FM / examples

/usr/share/doc/python3-dns/examples

Name	Size	Mode	Actions
async_dns.py	874	0644	edit dl rm
ddns.py	1194	0644	edit dl rm
ddr.py	950	0644	edit dl rm
doh-json.py	3001	0644	edit dl rm
doh.py	534	0644	edit dl rm
doq.py	3143	0644	edit dl rm
e164.py	115	0644	edit dl rm
ecs.py	450	0644	edit dl rm
edns.py	1739	0644	edit dl rm
edns_resolver.py	1532	0644	edit dl rm
mx.py	189	0644	edit dl rm
name.py	356	0644	edit dl rm
query_specific.py	1655	0644	edit dl rm
receive_notify.py	1022	0644	edit dl rm
reverse.py	1389	0644	edit dl rm
reverse_name.py	140	0644	edit dl rm
send_notify.py	2462	0644	edit dl rm
wire_read_tcp.py	1659	0644	edit dl rm
xfr.py	340	0644	edit dl rm
zonediff.py	12173	0644	edit dl rm

Edit: /usr/share/doc/python3-dns/examples/send_notify.py (2462B)

#!/usr/bin/python
"""
Minimalistic RFC 1996-like NOTIFY sender.
"""
import argparse
import ipaddress
import socket

import dns.flags
import dns.inet
import dns.message
import dns.name
import dns.opcode
import dns.query
import dns.rrset
import dns.rdataclass
import dns.rdatatype

def main():
    """Also prints all inputs and intermediate values"""
    parser = argparse.ArgumentParser(
        description="Send DNS NOTIFY mesage via UDP, optionally with synthetized SOA RR "
        "in ANSWER section. No checks. It's not RFC 1996 sect 3.6 compliant sender."
    )
    parser.add_argument("--source", type=ipaddress.ip_address, help="source IP address")
    parser.add_argument("--port", type=int, help="target port", default=53)
    parser.add_argument("target", type=ipaddress.ip_address, help="target IP address")
    parser.add_argument("zone", type=dns.name.from_text)
    parser.add_argument(
        "serial",
        nargs="?",
        type=int,
        help="optional serial - adds SOA RR into ANSWER section",
    )
    parser.add_argument(
        "--rdclass",
        default=dns.rdataclass.IN,
        type=dns.rdataclass.from_text,
        help="DNS class, defaults to IN",
    )
    args = parser.parse_args()
    if args.source:
        if dns.inet.af_for_address(str(args.target)) != dns.inet.af_for_address(
            str(args.source)
        ):
            parser.error("address family for source and target must be the same")

print(args)
    msg = construct_msg(args)
    print(msg)
    udp_send(msg, args)

def construct_msg(args):
    """if args.serial is specified it creates fake SOA RR with given serial"""
    msg = dns.message.make_query(
        args.zone, dns.rdatatype.SOA, rdclass=args.rdclass, flags=dns.flags.AA
    )
    msg.set_opcode(dns.opcode.NOTIFY)
    if args.serial:
        soa = dns.rrset.from_text_list(
            name=args.zone,
            ttl=0,
            rdclass=args.rdclass,
            rdtype=dns.rdatatype.SOA,
            text_rdatas=[f". . {args.serial} 0 0 0 0"],
        )
        msg.answer.append(soa)
    return msg

def udp_send(msg, args):
    """ignores checks prescribed by RFC 1996 sect 3.6"""
    afam = dns.inet.af_for_address(str(args.target))
    sock = socket.socket(afam, socket.SOCK_DGRAM)
    if args.source:
        sock.bind((str(args.source), 0))
    dns.query.send_udp(sock, what=msg, destination=(str(args.target), args.port))

if __name__ == "__main__":
    main()

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