/* Various stub functions and uIP variables other code might need to
 * compile. Allows you to save needing to compile all of uIP in just
 * to get a few things */


#include "net/uip.h"
#include <string.h>

#define UIP_IP_BUF   ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])

u8_t uip_buf[UIP_BUFSIZE + 2];

u16_t uip_len;

struct uip_stats uip_stat;

uip_lladdr_t uip_lladdr;

u16_t htons(u16_t val) { return HTONS(val);}


/********** UIP_NETIF.c **********/

void
uip_netif_addr_autoconf_set(uip_ipaddr_t *ipaddr, uip_lladdr_t *lladdr)
{
  /* We consider only links with IEEE EUI-64 identifier or
     IEEE 48-bit MAC addresses */
#if (UIP_LLADDR_LEN == 8)
  memcpy(ipaddr->u8 + 8, lladdr, UIP_LLADDR_LEN);
  ipaddr->u8[8] ^= 0x02;
#elif (UIP_LLADDR_LEN == 6)
  memcpy(ipaddr->u8 + 8, lladdr, 3);
  ipaddr->u8[11] = 0xff;
  ipaddr->u8[12] = 0xfe;
  memcpy(ipaddr->u8 + 13, lladdr + 3, 3);
  ipaddr->u8[8] ^= 0x02;
#else
  /*
    UIP_LOG("CAN NOT BUIL INTERFACE IDENTIFIER");
    UIP_LOG("THE STACK IS GOING TO SHUT DOWN");
    UIP_LOG("THE HOST WILL BE UNREACHABLE");
  */
  exit(-1);
#endif
}

/********** UIP.c ****************/

static u16_t
chksum(u16_t sum, const u8_t *data, u16_t len)
{
  u16_t t;
  const u8_t *dataptr;
  const u8_t *last_byte;

  dataptr = data;
  last_byte = data + len - 1;

  while(dataptr < last_byte) {   /* At least two more bytes */
    t = (dataptr[0] << 8) + dataptr[1];
    sum += t;
    if(sum < t) {
      sum++;      /* carry */
    }
    dataptr += 2;
  }

  if(dataptr == last_byte) {
    t = (dataptr[0] << 8) + 0;
    sum += t;
    if(sum < t) {
      sum++;      /* carry */
    }
  }

  /* Return sum in host byte order. */
  return sum;
}

static u16_t
upper_layer_chksum(u8_t proto)
{
  u16_t upper_layer_len;
  u16_t sum;

  upper_layer_len = (((u16_t)(UIP_IP_BUF->len[0]) << 8) + UIP_IP_BUF->len[1]) ;

  /* First sum pseudoheader. */
  /* IP protocol and length fields. This addition cannot carry. */
  sum = upper_layer_len + proto;
  /* Sum IP source and destination addresses. */
  sum = chksum(sum, (u8_t *)&UIP_IP_BUF->srcipaddr, 2 * sizeof(uip_ipaddr_t));

  /* Sum TCP header and data. */
  sum = chksum(sum, &uip_buf[UIP_IPH_LEN + UIP_LLH_LEN],
               upper_layer_len);

  return (sum == 0) ? 0xffff : htons(sum);
}

/*---------------------------------------------------------------------------*/
u16_t
uip_icmp6chksum(void)
{
  return upper_layer_chksum(UIP_PROTO_ICMP6);
}