11 sys.stderr.write('backend (%s): %s\n' % (os.getpid(), msg))
19 if DEBUG: log('writing: %s' % a)
22 if DEBUG: log('writetab')
23 sys.stdout.write('\t')
24 if DEBUG: log('writenewline')
25 sys.stdout.write('\n')
30 if DEBUG: log('reading now')
31 l = sys.stdin.readline()
32 if DEBUG: log('read line: %s' % l)
33 return l.strip().split('\t')
43 self.name_servers = {}
46 fname = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'backend.conf')
47 if not os.path.exists(fname):
48 log('%s does not exist' % fname)
52 config = ConfigParser.ConfigParser()
56 self.id = config.get('soa', 'id')
57 self.soa = '%s %s %s' % (config.get('soa', 'ns'), config.get('soa','hostmaster'), self.id)
58 self.domain = config.get('main', 'domain')
59 self.ip_address = config.get('main', 'ipaddress')
60 self.ttl = config.get('main', 'ttl')
62 for entry in config.items('nameservers'):
63 self.name_servers[entry[0]] = entry[1]
65 log('Name servers: %s' % self.name_servers)
66 log('ID: %s' % self.id)
67 log('TTL %s' % self.ttl)
68 log('SOA: %s' % self.soa)
69 log('IP Address: %s' % self.ip_address)
70 log('DOMAIN: %s' % self.domain)
74 handshake = get_next()
75 if handshake[1] != '1':
76 log('Not version 1: %s' % handshake)
78 write('OK', 'We are good')
86 log('did not understand: %s' % cmd)
90 qname = cmd[1].lower()
93 if (qtype == 'A' or qtype == 'ANY') and qname.endswith(self.domain):
94 if qname == self.domain:
95 self.handle_self(self.domain)
96 elif qname in self.name_servers:
97 self.handle_nameservers(qname)
99 self.handle_subdomains(qname)
100 elif qtype == 'SOA' and qname.endswith(self.domain):
101 self.handle_soa(qname)
103 self.handle_unknown(qtype, qname)
105 def handle_self(self, name):
106 write('DATA', name, 'IN', 'A', self.ttl, self.id, self.ip_address)
107 self.write_name_servers(name)
110 def handle_subdomains(self, qname):
111 subdomain = qname[0:qname.find(self.domain)-1]
113 subparts = subdomain.split('.')
114 if len(subparts) < 4:
115 if DEBUG: log('subparts less than 4')
116 self.handle_self(qname)
119 ipaddress = subparts[-4:]
120 if DEBUG: log('ip: %s' % ipaddress)
121 for part in ipaddress:
122 if re.match('^\d{1,3}$', part) is None:
123 if DEBUG: log('%s is not a number' % part)
124 self.handle_self(qname)
127 if parti < 0 or parti > 255:
128 if DEBUG: log('%d is too big/small' % parti)
129 self.handle_self(qname)
132 write('DATA', qname, 'IN', 'A', self.ttl, self.id, '%s.%s.%s.%s' % (ipaddress[0], ipaddress[1], ipaddress[2], ipaddress[3]))
133 self.write_name_servers(qname)
136 def handle_nameservers(self, qname):
137 ip = self.name_servers[qname]
138 write('DATA', qname, 'IN', 'A', self.ttl, self.id, ip)
141 def write_name_servers(self, qname):
142 for nameServer in self.name_servers:
143 write('DATA', qname, 'IN', 'NS', self.ttl, self.id, nameServer)
145 def handle_soa(self, qname):
146 write('DATA', qname, 'IN', 'SOA', self.ttl, self.id, self.soa)
149 def handle_unknown(self, qtype, qname):
150 write('LOG', 'Unknown type: %s, domain: %s' % (qtype, qname))
154 if __name__ == '__main__':
156 backend = DynamicBackend()