contrib/seeds/generate-seeds.py

   1 #!/usr/bin/env python3
   2 # Copyright (c) 2014-2017 Wladimir J. van der Laan
   3 # Distributed under the MIT software license, see the accompanying
   4 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5 '''
   6 Script to generate list of seed nodes for chainparams.cpp.
   7
   8 This script expects two text files in the directory that is passed as an
   9 argument:
  10
  11     nodes_main.txt
  12     nodes_test.txt
  13
  14 These files must consist of lines in the format
  15
  16     <ip>
  17     <ip>:<port>
  18     [<ipv6>]
  19     [<ipv6>]:<port>
  20     <onion>.onion
  21     0xDDBBCCAA (IPv4 little-endian old pnSeeds format)
  22
  23 The output will be two data structures with the peers in binary format:
  24
  25    static SeedSpec6 pnSeed6_main[]={
  26    ...
  27    }
  28    static SeedSpec6 pnSeed6_test[]={
  29    ...
  30    }
  31
  32 These should be pasted into `src/chainparamsseeds.h`.
  33 '''
  34
  35 from base64 import b32decode
  36 from binascii import a2b_hex
  37 import sys, os
  38 import re
  39
  40 # ipv4 in ipv6 prefix
  41 pchIPv4 = bytearray([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff])
  42 # tor-specific ipv6 prefix
  43 pchOnionCat = bytearray([0xFD,0x87,0xD8,0x7E,0xEB,0x43])
  44
  45 def name_to_ipv6(addr):
  46     if len(addr)>6 and addr.endswith('.onion'):
  47         vchAddr = b32decode(addr[0:-6], True)
  48         if len(vchAddr) != 16-len(pchOnionCat):
  49             raise ValueError('Invalid onion %s' % s)
  50         return pchOnionCat + vchAddr
  51     elif '.' in addr: # IPv4
  52         return pchIPv4 + bytearray((int(x) for x in addr.split('.')))
  53     elif ':' in addr: # IPv6
  54         sub = [[], []] # prefix, suffix
  55         x = 0
  56         addr = addr.split(':')
  57         for i,comp in enumerate(addr):
  58             if comp == '':
  59                 if i == 0 or i == (len(addr)-1): # skip empty component at beginning or end
  60                     continue
  61                 x += 1 # :: skips to suffix
  62                 assert(x < 2)
  63             else: # two bytes per component
  64                 val = int(comp, 16)
  65                 sub[x].append(val >> 8)
  66                 sub[x].append(val & 0xff)
  67         nullbytes = 16 - len(sub[0]) - len(sub[1])
  68         assert((x == 0 and nullbytes == 0) or (x == 1 and nullbytes > 0))
  69         return bytearray(sub[0] + ([0] * nullbytes) + sub[1])
  70     elif addr.startswith('0x'): # IPv4-in-little-endian
  71         return pchIPv4 + bytearray(reversed(a2b_hex(addr[2:])))
  72     else:
  73         raise ValueError('Could not parse address %s' % addr)
  74
  75 def parse_spec(s, defaultport):
  76     match = re.match('\[([0-9a-fA-F:]+)\](?::([0-9]+))?$', s)
  77     if match: # ipv6
  78         host = match.group(1)
  79         port = match.group(2)
  80     elif s.count(':') > 1: # ipv6, no port
  81         host = s
  82         port = ''
  83     else:
  84         (host,_,port) = s.partition(':')
  85
  86     if not port:
  87         port = defaultport
  88     else:
  89         port = int(port)
  90
  91     host = name_to_ipv6(host)
  92
  93     return (host,port)
  94
  95 def process_nodes(g, f, structname, defaultport):
  96     g.write('static SeedSpec6 %s[] = {\n' % structname)
  97     first = True
  98     for line in f:
  99         comment = line.find('#')
 100         if comment != -1:
 101             line = line[0:comment]
 102         line = line.strip()
 103         if not line:
 104             continue
 105         if not first:
 106             g.write(',\n')
 107         first = False
 108
 109         (host,port) = parse_spec(line, defaultport)
 110         hoststr = ','.join(('0x%02x' % b) for b in host)
 111         g.write('    {{%s}, %i}' % (hoststr, port))
 112     g.write('\n};\n')
 113
 114 def main():
 115     if len(sys.argv)<2:
 116         print(('Usage: %s <path_to_nodes_txt>' % sys.argv[0]), file=sys.stderr)
 117         sys.exit(1)
 118     g = sys.stdout
 119     indir = sys.argv[1]
 120     g.write('#ifndef BITCOIN_CHAINPARAMSSEEDS_H\n')
 121     g.write('#define BITCOIN_CHAINPARAMSSEEDS_H\n')
 122     g.write('/**\n')
 123     g.write(' * List of fixed seed nodes for the bitcoin network\n')
 124     g.write(' * AUTOGENERATED by contrib/seeds/generate-seeds.py\n')
 125     g.write(' *\n')
 126     g.write(' * Each line contains a 16-byte IPv6 address and a port.\n')
 127     g.write(' * IPv4 as well as onion addresses are wrapped inside a IPv6 address accordingly.\n')
 128     g.write(' */\n')
 129     with open(os.path.join(indir,'nodes_main.txt'),'r') as f:
 130         process_nodes(g, f, 'pnSeed6_main', 8333)
 131     g.write('\n')
 132     with open(os.path.join(indir,'nodes_test.txt'),'r') as f:
 133         process_nodes(g, f, 'pnSeed6_test', 18333)
 134     g.write('#endif // BITCOIN_CHAINPARAMSSEEDS_H\n')
 135
 136 if __name__ == '__main__':
 137     main()
 138