11 sys.stderr.write('backend: %s\n' % msg)
18 if DEBUG: log('writing: %s' % a)
21 if DEBUG: log('writetab')
22 sys.stdout.write('\t')
23 if DEBUG: log('writenewline')
24 sys.stdout.write('\n')
28 if DEBUG: log('reading now')
29 l = sys.stdin.readline()
30 if DEBUG: log('read line: %s' % l)
31 return l.strip().split('\t')
41 self.name_servers = {}
44 fname = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'backend.conf')
45 if not os.path.exists(fname):
46 log('%s does not exist' % fname)
50 config = ConfigParser.ConfigParser()
54 self.id = config.get('soa', 'id')
55 self.soa = '%s %s %s' % (config.get('soa', 'ns'), config.get('soa','hostmaster'), self.id)
56 self.domain = config.get('main', 'domain')
57 self.ip_address = config.get('main', 'ipaddress')
58 self.ttl = config.get('main', 'ttl')
60 for entry in config.items('nameservers'):
61 self.name_servers[entry[0]] = entry[1]
63 log('Name servers: %s' % self.name_servers)
64 log('ID: %s' % self.id)
65 log('TTL %s' % self.ttl)
66 log('SOA: %s' % self.soa)
67 log('IP Address: %s' % self.ip_address)
68 log('DOMAIN: %s' % self.domain)
72 handshake = get_next()
73 if handshake[1] != '1':
74 log('Not version 1: %s' % handshake)
76 write('OK', 'We are good')
84 log('did not understand: %s' % cmd)
88 qname = cmd[1].lower()
91 if (qtype == 'A' or qtype == 'ANY') and qname.endswith(self.domain):
92 if qname == self.domain:
93 self.handle_self(self.domain)
94 elif qname in self.name_servers:
95 self.handle_nameservers(qname)
97 self.handle_subdomains(qname)
98 elif qtype == 'SOA' and qname.endswith(self.domain):
99 self.handle_soa(qname)
101 self.handle_unknown(qtype, qname)
103 def handle_self(self, name):
104 write('DATA', name, 'IN', 'A', self.ttl, self.id, self.ip_address)
105 self.write_name_servers(name)
108 def handle_subdomains(self, qname):
109 subdomain = qname[0:qname.find(self.domain)-1]
111 subparts = subdomain.split('.')
112 if len(subparts) < 4:
113 if DEBUG: log('subparts less than 4')
114 self.handle_self(qname)
117 ipaddress = subparts[-4:]
118 if DEBUG: log('ip: %s' % ipaddress)
119 for part in ipaddress:
120 if re.match('^\d{1,3}$', part) is None:
121 if DEBUG: log('%s is not a number' % part)
122 self.handle_self(qname)
125 if parti < 0 or parti > 255:
126 if DEBUG: log('%d is too big/small' % parti)
127 self.handle_self(qname)
130 write('DATA', qname, 'IN', 'A', self.ttl, self.id, '%s.%s.%s.%s' % (ipaddress[0], ipaddress[1], ipaddress[2], ipaddress[3]))
131 self.write_name_servers(qname)
134 def handle_nameservers(self, qname):
135 ip = self.name_servers[qname]
136 write('DATA', qname, 'IN', 'A', self.ttl, self.id, ip)
139 def write_name_servers(self, qname):
140 for nameServer in self.name_servers:
141 write('DATA', qname, 'IN', 'NS', self.ttl, self.id, nameServer)
143 def handle_soa(self, qname):
144 write('DATA', qname, 'IN', 'SOA', self.ttl, self.id, self.soa)
147 def handle_unknown(self, qtype, qname):
148 write('LOG', 'Unknown type: %s, domain: %s' % (qtype, qname))
152 if __name__ == '__main__':
154 backend = DynamicBackend()