packet.c

#include "packet.h"
#include <stdio.h>

void init_packet(packet *pckt){

//Initializes a packet structure

pckt->opcode = -1;
pckt->mode = -1;
pckt->block_number = -1;
pckt->error_code = -1;

}

/*helper functions*/
int is_read_request(int opcode){
	return opcode == RRQ;
}

int is_write_request(int opcode){
	return opcode == WRQ;        
}

int is_data_packet(int opcode){
	return opcode == DATA;
}

int is_error_packet(int opcode){
	return opcode == ERROR;
}

int is_ack_packet(int opcode){
	return (opcode == ACK);
}

/*creates the packet structure from buffer*/
/*Calls the corresponding functions for each type of packet*/
int strip_raw_packet(char *buffer, int blen, packet *pckt){
	int opcode;
	if(buffer[0] != '\0'){
		printf("Malformed packet\n");
		return 0;
	}
	else{
		if( ! (blen > 1 ) ){
			printf("Malformed packet\n");
			return 0;
		}
		opcode = (int) buffer[1];
		switch(opcode){
			case RRQ:
				//printf("Read request packet");
				break;
			case WRQ:
				//printf("Write request packet\n");
				break;
			case DATA:
				//printf("Data packet\n");
				pckt->opcode=DATA;
				return create_data_packet_from_raw(buffer+2, blen - 2, pckt);
				break;
			case ACK:
				//printf("Acknowledgement packet\n");
				pckt->opcode = ACK;
				return create_ack_packet_from_raw(buffer+2, blen-2, pckt);
				break;
			case ERROR:
				//printf("Error packet\n");
				pckt->opcode = ERROR;
				return create_error_packet_from_raw(buffer+2, blen-2,pckt);
				break;
			default:
				//printf("Malformed packet\n");
				return 0;
		}
	}
}