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
|
-- libunbound based net.adns replacement for Prosody IM
-- Copyright (C) 2012-2015 Kim Alvefur
-- Copyright (C) 2012 Waqas Hussain
--
-- This file is MIT licensed.
local setmetatable = setmetatable;
local table = table;
local t_concat = table.concat;
local t_insert = table.insert;
local s_byte = string.byte;
local s_char = string.char;
local s_format = string.format;
local s_gsub = string.gsub;
local s_sub = string.sub;
local s_match = string.match;
local s_gmatch = string.gmatch;
local have_net, net_util = pcall(require, "util.net");
if have_net and not net_util.ntop then -- Added in Prosody 0.11
have_net = false;
end
local chartohex = {};
for c = 0, 255 do
chartohex[s_char(c)] = s_format("%02X", c);
end
local function tohex(s)
return (s_gsub(s, ".", chartohex));
end
-- Converted from
-- http://www.iana.org/assignments/dns-parameters
-- 2020-06-25
local classes = {
IN = 1; "IN";
nil;
CH = 3; "CH";
HS = 4; "HS";
};
local types = {
"A";"NS";"MD";"MF";"CNAME";"SOA";"MB";"MG";"MR";"NULL";"WKS";"PTR";"HINFO";
"MINFO";"MX";"TXT";"RP";"AFSDB";"X25";"ISDN";"RT";"NSAP";"NSAP-PTR";"SIG";
"KEY";"PX";"GPOS";"AAAA";"LOC";"NXT";"EID";"NIMLOC";"SRV";"ATMA";"NAPTR";
"KX";"CERT";"A6";"DNAME";"SINK";"OPT";"APL";"DS";"SSHFP";"IPSECKEY";"RRSIG";
"NSEC";"DNSKEY";"DHCID";"NSEC3";"NSEC3PARAM";"TLSA";"SMIMEA";[55]="HIP";
[56]="NINFO";[57]="RKEY";[58]="TALINK";[59]="CDS";[60]="CDNSKEY";[61]="OPENPGPKEY";
[62]="CSYNC";[63]="ZONEMD";[99]="SPF";[100]="UINFO";[101]="UID";[102]="GID";
[103]="UNSPEC";[104]="NID";[105]="L32";[106]="L64";[107]="LP";[108]="EUI48";
[109]="EUI64";["CSYNC"]=62;["TXT"]=16;["NAPTR"]=35;["A6"]=38;["RP"]=17;
["TALINK"]=58;["NXT"]=30;["MR"]=9;["UINFO"]=100;["X25"]=19;["TKEY"]=249;
["CERT"]=37;["SMIMEA"]=53;[252]="AXFR";[253]="MAILB";["CDS"]=59;[32769]="DLV";
["RT"]=21;["WKS"]=11;[249]="TKEY";["LP"]=107;[250]="TSIG";["SSHFP"]=44;["DS"]=43;
["ISDN"]=20;["ATMA"]=34;["NS"]=2;[257]="CAA";["PX"]=26;["MX"]=15;["TSIG"]=250;
["EID"]=31;["TLSA"]=52;["GID"]=102;["KX"]=36;["SPF"]=99;["DOA"]=259;["GPOS"]=27;
["IPSECKEY"]=45;["NIMLOC"]=32;["RRSIG"]=46;["UID"]=101;["DNAME"]=39;["NSAP"]=22;
["DNSKEY"]=48;["SINK"]=40;["DHCID"]=49;[32768]="TA";["NSAP-PTR"]=23;["AAAA"]=28;
["PTR"]=12;["MINFO"]=14;["TA"]=32768;["EUI64"]=109;[260]="AMTRELAY";
["AMTRELAY"]=260;["CDNSKEY"]=60;[259]="DOA";["LOC"]=29;[258]="AVC";["AVC"]=258;
["CAA"]=257;["MB"]=7;["*"]=255;[256]="URI";["URI"]=256;["SRV"]=33;["EUI48"]=108;
[255]="*";[254]="MAILA";["MAILA"]=254;["MAILB"]=253;["CNAME"]=5;[251]="IXFR";
["APL"]=42;["OPENPGPKEY"]=61;["MD"]=3;["NINFO"]=56;["ZONEMD"]=63;["RKEY"]=57;
["L32"]=105;["NID"]=104;["HIP"]=55;["NSEC"]=47;["DLV"]=32769;["UNSPEC"]=103;
["NSEC3PARAM"]=51;["MF"]=4;["MG"]=8;["AFSDB"]=18;["A"]=1;["SIG"]=24;["NSEC3"]=50;
["HINFO"]=13;["IXFR"]=251;["NULL"]=10;["AXFR"]=252;["KEY"]=25;["OPT"]=41;
["SOA"]=6;["L64"]=106;
}
local errors = {
NoError = "No Error"; [0] = "NoError";
FormErr = "Format Error"; "FormErr";
ServFail = "Server Failure"; "ServFail";
NXDomain = "Non-Existent Domain"; "NXDomain";
NotImp = "Not Implemented"; "NotImp";
Refused = "Query Refused"; "Refused";
YXDomain = "Name Exists when it should not"; "YXDomain";
YXRRSet = "RR Set Exists when it should not"; "YXRRSet";
NXRRSet = "RR Set that should exist does not"; "NXRRSet";
NotAuth = "Server Not Authoritative for zone"; "NotAuth";
NotZone = "Name not contained in zone"; "NotZone";
};
-- Simplified versions of Waqas DNS parsers
-- Only the per RR parsers are needed and only feed a single RR
local parsers = {};
-- No support for pointers, but libunbound appears to take care of that.
local function readDnsName(packet, pos)
if s_byte(packet, pos) == 0 then return "."; end
local pack_len, r, len = #packet, {};
pos = pos or 1;
repeat
len = s_byte(packet, pos) or 0;
t_insert(r, s_sub(packet, pos + 1, pos + len));
pos = pos + len + 1;
until len == 0 or pos >= pack_len;
return t_concat(r, "."), pos;
end
-- These are just simple names.
parsers.CNAME = readDnsName;
parsers.NS = readDnsName
parsers.PTR = readDnsName;
local soa_mt = {
__tostring = function(rr)
return s_format("%s %s %d %d %d %d %d", rr.mname, rr.rname, rr.serial, rr.refresh, rr.retry, rr.expire, rr.minimum);
end;
};
function parsers.SOA(packet)
local mname, rname, offset;
mname, offset = readDnsName(packet, 1);
rname, offset = readDnsName(packet, offset);
-- Extract all the bytes of these fields in one call
local
s1, s2, s3, s4, -- serial
r1, r2, r3, r4, -- refresh
t1, t2, t3, t4, -- retry
e1, e2, e3, e4, -- expire
m1, m2, m3, m4 -- minimum
= s_byte(packet, offset, offset + 19);
return setmetatable({
mname = mname;
rname = rname;
serial = s1*0x1000000 + s2*0x10000 + s3*0x100 + s4;
refresh = r1*0x1000000 + r2*0x10000 + r3*0x100 + r4;
retry = t1*0x1000000 + t2*0x10000 + t3*0x100 + t4;
expire = e1*0x1000000 + e2*0x10000 + e3*0x100 + e4;
minimum = m1*0x1000000 + m2*0x10000 + m3*0x100 + m4;
}, soa_mt);
end
function parsers.A(packet)
return s_format("%d.%d.%d.%d", s_byte(packet, 1, 4));
end
local aaaa = { nil, nil, nil, nil, nil, nil, nil, nil, };
function parsers.AAAA(packet)
local hi, lo, ip, len, token;
for i = 1, 8 do
hi, lo = s_byte(packet, i * 2 - 1, i * 2);
aaaa[i] = s_format("%x", hi * 256 + lo); -- skips leading zeros
end
ip = t_concat(aaaa, ":", 1, 8);
len = (s_match(ip, "^0:[0:]+()") or 1) - 1;
for s in s_gmatch(ip, ":0:[0:]+") do
if len < #s then len, token = #s, s; end -- find longest sequence of zeros
end
return (s_gsub(ip, token or "^0:[0:]+", "::", 1));
end
if have_net then
parsers.A = net_util.ntop;
parsers.AAAA = net_util.ntop;
end
local mx_mt = {
__tostring = function(rr)
return s_format("%d %s", rr.pref, rr.mx)
end
};
function parsers.MX(packet)
local name = readDnsName(packet, 3);
local b1,b2 = s_byte(packet, 1, 2);
return setmetatable({
pref = b1*256+b2;
mx = name;
}, mx_mt);
end
local srv_mt = {
__tostring = function(rr)
return s_format("%d %d %d %s", rr.priority, rr.weight, rr.port, rr.target);
end
};
function parsers.SRV(packet)
local name = readDnsName(packet, 7);
local b1, b2, b3, b4, b5, b6 = s_byte(packet, 1, 6);
return setmetatable({
priority = b1*256+b2;
weight = b3*256+b4;
port = b5*256+b6;
target = name;
}, srv_mt);
end
local txt_mt = { __tostring = t_concat };
function parsers.TXT(packet)
local pack_len = #packet;
local r, pos, len = {}, 1;
repeat
len = s_byte(packet, pos) or 0;
t_insert(r, s_sub(packet, pos + 1, pos + len));
pos = pos + len + 1;
until pos >= pack_len;
return setmetatable(r, txt_mt);
end
parsers.SPF = parsers.TXT;
-- Acronyms from RFC 7218
local tlsa_usages = {
[0] = "PKIX-CA";
[1] = "PKIX-EE";
[2] = "DANE-TA";
[3] = "DANE-EE";
[255] = "PrivCert";
};
local tlsa_selectors = {
[0] = "Cert",
[1] = "SPKI",
[255] = "PrivSel",
};
local tlsa_match_types = {
[0] = "Full",
[1] = "SHA2-256",
[2] = "SHA2-512",
[255] = "PrivMatch",
};
local tlsa_mt = {
__tostring = function(rr)
return s_format("%s %s %s %s",
tlsa_usages[rr.use] or rr.use,
tlsa_selectors[rr.select] or rr.select,
tlsa_match_types[rr.match] or rr.match,
tohex(rr.data));
end;
__index = {
getUsage = function(rr) return tlsa_usages[rr.use] end;
getSelector = function(rr) return tlsa_selectors[rr.select] end;
getMatchType = function(rr) return tlsa_match_types[rr.match] end;
}
};
function parsers.TLSA(packet)
local use, select, match = s_byte(packet, 1,3);
return setmetatable({
use = use;
select = select;
match = match;
data = s_sub(packet, 4);
}, tlsa_mt);
end
local params = {
TLSA = {
use = tlsa_usages;
select = tlsa_selectors;
match = tlsa_match_types;
};
};
local fallback_mt = {
__tostring = function(rr)
return s_format([[\# %d %s]], #rr.raw, tohex(rr.raw));
end;
};
local function fallback_parser(packet)
return setmetatable({ raw = packet },fallback_mt);
end
setmetatable(parsers, { __index = function() return fallback_parser end });
return {
parsers = parsers;
classes = classes;
types = types;
errors = errors;
params = params;
};
|