12 sys.stderr.write('backend (%s): %s\n' % (os.getpid(), msg))
21 log('writing: %s' % a)
26 sys.stdout.write('\t')
29 sys.stdout.write('\n')
36 l = sys.stdin.readline()
38 log('read line: %s' % l)
39 return l.strip().split('\t')
49 self.name_servers = {}
52 fname = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'backend.conf')
53 if not os.path.exists(fname):
54 log('%s does not exist' % fname)
58 config = ConfigParser.ConfigParser()
62 self.id = config.get('soa', 'id')
63 self.soa = '%s %s %s' % (config.get('soa', 'ns'), config.get('soa', 'hostmaster'), self.id)
64 self.domain = config.get('main', 'domain')
65 self.ip_address = config.get('main', 'ipaddress')
66 self.ttl = config.get('main', 'ttl')
68 for entry in config.items('nameservers'):
69 self.name_servers[entry[0]] = entry[1]
71 log('Name servers: %s' % self.name_servers)
72 log('ID: %s' % self.id)
73 log('TTL %s' % self.ttl)
74 log('SOA: %s' % self.soa)
75 log('IP Address: %s' % self.ip_address)
76 log('DOMAIN: %s' % self.domain)
80 handshake = get_next()
81 if handshake[1] != '1':
82 log('Not version 1: %s' % handshake)
84 write('OK', 'We are good')
93 log('did not understand: %s' % cmd)
97 qname = cmd[1].lower()
100 if (qtype == 'A' or qtype == 'ANY') and qname.endswith(self.domain):
101 if qname == self.domain:
102 self.handle_self(self.domain)
103 elif qname in self.name_servers:
104 self.handle_nameservers(qname)
106 self.handle_subdomains(qname)
107 elif qtype == 'SOA' and qname.endswith(self.domain):
108 self.handle_soa(qname)
110 self.handle_unknown(qtype, qname)
112 def handle_self(self, name):
113 write('DATA', name, 'IN', 'A', self.ttl, self.id, self.ip_address)
114 self.write_name_servers(name)
117 def handle_subdomains(self, qname):
118 subdomain = qname[0:qname.find(self.domain) - 1]
120 subparts = subdomain.split('.')
121 if len(subparts) < 4:
123 log('subparts less than 4')
124 self.handle_self(qname)
127 ipaddress = subparts[-4:]
129 log('ip: %s' % ipaddress)
130 for part in ipaddress:
131 if re.match('^\d{1,3}$', part) is None:
133 log('%s is not a number' % part)
134 self.handle_self(qname)
137 if parti < 0 or parti > 255:
139 log('%d is too big/small' % parti)
140 self.handle_self(qname)
143 write('DATA', qname, 'IN', 'A', self.ttl, self.id, '%s.%s.%s.%s' % (ipaddress[0], ipaddress[1], ipaddress[2], ipaddress[3]))
144 self.write_name_servers(qname)
147 def handle_nameservers(self, qname):
148 ip = self.name_servers[qname]
149 write('DATA', qname, 'IN', 'A', self.ttl, self.id, ip)
152 def write_name_servers(self, qname):
153 for nameServer in self.name_servers:
154 write('DATA', qname, 'IN', 'NS', self.ttl, self.id, nameServer)
156 def handle_soa(self, qname):
157 write('DATA', qname, 'IN', 'SOA', self.ttl, self.id, self.soa)
160 def handle_unknown(self, qtype, qname):
161 write('LOG', 'Unknown type: %s, domain: %s' % (qtype, qname))
165 if __name__ == '__main__':
166 backend = DynamicBackend()