/*
   * Copyright (C) 2015 Martin Landsmann <Martin.Landsmann@HAW-Hamburg.de>
   *
   * This file is subject to the terms and conditions of the GNU Lesser
   * General Public License v2.1. See the file LICENSE in the top level
   * directory for more details.
   */
  
  /**
   * @ingroup     sys_shell_commands
   * @{
   *
   * @file
   * @brief       Provides shell commands to manage and show FIB Entries
   *
   * @author      2015 Martin Landsmann <Martin.Landsmann@HAW-Hamburg.de>
   *
   * @}
   */
  
  #include <arpa/inet.h>
  #include <stdio.h>
  #include <stdint.h>
  #include <string.h>
  #include <stdlib.h>
  #include "thread.h"
  #include "net/af.h"
  #ifdef MODULE_GNRC_NETIF
  #include "net/gnrc/netif.h"
  #endif
  #include "net/fib.h"
  #include "net/gnrc/ipv6.h"
  
  #define INFO1_TXT "fibroute add <destination> via <next hop> [dev <device>]"
  #define INFO2_TXT " [lifetime <lifetime>]"
  #define INFO3_TXT "       <destination> - the destination address with optional prefix size, e.g. /116\n" \
                    "       <next hop>    - the address of the next-hop towards the <destination>\n" \
                    "       <device>      - the device id of the Interface to use." \
                    " Optional if only one interface is available.\n"
  #define INFO4_TXT "       <lifetime>    - optional lifetime in ms when the entry automatically invalidates\n"
  #define INFO5_TXT "fibroute del <destination>\n" \
                    "       <destination> - the destination address of the entry to be deleted\n"
  
  static unsigned char tmp_ipv4_dst[INADDRSZ];  /**< buffer for ipv4 address conversion */
  static unsigned char tmp_ipv4_nxt[INADDRSZ];  /**< buffer for ipv4 address conversion */
  static unsigned char tmp_ipv6_dst[IN6ADDRSZ]; /**< buffer for ipv6 address conversion */
  static unsigned char tmp_ipv6_nxt[IN6ADDRSZ]; /**< buffer for ipv6 address conversion */
  
  static void _fib_usage(int info)
  {
      switch (info) {
          case 0: {
              puts("\nsee <fibroute [add|del]> for more information\n"
                   "<fibroute flush [interface]> removes all entries [associated with interface]\n");
              break;
          }
          case 1: {
              puts("\nbrief: adds a new entry to the FIB.\nusage: "
                   INFO1_TXT "\n" INFO3_TXT);
              break;
          }
  
          case 2: {
              puts("\nbrief: adds a new entry to the FIB.\nusage: "
                   INFO1_TXT INFO2_TXT "\n" INFO3_TXT INFO4_TXT);
              break;
          }
  
          case 3: {
              puts("\nbrief: deletes an entry from the FIB.\nusage: "
                   INFO5_TXT);
              break;
          }
  
          default:
              break;
      };
  }
  
  static void _fib_add(const char *dest, const char *next, kernel_pid_t pid, uint32_t lifetime)
  {
      uint32_t prefix = 0;
      /* Get the prefix length */
      size_t i = 0;
      for (i = strlen(dest); i > 0; --i) {
          if (dest[i] == '/') {
             prefix = atoi(&dest[i+1]);
             break;
          }
          if (dest[i] == ':' || dest[i] == '.') {
             i = strlen(dest);
             break;
          }
      }
  
      size_t dst_size = (i+1);
      unsigned char dst_arr[dst_size];
      memset(dst_arr, 0, dst_size);
      memcpy(dst_arr, dest, i);
      unsigned char *dst = &dst_arr[0];
      uint32_t dst_flags = 0;
  
      unsigned char *nxt = (unsigned char *)next;
      size_t nxt_size = (strlen(next));
      uint32_t nxt_flags = 0;
  
      /* determine destination address */
      if (inet_pton(AF_INET6, (char*)dst, tmp_ipv6_dst)) {
          dst = tmp_ipv6_dst;
          dst_size = IN6ADDRSZ;
      }
      else if (inet_pton(AF_INET, dest, tmp_ipv4_dst)) {
          dst = tmp_ipv4_dst;
          dst_size = INADDRSZ;
      }
  
      /* determine next-hop address */
      if (inet_pton(AF_INET6, next, tmp_ipv6_nxt)) {
          nxt = tmp_ipv6_nxt;
          nxt_size = IN6ADDRSZ;
      }
      else if (inet_pton(AF_INET, next, tmp_ipv4_nxt)) {
          nxt = tmp_ipv4_nxt;
          nxt_size = INADDRSZ;
      }
  
      dst_flags |= (prefix << FIB_FLAG_NET_PREFIX_SHIFT);
      fib_add_entry(&gnrc_ipv6_fib_table, pid, dst, dst_size, dst_flags, nxt,
                    nxt_size, nxt_flags, lifetime);
  }
  
  int _fib_route_handler(int argc, char **argv)
  {
      /* e.g. fibroute right now dont care about the adress/protocol family */
      if (argc == 1) {
          fib_print_routes(&gnrc_ipv6_fib_table);
          return 0;
      }
  
      /* e.g. firoute [add|del] */
      if (argc == 2) {
          if ((strcmp("add", argv[1]) == 0)) {
              _fib_usage(2);
          }
          else if ((strcmp("del", argv[1]) == 0)) {
              _fib_usage(3);
          }
          else if ((strcmp("flush", argv[1]) == 0)) {
              fib_flush(&gnrc_ipv6_fib_table, KERNEL_PID_UNDEF);
              puts("successfully flushed all entries");
          }
          else {
              _fib_usage(0);
          }
  
          return 1;
      }
  
      if (argc > 2 && !((strcmp("add", argv[1]) == 0) ||
                        (strcmp("del", argv[1]) == 0) ||
                        (strcmp("flush", argv[1]) == 0))) {
          puts("\nunrecognized parameter2.\nPlease enter fibroute [add|del] for more information.");
          return 1;
      }
  
      /* e.g. fibroute del <destination> */
      if (argc == 3) {
          if ((strcmp("flush", argv[1]) == 0)) {
              kernel_pid_t iface = atoi(argv[2]);
              if (gnrc_netif_exist(iface)) {
                  fib_flush(&gnrc_ipv6_fib_table, iface);
                  printf("successfully flushed all entries for interface %" PRIu16"\n", iface);
              }
              else {
                  printf("interface %" PRIu16" does not exist\n", iface);
              }
          }
          else if (inet_pton(AF_INET6, argv[2], tmp_ipv6_dst)) {
              fib_remove_entry(&gnrc_ipv6_fib_table, tmp_ipv6_dst, IN6ADDRSZ);
          }
          else if (inet_pton(AF_INET, argv[2], tmp_ipv4_dst)) {
              fib_remove_entry(&gnrc_ipv6_fib_table, tmp_ipv4_dst, INADDRSZ);
          }
          else {
              fib_remove_entry(&gnrc_ipv6_fib_table, (uint8_t *)argv[2],
                               (strlen(argv[2])));
          }
  
          return 0;
      }
  
  #ifdef MODULE_GNRC_NETIF
      /* e.g. fibroute add <destination> via <next hop> */
      if ((argc == 5) && (strcmp("add", argv[1]) == 0) && (strcmp("via", argv[3]) == 0)) {
          kernel_pid_t ifs[GNRC_NETIF_NUMOF];
          size_t ifnum = gnrc_netif_get(ifs);
          if (ifnum == 1) {
              _fib_add(argv[2], argv[4], ifs[0], (uint32_t)FIB_LIFETIME_NO_EXPIRE);
          }
          else {
              _fib_usage(1);
              return 1;
          }
  
          return 0;
      }
  
      /* e.g. fibroute add <destination> via <next hop> lifetime <lifetime> */
      if ((argc == 7) && (strcmp("add", argv[1]) == 0) && (strcmp("via", argv[3]) == 0)
              && (strcmp("lifetime", argv[5]) == 0)) {
          kernel_pid_t ifs[GNRC_NETIF_NUMOF];
          size_t ifnum = gnrc_netif_get(ifs);
          if (ifnum == 1) {
              _fib_add(argv[2], argv[4], ifs[0], (uint32_t)atoi(argv[6]));
          }
          else {
              _fib_usage(1);
              return 1;
          }
  
          return 0;
      }
  #endif
  
      /* e.g. fibroute add <destination> via <next hop> dev <device> */
      if (argc == 7) {
          if ((strcmp("add", argv[1]) == 0) && (strcmp("via", argv[3]) == 0)
              && (strcmp("dev", argv[5]) == 0)) {
              _fib_add(argv[2], argv[4], (kernel_pid_t)atoi(argv[6]), (uint32_t)FIB_LIFETIME_NO_EXPIRE);
          }
          else {
              _fib_usage(1);
              return 1;
          }
  
          return 0;
      }
  
      /* e.g. fibroute add <destination> via <next hop> dev <device> lifetime <lifetime> */
      if (argc == 9) {
          if ((strcmp("add", argv[1]) == 0) && (strcmp("via", argv[3]) == 0)
              && (strcmp("dev", argv[5]) == 0)
              && (strcmp("lifetime", argv[7]) == 0)) {
              _fib_add(argv[2], argv[4], (kernel_pid_t )atoi(argv[6]), (uint32_t)atoi(argv[8]));
          }
          else {
              _fib_usage(2);
              return 1;
          }
  
          return 0;
      }
  
      puts("\nunrecognized parameters.\nPlease enter fibroute [add|del] for more information.");
      return 1;
  }