#include "types.h"
#include "skbuff.h"
#include "eth.h"
#include "arp.h"
#include "ip.h"
#include "udp.h"
#include "tftp.h"
#include "tftpput.h"
#include "utils.h"

unsigned long client_ip;unsigned short client_port;unsigned short client_block;int tftp_send_ack(struct tftphdr *tftp_hdr, int block){	struct tftphdr *tftp_ack;	struct sk_buff *skb;
	skb = alloc_skb(ETH_FRAME_LEN);
	udp_skb_reserve(skb);
	tftp_ack = (struct tftphdr *)skb_put(skb, sizeof(struct tftphdr));	tftp_ack->th_opcode = htons(ACK);	tftp_ack->th_block = htons(block);
	udp_send(skb, client_ip, TFTP, client_port);
	return 0;}int tftp_rcv_wrq(struct sk_buff *skb){	struct tftphdr *tftp_hdr;	client_ip = ip_get_source_ip(skb);	client_port = udp_get_source_port(skb);	tftp_hdr = (struct tftphdr *)skb->data;	tftp_send_ack(tftp_hdr, 0);	client_block = 1;	tftp_put_begin();	return 0;}int tftp_rcv_data(struct sk_buff *skb){	struct tftphdr *tftp_hdr;	int len;	if (client_ip != ip_get_source_ip(skb))		return -1;	if (client_port != udp_get_source_port(skb))		return -1;	tftp_hdr = (struct tftphdr *)skb->data;	if (client_block == ntohs(tftp_hdr->th_block)) {		len = skb->len - sizeof(struct tftphdr);		tftp_put(tftp_hdr->th_data, len);		tftp_send_ack(tftp_hdr, client_block);		client_block++;		if (len < 512)			tftp_put_end();	} else if (client_block > ntohs(tftp_hdr->th_block)) {		tftp_send_ack(tftp_hdr, ntohs(tftp_hdr->th_block));	} else {		tftp_send_ack(tftp_hdr, client_block);	}	return 0;}
int tftp_rcv_packet(struct sk_buff *skb)
{	struct tftphdr *tftp_hdr;		tftp_hdr = (struct tftphdr *)skb->data;	switch (ntohs(tftp_hdr->th_opcode)) {	case RRQ:		break;	case WRQ:		tftp_rcv_wrq(skb);		break;	case DATA:		tftp_rcv_data(skb);		break;	case ACK:		break;	case ERROR:		break;	default:		break;	}	return 0;
}