#define UIP_CONF_IPV6 1
#define UIP_CONF_LL_802154 1
#include <string.h>
#define DEBUG DEBUG_NONE
#include "net/ip/uip-debug.h"
#include "ip-process.h"
#include <stdio.h>
#undef uip_buf
extern unsigned char *uip_buf;
extern uint16_t uip_len;
#define UIP_IP_BUF ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])
uint8_t mac_createEthernetAddr(uint8_t * ethernet, uip_lladdr_t * lowpan);
int8_t mac_translateIcmpLinkLayer();
int8_t mac_translateIPLinkLayer();
/**
* \brief Translate IP packet's possible link-layer addresses, passing
* the message to the appropriate higher level function for this
* packet (aka: ICMP)
* \param target The target we want to end up with - either ll_8023_type
* for ethernet, or ll_802154_type for 802.15.4
* \return Returns how successful the translation was
* \retval 0 Addresses, if present, were translated.
* \retval <0 Negative return values indicate various errors, as defined
* by the higher level function.
*/
int8_t mac_translateIPLinkLayer()
{
if (UIP_IP_BUF->proto == UIP_PROTO_ICMP6) {
PRINTF("eth2low: ICMP Message detected\n");
return mac_translateIcmpLinkLayer();
}
return 0;
}
#include "net/ipv6/uip-icmp6.h"
#include "net/ipv6/uip-nd6.h"
typedef struct {
uint8_t type;
uint8_t length;
uint8_t data[16];
} icmp_opts_t;
#define UIP_ICMP_BUF ((struct uip_icmp_hdr *)&uip_buf[UIP_LLH_LEN + UIP_IPH_LEN])
#define UIP_ICMP_OPTS(x) ((icmp_opts_t *)&uip_buf[UIP_LLH_LEN + UIP_IPH_LEN + x])
void slide(uint8_t * data, uint8_t length, int16_t slide);
/**
* \brief Translate the link-layer (L2) addresses in an ICMP packet.
* This will just be NA/NS/RA/RS packets currently.
* \param target The target we want to end up with - either ll_8023_type
* for ethernet, or ll_802154_type for 802.15.4
* \return Returns how successful the translation was
* \retval 0 Addresses, if present, were translated.
* \retval -1 ICMP message was unknown type, nothing done.
* \retval -2 ICMP Length does not make sense?
* \retval -3 Unknown 'target' type
*/
int8_t mac_translateIcmpLinkLayer()
{
uint16_t icmp_opt_offset = 0;
int16_t len = UIP_IP_BUF->len[1] | (UIP_IP_BUF->len[0] << 8);
uint16_t iplen;
uint8_t i;
int16_t sizechange;
uint8_t llbuf[16];
//Figure out offset to start of options
switch(UIP_ICMP_BUF->type) {
case ICMP6_NS:
case ICMP6_NA:
icmp_opt_offset = 24;
break;
case ICMP6_RS:
icmp_opt_offset = 8;
break;
case ICMP6_RA:
icmp_opt_offset = 16;
break;
case ICMP6_REDIRECT:
icmp_opt_offset = 40;
break;
/** Things without link-layer */
case ICMP6_DST_UNREACH:
case ICMP6_PACKET_TOO_BIG:
case ICMP6_TIME_EXCEEDED:
case ICMP6_PARAM_PROB:
case ICMP6_ECHO_REQUEST:
case ICMP6_ECHO_REPLY:
return 0;
break;
default:
return -1;
}
//Figure out length of options
len -= icmp_opt_offset;
//Sanity check
if (len < 8) return -2;
//While we have options to do...
while (len >= 8){
//If we have one of these, we have something useful!
if (((UIP_ICMP_OPTS(icmp_opt_offset)->type) == UIP_ND6_OPT_SLLAO) ||
((UIP_ICMP_OPTS(icmp_opt_offset)->type) == UIP_ND6_OPT_TLLAO) ) {
/* Shrinking the buffer may thrash things, so we store the old
link-layer address */
for(i = 0; i < (UIP_ICMP_OPTS(icmp_opt_offset)->length*8 - 2); i++) {
llbuf[i] = UIP_ICMP_OPTS(icmp_opt_offset)->data[i];
}
//Shrink/grow buffer as needed
/* Current is 802.15.4, Hence current link-layer option is 14 extra
* bytes.
* (Actual LL is 8 bytes, but total option length is in multiples of
* 8 Bytes, hence 8 + 2 = 10. Closest is 16 bytes, then 16 bytes for
* total optional length - 2 bytes for type + length leaves 14 )
*/
sizechange = -8;
slide(UIP_ICMP_OPTS(icmp_opt_offset)->data + 14, len - 14, sizechange);
mac_createEthernetAddr(UIP_ICMP_OPTS(icmp_opt_offset)->data, (uip_lladdr_t *)llbuf);
//Adjust the length
UIP_ICMP_OPTS(icmp_opt_offset)->length = 1;
//Adjust the IP header length, as well as uIP length
iplen = UIP_IP_BUF->len[1] | (UIP_IP_BUF->len[0]<<8);
iplen += sizechange;
len += sizechange;
UIP_IP_BUF->len[1] = (uint8_t)iplen;
UIP_IP_BUF->len[0] = (uint8_t)(iplen >> 8);
uip_len += sizechange;
//We broke ICMP checksum, be sure to fix that
UIP_ICMP_BUF->icmpchksum = 0;
UIP_ICMP_BUF->icmpchksum = ~uip_icmp6chksum();
//Finally set up next run in while loop
len -= 8 * UIP_ICMP_OPTS(icmp_opt_offset)->length;
icmp_opt_offset += 8 * UIP_ICMP_OPTS(icmp_opt_offset)->length;
} else {
//Not an option we care about, ignore it
len -= 8 * UIP_ICMP_OPTS(icmp_opt_offset)->length;
//This shouldn't happen!
if (UIP_ICMP_OPTS(icmp_opt_offset)->length == 0) {
PRINTF("Option in ND packet has length zero, error?\n");
len = 0;
}
icmp_opt_offset += 8 * UIP_ICMP_OPTS(icmp_opt_offset)->length;
} //If ICMP_OPT is one we care about
} //while(len >= 8)
return 0;
}
/**
* \brief Create a 802.3 address from a 802.15.4 long address
* \param ethernet Pointer to ethernet address
* \param lowpan Pointer to 802.15.4 address
*/
uint8_t mac_createEthernetAddr(uint8_t * ethernet, uip_lladdr_t * lowpan)
{
/* uint8_t j, match; */
uint8_t tmp[8];
memcpy(tmp,lowpan,sizeof(uip_lladdr_t));
memcpy(ethernet, tmp, 3);
memcpy(ethernet+3, tmp+5, 3);
ethernet[0] |= 0x02;
return 1;
}
/**
* \brief Slide the pointed to memory up a certain amount,
* growing/shrinking a buffer
* \param data Pointer to start of data buffer
* \param length Length of the data buffer
* \param slide How many bytes to slide the buffer up in memory (if +) or
* down in memory (if -)
*/
void slide(uint8_t * data, uint8_t length, int16_t slide)
{
//Sanity checks
if (!length) return;
if (!slide) return;
uint8_t i = 0;
while(length) {
length--;
//If we are sliding up, we do from the top of the buffer down
if (slide > 0) {
*(data + length + slide) = *(data + length);
//If we are sliding down, we do from the bottom of the buffer up
} else {
*(data + slide + i) = *(data + i);
}
i++;
}
}
uint16_t ip_process(unsigned char *buf, unsigned int len)
{
uip_buf = buf;
uip_len = len;
mac_translateIPLinkLayer();
return uip_len;
}