static void create_igmp_msg(int msgtype,
uip_ipaddr_t dest_addr,
uip_ipaddr_t group_addr)
{
u16_t checksum;
unsigned char dest_hwaddr[6];
uip_len = sizeof(struct ethip_hdr) +
sizeof(ip_options_t) +
sizeof(igmp_msg_t);
dest_hwaddr[0] = 0x01;
dest_hwaddr[1] = 0x00;
dest_hwaddr[2] = 0x5e;
dest_hwaddr[3] = dest_addr[0] >> 8;
dest_hwaddr[4] = dest_addr[1] & 0xf;
dest_hwaddr[5] = dest_addr[1] >> 8;
memcpy(IPBUF->ethhdr.dest.addr, dest_hwaddr, 6);
memcpy(IPBUF->ethhdr.src.addr, uip_ethaddr.addr, 6);
uip_ipaddr_copy(IPBUF->destipaddr, dest_addr);
uip_ipaddr_copy(IPBUF->srcipaddr, uip_hostaddr);
IPBUF->ethhdr.type = HTONS(UIP_ETHTYPE_IP);
IPBUF->vhl = 0x46;
IPBUF->tos = 0;
IPBUF->len[0] = (32 >> 8);
IPBUF->len[1] = (32 & 0xff);
IPBUF->ipid[0] = ipid >> 8 ;
IPBUF->ipid[1] = ipid & 0xff;
ipid++;
IPBUF->ipoffset[0] = IPBUF->ipoffset[1] = 0;
IPBUF->ttl = 1;//UIP_TTL;
IPBUF->proto = PROTO_IGMP;
IPBUF->ipchksum = 0;
OPTBUF->options[0] = 0x94;
OPTBUF->options[1] = 0x04;
OPTBUF->options[2] = 0x00;
OPTBUF->options[3] = 0x00;
checksum = uip_chksum((u16_t *) &uip_buf[UIP_LLH_LEN], UIP_IPH_LEN+sizeof(ip_options_t));
if (checksum == 0)
checksum = 0xffff;
// checksum = uip_ipchksum();
IPBUF->ipchksum = ~checksum;
IGMPBUF->msgtype = msgtype;
IGMPBUF->max_response = 0x0;
checksum = (IGMPBUF->msgtype);
checksum += group_addr[0];
checksum += group_addr[1];
IGMPBUF->checksum = ~checksum;
uip_ipaddr_copy(IGMPBUF->addr, group_addr);
return;
}
/*------------------------------------------------------------------------------*/
static void
time_exceeded(void)
{
/* We don't send out ICMP errors for ICMP messages (unless they are pings). */
if(ICMPBUF->proto == UIP_PROTO_ICMP &&
ICMPBUF->type != ICMP_ECHO) {
uip_len = 0;
return;
}
/* Copy fields from packet header into payload of this ICMP packet. */
memcpy(&(ICMPBUF->payload[0]), ICMPBUF, UIP_IPH_LEN + 8);
/* Set the ICMP type and code. */
ICMPBUF->type = ICMP_TE;
ICMPBUF->icode = 0;
/* Calculate the ICMP checksum. */
ICMPBUF->icmpchksum = 0;
ICMPBUF->icmpchksum = ~((int)uip_chksum((u16_t *)&(ICMPBUF->type), 36));
/* Set the IP destination address to be the source address of the
original packet. */
uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr);
/* Set our IP address as the source address. */
uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr);
/* The size of the ICMP time exceeded packet is 36 + the size of the
IP header (20) = 56. */
uip_len = 56;
ICMPBUF->len[0] = 0;
ICMPBUF->len[1] = (u8_t)uip_len;
/* Fill in the other fields in the IP header. */
ICMPBUF->vhl = 0x45;
ICMPBUF->tos = 0;
ICMPBUF->ipoffset[0] = ICMPBUF->ipoffset[1] = 0;
ICMPBUF->ttl = UIP_TTL;
ICMPBUF->proto = UIP_PROTO_ICMP;
/* Calculate IP checksum. */
ICMPBUF->ipchksum = 0;
ICMPBUF->ipchksum = ~((int)uip_ipchksum());
}
static uint16_t uip_igmpchksum(FAR uint8_t *buffer, int buflen)
{
uint16_t sum = uip_chksum((FAR uint16_t*)buffer, buflen);
return sum ? sum : 0xffff;
}
