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authorKim Alvefur <zash@zash.se>2019-03-09 21:16:27 +0100
committerKim Alvefur <zash@zash.se>2019-03-09 21:16:27 +0100
commit49dd598e71d066441f44a21f86a755c959bdcbf3 (patch)
tree34cde332760b077229e47be9be47e9f878f5acb7 /util
parent558a365575c4ac2d601c19fcbd2bd6fd27078ac6 (diff)
downloadprosody-49dd598e71d066441f44a21f86a755c959bdcbf3.tar.gz
prosody-49dd598e71d066441f44a21f86a755c959bdcbf3.zip
util.dns: Library for decoding DNS records
Imported from luaunbound-prosody 5f7c771138b1
Diffstat (limited to 'util')
-rw-r--r--util/dns.lua271
1 files changed, 271 insertions, 0 deletions
diff --git a/util/dns.lua b/util/dns.lua
new file mode 100644
index 00000000..2a15fbc4
--- /dev/null
+++ b/util/dns.lua
@@ -0,0 +1,271 @@
+-- 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
+-- 2015-05-19
+
+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";[55]="HIP";[56]="NINFO";
+[57]="RKEY";[58]="TALINK";[59]="CDS";[60]="CDNSKEY";[61]="OPENPGPKEY";
+[62]="CSYNC";TLSA=52;NS=2;[249]="TKEY";[251]="IXFR";NSAP=22;UID=101;APL=42;
+MG=8;NIMLOC=32;DHCID=49;TALINK=58;HINFO=13;MINFO=14;EID=31;DS=43;CSYNC=62;
+RKEY=57;TKEY=249;NID=104;NAPTR=35;RT=21;LP=107;L32=105;KEY=25;MD=3;MX=15;
+A6=38;KX=36;PX=26;CAA=257;WKS=11;TSIG=250;MAILA=254;CDS=59;SINK=40;LOC=29;
+DLV=32769;[32769]="DLV";TA=32768;[32768]="TA";GID=102;IXFR=251;MAILB=253;
+[256]="URI";[250]="TSIG";[252]="AXFR";NSEC=47;HIP=55;[254]="MAILA";[255]="*";
+NSEC3PARAM=51;["*"]=255;URI=256;[253]="MAILB";AXFR=252;SPF=99;NXT=30;AFSDB=18;
+EUI48=108;NINFO=56;CDNSKEY=60;ISDN=20;L64=106;SRV=33;DNSKEY=48;X25=19;TXT=16;
+RRSIG=46;OPENPGPKEY=61;DNAME=39;CNAME=5;EUI64=109;A=1;MR=9;IPSECKEY=45;OPT=41;
+UNSPEC=103;["NSAP-PTR"]=23;[103]="UNSPEC";[257]="CAA";UINFO=100;[99]="SPF";
+MF=4;[101]="UID";[102]="GID";SOA=6;[104]="NID";[105]="L32";[106]="L64";
+[107]="LP";[108]="EUI48";[109]="EUI64";NSEC3=50;RP=17;PTR=12;[100]="UINFO";
+NULL=10;AAAA=28;MB=7;GPOS=27;SSHFP=44;CERT=37;SIG=24;ATMA=34
+};
+
+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;
+};