
   8
   9 #include "libbb.h"
  10 #include <net/if_arp.h>
  11 #include <net/ethernet.h>
  12
  13 /* Convert Ethernet address from "XX[:]XX[:]XX[:]XX[:]XX[:]XX" to sockaddr.
  14  * Return nonzero on error.
  15  */
  16 int FAST_FUNC in_ether(const char *bufp, struct sockaddr *sap)
  17 {
  18         char *ptr;
  19         int i, j;
  20         unsigned char val;
  21         unsigned char c;
  22
  23         sap->sa_family = ARPHRD_ETHER;
  24         ptr = (char *) sap->sa_data;
  25
  26         i = ETH_ALEN;
  27         goto first;
  28         do {
  29                 /* We might get a semicolon here */
  30                 if (*bufp == ':')
  31                         bufp++;
  32  first:
  33                 j = val = 0;
  34                 do {
  35                         c = *bufp;
  36                         if (((unsigned char)(c - '0')) <= 9) {
  37                                 c -= '0';
  38                         } else if ((unsigned char)((c|0x20) - 'a') <= 5) {
  39                                 c = (unsigned char)((c|0x20) - 'a') + 10;
  40                         } else {
  41                                 if (j && (c == ':' || c == '\0'))
  42                                         /* One-digit byte: __:X:__ */
  43                                         break;
  44                                 return -1;
  45                         }
  46                         ++bufp;
  47                         val <<= 4;
  48                         val += c;
  49                         j ^= 1;
  50                 } while (j);
  51
  52                 *ptr++ = val;
  53         } while (--i);
  54
  55         /* Error if we aren't at end of string */
  56         return *bufp;
  57 }