Add VXLAN support (#501)

This patch adds a new PDU class to support VXLAN. Several VXLAN-related
tests have also been added.

Signed-off-by: James Raphael Tiovalen <jamestiotio@gmail.com>

include/tins/pdu.h

@@ -180,6 +180,7 @@ public:
         PKTAP,
         MPLS,
         DOT11_CONTROL_TA,
+        VXLAN,
         UNKNOWN = 999,
         USER_DEFINED_PDU = 1000
     };

include/tins/tins.h

@@ -78,7 +78,7 @@
 #include <tins/pdu_allocator.h>
 #include <tins/ipsec.h>
 #include <tins/ip_reassembler.h>
-
 #include <tins/pdu_iterator.h>
+#include <tins/vxlan.h>
 
 #endif // TINS_TINS_H

include/tins/vxlan.h

@@ -0,0 +1,98 @@
+#ifndef TINS_VXLAN_H
+#define TINS_VXLAN_H
+
+#include <tins/pdu.h>
+#include <tins/small_uint.h>
+
+namespace Tins {
+
+/** 
+ * \class VXLAN
+ * \brief Represents a VXLAN PDU.
+ *
+ * This class represents a VXLAN PDU.
+ *
+ * \sa RawPDU
+ */
+class TINS_API VXLAN : public PDU {
+public:
+    /**
+     * \brief This PDU's flag.
+     */
+    static const PDU::PDUType pdu_flag = PDU::VXLAN;
+
+    /**
+     * \brief Constructs a VXLAN PDU.
+     *
+     * \param vni VXLAN Network Identifier.
+     */
+    VXLAN(const small_uint<24> vni = 0);
+
+    /**
+     * \brief Constructs a VXLAN object from a buffer and adds
+     * the Ethernet II PDU.
+     *
+     * \param buffer The buffer from which this PDU will be constructed.
+     * \param total_sz The total size of the buffer.
+     */
+    VXLAN(const uint8_t* buffer, uint32_t total_sz);
+
+    /**
+     * \brief Getter for the flags.
+     */
+    uint8_t get_flags() const { return Endian::be_to_host(header_.flags) >> 24; }
+
+    /**
+     * \brief Getter for the VNI.
+     */
+    small_uint<24> get_vni() const { return Endian::be_to_host(header_.vni) >> 8; }
+
+    /**
+     * \brief Setter for the flags.
+     * \param new_flags The new flags.
+     */
+    void set_flags(uint8_t new_flags) { header_.flags = Endian::host_to_be(new_flags << 24); }
+
+    /**
+     * \brief Setter for the VNI.
+     * \param new_vni The new VNI.
+     */
+    void set_vni(small_uint<24> new_vni) { header_.vni = Endian::host_to_be(new_vni << 8); }
+
+    /**
+     * \brief Returns the VXLAN frame's header length.
+     * 
+     * This method overrides PDU::header_size. This size includes the
+     * payload and options size.
+     *
+     * \return An uint32_t with the header's size.
+     * \sa PDU::header_size
+     */
+    uint32_t header_size() const { return sizeof(header_); }
+
+    /**
+     * \brief Getter for the PDU's type.
+     * \sa PDU::pdu_type
+     */
+    PDUType pdu_type() const { return pdu_flag; }
+
+    /**
+     * \sa PDU::clone
+     */
+    VXLAN *clone() const { return new VXLAN(*this); }
+
+private:
+    TINS_BEGIN_PACK
+    struct vxlan_header {
+        uint32_t flags;
+        uint32_t vni;
+    } TINS_END_PACK;
+
+    void write_serialization(uint8_t* buffer, uint32_t total_sz);
+
+    vxlan_header header_;
+};
+
+} // Tins
+
+#endif // TINS_VXLAN_H

src/CMakeLists.txt

@@ -73,6 +73,7 @@ set(SOURCES
     utils/routing_utils.cpp
     utils/resolve_utils.cpp
     utils/pdu_utils.cpp
+    vxlan.cpp
 )
 
 set(HEADERS

src/vxlan.cpp

@@ -0,0 +1,36 @@
+#include <tins/internals.h>
+#include <tins/memory_helpers.h>
+#include <tins/small_uint.h>
+#include <tins/vxlan.h>
+
+using Tins::Memory::InputMemoryStream;
+using Tins::Memory::OutputMemoryStream;
+
+namespace Tins {
+
+VXLAN::VXLAN(const small_uint<24> vni) {
+    set_flags(8);
+    set_vni(vni);
+}
+
+VXLAN::VXLAN(const uint8_t* buffer, uint32_t total_sz) {
+    InputMemoryStream stream(buffer, total_sz);
+    stream.read(header_);
+    // If there is any size left
+    if (stream) {
+        inner_pdu(
+            Internals::pdu_from_flag(
+                PDU::ETHERNET_II,
+                stream.pointer(),
+                stream.size()
+            )
+        );
+    }
+}
+
+void VXLAN::write_serialization(uint8_t* buffer, uint32_t total_sz) {
+    OutputMemoryStream stream(buffer, total_sz);
+    stream.write(header_);
+}
+
+} // Tins

tests/src/CMakeLists.txt

@@ -70,6 +70,7 @@ CREATE_TEST(tcp)
 CREATE_TEST(tcp_ip)
 CREATE_TEST(udp)
 CREATE_TEST(utils)
+CREATE_TEST(vxlan)
 
 IF(LIBTINS_ENABLE_PCAP)
     CREATE_TEST(offline_packet_filter)

tests/src/vxlan_test.cpp

@@ -0,0 +1,90 @@
+#include <gtest/gtest.h>
+#include <string>
+#include <tins/ethernetII.h>
+#include <tins/ip.h>
+#include <tins/tcp.h>
+#include <tins/udp.h>
+#include <tins/pdu.h>
+#include <tins/small_uint.h>
+#include <tins/vxlan.h>
+
+#define PACKET_SIZE 68ul
+
+using namespace std;
+using namespace Tins;
+
+class VXLANTest : public testing::Test {
+public:
+    static const uint8_t expected_packet[PACKET_SIZE];
+    static const uint8_t flags;
+    static const uint16_t dport, sport, p_type;
+    static const small_uint<24> vni;
+    static const IP::address_type dst_ip, src_ip;
+    static const EthernetII::address_type dst_addr, src_addr;
+};
+
+const uint8_t VXLANTest::expected_packet[PACKET_SIZE] = {
+    0x08, 0x00, 0x00, 0x00,
+    0xff, 0xff, 0xff, 0x00,
+    0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff,
+    0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+};
+
+const uint8_t VXLANTest::flags = 8;
+const uint16_t VXLANTest::dport = 19627;
+const uint16_t VXLANTest::sport = 4789;
+const uint16_t VXLANTest::p_type = 0xd0ab;
+const small_uint<24> VXLANTest::vni = 0xffffff;
+const IP::address_type VXLANTest::dst_ip = IP::address_type{"2.2.2.2"};
+const IP::address_type VXLANTest::src_ip = IP::address_type{"1.1.1.1"};
+const EthernetII::address_type VXLANTest::dst_addr = EthernetII::address_type{"aa:bb:cc:dd:ee:ff"};
+const EthernetII::address_type VXLANTest::src_addr = EthernetII::address_type{"8a:8b:8c:8d:8e:8f"};
+
+TEST_F(VXLANTest, Flags) {
+    auto const vxlan = VXLAN{};
+    EXPECT_EQ(vxlan.get_flags(), flags);
+}
+
+TEST_F(VXLANTest, VNI) {
+    auto const vxlan = VXLAN{vni};
+    EXPECT_EQ(vxlan.get_vni(), vni);
+}
+
+TEST_F(VXLANTest, Find) {
+    auto const pdu = VXLAN{} / EthernetII{dst_addr, src_addr};
+    auto const eth = pdu.find_pdu<EthernetII>();
+    ASSERT_TRUE(eth != nullptr);
+    EXPECT_EQ(eth->dst_addr(), dst_addr);
+    EXPECT_EQ(eth->src_addr(), src_addr);
+}
+
+TEST_F(VXLANTest, Serialize) {
+    auto eth = EthernetII{dst_addr, src_addr};
+    eth.payload_type(p_type);
+    auto vxlan = VXLAN{vni};
+    vxlan.inner_pdu(eth);
+    auto serialized = vxlan.serialize();
+    ASSERT_EQ(serialized.size(), PACKET_SIZE);
+    EXPECT_TRUE(std::equal(serialized.begin(), serialized.end(), expected_packet));
+}
+
+TEST_F(VXLANTest, ConstructorFromBuffer) {
+    auto vxlan = VXLAN{expected_packet, PACKET_SIZE};
+    EXPECT_EQ(vxlan.get_vni(), vni);
+    EXPECT_EQ(vxlan.get_flags(), flags);
+    auto const eth = vxlan.find_pdu<EthernetII>();
+    ASSERT_TRUE(eth != nullptr);
+    EXPECT_EQ(eth->dst_addr(), dst_addr);
+    EXPECT_EQ(eth->src_addr(), src_addr);
+}
+
+TEST_F(VXLANTest, OuterUDP) {
+    auto pkt = IP{dst_ip, src_ip} / UDP{dport, sport} / VXLAN{expected_packet, PACKET_SIZE};
+    auto const vxlan = pkt.find_pdu<VXLAN>();
+    ASSERT_TRUE(vxlan != nullptr);
+    EXPECT_EQ(vxlan->get_flags(), flags);
+    EXPECT_EQ(vxlan->get_vni(), vni);
+}