feature: added support for TXT queries and records.

README.markdown

@@ -111,6 +111,8 @@ which usually takes some of the following fields:
 	A domain-name which specifies a host which should be authoritative for the specified class and domain. Usually present for `NS` type records.
 * `rdata`
 	The raw resource data (RDATA) for resource records that are not recognized.
+* `txt`
+	The record value for `TXT` records.
 
 This method also takes an optional `options` argument table, which takes the following fields:
 
@@ -192,6 +194,11 @@ TYPE_NS
 
 The `NS` resource record type, equal to the decimal number `2`.
 
+TYPE_TXT
+--------
+
+The `TXT` resource record type, equal to the decimal number `16`.
+
 TYPE_AAAA
 ---------
 `syntax: typ = r.TYPE_AAAA`
@@ -222,7 +229,7 @@ TODO
 ====
 
 * Concurrent (or parallel) query mode
-* Better support for other resource record types like `PTR`, and `TXT`.
+* Better support for other resource record types like `PTR`.
 * Support for the DNS inverse queries
 
 Author

lib/resty/dns/resolver.lua

@@ -35,6 +35,7 @@ TYPE_A      = 1
 TYPE_NS     = 2
 TYPE_CNAME  = 5
 TYPE_MX     = 15
+TYPE_TXT    = 16
 TYPE_AAAA   = 28
 
 CLASS_IN    = 1
@@ -509,6 +510,11 @@ local function parse_response(buf, id)
 
             ans.nsdname = name
 
+        elseif typ == TYPE_TXT then
+
+            ans.txt = substr(buf, pos, pos + len - 1)
+            pos = pos + len
+
         else
             -- for unknown types, just forward the raw value
 

t/sanity.t

@@ -242,3 +242,67 @@ GET /t
 --- no_error_log
 [error]
 
+
+
+=== TEST 8: TXT query (no ans)
+--- http_config eval: $::HttpConfig
+--- config
+    location /t {
+        content_by_lua '
+            local resolver = require "resty.dns.resolver"
+
+            local r, err = resolver:new{ nameservers = { "$TEST_NGINX_RESOLVER" } }
+            if not r then
+                ngx.say("failed to instantiate resolver: ", err)
+                return
+            end
+
+            local ans, err = r:query("agentzh.org", { qtype = r.TYPE_TXT })
+            if not ans then
+                ngx.say("failed to query: ", err)
+                return
+            end
+
+            local cjson = require "cjson"
+            ngx.say("records: ", cjson.encode(ans))
+        ';
+    }
+--- request
+GET /t
+--- response_body
+records: {}
+--- no_error_log
+[error]
+
+
+
+=== TEST 9: TXT query (with ans)
+--- http_config eval: $::HttpConfig
+--- config
+    location /t {
+        content_by_lua '
+            local resolver = require "resty.dns.resolver"
+
+            local r, err = resolver:new{ nameservers = { "$TEST_NGINX_RESOLVER" } }
+            if not r then
+                ngx.say("failed to instantiate resolver: ", err)
+                return
+            end
+
+            local ans, err = r:query("gmail.com", { qtype = r.TYPE_TXT })
+            if not ans then
+                ngx.say("failed to query: ", err)
+                return
+            end
+
+            local cjson = require "cjson"
+            ngx.say("records: ", cjson.encode(ans))
+        ';
+    }
+--- request
+GET /t
+--- response_body_like chop
+^records: \[\{.*?"txt":"[^"]+".*?\}\]$
+--- no_error_log
+[error]
+