icmp.c

LPC2292 bios测试程序 说明：YL_LPC229X_BIOS_Data的目录说明

#include "../../inc/config.h"
#include "eth.h"
#include "skbuff.h"
#include "ip.h"
#include "icmp.h"
#include "utils.h"

#ifdef	TFTP_DOWNLOAD_SUPPORT

static unsigned long client_ip;

static int icmp_send_echo( struct sk_buff* skb )
{
	struct icmphdr* icmp_hdr, * icmp_echo;	
	unsigned int tmp, sum, i, cnt;		

	cnt = skb->len;		
	if ( cnt % 2 )
		cnt++;		

	icmp_hdr = ( struct icmphdr * ) ( skb->data );
	skb = alloc_skb( ETH_FRAME_LEN );
	ip_skb_reserve( skb );		//reserve for eth and ip stack	
	icmp_echo = ( struct icmphdr * ) skb_put( skb , cnt );	

	icmp_echo->type = 0;
	icmp_echo->code = 0;	
	sum = 0;			
	for ( i = 2; i < cnt / 2; i++ )
	{
		tmp = *( ( unsigned short * ) ( &icmp_hdr->type ) + i );
		*( ( unsigned short * ) ( &icmp_echo->type ) + i ) = tmp;
		sum += tmp;
	}
	i = sum >> 16;
	icmp_echo->check = 0xffffu - ( sum & 0xffff ) - i;			
	ip_send( skb , client_ip , ICMP );

	return 0;
}

static int icmp_rcv_echo( struct sk_buff* skb )
{
	client_ip = ip_get_source_ip( skb );

	icmp_send_echo( skb );

	return 0;
}

int icmp_rcv_packet( struct sk_buff* skb )
{
	struct icmphdr* icmp_hdr = ( struct icmphdr* ) ( skb->data );

	switch ( icmp_hdr->type )
	{
		case 8:
			icmp_rcv_echo( skb );
	}

	return 0;
}

#endif