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I have been working on a program lately for raw packets. We recently had a lecture about raw packets so I have been trying to learn and do exactly what my professor told me. I have a problem with my program it comes up with an error saying destination address required, its raw so I don't want to do socket.connect(destaddr) even though that will fix the error. Here is my code: Here is the class and function:

#not real mac address to protect privacy also removed preamble
class packet(object):
    b = ""
    def __init__(self, payload):
        self.payload = payload

    def ether(self):
        #preamble = "55555555555555D5" 
        macdest = "123456789101" #my mac address - needed to remove colons 
        macsource = "123456789101" #router mac address without colons
        ethertype = "0800" #removed 0x because it is not needed
        fcs = "" #frame check sequence none so far
        frame = macdest+macsource+ethertype
        return frame

    def ip(self): #in hexadecimal
        version = "4" #ipv4 hex
        ihl = "5" #header length hex
        dscp = "00" #default
        ecn = "00" #default
        length = "36" #ether-24 + ip-20 + tcp-30 = 54 to hexa = 35
        idip="0000" #random id
        flags = "40" #dont fragment flag is 2 to hex is 4
        offset = "00" #space taker
        ttl = "40"#hex(64) = 40
        protocol = "06" #for tcp
        checksum = "0000"
        ipaddrfrom = "c0a8010a"
        ipaddrto =   "c0a80101"
        datagram = version+ihl+dscp+ecn+length+idip+flags+offset+ttl+protocol+checksum+ipaddrfrom+ipaddrto
        return datagram

    def tcp(self):
        portsrc = "15c0" #5568
        portdest = "0050" #80
        syn = "00000000" 
        ack = "00000000"
        nonce = "80"
        fin = "10"
        windowscale = "813b"
        checksum = "0000"
        segment = portsrc+portdest+syn+ack+nonce+fin+windowscale + checksum
        return segment

    def getpacket(self):
        frame = self.ether()
        datagram = self.ip()
        segment = self.tcp()
        payload = self.payload
        packet = frame+datagram+segment+payload

        a = 0
        b = ""
        for char in packet:
            a = a+1
            b = b + char
            if a == 4:
                b = b + " "
                a=0
        self.fmtpacket = b
        return packet

def raw():
    s = socket(AF_INET, SOCK_RAW, IPPROTO_IP)
    s.bind(('192.168.1.10', 0))
    pckt = packet("")
    netpacket = pckt.getpacket()
    print "Sending: " + pckt.fmtpacket
    print ""
    s.sendall(netpacket)
    data = s.recv(4096)
    print data
huon
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Noah Koster
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  • have you tried looking for similar questions? for example: http://stackoverflow.com/questions/1117958/how-do-i-use-raw-socket-in-python – davidbrai Aug 31 '12 at 19:21
  • [Windows Desktop does not allow raw TCP sockets](https://stackoverflow.com/questions/62281097/why-am-i-getting-an-exception-on-windows-8-using-raw-sockets-with-ipproto-tcp) – Josiah Yoder Oct 28 '22 at 17:07
  • This question could be improved by reducing your question to a minimal example and clarifying where you are getting stuck. The question I linked in my previous comment has some good minimal examples on this topic. – Josiah Yoder Oct 28 '22 at 17:08

3 Answers3

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If your professor is okay with it, you may find Scapy a lot easier to work with in creating raw packets in python.

From their website:

Scapy is a powerful interactive packet manipulation program. It is able to forge or decode packets of a wide number of protocols, send them on the wire, capture them, match requests and replies, and much more. It can easily handle most classical tasks like scanning, tracerouting, probing, unit tests, attacks or network discovery (it can replace hping, 85% of nmap, arpspoof, arp-sk, arping, tcpdump, tethereal, p0f, etc.)

Jay Atkinson
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Is there a reason for binding to '0.0.0.0'? When you create a raw socket, you'll need to bind it to an interface.

One thing I notice is that you'll need the '\x' prefix for hex.

Right now, you're stringing together chars.

For example, in ip(), version + ihl = '45'. That's a string, not a hex value. When you're sending this along, as a raw packet, that's two bytes instead of the one that you want. You want to send '\x45', not '45'.

Pochi
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  • i binded it to an interface i just didnt put it in the code example – Noah Koster Aug 31 '12 at 19:33
  • You should update the code sample then. If people don't know what you're really doing, it's a bit hard to figure out what you might be doing wrong. – Pochi Aug 31 '12 at 19:36
  • thanks for ur response im sorry if i didnt give u enought information. do you know if i can just transfer this whole string into hex by using the pack module? and if so how? – Noah Koster Aug 31 '12 at 19:41
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packet to be sent should contain the actual bytes and not the string.

Prabhjot Singh Sethi
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