def recData(destination_ip,source_ip,source_port,client_seq,client_ack,server_seq,server_ack):
# declaring variables
data1=''
recsock=createRecvSock()
server_seq_dict={}
server_ack_dict={}
i=1
dup_pac_count=0
ack_dict={}
raw1 = recv(recsock)
[src_ip,server_seq,server_ack,dest_port,payLength,flag,data]=getImpData(raw1)
dict_seq=str(server_seq)+"."+str(server_ack)
serverSeqList=server_seq_dict.keys()
# while loop
while True:
if src_ip == destination_ip and dest_port==source_port and (dict_seq not in serverSeqList) and payLength>0 and flag!="FINACK":
##considering only packets with non duplicate packets with data
client_seq=server_ack
client_ack=payLength+server_seq
#chkSum=layer4.getTcpCheckSum(source_ip, destination_ip,tcp_header,data)
dict_seq=str(server_seq)+"."+str(server_ack)
server_seq_dict[str(server_seq)+"."+str(server_ack)]=data
server_ack_dict[str(server_seq)+"."+str(server_ack)]=str(client_seq)+'.'+str(client_ack)
serverSeqList=server_seq_dict.keys()
layer5.sendAck(source_ip,destination_ip, source_port,client_seq,client_ack)
i+=1
print flag+ " recieved. Packet " + str(i)+". packet length "+ str(payLength)
#server_ack=client_seq
#server_seq=client_ack
raw1 = recv(recsock)
[src_ip,server_seq,server_ack,dest_port,payLength,flag,data]=getImpData(raw1)
dict_seq=str(server_seq)+"."+str(server_ack)
elif src_ip == destination_ip and dest_port==source_port and (dict_seq not in serverSeqList) and payLength==0 and flag!="FINACK" : ##considering only packets with acks with no datas
client_seq=server_ack
client_ack=server_seq
ack_dict[str(client_seq)+'.'+str(client_ack)]=str(server_seq)+'.'+str(server_ack)
server_ack_dict[str(server_seq)+"."+str(server_ack)]=str(client_seq)+'.'+str(client_ack)
layer5.sendAck(source_ip,destination_ip, source_port,client_seq,client_ack)
#print flag+ " recieved"
#server_ack=client_seq
#server_seq=client_ack
raw1 = recv(recsock)
[src_ip,server_seq,server_ack,dest_port,payLength,flag,data]=getImpData(raw1)
dict_seq=str(server_seq)+"."+str(server_ack)
elif dup_pac_count>18:
break
elif src_ip == destination_ip and dest_port==source_port and (dict_seq in serverSeqList) and payLength==0 and dup_pac_count<18: ##considering only duplicate packets with acks no data
dup_pac_count+=1
raw1 = recv(recsock)
[src_ip,server_seq,server_ack,dest_port,payLength,flag,data]=getImpData(raw1)
dict_seq=str(server_seq)+"."+str(server_ack)
elif src_ip == destination_ip and dest_port==source_port and (dict_seq in serverSeqList) and payLength>0 and dup_pac_count<18: ##considering only duplicate packets with data
dup_pac_count+=1
#print flag+ " recieved"
kValue=server_ack_dict[dict_seq]
clis_seq,clis_ack=kValue.split('.')
cli_seq=int(clis_seq)
cli_ack=int(clis_ack)
layer5.sendAck(source_ip,destination_ip, source_port,cli_seq,cli_ack)
#print "ack sent for the packet with seq no. "+str(cli_seq)+" and ack no. " +str(cli_ack)
raw1 = recv(recsock)
[src_ip,server_seq,server_ack,dest_port,payLength,flag,data]=getImpData(raw1)
dict_seq=str(server_seq)+"."+str(server_ack)
elif src_ip == destination_ip and dest_port==source_port and (flag=='FINACK' or flag=='FIN'):
#print "FINACK recieved"
#debugPrintSeqNo(client_seq,client_ack,server_seq,server_ack)
##close connection if fin or finack recieved
#print flag+ " recieved"
client_seq=server_ack
client_ack=1+server_seq
#closeConnection(source_ip,destination_ip, source_port,client_seq,client_ack)
layer5.sendAck(source_ip,destination_ip, source_port,client_seq,client_ack)
layer5.sendFinAck(source_ip,destination_ip, source_port,client_seq,client_ack)
break
else:
#debugPrintSeqNo(client_seq,client_ack,server_seq,server_ack)
if src_ip == destination_ip and dest_port==source_port:
sys.exit("No condition met.Unknown problem")
arrList=server_seq_dict.keys()
#arrList = [ double(x) for x in arrList ]## converting every sting seq-ack combo into integer
arrList.sort()
#print server_seq_dict
for i in arrList:
data1=data1+server_seq_dict[i]
#print data1
print "Data end"
#continue
return data1
def closeConnection(source_ip,destination_ip, source_port,client_seq,client_ack): layer5.sendAck(source_ip,destination_ip, source_port,client_seq,client_ack) layer5.sendFinAck(source_ip,destination_ip, source_port,client_seq,client_ack) print "attempting to close connection"