From 3314d879666beaa1aa724ff28ad15326167e548f Mon Sep 17 00:00:00 2001 From: "Wladimir J. van der Laan" Date: Tue, 1 Oct 2019 11:00:53 +0200 Subject: [PATCH] contrib: makeseeds: Factor out ASN lookup --- contrib/seeds/makeseeds.py | 55 +++++++++++++++++++++----------------- 1 file changed, 31 insertions(+), 24 deletions(-) diff --git a/contrib/seeds/makeseeds.py b/contrib/seeds/makeseeds.py index f5484ab33..710881b1a 100755 --- a/contrib/seeds/makeseeds.py +++ b/contrib/seeds/makeseeds.py @@ -121,6 +121,31 @@ def filtermultiport(ips): hist[ip['sortkey']].append(ip) return [value[0] for (key,value) in list(hist.items()) if len(value)==1] +def lookup_asn(net, ip): + ''' + Look up the asn for an IP (4 or 6) address by querying cymry.com, or None + if it could not be found. + ''' + try: + if net == 'ipv4': + ipaddr = ip + prefix = '.origin' + else: # http://www.team-cymru.com/IP-ASN-mapping.html + res = str() # 2001:4860:b002:23::68 + for nb in ip.split(':')[:4]: # pick the first 4 nibbles + for c in nb.zfill(4): # right padded with '0' + res += c + '.' # 2001 4860 b002 0023 + ipaddr = res.rstrip('.') # 2.0.0.1.4.8.6.0.b.0.0.2.0.0.2.3 + prefix = '.origin6' + + asn = int([x.to_text() for x in dns.resolver.query('.'.join( + reversed(ipaddr.split('.'))) + prefix + '.asn.cymru.com', + 'TXT').response.answer][0].split('\"')[1].split(' ')[0]) + return asn + except Exception: + sys.stderr.write('ERR: Could not resolve ASN for "' + ip + '"\n') + return None + # Based on Greg Maxwell's seed_filter.py def filterbyasn(ips, max_per_asn, max_total): # Sift out ips by type @@ -129,33 +154,15 @@ def filterbyasn(ips, max_per_asn, max_total): # Filter IPv46 by ASN result = [] - asn_count = {} + asn_count = collections.defaultdict(int) for ip in ips_ipv46: if len(result) == max_total: break - try: - if ip['net'] == 'ipv4': - ipaddr = ip['ip'] - prefix = '.origin' - else: # http://www.team-cymru.com/IP-ASN-mapping.html - res = str() # 2001:4860:b002:23::68 - for nb in ip['ip'].split(':')[:4]: # pick the first 4 nibbles - for c in nb.zfill(4): # right padded with '0' - res += c + '.' # 2001 4860 b002 0023 - ipaddr = res.rstrip('.') # 2.0.0.1.4.8.6.0.b.0.0.2.0.0.2.3 - prefix = '.origin6' - - asn = int([x.to_text() for x in dns.resolver.query('.'.join( - reversed(ipaddr.split('.'))) + prefix + '.asn.cymru.com', - 'TXT').response.answer][0].split('\"')[1].split(' ')[0]) - if asn not in asn_count: - asn_count[asn] = 0 - if asn_count[asn] == max_per_asn: - continue - asn_count[asn] += 1 - result.append(ip) - except: - sys.stderr.write('ERR: Could not resolve ASN for "' + ip['ip'] + '"\n') + asn = lookup_asn(ip['net'], ip['ip']) + if asn is None or asn_count[asn] == max_per_asn: + continue + asn_count[asn] += 1 + result.append(ip) # Add back Onions result.extend(ips_onion)