add NAPTR record support

README.markdown

@@ -28,6 +28,7 @@ Table of Contents
     * [TYPE_TXT](#type_txt)
     * [TYPE_AAAA](#type_aaaa)
     * [TYPE_SRV](#type_srv)
+    * [TYPE_NAPTR](#type_naptr)
     * [TYPE_SPF](#type_spf)
     * [CLASS_IN](#class_in)
     * [SECTION_AN](#section_an)
@@ -375,6 +376,16 @@ See RFC 2782 for details.
 
 [Back to TOC](#table-of-contents)
 
+TYPE_NAPTR
+----------
+`syntax: typ = r.TYPE_NAPTR`
+
+The `NAPTR` resource record type, equal to the decimal number `35`.
+
+See RFC 2915 for details.
+
+[Back to TOC](#table-of-contents)
+
 TYPE_SPF
 ---------
 `syntax: typ = r.TYPE_SPF`

lib/resty/dns/resolver.lua

@@ -46,6 +46,7 @@ local TYPE_MX     = 15
 local TYPE_TXT    = 16
 local TYPE_AAAA   = 28
 local TYPE_SRV    = 33
+local TYPE_NAPTR  = 35
 local TYPE_SPF    = 99
 
 local CLASS_IN    = 1
@@ -65,6 +66,7 @@ local _M = {
     TYPE_TXT    = TYPE_TXT,
     TYPE_AAAA   = TYPE_AAAA,
     TYPE_SRV    = TYPE_SRV,
+    TYPE_NAPTR  = TYPE_NAPTR,
     TYPE_SPF    = TYPE_SPF,
     CLASS_IN    = CLASS_IN,
     SECTION_AN  = SECTION_AN,
@@ -208,6 +210,21 @@ local function _encode_name(s)
 end
 
 
+local function _decode_string(buf, pos)
+    local slen = byte(buf, pos)
+
+    if slen == 0 then
+        return "", pos + 1
+    end
+
+    if pos + 1 + slen > #buf then
+        return nil, 'truncated'
+    end
+
+    return sub(buf, pos + 1, pos + slen), pos + slen + 1
+end
+
+
 local function _decode_name(buf, pos)
     local labels = {}
     local nptrs = 0
@@ -481,6 +498,50 @@ local function parse_section(answers, section, buf, start_pos, size,
 
             pos = p
 
+        elseif typ == TYPE_NAPTR then
+            if len < 7 then
+                return nil, "bad NAPTR record value length: " .. len
+            end
+
+            local order_hi = byte(buf, pos)
+            local order_lo = byte(buf, pos + 1)
+            ans.order = lshift(order_hi, 8) + order_lo
+
+            local preference_hi = byte(buf, pos + 2)
+            local preference_lo = byte(buf, pos + 3)
+            ans.preference = lshift(preference_hi, 8) + preference_lo
+
+            local flags_str, p = _decode_string(buf, pos + 4)
+            if not flags_str then
+                return nil, pos
+            end
+            ans.flags = flags_str
+
+            local services_str, p = _decode_string(buf, p)
+            if not services_str then
+                return nil, pos
+            end
+            ans.services = services_str
+
+            local regexp_str, p = _decode_string(buf, p)
+            if not regexp_str then
+                return nil, pos
+            end
+            ans.regexp = regexp_str
+
+            local replacements_str,p = _decode_name(buf, p)
+            if not replacements_str then
+                return nil, pos
+            end
+            ans.replacements = replacements_str
+
+            if p - pos ~= len then
+                return nil, format("bad NAPTR record length: %d ~= %d",
+                                   p - pos, len)
+            end
+
+            pos = p
+
         elseif typ == TYPE_NS then
 
             local name, p = _decode_name(buf, pos)

t/TestDNS.pm

@@ -13,6 +13,7 @@ use constant {
     TYPE_CNAME => 5,
     TYPE_AAAA => 28,
     TYPE_SRV => 33,
+    TYPE_NAPTR => 35,
     CLASS_INTERNET => 1,
 };
 
@@ -261,6 +262,11 @@ sub encode_name ($) {
     return $name;
 }
 
+sub encode_str ($) {
+    my $str = shift;
+    return chr(length($str)) . $str;
+}
+
 sub encode_record ($) {
     my $ans = shift;
     my $name = $ans->{name};
@@ -304,7 +310,6 @@ sub encode_record ($) {
         $class //= CLASS_INTERNET;
     }
 
-
     my $srv = $ans->{srv};
     if (defined $srv) {
         $rddata //= pack("nnn", $ans->{priority}, $ans->{weight}, $ans->{port}) . encode_name($srv);
@@ -313,6 +318,18 @@ sub encode_record ($) {
         $class //= CLASS_INTERNET;
     }
 
+    my $services = $ans->{services};
+    if (defined $services) {
+        $rddata //= pack("nn", $ans->{order}, $ans->{preference})
+          . encode_str($ans->{flags})
+          . encode_str($ans->{services})
+          . encode_str($ans->{regexp})
+          . encode_name($ans->{replacements});
+        $rdlength //= length $rddata;
+        $type //= TYPE_NAPTR;
+        $class //= CLASS_INTERNET;
+    }
+
     $type //= 0;
     $class //= 0;
     $ttl //= 0;

t/mock.t

@@ -1721,3 +1721,54 @@ GET /t
 records: [{"address":"127.0.0.1","section":1,"type":1,"class":1,"name":"www.google.com","ttl":123456}]
 --- no_error_log
 [error]
+
+
+=== TEST 35: NAPTR
+--- http_config eval: $::HttpConfig
+--- config
+    location /t {
+        content_by_lua '
+            local resolver = require "resty.dns.resolver"
+
+            local r, err = resolver:new{
+                nameservers = { {"127.0.0.1", 1953} }
+            }
+            if not r then
+                ngx.say("failed to instantiate resolver: ", err)
+                return
+            end
+
+            r._id = 125
+
+            local ans, err = r:query("5.4.3.2.1.e164.arpa", { qtype = r.TYPE_NAPTR })
+            if not ans then
+                ngx.say("failed to query: ", err)
+                return
+            end
+
+            local cjson = require "cjson"
+            ngx.say("records: ", cjson.encode(ans))
+        ';
+    }
+--- udp_listen: 1953
+--- udp_reply dns
+{
+    id => 125,
+    opcode => 0,
+    qtype => 35,  # NAPTR
+    qname => '5.4.3.2.1.e164.arpa',
+    answer => [
+        { name => "5.4.3.2.1.e164.arpa", ttl => 2, order => 10, preference => 100,
+          flags => "u",
+          services => "E2U+sip",
+          regexp => "!^\\+123456(.*)\$!sip:\\1\@example.org!",
+          replacements => ""
+        }
+    ],
+}
+--- request
+GET /t
+--- response_body
+records: [{"order":10,"preference":100,"class":1,"regexp":"!^\\+123456(.*)$!sip:\\[email protected]!","replacements":"","section":1,"flags":"u","type":35,"ttl":2,"name":"5.4.3.2.1.e164.arpa","services":"E2U+sip"}]
+--- no_error_log
+[error]