/*
 mac2eui64.c 

 Conversion from the IEEE 802 MAC format to the (modified) IEEE EUI-64 format.
 Displays values suitable for use as a 64 bit interface ID in AAAA and A6 RRs.
 Also displays labels suitable for use with PTR RRs in the reverse zone
 ip6.arpa.

 Updated in 2015 to conform to ISO C 2011.

 Copyright (C) 2003 Trond Endrestøl <Trond.Endrestol@ximalas.info>

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.

 $Ximalas$
*/
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

void Usage(const char * const argv0, int ReturnValue) __attribute__((noreturn));
void Version(const char * const argv0) __attribute__((noreturn));
void TransformMAC(const char * const argv0, const char * const argvi);

int main(int argc, char **argv)
{
  int c;
  ssize_t i;

  opterr = 0;
  while ((c = getopt(argc, argv, "hv")) != -1) {
    switch (c) {
      case 'h':
        Usage(argv[0], EXIT_SUCCESS);
        //break;

      case 'v':
        Version(argv[0]);
        //break;

      case '?':
        fprintf(stderr, "%s: invalid option -%c\n", argv[0], optopt);
        break;

      default:
        fprintf(stderr, "%s: something is dead wrong with getopt() or with this program\n", argv[0]);
        return EXIT_FAILURE;
        //break;
      }
    }

  i = optind;

  if (i == argc)
    Usage(argv[0], EXIT_FAILURE);

  TransformMAC(argv[0], argv[i++]);

  while (i < argc) {
    puts("");
    TransformMAC(argv[0], argv[i++]);
    }

  return EXIT_SUCCESS;
} /* main() */

void Usage(const char * const argv0, int ReturnValue)
{
  fprintf((ReturnValue == EXIT_SUCCESS) ? stdout : stderr,
          "Usage: %s [-h | -v | <macaddress1> [macaddress2] ... [macaddressN]]\n\n"

          "Options:\n"
          "-h      show this help\n"
          "-v      display version and copyright\n\n"

          "MAC addresses must consist of 12 hex digits with leading zeroes.\n"
          "Any punctuation is ignored. Examples of valid MAC addresses:\n\n"

          "  00:50:DA:2C:8F:55\n"
          "  00-50-DA-2C-8F-55\n"
          "  0050.DA2C.8F55\n"
          "  0050DA2C8F55\n",
          argv0);
  exit(ReturnValue);
} /* Usage() */

void Version(const char * const argv0)
{
  printf("%s version 1.0\n\n"

         "Conversion from the IEEE 802 MAC format to the (modified) IEEE EUI-64 format.\n"
         "Displays values suitable for use as a 64 bit interface ID in AAAA and A6 RRs.\n"
         "Also displays labels suitable for use with PTR RRs in the reverse zone\n"
         "ip6.arpa.\n\n"

         "Updated in 2015 to conform to ISO C 2011.\n\n"

         "Copyright (C) 2003 Trond Endrestøl <Trond.Endrestol@ximalas.info>\n\n"

         "This program is free software; you can redistribute it and/or modify\n"
         "it under the terms of the GNU General Public License as published by\n"
         "the Free Software Foundation; either version 2 of the License, or\n"
         "(at your option) any later version.\n\n"

         "This program is distributed in the hope that it will be useful,\n"
         "but WITHOUT ANY WARRANTY; without even the implied warranty of\n"
         "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n"
         "GNU General Public License for more details.\n\n"

         "You should have received a copy of the GNU General Public License\n"
         "along with this program; if not, write to the Free Software\n"
         "Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.\n",
         argv0);

  exit(EXIT_SUCCESS);
} /* Version */

int ConstructMAC(const char *argvi, unsigned char *MAC);
void ConstructEUI64(const unsigned char * const MAC, unsigned char * const EUI64);
void ConstructModEUI64(const unsigned char * const EUI64, unsigned char * const ModEUI64);

void PrintMAC(const unsigned char * const MAC);
void PrintEUI64(const unsigned char * const EUI64);
void PrintModEUI64(const unsigned char * const EUI64);
void PrintEUI64_InterfaceID(const unsigned char * const EUI64);
void PrintEUI64_IP6_ARPA(const unsigned char * const EUI64);
//void PrintEUI64_IP6_INT(const unsigned char * const EUI64);

void TransformMAC(const char * const argv0, const char * const argvi)
{
  unsigned char MAC[6], EUI64[8], ModEUI64[8];

  if (ConstructMAC(argvi, MAC)) {
    fprintf(stderr, "%s: invalid MAC address: %s\n", argv0, argvi);
    return;
    }

  ConstructEUI64(MAC, EUI64);
  ConstructModEUI64(EUI64, ModEUI64);

  PrintMAC(MAC);
  PrintEUI64(EUI64);
  PrintModEUI64(ModEUI64);
  PrintEUI64_InterfaceID(ModEUI64);
  PrintEUI64_IP6_ARPA(ModEUI64);
  //PrintEUI64_IP6_INT(ModEUI64);
} /* TransformMAC() */

int ConstructMAC(const char *argvi, unsigned char * MAC)
{
  unsigned char ConstructHexByte(unsigned char MSNybble, unsigned char LSNybble);

  int ReturnValue = EXIT_SUCCESS, NumDigits = 0;
  size_t i = 0;
  unsigned char MSNybble, LSNybble;

  while (*argvi) {
    if (isxdigit(*argvi)) {
      NumDigits++;
      MSNybble = (unsigned char)*argvi++;

      if (!isxdigit(*argvi)) {
        break;
        }

      NumDigits++;
      LSNybble = (unsigned char)*argvi;

      MAC[i++] = ConstructHexByte(MSNybble, LSNybble);
      }

    argvi++;
    }

  if (NumDigits != 12)
    ReturnValue = EXIT_FAILURE;

  return ReturnValue;
} /* ConstructMAC() */

unsigned char ConstructHexByte(unsigned char MSNybble, unsigned char LSNybble);

unsigned char ConstructHexByte(unsigned char MSNybble, unsigned char LSNybble)
{
  unsigned char Byte;

  MSNybble = (unsigned char)toupper(MSNybble);
  LSNybble = (unsigned char)toupper(LSNybble);

  if (MSNybble >= 'A') {
    MSNybble = 0x0A + MSNybble - 'A';
    }
  else {
    MSNybble -= '0';
    }

  if (LSNybble >= 'A') {
    LSNybble = 0x0A + LSNybble - 'A';
    }
  else {
    LSNybble -= '0';
    }

  Byte = (unsigned char)((MSNybble << 4) | LSNybble);

  return Byte;
} /* ConstructHexByte() */

void ConstructEUI64(const unsigned char * const MAC, unsigned char * const EUI64)
{
  EUI64[0] = MAC[0];
  EUI64[1] = MAC[1];
  EUI64[2] = MAC[2];
  EUI64[3] = 0xFF;
  EUI64[4] = 0xFF;
  EUI64[5] = MAC[3];
  EUI64[6] = MAC[4];
  EUI64[7] = MAC[5];
} /* ConstructEUI64() */

void InvertUniversalLocalBit(unsigned char * const EUI64);

void ConstructModEUI64(const unsigned char * const EUI64, unsigned char * const ModEUI64)
{
  ModEUI64[0] = EUI64[0];
  ModEUI64[1] = EUI64[1];
  ModEUI64[2] = EUI64[2];
  ModEUI64[3] = EUI64[3];
  ModEUI64[4] = 0xFE;
  ModEUI64[5] = EUI64[5];
  ModEUI64[6] = EUI64[6];
  ModEUI64[7] = EUI64[7];

  InvertUniversalLocalBit(ModEUI64);
} /* ConstructModEUI64() */

void InvertUniversalLocalBit(unsigned char * const EUI64)
{
  if (EUI64[0] & 0x02)
    EUI64[0] &= ~0x02;
  else
    EUI64[0] |= 0x02;
} /* InvertUniversalLocalBit() */

void PrintMAC(const unsigned char * const MAC)
{
  printf("MAC:\t\t%02X:%02X:%02X:%02X:%02X:%02X\n",
         MAC[0], MAC[1], MAC[2], MAC[3], MAC[4], MAC[5]);
} /* PrintMAC() */

void PrintEUI64(const unsigned char * const EUI64)
{
  printf("EUI-64:\t\t%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X\n",
         EUI64[0], EUI64[1], EUI64[2], EUI64[3],
         EUI64[4], EUI64[5], EUI64[6], EUI64[7]);
} /* PrintEUI64() */

void PrintModEUI64(const unsigned char * const EUI64)
{
  printf("Mod. EUI-64:\t%02X:%02X:%02X:%02X:%02X:%02X:%02X:%02X\n",
         EUI64[0], EUI64[1], EUI64[2], EUI64[3],
         EUI64[4], EUI64[5], EUI64[6], EUI64[7]);
} /* PrintModEUI64() */

void PrintEUI64_InterfaceID(const unsigned char * const EUI64)
{
  printf("Interface ID:\t::%02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
         EUI64[0], EUI64[1], EUI64[2], EUI64[3],
         EUI64[4], EUI64[5], EUI64[6], EUI64[7]);
} /* PrintEUI64_InterfaceID() */

void PrintEUI64_IP6_ARPA(const unsigned char * const EUI64)
{
//  printf("ip6.arpa:\t\\[x%02X%02X%02X%02X%02X%02X%02X%02X/64]\n",
//         EUI64[0], EUI64[1], EUI64[2], EUI64[3],
//         EUI64[4], EUI64[5], EUI64[6], EUI64[7]);

  printf("ip6.arpa/64:\t%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x\n",
         EUI64[7] & 0x0F, EUI64[7] >> 4,
         EUI64[6] & 0x0F, EUI64[6] >> 4,
         EUI64[5] & 0x0F, EUI64[5] >> 4,
         EUI64[4] & 0x0F, EUI64[4] >> 4,
         EUI64[3] & 0x0F, EUI64[3] >> 4,
         EUI64[2] & 0x0F, EUI64[2] >> 4,
         EUI64[1] & 0x0F, EUI64[1] >> 4,
         EUI64[0] & 0x0F, EUI64[0] >> 4);
} /* PrintEUI64_IP6_ARPA() */

//void PrintEUI64_IP6_INT(const unsigned char * const EUI64)
//{
//  printf("ip6.int/64:\t%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x\n",
//         EUI64[7] & 0x0F, EUI64[7] >> 4,
//         EUI64[6] & 0x0F, EUI64[6] >> 4,
//         EUI64[5] & 0x0F, EUI64[5] >> 4,
//         EUI64[4] & 0x0F, EUI64[4] >> 4,
//         EUI64[3] & 0x0F, EUI64[3] >> 4,
//         EUI64[2] & 0x0F, EUI64[2] >> 4,
//         EUI64[1] & 0x0F, EUI64[1] >> 4,
//         EUI64[0] & 0x0F, EUI64[0] >> 4);
//} /* PrintEUI64_IP6_INT() */

/* mac2eui64.c */