merge_geoip_csv

#!/usr/bin/env python

from argparse import ArgumentParser
import sys, os
from csv import reader, writer, Sniffer, QUOTE_ALL
from ipaddress import IPv6Address

arg_parser = ArgumentParser()
arg_parser.add_argument('-o', '--output', default=None,
        help = 'Output to the specified file name (default is stdout)')
arg_parser.add_argument('ipv4_csv', help = 'Maxmind\'s GeoIP IPv4 country file to merge')
arg_parser.add_argument('ipv6_csv', help = 'Maxmind\'s GeoIP IPv6 country file to merge')

args = arg_parser.parse_args()

if args.output is None :
    output = sys.stdout
else :
    output = open(args.output, 'w')

ipv4_csv = open(args.ipv4_csv, 'r')
ipv6_csv = open(args.ipv6_csv, 'r')

# Sniff the format
dialect = Sniffer().sniff(ipv6_csv.read(1024))
ipv6_csv.seek(0)

output_csv = writer(output, dialect, quoting = QUOTE_ALL)

lsnat_ip = (
    "0:0:0:0:0:ffff:100.64.0.1",
    "0:0:0:0:0:ffff:100.127.255.254", 
    281472363659265,
    281472367853566,
    "TH",
    "Thailand",
)

# For V4, we need to translate it to v6
lsnat_inserted = False
for row in reader(ipv4_csv, dialect) :
    v6_start = '0:0:0:0:0:ffff:' + row[0]
    v6_start_int = int(IPv6Address(unicode(v6_start)))
    v6_end = '0:0:0:0:0:ffff:' + row[1]
    v6_end_int = int(IPv6Address(unicode(v6_end)))
    if not lsnat_inserted and (v6_start_int > lsnat_ip[2]) :
        output_csv.writerow(lsnat_ip)
        lsnat_inserted = True

    output_csv.writerow([
        v6_start, v6_end,
        v6_start_int, v6_end_int,
        row[4], row[5],
    ])

for row in reader(ipv6_csv, dialect) :
    output_csv.writerow(row)

ipv4_csv.close()
ipv6_csv.close()

if not args.output is None :
    output.close()