-
Notifications
You must be signed in to change notification settings - Fork 0
/
host-files-from-dns.py
307 lines (280 loc) · 12 KB
/
host-files-from-dns.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
#!/usr/bin/python
# Generate Chaos host info from DNS
# - ITS H3TEXT [see https://github.com/PDP-10/its/blob/master/build/h3text.2014#L134-L150]
# - Lispm HOSTS TEXT [see https://github.com/LM-3/chaos/issues/61]
# - BSD hosts file [see https://github.com/LM-3/chaos/issues/61] (same format as LISPM?)
# - global ITS config [see e.g. https://github.com/PDP-10/its/pull/532]
# - MINITS code? [https://github.com/LM-3/chaos/issues/61]
# Options:
# -3 to generate hosts3 format ("extended" RFC 810) for ITS
# -l to generate lispm format (RFC 608, I think) which looks like it matches the 4.1BSD format?
# -i to generate a list of short ITS names, suitable for ITSIRP in SYSTEM;CONFIG
# -a to remove trailing .Chaosnet.NET domain in aliases (so you can parse two-letter abbrevs easily)
# -d domain to set local domain, which is also removed from aliases
# Should perhaps retain the original aliases?
# Should perhaps strip the local domain from the main name too, if the short one should be the canonical?
# Note to self:
# don't forget PYTHONPATH=whereverdnspythonsis:
# or similar
# dnspython is at https://github.com/rthalley/dnspython,
# and a fork which supports Chaos A records is at https://github.com/bictorv/dnspython/tree/chaos-addresses
# (a PR has been done on Nov 12, 2018)
import dns.resolver
import dns.zone
# import dns.query
# import dns.rdataclass
import struct
import sys
import getopt
from datetime import date
from socket import gethostbyname
aosnet_its_pruning = False
local_domain = None
def get_host_info(name, printJunk=False):
hinfo = {}
rpdict = {}
a = []
txt = ""
try:
h = dns.query.udp(dns.message.make_query(name, dns.rdatatype.ANY, rdclass=dns.rdataclass.CH), gethostbyname('dns.chaosnet.net'))
# answer is a set, find only the interesting ones
for t in h.answer:
# t is a dns.rrset.RRset object
if t.rdtype == dns.rdatatype.HINFO:
for d in t:
hinfo['OS'] = str(d.os.decode())
hinfo['CPU'] = str(d.cpu.decode())
elif t.rdtype == dns.rdatatype.TXT:
# Not used
for d in t:
txt += d.to_text()
elif t.rdtype == dns.rdatatype.RP:
# Not used
for d in t:
(u, dom) = d.mbox.split(len(d.mbox.labels)-1)
# @@@@ should unescape u (\. => .)
em = "{0}@{1}".format(u.to_text(), dom.to_text(omit_final_dot=True))
rptxt = []
if not(d.txt == dns.name.root):
rps = dns.query.udp(dns.message.make_query(str(d.txt), dns.rdatatype.TXT, rdclass=dns.rdataclass.CH), gethostbyname('dns.chaosnet.net'))
for rp in rps.answer:
for t in rp:
rptxt.append(t.to_text())
rpdict[em] = rptxt
elif t.rdtype == dns.rdatatype.A:
try:
for d in t:
a.append(d.address)
except AttributeError:
# dnspython not updated with support for Chaos A records
print("## A failure for {}".format(name), file=sys.stderr)
a = a
elif printJunk:
print(dns.rdatatype.to_text(t.rdtype), end=' ', file=sys.stderr)
for d in t:
print("-", d.to_text(), file=sys.stderr)
except dns.exception.DNSException as e:
print("Error", e, file=sys.stderr)
return (a, hinfo, rpdict, txt)
soas = {}
def get_ch_addr_zone():
z = dns.zone.from_xfr(dns.query.xfr(gethostbyname('dns.chaosnet.net'), 'ch-addr.net.', rdclass=dns.rdataclass.CH))
soa = z.find_rdataset('@', dns.rdatatype.SOA)
print(";;; Generated on", date.today().isoformat())
# soas['CH-ADDR.NET.'] = soa[0].serial
print(";; based on serial", soa[0].serial, "of CH-ADDR.NET.")
return z
haddrs = {}
doms = set()
nets = {}
# Collect all hosts being PTRed to, and all their addresses
def collect_all_hosts(z):
global haddrs, doms, nets
for (addr, ttl, rdata) in z.iterate_rdatas('PTR'):
if rdata.rdtype == dns.rdatatype.PTR:
if int(addr.to_text(), 8) & 0xff != 0:
hname = rdata.target.to_text()
addstr = addr.to_text()
if hname not in haddrs:
haddrs[hname] = []
haddrs[hname].append(int(addstr, 8))
# Only collect non-TLDs
pdom = rdata.target.parent().to_text(omit_final_dot=True)
domstr = "{}.".format(pdom) if "." in pdom else rdata.target.to_text()
doms.add(domstr)
else:
nname = rdata.target.to_text(omit_final_dot=True)
addstr = "{:o}".format(int(addr.to_text(), 8) >> 8)
nets[addstr] = nname
# Scan for CNAMEs in relevant zones
# Should use the right NS for xfr (but Psilo has everything so far, so punt)
aliases = {}
def scan_for_cnames(doms):
global aliases, soas
for dom in doms:
#### Should look up the NS (in the IN class) of the domain, and use the NS for that
# need to try all NS, and perhaps all their addresses.
# Too much bother as long as Psilo knows everything
za = dns.zone.from_xfr(dns.query.xfr(gethostbyname('dns.chaosnet.net'), dom, rdclass=dns.rdataclass.CH, relativize=False), relativize=False)
soa = za.find_rdataset(dom, dns.rdatatype.SOA)
soas[dom] = soa[0].serial
for (name, ttl, rdata) in za.iterate_rdatas('CNAME'):
alias = name.to_text(omit_final_dot=True)
host = rdata.target.to_text().lower()
if host not in aliases:
aliases[host] = []
aliases[host].append(alias)
def parent_domain_equal_to(child, domain):
# BUG: doing == on dns.name.Name should be case insensitive!!
ll = dns.name.from_text(child)
# for python 3?
# return ll.parent().to_text().casefold() == dom.casefold()
return ll.parent().to_text().lower() == domain.lower()
# return the first label of dom (a string)
def domain_first_label(dom):
ll = dns.name.from_text(dom)
(hd, tl) = ll.split(len(ll.labels)-1)
return hd.to_text()
# based on aosnet_its_pruning and local_domain
def maybe_prune_domain_parent(a, hinfo):
global aosnet_its_pruning, local_domain
if (aosnet_its_pruning and hinfo['OS'] == "ITS" and parent_domain_equal_to(a, "Chaosnet.NET.")) \
or (local_domain != None and parent_domain_equal_to(a, local_domain)):
return domain_first_label(a)
else:
return a
# Print a NET entry in h3text format - hack
h3netprinted = False
def h3textnet(net, name):
global h3netprinted
if not h3netprinted:
# @@@@ look up where it is wired, and fix it?
print(";;; Definition of Chaosnet for HOSTS3 UNTERNET scheme.")
print(";;; This is not a value you can change, it's wired into the ITS monitor.")
print("NET : UN 7.0.0.0 : CHAOS :")
h3netprinted = True
# print a HOST entry in h3text format
def h3texthost(hname, haliases, addrs, hinfo):
global aosnet_its_pruning
try:
print("HOST", ":", ", ".join(["CHAOS {:o}".format(s) for s in addrs]),
":", maybe_prune_domain_parent(dns.name.from_text(hname).to_text(omit_final_dot=True), hinfo) +
(len(haliases) > 0 and ", " or "") +
", ".join(set([maybe_prune_domain_parent(x, hinfo) for x in haliases])),
":", hinfo['CPU'].upper(), ":", hinfo['OS'].upper(), ": :")
except KeyError:
print("## Host info error for", hname, "HINFO", hinfo, file=sys.stderr)
## terminate line started within try
print()
def itslist(haddrs):
global aliases
hnames = list(haddrs.keys())
itses = []
for n in hnames:
(a, hinfo, x, y) = get_host_info(n)
if 'OS' in hinfo and hinfo['OS'] == 'ITS':
nms = list(map(lambda x: maybe_prune_domain_parent(x, hinfo), aliases[n.lower()]))
nms.sort(key=lambda x: len(x))
itses.append(nms[0])
print(" ".join(itses))
# Print a lispm format NET entry
def lispmnet(net, name):
# Oddly, the NET number is decimal
hack = int(net,8)
print("NET", str(hack)+",", name)
# Print a lispm format HOST entry
def lispmhost(hname, haliases, addrs, hinfo):
global aosnet_its_pruning
## USER vs SERVER vs TIP vs UNKNOWN - does anybody care? I don't.
try:
print("HOST", maybe_prune_domain_parent(dns.name.from_text(hname).to_text(omit_final_dot=True), hinfo)+",",
(len(addrs) > 1 and "["+", ".join(["CHAOS {:o}".format(s) for s in addrs])+"]"
or "CHAOS {:o}".format(addrs[0])) +
", USER, "+hinfo['OS'].upper()+", "+hinfo['CPU'].upper() +
(len(haliases) > 0 and ", ["+", ".join(set([maybe_prune_domain_parent(x, hinfo) for x in haliases]))+"]"
or ""))
except KeyError:
print("## Host info error for", hname, "HINFO", hinfo, file=sys.stderr)
## terminate line started within try
print()
# Print a hosts file in some format
def hostsfile(soas, haddrs, hostformatter, netformatter):
for d in soas:
print(";; and on serial", soas[d], "of", d)
print()
# sorted by net number
nnums = list(nets.keys())
nnums.sort(key=lambda x: int(x, 8))
if len(nnums) > 0:
print(";; Network{} (decimal):".format("s" if len(nnums) != 1 else ""))
for n in nnums:
netformatter(n, nets[n])
print()
# Sorted by reversed domain name
if len(haddrs) > 0:
print(";; Host{}:".format("s" if len(haddrs) != 1 else ""))
hnames = list(haddrs.keys())
hnames.sort(key=lambda x: ".".join(reversed(list(str(dns.name.from_text(x).labels)))))
for n in hnames:
(a, hinfo, rp, txt) = get_host_info(n)
# check if dnspython supports Chaos A records (len(a) > 0), otherwise ignore difference
if len(a) > 0 and len(set(haddrs[n])) != len(set(a)):
print("## For", n, "A is", list(map(oct, set(a))), "which is different from CH-ADDR.NET",
list(map(oct, set(haddrs[n]))), file=sys.stderr)
if len(set(a)) < 3 and len(set(haddrs[n])) >= 3:
# See https://gitlab.isc.org/isc-projects/bind9/issues/562
print("## This is probably caused the DNS server not being updated yet", file=sys.stderr)
# Use the longer list
if len(a) < len(haddrs[n]):
a = haddrs[n]
if n.lower() in aliases:
al = aliases[n.lower()]
else:
al = []
hostformatter(n, al, a, hinfo)
def usage():
print("use\n",
" -3 for hosts3 format (RFC 810),\n",
" -l for lispm format (RFC 752)\n",
" -d dom for local domain\n",
" -i to create a list of ITS shortnames, suitable for ITSIRP in SYSTEM;CONFIG\n",
" -a to add short aliases for Chaosnet.NET hosts", file=sys.stderr)
def main(argv):
global aosnet_its_pruning, local_domain
try:
opts, args = getopt.getopt(argv, "3laid:")
except getopt.GetoptError:
usage()
sys.exit(1)
h3 = False
lispm = False
its_shortnames_only = False
for opt, arg in opts:
if opt == '-3':
h3 = True
elif opt == '-l':
lispm = True
elif opt == '-a':
aosnet_its_pruning = True
elif opt == '-i':
its_shortnames_only = True
aosnet_its_pruning = True
elif opt == '-d':
local_domain = arg
if dns.name.from_text(local_domain) == None:
print("Bad -d domain", arg, file=sys.stderr)
sys.exit(1)
if not(h3 or lispm or its_shortnames_only):
usage()
sys.exit(1)
z = get_ch_addr_zone()
collect_all_hosts(z)
scan_for_cnames(doms)
if h3:
hostsfile(soas, haddrs, h3texthost, h3textnet)
elif lispm:
hostsfile(soas, haddrs, lispmhost, lispmnet)
elif its_shortnames_only:
itslist(haddrs)
if __name__ == "__main__":
main(sys.argv[1:])