fix(client) resolve FQDNs ending in dots (#122)

spec/client_spec.lua

@@ -265,6 +265,73 @@ describe("[DNS client]", function()
 
     end)
 
+    describe("FQDN without type", function()
+      it("works with a 'search' option", function()
+        assert(client.init({
+            resolvConf = {
+              "nameserver 8.8.8.8",
+              "search one.com two.com",
+              "options ndots:1",
+            }
+          }))
+        local list = {}
+        for qname, qtype in client._search_iter("host.", nil) do
+          table.insert(list, tostring(qname)..":"..tostring(qtype))
+        end
+        assert.same({
+            'host.:33',
+            'host.:1',
+            'host.:28',
+            'host.:5',
+          }, list)
+      end)
+
+      it("works with a 'domain' option", function()
+        assert(client.init({
+            resolvConf = {
+              "nameserver 8.8.8.8",
+              "domain local.domain.com",
+              "options ndots:1",
+            }
+          }))
+        local list = {}
+        for qname, qtype in client._search_iter("host.", nil) do
+          table.insert(list, tostring(qname)..":"..tostring(qtype))
+        end
+        assert.same({
+          'host.:33',
+          'host.:1',
+          'host.:28',
+          'host.:5',
+        }, list)
+      end)
+
+      it("handles last successful type", function()
+        assert(client.init({
+            resolvConf = {
+              "nameserver 8.8.8.8",
+              "search one.com two.com",
+              "options ndots:1",
+            }
+          }))
+        local lrucache = client.getcache()
+        -- insert a last successful type
+        local hostname = "host."
+        lrucache:set(hostname, client.TYPE_CNAME)
+        local list = {}
+        for qname, qtype in client._search_iter(hostname, nil) do
+          table.insert(list, tostring(qname)..":"..tostring(qtype))
+        end
+        assert.same({
+            'host.:5',
+            'host.:33',
+            'host.:1',
+            'host.:28',
+          }, list)
+      end)
+
+    end)
+
     describe("with type", function()
       it("works with a 'search' option", function()
         assert(client.init({
@@ -329,6 +396,65 @@ describe("[DNS client]", function()
 
     end)
 
+    describe("FQDN with type", function()
+      it("works with a 'search' option", function()
+        assert(client.init({
+            resolvConf = {
+              "nameserver 8.8.8.8",
+              "search one.com two.com",
+              "options ndots:1",
+            }
+          }))
+        local list = {}
+        -- search using IPv6 type
+        for qname, qtype in client._search_iter("host.", client.TYPE_AAAA) do
+          table.insert(list, tostring(qname)..":"..tostring(qtype))
+        end
+        assert.same({
+            'host.:28',
+          }, list)
+      end)
+
+      it("works with a 'domain' option", function()
+        assert(client.init({
+            resolvConf = {
+              "nameserver 8.8.8.8",
+              "domain local.domain.com",
+              "options ndots:1",
+            }
+          }))
+        local list = {}
+        -- search using IPv6 type
+        for qname, qtype in client._search_iter("host.", client.TYPE_AAAA) do
+          table.insert(list, tostring(qname)..":"..tostring(qtype))
+        end
+        assert.same({
+          'host.:28',
+        }, list)
+      end)
+
+      it("ignores last successful type", function()
+        assert(client.init({
+            resolvConf = {
+              "nameserver 8.8.8.8",
+              "search one.com two.com",
+              "options ndots:1",
+            }
+          }))
+        -- insert a last successful type
+        client.getcache()["host"] = client.TYPE_CNAME
+        local list = {}
+        -- search using IPv6 type
+        for qname, qtype in client._search_iter("host.", client.TYPE_AAAA) do
+          table.insert(list, tostring(qname)..":"..tostring(qtype))
+        end
+        assert.same({
+            'host.:28',
+          }, list)
+      end)
+
+    end)
+
     it("honours 'ndots'", function()
       assert(client.init({
           resolvConf = {
@@ -430,6 +556,18 @@ describe("[DNS client]", function()
     assert.are.equal(#answers, 1)
   end)
 
+  it("fetching a CNAME record FQDN", function()
+    assert(client.init())
+
+    local host = "smtp.thijsschreijer.nl"
+    local typ = client.TYPE_CNAME
+
+    local answers = assert(client.resolve(host .. ".", { qtype = typ }))
+    assert.are.equal(host, answers[1].name)
+    assert.are.equal(typ, answers[1].type)
+    assert.are.equal(#answers, 1)
+  end)
+
   it("expire and touch times", function()
     assert(client.init())
 
@@ -500,6 +638,20 @@ describe("[DNS client]", function()
     assert.are.equal(typ, answers[2].type)
   end)
 
+  it("fetching multiple A records FQDN", function()
+    assert(client.init())
+
+    local host = "atest.thijsschreijer.nl"
+    local typ = client.TYPE_A
+
+    local answers = assert(client.resolve(host .. ".", { qtype = typ }))
+    assert.are.equal(#answers, 2)
+    assert.are.equal(host, answers[1].name)
+    assert.are.equal(typ, answers[1].type)
+    assert.are.equal(host, answers[2].name)
+    assert.are.equal(typ, answers[2].type)
+  end)
+
   it("fetching A record redirected through 2 CNAME records (un-typed)", function()
     assert(client.init())
     local lrucache = client.getcache()

spec/utils_spec.lua

@@ -345,6 +345,11 @@ options ndots:2
       assert.are.same("ipv6", dnsutils.hostnameType("2345::6789"))
       assert.are.same("ipv6", dnsutils.hostnameType("0001:0001:0001:0001:0001:0001:0001:0001"))
     end)
+    it("checks valid FQDN address types", function()
+      assert.are.same("name", dnsutils.hostnameType("konghq."))
+      assert.are.same("name", dnsutils.hostnameType("konghq.com."))
+      assert.are.same("name", dnsutils.hostnameType("www.konghq.com."))
+    end)
   end)
 
   describe("parseHostname", function()
@@ -368,6 +373,14 @@ options ndots:2
       assert.are.same({"somename456.domain.local789", nil, "name"}, {dnsutils.parseHostname("somename456.domain.local789")})
       assert.are.same({"somename456.domain.local789", 123, "name"}, {dnsutils.parseHostname("somename456.domain.local789:123")})
     end)
+    it("parses valid FQDN address types", function()
+      assert.are.same({"somename.", nil, "name"}, {dnsutils.parseHostname("somename.")})
+      assert.are.same({"somename.", 123, "name"}, {dnsutils.parseHostname("somename.:123")})
+      assert.are.same({"somename456.", nil, "name"}, {dnsutils.parseHostname("somename456.")})
+      assert.are.same({"somename456.", 123, "name"}, {dnsutils.parseHostname("somename456.:123")})
+      assert.are.same({"somename456.domain.local789.", nil, "name"}, {dnsutils.parseHostname("somename456.domain.local789.")})
+      assert.are.same({"somename456.domain.local789.", 123, "name"}, {dnsutils.parseHostname("somename456.domain.local789.:123")})
+    end)
   end)
 
 end)

src/resty/dns/client.lua

@@ -626,13 +626,23 @@ local function parseAnswer(qname, qtype, answers, try_list)
   -- eg. A, AAAA, SRV records may be accompanied by CNAME records
   -- store them all, leaving only the requested type in so we can return that set
   local others = {}
+
+  -- remove last '.' from FQDNs as the answer does not contain it
+  local check_qname do
+    if qname:sub(-1, -1) == "." then
+      check_qname = qname:sub(1, -2) -- FQDN, drop the last dot
+    else
+      check_qname = qname
+    end
+  end
+
   for i = #answers, 1, -1 do -- we're deleting entries, so reverse the traversal
     local answer = answers[i]
 
     -- normalize casing
     answer.name = string_lower(answer.name)
 
-    if (answer.type ~= qtype) or (answer.name ~= qname) then
+    if (answer.type ~= qtype) or (answer.name ~= check_qname) then
       local key = answer.type..":"..answer.name
       try_status(try_list, key .. " removed")
       local lst = others[key]
@@ -987,7 +997,14 @@ local function search_iter(qname, qtype)
   type_end = #type_list
 
   local i_type = type_start
-  local search = config.search
+  local search do
+    if qname:sub(-1, -1) == "." then
+      -- this is a FQDN, so no searches
+      search = {}
+    else
+      search = config.search
+    end
+  end
   local i_search, search_start, search_end
   local type_done = {}
   local type_current