Merge branch 'trac583'

src/lib/asiolink/Makefile.am

@@ -35,6 +35,7 @@ libasiolink_la_SOURCES += tcp_socket.h
 libasiolink_la_SOURCES += udp_endpoint.h
 libasiolink_la_SOURCES += udp_server.h udp_server.cc
 libasiolink_la_SOURCES += udp_socket.h
+libasiolink_la_SOURCES += qid_gen.cc qid_gen.h
 # Note: the ordering matters: -Wno-... must follow -Wextra (defined in
 # B10_CXXFLAGS)
 libasiolink_la_CXXFLAGS = $(AM_CXXFLAGS)

src/lib/asiolink/io_fetch.cc

@@ -26,6 +26,8 @@
 #include <dns/rcode.h>
 #include <log/dummylog.h>
 
+#include <asiolink/qid_gen.h>
+
 #include <asio.hpp>
 #include <asiolink/io_fetch.h>
 
@@ -34,8 +36,9 @@ using namespace isc::dns;
 using namespace isc::log;
 using namespace std;
 
-namespace asiolink {
 
+
+namespace asiolink {
 /// IOFetch Constructor - just initialize the private data
 
 IOFetch::IOFetch(int protocol, IOService& service,
@@ -64,8 +67,7 @@ IOFetch::operator()(error_code ec, size_t length) {
         {
             Message msg(Message::RENDER);
             
-            // TODO: replace with boost::random or some other suitable PRNG
-            msg.setQid(0);
+            msg.setQid(QidGenerator::getInstance().generateQid());
             msg.setOpcode(Opcode::QUERY());
             msg.setRcode(Rcode::NOERROR());
             msg.setHeaderFlag(Message::HEADERFLAG_RD);

src/lib/asiolink/qid_gen.cc

@@ -0,0 +1,56 @@
+// Copyright (C) 2011  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+// qid_gen defines a generator for query id's
+//
+// We probably want to merge this with the weighted random in the nsas
+// (and other parts where we need randomness, perhaps another thing
+// for a general libutil?)
+
+#include <asiolink/qid_gen.h>
+
+#include <sys/time.h>
+
+namespace {
+    asiolink::QidGenerator qid_generator_instance;
+}
+
+namespace asiolink {
+
+QidGenerator&
+QidGenerator::getInstance() {
+    return (qid_generator_instance);
+}
+
+QidGenerator::QidGenerator() : dist_(0, 65535),
+                               vgen_(generator_, dist_)
+{
+    seed();
+}
+
+void
+QidGenerator::seed() {
+    struct timeval tv;
+    gettimeofday(&tv, 0);
+    long int seed;
+    seed = (tv.tv_sec * 1000000) + tv.tv_usec;
+    generator_.seed(seed);
+}
+
+isc::dns::qid_t
+QidGenerator::generateQid() {
+    return (vgen_());
+}
+
+} // namespace asiolink

src/lib/asiolink/qid_gen.h

@@ -0,0 +1,85 @@
+// Copyright (C) 2011  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+// qid_gen defines a generator for query id's
+//
+// We probably want to merge this with the weighted random in the nsas
+// (and other parts where we need randomness, perhaps another thing
+// for a general libutil?)
+
+#ifndef __QID_GEN_H
+#define __QID_GEN_H
+
+#include <dns/message.h>
+#include <boost/random/mersenne_twister.hpp>
+#include <boost/random/uniform_int.hpp>
+#include <boost/random/variate_generator.hpp>
+
+
+namespace asiolink {
+    
+/// This class generates Qids for outgoing queries
+///
+/// It is implemented as a singleton; the public way to access it
+/// is to call getInstance()->generateQid().
+///
+/// It automatically seeds it with the current time when it is first
+/// used.
+class QidGenerator {
+public:
+    /// \brief Returns the singleton instance of the QidGenerator
+    ///
+    /// Returns a reference to the singleton instance of the generator
+    static QidGenerator& getInstance();
+
+    /// \brief Default constructor
+    ///
+    /// It is recommended that getInstance is used rather than creating
+    /// separate instances of this class.
+    /// 
+    /// The constructor automatically seeds the generator with the
+    /// current time.
+    QidGenerator();
+
+    /// Generate a Qid
+    ///
+    /// \return A random Qid
+    isc::dns::qid_t generateQid();
+
+    /// \brief Seeds the QidGenerator (based on the current time)
+    ///
+    /// This is automatically called by the constructor
+    void seed();
+    
+private:
+    // "Mersenne Twister: A 623-dimensionally equidistributed 
+    // uniform pseudo-random number generator", Makoto Matsumoto and 
+    // Takuji Nishimura, ACM Transactions on Modeling and Computer 
+    // Simulation: Special Issue on Uniform Random Number Generation, 
+    // Vol. 8, No. 1, January 1998, pp. 3-30. 
+    //
+    // mt19937 is an implementation of one of the pseudo random
+    // generators described in this paper.
+    boost::mt19937 generator_;
+    
+    // For qid's we want a uniform distribution
+    boost::uniform_int<> dist_;
+    
+    boost::variate_generator<boost::mt19937&, boost::uniform_int<> > vgen_;
+};
+
+
+} // namespace asiolink
+
+#endif // __QID_GEN_H

src/lib/asiolink/tests/Makefile.am

@@ -27,6 +27,7 @@ run_unittests_SOURCES += interval_timer_unittest.cc
 run_unittests_SOURCES += recursive_query_unittest.cc
 run_unittests_SOURCES += udp_endpoint_unittest.cc
 run_unittests_SOURCES += udp_socket_unittest.cc
+run_unittests_SOURCES += qid_gen_unittest.cc
 
 run_unittests_CPPFLAGS = $(AM_CPPFLAGS) $(GTEST_INCLUDES)
 

src/lib/asiolink/tests/qid_gen_unittest.cc

@@ -0,0 +1,59 @@
+// Copyright (C) 2011  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+// Copyright (C) 2011  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+
+/// \brief Test of QidGenerator
+///
+
+#include <gtest/gtest.h>
+
+#include <asiolink/qid_gen.h>
+#include <dns/message.h>
+
+// Tests the operation of the Qid generator
+
+// Check that getInstance returns a singleton
+TEST(QidGenerator, singleton) {
+    asiolink::QidGenerator& g1 = asiolink::QidGenerator::getInstance();
+    asiolink::QidGenerator& g2 = asiolink::QidGenerator::getInstance();
+
+    EXPECT_TRUE(&g1 == &g2);
+}
+
+TEST(QidGenerator, generate) {
+    // We'll assume that boost's generator is 'good enough', and won't
+    // do full statistical checking here. Let's just call it the xkcd
+    // test (http://xkcd.com/221/), and check if three consecutive
+    // generates are not all the same.
+    isc::dns::qid_t one, two, three;
+    asiolink::QidGenerator& gen = asiolink::QidGenerator::getInstance();
+    one = gen.generateQid();
+    two = gen.generateQid();
+    three = gen.generateQid();
+    ASSERT_FALSE((one == two) && (one == three));
+}