From: Pieter Lexis <pieter.lexis@powerdns.com>
Date: Mon, 18 Feb 2019 12:29:52 +0000 (+0100)
Subject: Lua: expose `dns_random` as `pdnsrandom`
X-Git-Tag: auth-4.2.0-beta1~13^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2c41983154a2c0c89345a69692c1df02f64416a8;p=thirdparty%2Fpdns.git

Lua: expose `dns_random` as `pdnsrandom`

Fixes the usecase in #6853
---

diff --git a/docs/lua-records/reference/misc.rst b/docs/lua-records/reference/misc.rst
index 247f25049f..c1029c9526 100644
--- a/docs/lua-records/reference/misc.rst
+++ b/docs/lua-records/reference/misc.rst
@@ -20,3 +20,9 @@ Other functions
    - `pdns.loglevels.Notice`
    - `pdns.loglevels.Warning`
    - `pdns.loglevels.Error`
+
+.. function:: pdnsrandom([maximum])
+
+  Get a random number.
+
+  :param int maximum: The largest number to return. This is 2^32 by default.
diff --git a/pdns/lua-base4.cc b/pdns/lua-base4.cc
index 34be790dad..39dbb391c3 100644
--- a/pdns/lua-base4.cc
+++ b/pdns/lua-base4.cc
@@ -10,6 +10,7 @@
 #include "namespaces.hh"
 #include "ednssubnet.hh"
 #include "lua-base4.hh"
+#include "dns_random.hh"
 
 BaseLua4::BaseLua4() {
 }
@@ -190,6 +191,7 @@ void BaseLua4::prepareContext() {
 
   // pdnsload
   d_lw->writeFunction("pdnslog", [](const std::string& msg, boost::optional<int> loglevel) { g_log << (Logger::Urgency)loglevel.get_value_or(Logger::Warning) << msg<<endl; });
+  d_lw->writeFunction("pdnsrandom", [](boost::optional<uint32_t> maximum) { return dns_random(maximum.get_value_or(0xffffffff)); });
 
   // certain constants
   d_pd.push_back({"PASS", (int)PolicyDecision::PASS});
diff --git a/pdns/recursordist/docs/lua-scripting/functions.rst b/pdns/recursordist/docs/lua-scripting/functions.rst
index 356b2f34d9..df6ca553c5 100644
--- a/pdns/recursordist/docs/lua-scripting/functions.rst
+++ b/pdns/recursordist/docs/lua-scripting/functions.rst
@@ -15,3 +15,9 @@ These are some functions that don't really have a place in one of the other cate
 .. function:: getRecursorThreadId() -> int
 
   returns an unsigned integer identifying the thread handling the current request.
+
+.. function:: pdnsrandom([maximum])
+
+  Get a random number.
+
+  :param int maximum: The largest number to return. This is 2^32 by default.
diff --git a/regression-tests.recursor-dnssec/test_Lua.py b/regression-tests.recursor-dnssec/test_Lua.py
index e126d91d02..f000bcf7a9 100644
--- a/regression-tests.recursor-dnssec/test_Lua.py
+++ b/regression-tests.recursor-dnssec/test_Lua.py
@@ -468,3 +468,30 @@ class DNS64Test(RecursorTest):
             self.assertEqual(len(res.answer), 2)
             self.assertEqual(len(res.authority), 0)
             self.assertResponseMatches(query, expected, res)
+
+
+class PDNSRandomTest(RecursorTest):
+    """Tests if pdnsrandom works"""
+
+    _confdir = 'pdnsrandom'
+    _config_template = """
+    """
+    _lua_dns_script_file = """
+    function preresolve (dq)
+      dq.rcode = pdns.NOERROR
+      dq:addAnswer(pdns.TXT, pdnsrandom())
+      return true
+    end
+    """
+
+    def testRandom(self):
+        query = dns.message.make_query('whatever.example.', 'TXT')
+
+        ans = set()
+
+        ret = self.sendUDPQuery(query)
+        ans.add(ret.answer[0])
+        ret = self.sendUDPQuery(query)
+        ans.add(ret.answer[0])
+
+        self.assertEqual(len(ans), 2)