icmp response not coming?

Question

linux

I have a python code that accepts icmp pings and sends back a response. Pings come and the answer is not.

import socket
r = socket
s = socket.socket(r.AF_INET, r.SOCK_RAW, r.IPPROTO_ICMP)
#s.setsockopt(socket.SOL_IP, socket.IP_HDRINCL,0)
while True:
 data,addr = s.recvfrom(4096)
 d = data.split(b"\x08\x00")[1]
 chk = bytes([d[0]]),bytes([d[1]])
 id = bytes([d[2]]),bytes([d[3]])
 seq = bytes([d[4]]),bytes([d[5]])
 payload = b''
 for x in d:
  if x == d[0]:
   continue
  elif x == d[1]:
   continue
  elif x == d[2]:
   continue
  elif x == d[3]:
   continue
  elif x == d[4]:
   continue
  elif x == d[5]:
   continue
  else:
   payload += bytes([x])

 print("Checksum: ",chk)
 print("Id: ",id)
 print("Seq num: ",seq)
 print("Payload: ",payload.decode("utf-8"))
 rsp = b"\x00\x00\x00\x00"+id[0]+id[1]+seq[0]+seq[1]+payload
 print(rsp)
 s.sendto(rsp,addr)

At the output from the server, nothing is visible either, that is, the kernel does not let the packet through.

Answer 1

the kernel does not let the packet through.

Well icmp type 8 is the request and type 0 is the response. You may have a packet blocked in iptables by a rule like

iptables -A OUTPUT -p icmp -m icmp --icmp-type 8 -j DROP

Do it first
iptables -F
and try again.
PS I'm not savvy in python, so there may be an error in the code.