Correctly serialize PPPoE session packets

cpkt9762 · Jan 1, 2016 · f5a82b1 · f5a82b1
1 parent 2c16aaa
commit f5a82b1
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Showing 2 changed files with 44 additions and 4 deletions.
diff --git a/src/ethernetII.cpp b/src/ethernetII.cpp
@@ -44,6 +44,7 @@
 #include "ethernetII.h"
 #include "packet_sender.h"
 #include "rawpdu.h"
+#include "pppoe.h"
 #include "ip.h"
 #include "ipv6.h"
 #include "arp.h"
@@ -152,9 +153,17 @@ bool EthernetII::matches_response(const uint8_t *ptr, uint32_t total_sz) const {
 void EthernetII::write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent) {
     OutputMemoryStream stream(buffer, total_sz);
     if (inner_pdu()) {
-        Constants::Ethernet::e flag = Internals::pdu_flag_to_ether_type(
-            inner_pdu()->pdu_type()
-        );
+        Constants::Ethernet::e flag;
+        const PDUType type = inner_pdu()->pdu_type();
+        // Dirty trick to sucessfully tag PPPoE session/discovery packets
+        if (type == PDU::PPPOE) {
+            const PPPoE* pppoe = static_cast<const PPPoE*>(inner_pdu());
+            flag = (pppoe->code() == 0) ? Constants::Ethernet::PPPOES 
+                                        : Constants::Ethernet::PPPOED;
+        }
+        else {
+            flag = Internals::pdu_flag_to_ether_type(type);
+        }
         if (flag != Constants::Ethernet::UNKNOWN) {
             payload_type(static_cast<uint16_t>(flag));
         }
@@ -188,4 +197,5 @@ PDU *EthernetII::recv_response(PacketSender &sender, const NetworkInterface &ifa
     #endif
 }
 #endif // _WIN32
-}
+
+} // Tins
diff --git a/tests/src/pppoe.cpp b/tests/src/pppoe.cpp
@@ -14,6 +14,7 @@ class PPPoETest : public testing::Test {
     static const uint8_t expected_packet[];
     static const uint8_t session_packet[];
     static const uint8_t full_session_packet[];
+    static const uint8_t full_session_packet2[];
 };
 
 const uint8_t PPPoETest::expected_packet[] = {
@@ -33,6 +34,13 @@ const uint8_t PPPoETest::full_session_packet[] = {
     , 0, 0, 0, 0, 0, 0, 0
 };
 
+const uint8_t PPPoETest::full_session_packet2[] = {
+    255, 255, 255, 255, 255, 255, 0, 12, 41, 87, 232, 60, 136, 100, 17, 
+    0, 0, 0, 0, 50, 0, 87, 96, 0, 0, 0, 0, 8, 58, 1, 254, 128, 0, 0, 0, 
+    0, 0, 0, 2, 12, 41, 255, 254, 87, 232, 60, 255, 2, 0, 0, 0, 0, 0, 0, 
+    0, 0, 0, 0, 0, 0, 0, 2, 151, 20, 88, 131, 0, 0, 0, 0
+};
+
 TEST_F(PPPoETest, DefaultConstructor) {
     PPPoE pdu;
     EXPECT_EQ(1, pdu.version());
@@ -69,6 +77,28 @@ TEST_F(PPPoETest, ConstructorFromFullSessionBuffer) {
     const RawPDU* raw = pdu.find_pdu<RawPDU>();
     ASSERT_TRUE(raw != NULL);
     EXPECT_EQ(21U, raw->payload_size());
+
+    PDU::serialization_type buffer = eth.serialize();
+    EXPECT_EQ(
+        PDU::serialization_type(
+            full_session_packet, 
+            full_session_packet + sizeof(full_session_packet)
+        ),
+        buffer
+    );
+}
+
+TEST_F(PPPoETest, ConstructorFromFullSessionBuffer2) {
+    EthernetII eth(full_session_packet2, sizeof(full_session_packet2));
+
+    PDU::serialization_type buffer = eth.serialize();
+    EXPECT_EQ(
+        PDU::serialization_type(
+            full_session_packet2, 
+            full_session_packet2 + sizeof(full_session_packet2)
+        ),
+        buffer
+    );
 }
 
 TEST_F(PPPoETest, ConstructorFromBuffer) {