def __init__(self, l_obj):
#object reference from Link_Maintain module
self.linkObj = l_obj
#rsa key object
self.Rsa_key = RSAKeys()
#aes object for enc and dec files
self.Aes_key = AESCipher()
for i in self.Aes_key.aes_key:
print ord(i),
print
#start a udp listener here with
#port configured in the config file
#create the UDP Socket
self.soc = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self.soc.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
self.soc.bind((Config.ANY_INTF, Config.D_UDP_LISTEN_PORT))
#stores the query caches
#format: src_ip|search_query
self.query_cache = []
#object for storing search results
#format: [query,size,origin-ip,aes-key]
self.search_results = []
#object for user's choice from
#search results
self.user_choice = -1
thread.start_new_thread(self.listen, ())
#variable to store req. file
self.req_file = ''
#stores the aes key of the receipient
self.recv_key = ''
def __init__(self,l_obj): #object reference from Link_Maintain module self.linkObj = l_obj #rsa key object self.Rsa_key = RSAKeys() #aes object for enc and dec files self.Aes_key = AESCipher() for i in self.Aes_key.aes_key: print ord(i), print #start a udp listener here with #port configured in the config file #create the UDP Socket self.soc = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) self.soc.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) self.soc.bind((Config.ANY_INTF, Config.D_UDP_LISTEN_PORT)) #stores the query caches #format: src_ip|search_query self.query_cache = [] #object for storing search results #format: [query,size,origin-ip,aes-key] self.search_results=[] #object for user's choice from #search results self.user_choice=-1 thread.start_new_thread(self.listen, ()) #variable to store req. file self.req_file='' #stores the aes key of the receipient self.recv_key=''
def uploadFile(self, ip, port):
#connect to the ip:port and start sending the data
#first open the file
fd = open(self.req_file, 'r')
tcps = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print 'Started upload thread'
tcps.connect((ip, port))
tmpAes = AESCipher(self.recv_key)
iv = tmpAes.generateIV()
#first send the iv in plain
tcps.send(iv)
while 1:
st = fd.read(15) #read 16-bytes. encrypt them & send
print 'Got', len(st), 'bytes'
cip = tmpAes.n_encrypt(st)
tcps.send(cip)
if len(st) < 15:
break
print 'Done Uploading..'
tcps.close()
def uploadFile(self,ip,port): #connect to the ip:port and start sending the data #first open the file fd = open(self.req_file, 'r') tcps = socket.socket(socket.AF_INET, socket.SOCK_STREAM) print 'Started upload thread' tcps.connect((ip, port)) tmpAes = AESCipher(self.recv_key) iv = tmpAes.generateIV() #first send the iv in plain tcps.send(iv) while 1: st = fd.read(15)#read 16-bytes. encrypt them & send print 'Got',len(st),'bytes' cip = tmpAes.n_encrypt(st) tcps.send(cip) if len(st)<15: break print 'Done Uploading..' tcps.close()
class Downloader:
def __init__(self, l_obj):
#object reference from Link_Maintain module
self.linkObj = l_obj
#rsa key object
self.Rsa_key = RSAKeys()
#aes object for enc and dec files
self.Aes_key = AESCipher()
for i in self.Aes_key.aes_key:
print ord(i),
print
#start a udp listener here with
#port configured in the config file
#create the UDP Socket
self.soc = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self.soc.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
self.soc.bind((Config.ANY_INTF, Config.D_UDP_LISTEN_PORT))
#stores the query caches
#format: src_ip|search_query
self.query_cache = []
#object for storing search results
#format: [query,size,origin-ip,aes-key]
self.search_results = []
#object for user's choice from
#search results
self.user_choice = -1
thread.start_new_thread(self.listen, ())
#variable to store req. file
self.req_file = ''
#stores the aes key of the receipient
self.recv_key = ''
def updateQueryCache(self, val):
#wait for some time
time.sleep(Config.QUERY_CACHE_TIME)
self.query_cache.remove(val)
def decryptPacket(self, data):
#leave away the first 4 bytes
#its ip
#check the fifth byte
if ord(data[4]) == 1:
#its a search query
#not encrypted at all so don't proceed
#furthur
return data
elif ord(data[4]) == 2:
#they are search results
#directed to us
#decrypt them with the RSA Key
#decryption starts from the 6th byte
res = self.Rsa_key.decrypt(data[5:])
return data[:5] + res
elif ord(data[4]) == 3:
#its a download request
#encrypted with AES
#last 16-bytes is the IV
iv = data[-16:]
#decrypt from 6th byte to last but 17th byte
p_txt = self.Aes_key.n_decrypt(data[5:-16], iv)
return data[:5] + p_txt
else:
#all other types are plain-texts
#so return as-it-is
return data
def listen(self):
#listens to:
# forwarding search queries,
# relay node requests
# aggregates search-results
while 1:
dat, addr = self.soc.recvfrom(1024)
#print 'Got a packet'
#print 'From:',addr
#print 'Data:',dat
#decrypt the packet if necessary
pac = self.decryptPacket(dat)
#print 'DData:',dat
# for i in dat:
# print ord(i),
# print
#now proceed for fragmenting
# for i in pac:
# print ord(i),
# print
pac = SearchPacket(pac)
is_invalid = 0
if not pac.isValid():
print 'Corrupted Packet', pac.getRequestType()
is_invalid = 1
if pac.getRequestType() == 1:
# its a search request
print 'Search Req from', addr[0]
#if its invalid just discard
if is_invalid:
print 'invalid Packet'
continue
#check if its already in the cache
if pac.getData() in self.query_cache:
#if it is, then ignore the packet
print 'duplicate query'
continue
print 'Searching the system..'
#forward this search query to all the neighbours
#we get the neighbours from the link object
for neig in self.linkObj.nodes:
if neig != addr[0]:
self.soc.sendto(pac.getRawMessage(),
(neig, Config.D_UDP_LISTEN_PORT))
self.query_cache.append(pac.getData())
#now start a thread to remove this after some time
thread.start_new_thread(self.updateQueryCache,
(pac.getData(), ))
#search in our file-system and get the results
res = self.searchFiles(pac.getData())
if len(res):
#if the result is non-empty
#first encrypt the results using
#the pulic-key sent in the packet
#print 'Results:'
#print res
#print 'RSA Key:',pac.getKey()
tmprsa = RSAKeys(pac.getKey())
#get the length of results
l_res = len(res)
#get the length of keys
l_keys = len(self.Aes_key.aes_key)
#form the packet
dat = chr(l_res/256) + chr(l_res%256) + res\
+ chr(l_keys/256) + chr(l_keys%256) +\
self.Aes_key.aes_key
print 'Got Some results!'
# print '***',dat,'***'
# for i in dat:
# print ord(i),
# print
#encrypt it
cipher = tmprsa.encrypt(dat)
#print 'Len:',len(cipher)
# print '********',cipher,'******',len(cipher)
#now, make a packet with these results
tmppac = SearchPacket()
#type:2,
#src-ip -> src of the query issuer
#send aes-key of this machine
tmppac.setPacketByFields(2, pac.getIP(), cipher)
#print 'Req IP:',pac.getIP()
#print tmppac.getRawMessage(),'|||||'
# for i in tmppac.getRawMessage():
# print ord(i),
# print
#get a random first hop from the
#neighours
nxt_ip = ''
#check if its the same node
#that is requesting
#
for i in self.linkObj.nodes:
if i != addr[0]:
nxt_ip = i
break
print 'Sending to:', nxt_ip
self.soc.sendto(tmppac.getRawMessage(),
(nxt_ip, Config.D_UDP_LISTEN_PORT))
else:
print 'No results'
elif pac.getRequestType() == 2:
#this is a search-results packet
#check if the IP matches with us
#print pac.getIP(),'===',self.linkObj.ip_address
if pac.getIP() == self.linkObj.ip_address:
#display the results
res = pac.getData()
# print 'Got the Key:'
# for i in pac.getKey():
# print ord(i),
# print
for r in res.split("||"):
f = r.split()
if len(f) == 2:
self.search_results.append(
[f[0], f[1], addr[0],
pac.getKey()])
print str(len(
self.search_results)).ljust(4) + f[1].ljust(
16) + f[0].ljust(8) + addr[0].ljust(10)
else:
#this should be forwarded to
#the intended ip-address
#in this case, 'dat'
print 'forwarding to ', pac.getIP()
self.soc.sendto(dat,
(pac.getIP(), Config.D_UDP_LISTEN_PORT))
elif pac.getRequestType() == 3:
#a download request
#if is_invalid is set=>not intended for us
#forwarding to neighbours depends on the
#dest-address
if not is_invalid:
#intended for us
print 'Got a download request'
self.setupSourceRelayNode(pac)
elif is_invalid and \
pac.getIP()==self.linkObj.ip_address:
#its an interim node
#should forward to neighbours
print 'Forwarding to adjacent nodes'
for ip in self.linkObj.nodes:
self.soc.sendto(dat, (ip, Config.D_UDP_LISTEN_PORT))
elif pac.getRequestType() == 4:
#requesting this machine to act as
#relay node
#check the type bit first
print 'Got a relay-node request'
#print 'Data:',pac.getRawMessage()
if pac.getData()[0] == '0':
#forward data to src-ip
#create listening socket for src-ip to connect
print 'On receiving end'
tcpsoc1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc1.bind(('', 0))
#for the other node to connect
tcpsoc2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc2.bind(('', 0))
tmppac = SearchPacket()
tmppac.setPacketByFields(
5, self.linkObj.ip_address,
str(tcpsoc1.getsockname()[1]) + "|" +
str(tcpsoc2.getsockname()[1]))
self.soc.sendto(tmppac.getRawMessage(), addr)
#now create a thread which listens on these ports
thread.start_new_thread(self.receiveEndThread,
(tcpsoc1, tcpsoc2))
elif pac.getData()[0] == '1':
#get data from src-ip
#and forward it to some other node
#we will have the details of src-ip:port to
#connect
print 'r-req for sending end'
ip = pac.getData().split("|")[1]
ip, port = ip.split(":")[0], ip.split(":")[1]
tcpsoc1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc1.bind(('', 0))
tmppac = SearchPacket()
tmppac.setPacketByFields(5, self.linkObj.ip_address,
str(tcpsoc1.getsockname()[1]))
thread.start_new_thread(self.sendEndThread,
(ip, port, tcpsoc1))
time.sleep(2)
print 'Sending port to', addr[0]
self.soc.sendto(tmppac.getRawMessage(), addr)
elif pac.getRequestType() == 5:
#reply from the relay node
print 'Got a reply from relay-node'
#split by '|'
print pac.getData(), '**'
vals = pac.getData().split('|')
if len(vals) == 2:
#means this is on receiving end
#connect to the port and get the data.
thread.start_new_thread(self.downloadFile,
(addr[0], int(vals[0])))
time.sleep(1)
#send the other port details
#to the interim node
#format: file_name|ip:port
dat = self.search_results[self.user_choice - 1][1] + "|"
dat += addr[0] + ':' + vals[1]
dat = chr(len(dat) / 256) + chr(len(dat) % 256) + dat
key_aes = self.search_results[self.user_choice - 1][3]
our_key = self.Aes_key.aes_key
#encrypt the request with the other user's key
our_key = chr(len(our_key)/256)+\
chr(len(our_key)%256)+our_key
# print 'Ptxt:',int(len(dat+our_key))
# for q in dat+our_key:
# print ord(q),
# print
# print 'Encrypt-Key:'
# for h in key_aes:
# print ord(h),
# print
aesVar = AESCipher(key_aes)
rand_iv = aesVar.generateIV()
cipher = aesVar.n_encrypt(dat + our_key)
# print 'cipher:',int(len(cipher))
#destination is our intermediate node
dest_ip = self.search_results[self.user_choice - 1][2]
d_pac = SearchPacket()
d_pac.setPacketByFields(3, dest_ip, cipher)
tmps = d_pac.getRawMessage() + rand_iv
# for c in tmps:
# print ord(c),
# print
print 'Sending dwnld req to', dest_ip
self.soc.sendto(d_pac.getRawMessage() + rand_iv,
(dest_ip, Config.D_UDP_LISTEN_PORT))
else:
#the vals[0] is where we need to connect
#and then start uploading the file..
#so start a thread directly
print 'Starting the upload thread'
thread.start_new_thread(self.uploadFile,
(addr[0], int(vals[0])))
def uploadFile(self, ip, port):
#connect to the ip:port and start sending the data
#first open the file
fd = open(self.req_file, 'r')
tcps = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print 'Started upload thread'
tcps.connect((ip, port))
tmpAes = AESCipher(self.recv_key)
iv = tmpAes.generateIV()
#first send the iv in plain
tcps.send(iv)
while 1:
st = fd.read(15) #read 16-bytes. encrypt them & send
print 'Got', len(st), 'bytes'
cip = tmpAes.n_encrypt(st)
tcps.send(cip)
if len(st) < 15:
break
print 'Done Uploading..'
tcps.close()
def downloadFile(self, ip, port):
#connect to the ip:port and wait for the data.
#get the file-name
print 'Started download-file thread'
f_name = self.search_results[self.user_choice - 1][1]
fd = open(f_name, 'w')
tcps = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print 'Connecting to', ip + ":" + str(port)
tcps.connect((ip, port))
print 'Connected'
#first 16-bytes are the IV
self.Aes_key.iv = tcps.recv(16)
print 'Got the IV'
while 1:
st = tcps.recv(16)
print 'Got', len(st), 'bytes..'
if st == '':
#connection closed
print 'Download Finished'
tcps.close()
fd.close()
break
pln = self.Aes_key.n_decrypt(st, self.Aes_key.iv)
print 'wrote..', pln
fd.write(pln)
print 'File-Contents:'
fr = open(f_name, 'r')
while 1:
st = fr.read(1024)
if st == '':
break
print st
def sendEndThread(self, ip, port, tcp1):
#tcp1 -> listen for connection from src_node
#connect itself to ip:port
print 'Starting send-end thread..'
tcp2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcp2.connect((ip, int(port)))
tcp1.listen(10)
print 'Listening on ' + ip + ':' + port
fd, addr = tcp1.accept()
print 'Got a connection'
while 1:
#transfer data from tcp1 to tcp2
#until connection is closed
st = fd.recv(16)
if st == '':
#closed connection
fd.close()
return
print 'Got', len(st), 'bytes'
tcp2.send(st)
print 'Closing connection..'
def receiveEndThread(self, tcp1, tcp2):
#wait for the incoming connection
#from the src_node
print 'Started recevive-end thread'
tcp1.listen(10)
fd1, addr = tcp1.accept()
print 'Connected to source-node'
#now wait for the other node to connect
tcp2.listen(10)
fd2, addr = tcp2.accept()
print 'Connected to other-end relay node'
while 1:
#write whatever data comes to tcp2
#into tcp1
st = fd2.recv(16)
if st == '':
#connection has been closed
#close this one also and kill this thread
fd1.close()
return
print 'Got', len(st), 'bytes'
fd1.send(st)
print 'Closing Connection...'
def searchNetwork(self, query):
#creates a search packet
#and sends it to adjacent nodes
qpac = SearchPacket()
qpac.setRequestType(1) #'1' for searching
qpac.setKey(self.Rsa_key.getPEMPublic())
qpac.setData(query)
qpac.setIP(self.linkObj.ip_address)
qpac.makePacket()
#first empty the search-results list
self.search_results = []
print 'Sending:', qpac.getRawMessage()
print self.Rsa_key.getPEMPublic(), self.linkObj.ip_address
#fire the query into the network
#via the adjacent nodes
for nds in self.linkObj.nodes:
self.soc.sendto(qpac.getRawMessage(),
(nds, Config.D_UDP_LISTEN_PORT))
print 'Sent to:', nds + ":" + str(Config.D_UDP_LISTEN_PORT)
print 'Search Query sent!\nWaiting for results'
print 'S.No'.ljust(4) + 'File-Name'.ljust(16) + 'Size'.ljust(
8), 'Source'.ljust(10)
def searchFiles(self, query):
#this searches our file file-system
#assumed that 'shared' is a directory
#with in the pwd of the program
command = 'wc -c * 2>/dev/null | grep '+query+\
' | awk \'{printf "%s||",$0}\''
print command
#execute the command
f = os.popen(command)
#get the results
res = f.read()
return res
def downloadRequest(self, choice):
#this function starts the dwnld process
#for a specific file
#choice is an integer corresponding to the entry in
#the search results list
self.user_choice = choice
#first create a packet for relay-node
rpac = SearchPacket()
#pick one of the r_node from the adj ones
r_node = ''
tmpnode = '' #in case r_node is empty
for i in self.linkObj.nodes:
tmpnode = i
if randint(1, 3) == 2:
r_node = i
break
if r_node == '':
r_node = tmpnode
#'0'=> wants to get data from relay-node
rpac.setPacketByFields(4, self.linkObj.ip_address, '0')
print 'Sending relay-request to', r_node
self.soc.sendto(rpac.getRawMessage(),
(r_node, Config.D_UDP_LISTEN_PORT))
#def setupDestRelayNode(self):
def setupSourceRelayNode(self, pac):
#this fn. requests for a relay nodes
#to open a socket and transfer
#data from this machine
#return ip-address:port pair
#where the relay node is listening
self.req_file = pac.getData().split("|")[0]
self.recv_key = pac.getKey()
ipport = pac.getData().split("|")[1]
msg = '1|' + ipport
pac = SearchPacket()
pac.setPacketByFields(4, self.linkObj.ip_address, msg)
#pick one of the r_node from the adj ones
r_node = ''
tmpnode = '' #in case r_node is non-empty
for i in self.linkObj.nodes:
tmpnode = i
if randint(1, 3) == 2 and i != ipport.split(":")[0]:
r_node = i
break
if r_node == '':
r_node = tmpnode
print 'Sending r-req to', r_node
self.soc.sendto(pac.getRawMessage(),
(r_node, Config.D_UDP_LISTEN_PORT))
def listen(self):
#listens to:
# forwarding search queries,
# relay node requests
# aggregates search-results
while 1:
dat, addr = self.soc.recvfrom(1024)
#print 'Got a packet'
#print 'From:',addr
#print 'Data:',dat
#decrypt the packet if necessary
pac = self.decryptPacket(dat)
#print 'DData:',dat
# for i in dat:
# print ord(i),
# print
#now proceed for fragmenting
# for i in pac:
# print ord(i),
# print
pac = SearchPacket(pac)
is_invalid = 0
if not pac.isValid():
print 'Corrupted Packet', pac.getRequestType()
is_invalid = 1
if pac.getRequestType() == 1:
# its a search request
print 'Search Req from', addr[0]
#if its invalid just discard
if is_invalid:
print 'invalid Packet'
continue
#check if its already in the cache
if pac.getData() in self.query_cache:
#if it is, then ignore the packet
print 'duplicate query'
continue
print 'Searching the system..'
#forward this search query to all the neighbours
#we get the neighbours from the link object
for neig in self.linkObj.nodes:
if neig != addr[0]:
self.soc.sendto(pac.getRawMessage(),
(neig, Config.D_UDP_LISTEN_PORT))
self.query_cache.append(pac.getData())
#now start a thread to remove this after some time
thread.start_new_thread(self.updateQueryCache,
(pac.getData(), ))
#search in our file-system and get the results
res = self.searchFiles(pac.getData())
if len(res):
#if the result is non-empty
#first encrypt the results using
#the pulic-key sent in the packet
#print 'Results:'
#print res
#print 'RSA Key:',pac.getKey()
tmprsa = RSAKeys(pac.getKey())
#get the length of results
l_res = len(res)
#get the length of keys
l_keys = len(self.Aes_key.aes_key)
#form the packet
dat = chr(l_res/256) + chr(l_res%256) + res\
+ chr(l_keys/256) + chr(l_keys%256) +\
self.Aes_key.aes_key
print 'Got Some results!'
# print '***',dat,'***'
# for i in dat:
# print ord(i),
# print
#encrypt it
cipher = tmprsa.encrypt(dat)
#print 'Len:',len(cipher)
# print '********',cipher,'******',len(cipher)
#now, make a packet with these results
tmppac = SearchPacket()
#type:2,
#src-ip -> src of the query issuer
#send aes-key of this machine
tmppac.setPacketByFields(2, pac.getIP(), cipher)
#print 'Req IP:',pac.getIP()
#print tmppac.getRawMessage(),'|||||'
# for i in tmppac.getRawMessage():
# print ord(i),
# print
#get a random first hop from the
#neighours
nxt_ip = ''
#check if its the same node
#that is requesting
#
for i in self.linkObj.nodes:
if i != addr[0]:
nxt_ip = i
break
print 'Sending to:', nxt_ip
self.soc.sendto(tmppac.getRawMessage(),
(nxt_ip, Config.D_UDP_LISTEN_PORT))
else:
print 'No results'
elif pac.getRequestType() == 2:
#this is a search-results packet
#check if the IP matches with us
#print pac.getIP(),'===',self.linkObj.ip_address
if pac.getIP() == self.linkObj.ip_address:
#display the results
res = pac.getData()
# print 'Got the Key:'
# for i in pac.getKey():
# print ord(i),
# print
for r in res.split("||"):
f = r.split()
if len(f) == 2:
self.search_results.append(
[f[0], f[1], addr[0],
pac.getKey()])
print str(len(
self.search_results)).ljust(4) + f[1].ljust(
16) + f[0].ljust(8) + addr[0].ljust(10)
else:
#this should be forwarded to
#the intended ip-address
#in this case, 'dat'
print 'forwarding to ', pac.getIP()
self.soc.sendto(dat,
(pac.getIP(), Config.D_UDP_LISTEN_PORT))
elif pac.getRequestType() == 3:
#a download request
#if is_invalid is set=>not intended for us
#forwarding to neighbours depends on the
#dest-address
if not is_invalid:
#intended for us
print 'Got a download request'
self.setupSourceRelayNode(pac)
elif is_invalid and \
pac.getIP()==self.linkObj.ip_address:
#its an interim node
#should forward to neighbours
print 'Forwarding to adjacent nodes'
for ip in self.linkObj.nodes:
self.soc.sendto(dat, (ip, Config.D_UDP_LISTEN_PORT))
elif pac.getRequestType() == 4:
#requesting this machine to act as
#relay node
#check the type bit first
print 'Got a relay-node request'
#print 'Data:',pac.getRawMessage()
if pac.getData()[0] == '0':
#forward data to src-ip
#create listening socket for src-ip to connect
print 'On receiving end'
tcpsoc1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc1.bind(('', 0))
#for the other node to connect
tcpsoc2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc2.bind(('', 0))
tmppac = SearchPacket()
tmppac.setPacketByFields(
5, self.linkObj.ip_address,
str(tcpsoc1.getsockname()[1]) + "|" +
str(tcpsoc2.getsockname()[1]))
self.soc.sendto(tmppac.getRawMessage(), addr)
#now create a thread which listens on these ports
thread.start_new_thread(self.receiveEndThread,
(tcpsoc1, tcpsoc2))
elif pac.getData()[0] == '1':
#get data from src-ip
#and forward it to some other node
#we will have the details of src-ip:port to
#connect
print 'r-req for sending end'
ip = pac.getData().split("|")[1]
ip, port = ip.split(":")[0], ip.split(":")[1]
tcpsoc1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc1.bind(('', 0))
tmppac = SearchPacket()
tmppac.setPacketByFields(5, self.linkObj.ip_address,
str(tcpsoc1.getsockname()[1]))
thread.start_new_thread(self.sendEndThread,
(ip, port, tcpsoc1))
time.sleep(2)
print 'Sending port to', addr[0]
self.soc.sendto(tmppac.getRawMessage(), addr)
elif pac.getRequestType() == 5:
#reply from the relay node
print 'Got a reply from relay-node'
#split by '|'
print pac.getData(), '**'
vals = pac.getData().split('|')
if len(vals) == 2:
#means this is on receiving end
#connect to the port and get the data.
thread.start_new_thread(self.downloadFile,
(addr[0], int(vals[0])))
time.sleep(1)
#send the other port details
#to the interim node
#format: file_name|ip:port
dat = self.search_results[self.user_choice - 1][1] + "|"
dat += addr[0] + ':' + vals[1]
dat = chr(len(dat) / 256) + chr(len(dat) % 256) + dat
key_aes = self.search_results[self.user_choice - 1][3]
our_key = self.Aes_key.aes_key
#encrypt the request with the other user's key
our_key = chr(len(our_key)/256)+\
chr(len(our_key)%256)+our_key
# print 'Ptxt:',int(len(dat+our_key))
# for q in dat+our_key:
# print ord(q),
# print
# print 'Encrypt-Key:'
# for h in key_aes:
# print ord(h),
# print
aesVar = AESCipher(key_aes)
rand_iv = aesVar.generateIV()
cipher = aesVar.n_encrypt(dat + our_key)
# print 'cipher:',int(len(cipher))
#destination is our intermediate node
dest_ip = self.search_results[self.user_choice - 1][2]
d_pac = SearchPacket()
d_pac.setPacketByFields(3, dest_ip, cipher)
tmps = d_pac.getRawMessage() + rand_iv
# for c in tmps:
# print ord(c),
# print
print 'Sending dwnld req to', dest_ip
self.soc.sendto(d_pac.getRawMessage() + rand_iv,
(dest_ip, Config.D_UDP_LISTEN_PORT))
else:
#the vals[0] is where we need to connect
#and then start uploading the file..
#so start a thread directly
print 'Starting the upload thread'
thread.start_new_thread(self.uploadFile,
(addr[0], int(vals[0])))
def listen(self):
#listens to:
# forwarding search queries,
# relay node requests
# aggregates search-results
while 1:
dat, addr = self.soc.recvfrom(1024)
#print 'Got a packet'
#print 'From:',addr
#print 'Data:',dat
#decrypt the packet if necessary
pac = self.decryptPacket(dat)
#print 'DData:',dat
# for i in dat:
# print ord(i),
# print
#now proceed for fragmenting
# for i in pac:
# print ord(i),
# print
pac = SearchPacket(pac)
is_invalid = 0
if not pac.isValid():
print 'Corrupted Packet',pac.getRequestType()
is_invalid=1
if pac.getRequestType()==1:
# its a search request
print 'Search Req from',addr[0]
#if its invalid just discard
if is_invalid:
print 'invalid Packet'
continue
#check if its already in the cache
if pac.getData() in self.query_cache:
#if it is, then ignore the packet
print 'duplicate query'
continue
print 'Searching the system..'
#forward this search query to all the neighbours
#we get the neighbours from the link object
for neig in self.linkObj.nodes:
if neig != addr[0]:
self.soc.sendto(pac.getRawMessage(),
(neig, Config.D_UDP_LISTEN_PORT))
self.query_cache.append(pac.getData())
#now start a thread to remove this after some time
thread.start_new_thread( self.updateQueryCache, (pac.getData(),))
#search in our file-system and get the results
res = self.searchFiles(pac.getData())
if len(res):
#if the result is non-empty
#first encrypt the results using
#the pulic-key sent in the packet
#print 'Results:'
#print res
#print 'RSA Key:',pac.getKey()
tmprsa = RSAKeys(pac.getKey())
#get the length of results
l_res = len(res)
#get the length of keys
l_keys = len(self.Aes_key.aes_key)
#form the packet
dat = chr(l_res/256) + chr(l_res%256) + res\
+ chr(l_keys/256) + chr(l_keys%256) +\
self.Aes_key.aes_key
print 'Got Some results!'
# print '***',dat,'***'
# for i in dat:
# print ord(i),
# print
#encrypt it
cipher = tmprsa.encrypt(dat)
#print 'Len:',len(cipher)
# print '********',cipher,'******',len(cipher)
#now, make a packet with these results
tmppac = SearchPacket()
#type:2,
#src-ip -> src of the query issuer
#send aes-key of this machine
tmppac.setPacketByFields(2,pac.getIP(),
cipher)
#print 'Req IP:',pac.getIP()
#print tmppac.getRawMessage(),'|||||'
# for i in tmppac.getRawMessage():
# print ord(i),
# print
#get a random first hop from the
#neighours
nxt_ip=''
#check if its the same node
#that is requesting
#
for i in self.linkObj.nodes:
if i!=addr[0]:
nxt_ip=i
break
print 'Sending to:',nxt_ip
self.soc.sendto(tmppac.getRawMessage(),
(nxt_ip, Config.D_UDP_LISTEN_PORT))
else:
print 'No results'
elif pac.getRequestType()==2:
#this is a search-results packet
#check if the IP matches with us
#print pac.getIP(),'===',self.linkObj.ip_address
if pac.getIP()==self.linkObj.ip_address:
#display the results
res = pac.getData()
# print 'Got the Key:'
# for i in pac.getKey():
# print ord(i),
# print
for r in res.split("||"):
f = r.split()
if len(f)==2:
self.search_results.append(
[f[0],f[1],addr[0],pac.getKey()]
)
print str(len(self.search_results)).ljust(4)+ f[1].ljust(16)+f[0].ljust(8)+addr[0].ljust(10)
else:
#this should be forwarded to
#the intended ip-address
#in this case, 'dat'
print 'forwarding to ',pac.getIP()
self.soc.sendto(dat, (pac.getIP(),
Config.D_UDP_LISTEN_PORT
))
elif pac.getRequestType()==3:
#a download request
#if is_invalid is set=>not intended for us
#forwarding to neighbours depends on the
#dest-address
if not is_invalid:
#intended for us
print 'Got a download request'
self.setupSourceRelayNode(pac)
elif is_invalid and \
pac.getIP()==self.linkObj.ip_address:
#its an interim node
#should forward to neighbours
print 'Forwarding to adjacent nodes'
for ip in self.linkObj.nodes:
self.soc.sendto(dat,
(ip, Config.D_UDP_LISTEN_PORT)
)
elif pac.getRequestType()==4:
#requesting this machine to act as
#relay node
#check the type bit first
print 'Got a relay-node request'
#print 'Data:',pac.getRawMessage()
if pac.getData()[0]=='0':
#forward data to src-ip
#create listening socket for src-ip to connect
print 'On receiving end'
tcpsoc1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc1.bind(('',0))
#for the other node to connect
tcpsoc2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc2.bind(('',0))
tmppac = SearchPacket()
tmppac.setPacketByFields(
5, self.linkObj.ip_address,
str(tcpsoc1.getsockname()[1])+"|"+
str(tcpsoc2.getsockname()[1])
)
self.soc.sendto(tmppac.getRawMessage(), addr)
#now create a thread which listens on these ports
thread.start_new_thread(
self.receiveEndThread,
(tcpsoc1, tcpsoc2))
elif pac.getData()[0]=='1':
#get data from src-ip
#and forward it to some other node
#we will have the details of src-ip:port to
#connect
print 'r-req for sending end'
ip = pac.getData().split("|")[1]
ip,port = ip.split(":")[0],ip.split(":")[1]
tcpsoc1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc1.bind(('',0))
tmppac = SearchPacket()
tmppac.setPacketByFields(
5, self.linkObj.ip_address,
str(tcpsoc1.getsockname()[1])
)
thread.start_new_thread(
self.sendEndThread,
(ip,port, tcpsoc1))
time.sleep(2)
print 'Sending port to',addr[0]
self.soc.sendto(tmppac.getRawMessage(),
addr)
elif pac.getRequestType()==5:
#reply from the relay node
print 'Got a reply from relay-node'
#split by '|'
print pac.getData(),'**'
vals = pac.getData().split('|')
if len(vals)==2:
#means this is on receiving end
#connect to the port and get the data.
thread.start_new_thread(self.downloadFile,
(addr[0], int(vals[0]))
)
time.sleep(1)
#send the other port details
#to the interim node
#format: file_name|ip:port
dat = self.search_results[self.user_choice-1][1]+"|"
dat += addr[0] +':'+vals[1]
dat = chr(len(dat)/256)+chr(len(dat)%256)+dat
key_aes = self.search_results[self.user_choice-1][3]
our_key = self.Aes_key.aes_key
#encrypt the request with the other user's key
our_key = chr(len(our_key)/256)+\
chr(len(our_key)%256)+our_key
# print 'Ptxt:',int(len(dat+our_key))
# for q in dat+our_key:
# print ord(q),
# print
# print 'Encrypt-Key:'
# for h in key_aes:
# print ord(h),
# print
aesVar = AESCipher(key_aes)
rand_iv = aesVar.generateIV()
cipher = aesVar.n_encrypt(dat + our_key)
# print 'cipher:',int(len(cipher))
#destination is our intermediate node
dest_ip = self.search_results[self.user_choice-1][2]
d_pac = SearchPacket()
d_pac.setPacketByFields( 3,
dest_ip,
cipher
)
tmps = d_pac.getRawMessage()+rand_iv
# for c in tmps:
# print ord(c),
# print
print 'Sending dwnld req to',dest_ip
self.soc.sendto(d_pac.getRawMessage()+rand_iv,
(dest_ip, Config.D_UDP_LISTEN_PORT))
else:
#the vals[0] is where we need to connect
#and then start uploading the file..
#so start a thread directly
print 'Starting the upload thread'
thread.start_new_thread(self.uploadFile,
(addr[0], int(vals[0])))
class Downloader:
def __init__(self,l_obj):
#object reference from Link_Maintain module
self.linkObj = l_obj
#rsa key object
self.Rsa_key = RSAKeys()
#aes object for enc and dec files
self.Aes_key = AESCipher()
for i in self.Aes_key.aes_key:
print ord(i),
print
#start a udp listener here with
#port configured in the config file
#create the UDP Socket
self.soc = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self.soc.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
self.soc.bind((Config.ANY_INTF, Config.D_UDP_LISTEN_PORT))
#stores the query caches
#format: src_ip|search_query
self.query_cache = []
#object for storing search results
#format: [query,size,origin-ip,aes-key]
self.search_results=[]
#object for user's choice from
#search results
self.user_choice=-1
thread.start_new_thread(self.listen, ())
#variable to store req. file
self.req_file=''
#stores the aes key of the receipient
self.recv_key=''
def updateQueryCache(self, val):
#wait for some time
time.sleep(Config.QUERY_CACHE_TIME)
self.query_cache.remove(val)
def decryptPacket(self,data):
#leave away the first 4 bytes
#its ip
#check the fifth byte
if ord(data[4])==1:
#its a search query
#not encrypted at all so don't proceed
#furthur
return data
elif ord(data[4])==2:
#they are search results
#directed to us
#decrypt them with the RSA Key
#decryption starts from the 6th byte
res = self.Rsa_key.decrypt(data[5:])
return data[:5]+res
elif ord(data[4])==3:
#its a download request
#encrypted with AES
#last 16-bytes is the IV
iv = data[-16:]
#decrypt from 6th byte to last but 17th byte
p_txt = self.Aes_key.n_decrypt(data[5:-16], iv)
return data[:5]+p_txt
else:
#all other types are plain-texts
#so return as-it-is
return data
def listen(self):
#listens to:
# forwarding search queries,
# relay node requests
# aggregates search-results
while 1:
dat, addr = self.soc.recvfrom(1024)
#print 'Got a packet'
#print 'From:',addr
#print 'Data:',dat
#decrypt the packet if necessary
pac = self.decryptPacket(dat)
#print 'DData:',dat
# for i in dat:
# print ord(i),
# print
#now proceed for fragmenting
# for i in pac:
# print ord(i),
# print
pac = SearchPacket(pac)
is_invalid = 0
if not pac.isValid():
print 'Corrupted Packet',pac.getRequestType()
is_invalid=1
if pac.getRequestType()==1:
# its a search request
print 'Search Req from',addr[0]
#if its invalid just discard
if is_invalid:
print 'invalid Packet'
continue
#check if its already in the cache
if pac.getData() in self.query_cache:
#if it is, then ignore the packet
print 'duplicate query'
continue
print 'Searching the system..'
#forward this search query to all the neighbours
#we get the neighbours from the link object
for neig in self.linkObj.nodes:
if neig != addr[0]:
self.soc.sendto(pac.getRawMessage(),
(neig, Config.D_UDP_LISTEN_PORT))
self.query_cache.append(pac.getData())
#now start a thread to remove this after some time
thread.start_new_thread( self.updateQueryCache, (pac.getData(),))
#search in our file-system and get the results
res = self.searchFiles(pac.getData())
if len(res):
#if the result is non-empty
#first encrypt the results using
#the pulic-key sent in the packet
#print 'Results:'
#print res
#print 'RSA Key:',pac.getKey()
tmprsa = RSAKeys(pac.getKey())
#get the length of results
l_res = len(res)
#get the length of keys
l_keys = len(self.Aes_key.aes_key)
#form the packet
dat = chr(l_res/256) + chr(l_res%256) + res\
+ chr(l_keys/256) + chr(l_keys%256) +\
self.Aes_key.aes_key
print 'Got Some results!'
# print '***',dat,'***'
# for i in dat:
# print ord(i),
# print
#encrypt it
cipher = tmprsa.encrypt(dat)
#print 'Len:',len(cipher)
# print '********',cipher,'******',len(cipher)
#now, make a packet with these results
tmppac = SearchPacket()
#type:2,
#src-ip -> src of the query issuer
#send aes-key of this machine
tmppac.setPacketByFields(2,pac.getIP(),
cipher)
#print 'Req IP:',pac.getIP()
#print tmppac.getRawMessage(),'|||||'
# for i in tmppac.getRawMessage():
# print ord(i),
# print
#get a random first hop from the
#neighours
nxt_ip=''
#check if its the same node
#that is requesting
#
for i in self.linkObj.nodes:
if i!=addr[0]:
nxt_ip=i
break
print 'Sending to:',nxt_ip
self.soc.sendto(tmppac.getRawMessage(),
(nxt_ip, Config.D_UDP_LISTEN_PORT))
else:
print 'No results'
elif pac.getRequestType()==2:
#this is a search-results packet
#check if the IP matches with us
#print pac.getIP(),'===',self.linkObj.ip_address
if pac.getIP()==self.linkObj.ip_address:
#display the results
res = pac.getData()
# print 'Got the Key:'
# for i in pac.getKey():
# print ord(i),
# print
for r in res.split("||"):
f = r.split()
if len(f)==2:
self.search_results.append(
[f[0],f[1],addr[0],pac.getKey()]
)
print str(len(self.search_results)).ljust(4)+ f[1].ljust(16)+f[0].ljust(8)+addr[0].ljust(10)
else:
#this should be forwarded to
#the intended ip-address
#in this case, 'dat'
print 'forwarding to ',pac.getIP()
self.soc.sendto(dat, (pac.getIP(),
Config.D_UDP_LISTEN_PORT
))
elif pac.getRequestType()==3:
#a download request
#if is_invalid is set=>not intended for us
#forwarding to neighbours depends on the
#dest-address
if not is_invalid:
#intended for us
print 'Got a download request'
self.setupSourceRelayNode(pac)
elif is_invalid and \
pac.getIP()==self.linkObj.ip_address:
#its an interim node
#should forward to neighbours
print 'Forwarding to adjacent nodes'
for ip in self.linkObj.nodes:
self.soc.sendto(dat,
(ip, Config.D_UDP_LISTEN_PORT)
)
elif pac.getRequestType()==4:
#requesting this machine to act as
#relay node
#check the type bit first
print 'Got a relay-node request'
#print 'Data:',pac.getRawMessage()
if pac.getData()[0]=='0':
#forward data to src-ip
#create listening socket for src-ip to connect
print 'On receiving end'
tcpsoc1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc1.bind(('',0))
#for the other node to connect
tcpsoc2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc2.bind(('',0))
tmppac = SearchPacket()
tmppac.setPacketByFields(
5, self.linkObj.ip_address,
str(tcpsoc1.getsockname()[1])+"|"+
str(tcpsoc2.getsockname()[1])
)
self.soc.sendto(tmppac.getRawMessage(), addr)
#now create a thread which listens on these ports
thread.start_new_thread(
self.receiveEndThread,
(tcpsoc1, tcpsoc2))
elif pac.getData()[0]=='1':
#get data from src-ip
#and forward it to some other node
#we will have the details of src-ip:port to
#connect
print 'r-req for sending end'
ip = pac.getData().split("|")[1]
ip,port = ip.split(":")[0],ip.split(":")[1]
tcpsoc1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsoc1.bind(('',0))
tmppac = SearchPacket()
tmppac.setPacketByFields(
5, self.linkObj.ip_address,
str(tcpsoc1.getsockname()[1])
)
thread.start_new_thread(
self.sendEndThread,
(ip,port, tcpsoc1))
time.sleep(2)
print 'Sending port to',addr[0]
self.soc.sendto(tmppac.getRawMessage(),
addr)
elif pac.getRequestType()==5:
#reply from the relay node
print 'Got a reply from relay-node'
#split by '|'
print pac.getData(),'**'
vals = pac.getData().split('|')
if len(vals)==2:
#means this is on receiving end
#connect to the port and get the data.
thread.start_new_thread(self.downloadFile,
(addr[0], int(vals[0]))
)
time.sleep(1)
#send the other port details
#to the interim node
#format: file_name|ip:port
dat = self.search_results[self.user_choice-1][1]+"|"
dat += addr[0] +':'+vals[1]
dat = chr(len(dat)/256)+chr(len(dat)%256)+dat
key_aes = self.search_results[self.user_choice-1][3]
our_key = self.Aes_key.aes_key
#encrypt the request with the other user's key
our_key = chr(len(our_key)/256)+\
chr(len(our_key)%256)+our_key
# print 'Ptxt:',int(len(dat+our_key))
# for q in dat+our_key:
# print ord(q),
# print
# print 'Encrypt-Key:'
# for h in key_aes:
# print ord(h),
# print
aesVar = AESCipher(key_aes)
rand_iv = aesVar.generateIV()
cipher = aesVar.n_encrypt(dat + our_key)
# print 'cipher:',int(len(cipher))
#destination is our intermediate node
dest_ip = self.search_results[self.user_choice-1][2]
d_pac = SearchPacket()
d_pac.setPacketByFields( 3,
dest_ip,
cipher
)
tmps = d_pac.getRawMessage()+rand_iv
# for c in tmps:
# print ord(c),
# print
print 'Sending dwnld req to',dest_ip
self.soc.sendto(d_pac.getRawMessage()+rand_iv,
(dest_ip, Config.D_UDP_LISTEN_PORT))
else:
#the vals[0] is where we need to connect
#and then start uploading the file..
#so start a thread directly
print 'Starting the upload thread'
thread.start_new_thread(self.uploadFile,
(addr[0], int(vals[0])))
def uploadFile(self,ip,port):
#connect to the ip:port and start sending the data
#first open the file
fd = open(self.req_file, 'r')
tcps = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print 'Started upload thread'
tcps.connect((ip, port))
tmpAes = AESCipher(self.recv_key)
iv = tmpAes.generateIV()
#first send the iv in plain
tcps.send(iv)
while 1:
st = fd.read(15)#read 16-bytes. encrypt them & send
print 'Got',len(st),'bytes'
cip = tmpAes.n_encrypt(st)
tcps.send(cip)
if len(st)<15:
break
print 'Done Uploading..'
tcps.close()
def downloadFile(self,ip,port):
#connect to the ip:port and wait for the data.
#get the file-name
print 'Started download-file thread'
f_name = self.search_results[self.user_choice-1][1]
fd = open(f_name, 'w')
tcps = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print 'Connecting to',ip+":"+str(port)
tcps.connect((ip, port))
print 'Connected'
#first 16-bytes are the IV
self.Aes_key.iv = tcps.recv(16)
print 'Got the IV'
while 1:
st = tcps.recv(16)
print 'Got',len(st),'bytes..'
if st=='':
#connection closed
print 'Download Finished'
tcps.close()
fd.close()
break
pln = self.Aes_key.n_decrypt(st,self.Aes_key.iv)
print 'wrote..',pln
fd.write(pln)
print 'File-Contents:'
fr = open(f_name, 'r')
while 1:
st = fr.read(1024)
if st=='':
break
print st
def sendEndThread(self, ip,port,tcp1):
#tcp1 -> listen for connection from src_node
#connect itself to ip:port
print 'Starting send-end thread..'
tcp2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcp2.connect((ip, int(port)))
tcp1.listen(10)
print 'Listening on '+ip+':'+port
fd,addr = tcp1.accept()
print 'Got a connection'
while 1:
#transfer data from tcp1 to tcp2
#until connection is closed
st = fd.recv(16)
if st=='':
#closed connection
fd.close()
return
print 'Got',len(st),'bytes'
tcp2.send(st)
print 'Closing connection..'
def receiveEndThread(self, tcp1, tcp2):
#wait for the incoming connection
#from the src_node
print 'Started recevive-end thread'
tcp1.listen(10)
fd1, addr = tcp1.accept()
print 'Connected to source-node'
#now wait for the other node to connect
tcp2.listen(10)
fd2, addr = tcp2.accept()
print 'Connected to other-end relay node'
while 1:
#write whatever data comes to tcp2
#into tcp1
st = fd2.recv(16)
if st=='':
#connection has been closed
#close this one also and kill this thread
fd1.close()
return
print 'Got',len(st),'bytes'
fd1.send(st)
print 'Closing Connection...'
def searchNetwork(self,query):
#creates a search packet
#and sends it to adjacent nodes
qpac = SearchPacket()
qpac.setRequestType(1)#'1' for searching
qpac.setKey(self.Rsa_key.getPEMPublic())
qpac.setData(query)
qpac.setIP(self.linkObj.ip_address)
qpac.makePacket()
#first empty the search-results list
self.search_results=[]
print 'Sending:',qpac.getRawMessage()
print self.Rsa_key.getPEMPublic(),self.linkObj.ip_address
#fire the query into the network
#via the adjacent nodes
for nds in self.linkObj.nodes:
self.soc.sendto(qpac.getRawMessage(),
(nds, Config.D_UDP_LISTEN_PORT))
print 'Sent to:',nds+":"+str(Config.D_UDP_LISTEN_PORT)
print 'Search Query sent!\nWaiting for results'
print 'S.No'.ljust(4)+'File-Name'.ljust(16)+'Size'.ljust(8),'Source'.ljust(10)
def searchFiles(self,query):
#this searches our file file-system
#assumed that 'shared' is a directory
#with in the pwd of the program
command = 'wc -c * 2>/dev/null | grep '+query+\
' | awk \'{printf "%s||",$0}\''
print command
#execute the command
f = os.popen(command)
#get the results
res = f.read()
return res
def downloadRequest(self,choice):
#this function starts the dwnld process
#for a specific file
#choice is an integer corresponding to the entry in
#the search results list
self.user_choice = choice
#first create a packet for relay-node
rpac = SearchPacket()
#pick one of the r_node from the adj ones
r_node = ''
tmpnode = ''#in case r_node is empty
for i in self.linkObj.nodes:
tmpnode = i
if randint(1,3)==2:
r_node = i
break
if r_node=='':
r_node = tmpnode
#'0'=> wants to get data from relay-node
rpac.setPacketByFields(4, self.linkObj.ip_address,
'0')
print 'Sending relay-request to',r_node
self.soc.sendto( rpac.getRawMessage(),
(r_node, Config.D_UDP_LISTEN_PORT))
#def setupDestRelayNode(self):
def setupSourceRelayNode(self,pac):
#this fn. requests for a relay nodes
#to open a socket and transfer
#data from this machine
#return ip-address:port pair
#where the relay node is listening
self.req_file = pac.getData().split("|")[0]
self.recv_key = pac.getKey()
ipport = pac.getData().split("|")[1]
msg = '1|'+ipport
pac = SearchPacket()
pac.setPacketByFields(4,
self.linkObj.ip_address,
msg)
#pick one of the r_node from the adj ones
r_node = ''
tmpnode = ''#in case r_node is non-empty
for i in self.linkObj.nodes:
tmpnode = i
if randint(1,3)==2 and i!=ipport.split(":")[0]:
r_node = i
break
if r_node=='':
r_node = tmpnode
print 'Sending r-req to',r_node
self.soc.sendto(pac.getRawMessage(),
(r_node, Config.D_UDP_LISTEN_PORT))
