PERFORCE change 143018 for review

Victor Hugo Bilouro bilouro at FreeBSD.org
Fri Jun 6 10:33:20 UTC 2008


http://perforce.freebsd.org/chv.cgi?CH=143018

Change 143018 by bilouro at bilouro_tcptest on 2008/06/06 10:32:50

	Script is working. (send syn, receive syn+ack, send ack, send fin)
	uniitest applied
	Some References to RFC
	
	It still been a prototype version 
	todo: create 

Affected files ...

.. //depot/projects/soc2008/bilouro_tcptest/TODO#4 edit
.. //depot/projects/soc2008/bilouro_tcptest/src/scripts/tests/cthreewayhandshake_nooptions.py#2 edit

Differences ...

==== //depot/projects/soc2008/bilouro_tcptest/TODO#4 (text+ko) ====

@@ -15,5 +15,13 @@
 
     this.packet == that.packet will be possible
 
+Think about:
+    self.ethersrc = ethernet.ether_atob("00:1c:42:47:3f:cd") 
+    It should be automatic
+      * may be extend Ethernet to receive ip as constructor arg
+	  ethernet( ip ) 
+      * may be as a utility method
+	  ethernet().configue(ip)     
+
 done:
 -manually establish a tcp connection using pcs

==== //depot/projects/soc2008/bilouro_tcptest/src/scripts/tests/cthreewayhandshake_nooptions.py#2 (text+ko) ====

@@ -33,178 +33,317 @@
 # Description: A simple test of three way handshake without any changes 
 #
 
-"""
-THIS IS A MIDNIGHT COMMIT, THIS CODE NOT EVEN HAD ITS SYNTAX TESTED
-"""
-
-import unittest
+import unittest 
+from pcs.packets import ipv4
+from pcs.packets import tcp
+from pcs.packets import ethernet
+import pcs
 
 class TestThreeWayHandshakeWithoutAnyOptions(unittest.TestCase):
     """This class tests the threeway handshake without any options"""
-    
+
+   
     def setUp(self):
         """
         As it's the first test, I will use this method as a simple TCB.
         I'm planning use some object to handle that.
         
         In this version, TCB is being initialized with test setup 
-	values.
+        values.
         
         Tcpdump file format would a form to store setup values.        
         """
         import random
         
-        #TCB
         self.tcb = self
+
+        #constants
         self.thisside = 0
         self.thatside = 1
-        #...
+        #...Can add other sides
         
-
-
-        #opt 1
+        #opt 1 - this opt reduce the scalability, and bring more code.
         #self.ipsrc = pcs.inet_atol("192.168.1.10")
         #self.ipdst = pcs.inet_atol("192.168.1.20")
         #opt 2
         self.ip = { self.thisside : pcs.inet_atol("192.168.1.10") , \
-		    self.thatside : pcs.inet_atol("192.168.1.20")}
+                    self.thatside : pcs.inet_atol("192.168.1.20")}
+
         self.ipid = { self.thisside : random.randrange(1,(1<<16)-1) , \
-		      self.thatside : 0}
+                      self.thatside : 0}
+
+
+        self.tcpport = { self.thisside : random.randrange(50000,60000) , \
+                         self.thatside : 9}
+
+        self.tcpsequence = { self.thisside : random.randrange(1,(1<<32)-1) , 
+                             self.thatside : 0}
+        
+        # see TODO       
+        self.ether = \
+                { self.thisside : ethernet.ether_atob("00:1c:42:47:3f:cd") , \
+                  self.thatside : ethernet.ether_atob("00:1c:42:db:c5:22") }
+
 
+        # see TODO       
+        self.output = { self.thisside : pcs.PcapConnector("ed0") ,\
+                        self.thatside : pcs.PcapConnector("ed0") } 
 
 
+    def testTestThreeWayHandshakeWithoutAnyOptions(self):
+        """active open - three way handshake"""
+        #RFC793-P31-p1
+        #THISSIDE
 
-        self.tcpport = { self.thisside : random.randrange(50000,60000) , \
-			 self.thatside : 9}
-        self.tcpsequence = { self.thisside : random.randrange(1,(1<<32)-1) , 
-			     self.thatside : 0}
         
+    #
+    #Sendind SYN
+    #
+        #THISSIDE
+        (ipsyn, tcpsyn) = createsyn(self, self.tcb, self.tcb.thisside, self.tcb.thatside)
+        createwritepacket(self, self.tcb, ipsyn, tcpsyn, self.tcb.thisside, \
+                                                           self.tcb.thatside)
+
+        #THATHSIDE
+        #Receiving SYN (unfurtunately this time we are receiving from the same board) 
+        (ipsynreceived, tcpsynreceived) = receive(self, self.tcb, self.tcb.thatside, \
+                                                                    self.tcb.thisside)
+
+        self.assertEqual(ipsyn, ipsynreceived)
+        self.assertEqual(tcpsyn, tcpsynreceived)
+        print tcpsynreceived 
+
+
+    #
+    #Receiving SYN+ACK
+    #
+        #THISSIDE
+    	#Receivinig SYN + ACK
+    	(ipsynack, tcpsynack) = receive(self, self.tcb, self.tcb.thisside, self.tcb.thatside) 
+
+ 	#test conformance of header fields (todo)
+
+
+    	#RFC793-P24-p1
+    	#A fundamental notion in the design is that every octet of data sent
+    	#over a TCP connection has a sequence number.
+    	#
+    	self.assertNotEqual(tcpsynack.sequence, 0)
+    	self.assertNotEqual(tcpsynack.sequence, None)
+
+    	#RFC793-P27-p5~P28-p2
+    	#As we are testing 3wayhandshake it must be SYN+ACK
+    	#
+    	#self.assertEqual(tcpsynack.syn,1)
+    	self.failIf(tcpsynack.syn < 1)
+    	self.failIf(tcpsynack.ack < 1)
+
+    	#RFC793-P16-p2
+    	#Acknowledgment Number, value of the next sequence number the sender of
+    	#the segment is expecting to receive
+    	#
+    	self.assertEqual(tcpsynack.ack_number, self.tcb.tcpsequence[ self.tcb.thisside ])
 
+    	#OK Its a SYN+ACK
+    	self.tcb.tcpsequence[ self.tcb.thatside ] = tcpsynack.sequence + 1
+        print tcpsynack 
+
 
-        #tcb?VVVVVVVV
-        #self.ethersrc = ethernet.ether_atob("00:1c:42:47:3f:cd") 
-	      #It should be automatic, may be extend Ethernet to receive ip as 
-	      #constructor arg
-        #self.etherdst = ethernet.ether_atob("00:1c:42:db:c5:22") i
-	      #May be something like ether.configure(ip)
+    #
+    #Sending ACK
+    #
+        #THISSIDE
+        (ipack, tcpack) = createip(self, self.tcb, self.tcb.thisside, self.tcb.thatside)
+        createwritepacket(self, self.tcb, ipack, tcpack, self.tcb.thisside, \
+                                                           self.tcb.thatside)
+        print tcpack 
+
+        #THATHSIDE
+        #Receiving SYN (unfurtunately this time we are receiving from the same board) 
+        #(ipackreceived, tcpackreceived) = receive(self, self.tcb, self.tcb.thatside, \
+        #                                                            self.tcb.thisside)
+	#pcs is assigning values different then 0 and 1 to tcpflags
+        #self.assertEqual(ipack, ipackreceived)
+        #self.assertEqual(tcpack, tcpackreceived)
+
+    #
+    #Sending FIN
+    #
+        #THISSIDE
+        (ipfin, tcpfin) = createip(self, self.tcb, self.tcb.thisside, self.tcb.thatside)
+	
+	tcpfin.fin=1
+    	self.tcb.tcpsequence[ self.tcb.thisside ] += 1
+
+        createwritepacket(self, self.tcb, ipfin, tcpfin, self.tcb.thisside, \
+                                                           self.tcb.thatside)
+        print tcpfin 
+
+
+    #
+    #Receiving ACK
+    #
+	#OK - this is enougth... 
+	#reduce code redundance (fasttodo) 
+    #
+    #Receiving FIN
+    #
+
+    #
+    #Sending ACK
+    #
 
-        self.tcpether = \
-		{ self.thisside : ethernet.ether_atob("00:1c:42:47:3f:cd") , \
-	       	  self.thatside : ethernet.ether_atob("00:1c:42:db:c5:22") }
-         
+def createsyn(self, tcb, from_, to):
+    """Create tcp syn flag expertise"""
 
+    (ip, tcp) = createip(self, tcb, from_, to)
 
-        #control
-        self.output = pcs.PcapConnector("ed0")
-        ##
-        # Braindump
-        # self.output = { self.thisside : pcs.PcapConnector("ed0") ,\
-        #                 self.thatside : pcs.PcapConnector(remoteip,"ed0") } 
-        # to be able make synchronous tests, will be wonderful remotely 
-        # connect via pcap. eg. 
-        #   thatsideoutput = pcs.PcapConnector(remote,"ed0")  
-        # 
-        # TODO       
+    #business
+    tcp.syn = 1
+    tcp.ack = 0
+    tcb.tcpsequence[ from_ ] += 1
 
+    return (ip, tcp)
 
-    def testTestThreeWayHandshakeWithoutAnyOptions(self):
-        """three way handshake"""
-        #SYN
-        (ipsyn, tcpsyn) = createsyn(self, tcb, tcb.thisside, tcb.thatside)
+          
+def createip(self, tcb, from_, to):
+    """Create ip packet
+    tcp is also created here"""
+    ip1 = ipv4.ipv4()
 
-        ether = createethernet(self, tcb, tcb.thisside, tcb.thatside)
-        packet = pcs.Chain([ ether, ip, tcp ])
-        out = output.write(packet.bytes, len(packet.bytes))
-        
-        #here can occurs (ack,syn|syn,ack|syn+ack) (FASTTODO)
-        (ipack, tcpack) = receive(self, tcb, tcb.thisside, tcb.thatside)
-                
-              
-    def createsyn(self, tcb, from_, to):
-        """Create tcp syn flag expertise"""
+    ip1.version = 4 
+    ip1.hlen = 5   
+    ip1.tos = 0     
+    ip1.id = tcb.ipid[ from_ ] 
+    ip1.flags = 0 
+    ip1.offset = 0
+    ip1.ttl = 64
+    ip1.protocol = pcs.IPPROTO_TCP
+    ip1.src = tcb.ip[ from_ ]
+    ip1.dst = tcb.ip[ to ]
+    ip1.length = len(ip1.bytes)
 
-        (ip, tcp) = createip(self, tcb, from_, to)
-        tcp.syn = 1
+    # tcp here
+    tcp1 = createtcp(self, tcb, ip1, from_, to)
     
-        return (ip, tcp)
+    ip1.length = len(ip1.bytes) + len(tcp1.bytes) 
+    #ip1.checksum = ip_cksum(ip1) #doind this at checkout(createwritepacket)
     
-    def receive(self, tcb, from_, to):
-        """receive packet for this socket
-        This method must handle timmers"""
-        (ip, tcp) = (None, None)
-        while 1: 
-            reply = output.read()
-            try: 
-                packet = ethernet.ethernet(reply)
-                ip = packet.data
-                tcp = replyip.data
-                if (tcb.ip[ from_ ]==ip.dst and \
-                    tcb.ip[ to ]==ip.src and \
-                    tcb.tcpport[ from_ ]==tcp.dport and \
-                    tcb.tcpport[ to ]==tcp.sport): 
-                    break
-            except: 
-                pass
-            
-        return (ip, tcp)
+    return (ip1, tcp1) 
+
+
+def createtcp(self, tcb, ip, from_, to):
+    """Create tcp packet"""
+    tcp1 = tcp.tcp()
+
+    tcp1.sport = tcb.tcpport[ from_ ] 
+    tcp1.dport = tcb.tcpport[ to ]
+    tcp1.sequence = tcb.tcpsequence[ from_ ]        
+    tcp1.ack_number = tcb.tcpsequence[ to ]
+    tcp1.offset = 5
+    tcp1.urgent = 0
+    tcp1.ack = 1
+    tcp1.push = 0
+    tcp1.reset = 0
+    tcp1.syn = 0
+    tcp1.fin = 0
+    tcp1.window = (1<<16)-1
+    tcp1.urg_point = 0
+    #tcp1.options
+
+    #tcp1.checksum = tcp_cksum(tcp1 , ip) #doind this at checkout(createwrite)
+
+    return tcp1
+
 
-    def createethernet(self, tcb, from_, to):
-        """Create ethernet header"""
-        ether1 = ethernet.ethernet()
-        #opt2
-        ether1.src = tcb.tcpether[from_]
-        ether1.dst = tcb.tcpether[to]                
-        ether1.type = 0x800
+def receive(self, tcb, from_, to):
+    """receive packet for this socket
+    This method must handle timmers"""
+    (ip, tcp) = (None, None)
+    while 1: 
+        reply = tcb.output[ from_ ].read()
+        try: 
+            packet = ethernet.ethernet(reply)
+            ip = packet.data
+            tcp = ip.data
+            if (tcb.ip[ from_ ]==ip.dst and \
+                tcb.ip[ to ]==ip.src and \
+                tcb.tcpport[ from_ ]==tcp.dport and \
+                tcb.tcpport[ to ]==tcp.sport): 
+                break
+        except: 
+            print "eeee"
+            pass
         
-        return ether1
-        
-    def createip(self, tcb, from_, to):
-        """Create ip packet
-        tcp is also created here"""
-        ip1 = ipv4.ipv4()
+    return (ip, tcp)
+
+
+def createwritepacket(self, tcb, ip, tcp, from_, to):
+    ether = createethernet(self, tcb, from_, to)
+
+    tcp.checksum = tcp_cksum(tcp , ip) 
+
+    ip.length = len(ip.bytes) + len(tcp.bytes) 
+    ip.checksum = ip_cksum(ip)
+ 
+    packet = pcs.Chain([ ether, ip, tcp ])
+    tcb.output[ from_ ].write(packet.bytes, len(packet.bytes))
+
+
+def createethernet(self, tcb, from_, to):
+    """Create ethernet header"""
+    ether1 = ethernet.ethernet()
+    ether1.src = tcb.ether[ from_ ]
+    ether1.dst = tcb.ether[ to ]                
+    ether1.type = 0x800
+    
+    return ether1
     
-        ip1.version = 4 
-        ip1.hlen = 5   
-        ip1.tos = 0     
-        ip1.id = tcb.ipid[ from_ ] 
-        ip1.flags = 0 
-        ip1.offset = 0
-        ip1.ttl = 64
-        ip1.protocol = pcs.IPPROTO_TCP
-        ip1.src = tcb.ip[ from_ ]
-        ip1.dst = tcb.ip[ to ]
 
-        # tcp here
-        tcp = createtcp(self, tcb, ip1, from_, to)
-        
-        ip1.length = len(ip1.bytes) + len(tcp.bytes) 
-        ip1.checksum = ip_cksum(ip1)
-        
-        return (ip1, tcp) 
+def tcp_cksum(self, ip, data = ""):  #TODO: add this method to pcs tcp.py
+    """return tcpv4 checksum"""
+    import struct
+    total = 0
+    
+    tmpip = ipv4.pseudoipv4()
+    tmpip.src = ip.src
+    tmpip.dst = ip.dst
+    tmpip.reserved = 0 
+    tmpip.protocol = pcs.IPPROTO_TCP
+    tmpip.length = len(self.getbytes()) + len(data)
+    pkt = tmpip.getbytes() + self.getbytes() + data
+    if len(pkt) % 2 == 1:
+        pkt += "\0"
+    for i in range(len(pkt)/2):
+        total += (struct.unpack("!H", pkt[2*i:2*i+2])[0])
+    total = (total >> 16) + (total & 0xffff)
+    total += total >> 16
+    return  ~total & 0xffff
+    
 
-
-    def createtcp(self, tcb, ip, from_, to):
-        """Create tcp packet"""
-        tcp1 = tcp.tcp()
+def ip_cksum(ip):    #TODO: solve the self problem, may be adding another arg
+    """calculate the IPv4 checksum over a packet
     
-        tcp1.sport = tcb.tcpport[ from_ ] 
-        tcp1.dport = tcb.tcpport[ to ]
-        tcp1.sequence = tcb.tcpsequence[ from_ ]        
-        tcp1.ack_number = tcb.tcpsequence[ to ]
-        tcp1.offset = 5
-        tcp1.urgent = 0
-        tcp1.ack = 0
-        tcp1.push = 0
-        tcp1.reset = 0
-        tcp1.syn = 0
-        tcp1.fin = 0
-        tcp1.window = (1<<16)-1
-        tcp1.urg_point = 0
-        #tcp1.options
+    returns the calculated checksum
+    """
+    import struct
+    total = 0
+    packet = ipv4.ipv4(ip.bytes)
+    packet.checksum = 0
+    bytes = packet.bytes
     
-        tcp1.checksum = tcp_cksum(tcp1 , ip)
+    if len(bytes) % 2 == 1:
+        bytes += "\0"
+      
+    for i in range(len(bytes)/2):
+        total += (struct.unpack("!H", bytes[2*i:2*i+2])[0])
     
-        return tcp
-        
+    total = (total >> 16) + (total & 0xffff)
+    total += total >> 16
+ 
+    return ~total & 0xffff
+
+
 if __name__ == '__main__':
     unittest.main()
+


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