Add ICMP extensions to ICMP PDU

The length field is still not being set

include/tins/icmp.h

@@ -353,10 +353,21 @@ namespace Tins {
          * \brief Returns the header size.
          *
          * This metod overrides PDU::header_size. This size includes the
-         * payload and options size. \sa PDU::header_size
+         * payload and options size. 
+         *
+         * \sa PDU::header_size
          */
         uint32_t header_size() const;
 
+        /**
+         * \brief Returns the trailer size.
+         *
+         * This metod overrides PDU::trailer_size. This size will hold the extensions size
+         *
+         * \sa PDU::header_size
+         */
+        uint32_t trailer_size() const;
+
         /**
          * \brief Check wether ptr points to a valid response for this PDU.
          *
@@ -366,7 +377,24 @@ namespace Tins {
          */
         bool matches_response(const uint8_t *ptr, uint32_t total_sz) const;
 
-        const ICMPExtensionsStructure& extensions() { return extensions_; }
+        /** 
+         * \brief Getter for the extensions field.
+         *
+         * \return The extensions field
+         */
+        const ICMPExtensionsStructure& extensions() const { return extensions_; }
+
+        /** 
+         * \brief Getter for the extensions field.
+         *
+         * \return The extensions field
+         */
+        ICMPExtensionsStructure& extensions() { return extensions_; }
+
+        /**
+         * \brief Indicates whether this object contains ICMP extensions
+         */
+        bool has_extensions() const { return !extensions_.extensions().empty(); }
 
         /**
          * \brief Getter for the PDU's type.

include/tins/icmp_extension.h

@@ -189,6 +189,13 @@ public:
      */
     const extensions_type& extensions() const { return extensions_; }
 
+    /**
+     * \brief Adds an extension to this structure
+     *
+     * \param extension The extension to be added;
+     */
+    void add_extension(const ICMPExtension& extension);
+
     /**
      * \brief Gets the size of this ICMP extensions structure
      *

src/icmp.cpp

@@ -140,9 +140,21 @@ uint32_t ICMP::header_size() const {
         extra = sizeof(uint32_t) * 3;
     else if(type() == ADDRESS_MASK_REQUEST || type() == ADDRESS_MASK_REPLY) 
         extra = sizeof(uint32_t);
+
     return sizeof(icmphdr) + extra;
 }
 
+uint32_t ICMP::trailer_size() const {
+    uint32_t output = 0;
+    if (has_extensions()) {
+        output += extensions_.size();
+        if (inner_pdu()) {
+            output += 128 - std::min(inner_pdu()->size(), 128U);
+        }
+    }
+    return output;
+}
+
 void ICMP::set_echo_request(uint16_t id, uint16_t seq) {
     type(ECHO_REQUEST);
     this->id(id);
@@ -216,6 +228,20 @@ void ICMP::write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *)
         uint32_t_buffer = address_mask();
         memcpy(buffer + sizeof(icmphdr), &uint32_t_buffer, sizeof(uint32_t));
     }
+
+    if (has_extensions()) {
+        uint8_t* extensions_ptr = buffer + sizeof(icmphdr);
+        if (inner_pdu()) {
+            uint32_t inner_pdu_size = inner_pdu()->size();
+            if (inner_pdu_size < 128) {
+                memset(buffer + sizeof(icmphdr) + inner_pdu_size, 0, 128 - inner_pdu_size);
+                inner_pdu_size = 128;
+            }
+            extensions_ptr += inner_pdu_size;
+        }
+        extensions_.serialize(extensions_ptr, total_sz - (extensions_ptr - buffer));
+    }
+
     // checksum calc
     _icmp.check = 0;
     memcpy(buffer, &_icmp, sizeof(icmphdr));

src/icmp_extension.cpp

@@ -76,8 +76,8 @@ ICMPExtension::serialization_type ICMPExtension::serialize() const {
 const uint32_t ICMPExtensionsStructure::BASE_HEADER_SIZE = sizeof(uint16_t) * 2;
 
 ICMPExtensionsStructure::ICMPExtensionsStructure() 
-: version_and_reserved_(0x2000), checksum_(0) {
+: version_and_reserved_(), checksum_(0) {
-
+    version(2);
 }
 
 ICMPExtensionsStructure::ICMPExtensionsStructure(const uint8_t* buffer, uint32_t total_sz) {
@@ -135,6 +135,10 @@ uint32_t ICMPExtensionsStructure::size() const {
     return output;
 }
 
+void ICMPExtensionsStructure::add_extension(const ICMPExtension& extension) {
+    extensions_.push_back(extension);
+}
+
 void ICMPExtensionsStructure::serialize(uint8_t* buffer, uint32_t buffer_size) {
     const uint32_t structure_size = size();
     if (buffer_size < structure_size) {

tests/src/icmp.cpp

@@ -14,7 +14,7 @@ using namespace Tins;
 class ICMPTest : public testing::Test {
 public:
     static const uint8_t expected_packets[][8];
-    static const uint8_t ts_request[], ts_reply[];
+    static const uint8_t ts_request[], ts_reply[], packet_with_extensions[];
     static const uint32_t expected_packet_count;
     
     void test_equals(const ICMP &icmp1, const ICMP &icmp2);
@@ -35,6 +35,16 @@ const uint8_t ICMPTest::ts_reply[] = {
     14, 0, 172, 45, 0, 0, 0, 0, 0, 0, 0, 0, 4, 144, 30, 89, 4, 144, 30, 89, 0, 0, 0, 0, 0, 0
 };
 
+const uint8_t ICMPTest::packet_with_extensions[] = { 
+    11, 0, 205, 4, 0, 0, 0, 0, 69, 0, 0, 40, 165, 76, 0, 0, 1, 17, 247, 111, 12, 4, 4, 4, 12, 
+    1, 1, 1, 165, 75, 130, 155, 0, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 32, 0, 197, 95, 0, 
+    8, 1, 1, 24, 150, 1, 1
+};
+
+
 
 TEST_F(ICMPTest, DefaultConstructor) {
     ICMP icmp;
@@ -289,10 +299,9 @@ TEST_F(ICMPTest, ConstructorFromBuffer) {
 }
 
 TEST_F(ICMPTest, ExtensionsParsingWithoutALengthField) {
-    const uint8_t packet[] = { 11, 0, 205, 4, 0, 0, 0, 0, 69, 0, 0, 40, 165, 76, 0, 0, 1, 17, 247, 111, 12, 4, 4, 4, 12, 1, 1, 1, 165, 75, 130, 155, 0, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 32, 0, 197, 95, 0, 8, 1, 1, 24, 150, 1, 1 };
     const uint8_t encapsulated[] = { 69, 0, 0, 40, 165, 76, 0, 0, 1, 17, 247, 111, 12, 4, 4, 4, 12, 1, 1, 1, 165, 75, 130, 155, 0, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
     const uint8_t ext[] = { 0, 8, 1, 1, 24, 150, 1, 1 };
-    ICMP icmp(packet, sizeof(packet));
+    ICMP icmp(packet_with_extensions, sizeof(packet_with_extensions));
     ICMPExtensionsStructure extensions = icmp.extensions();
     ASSERT_EQ(1, extensions.extensions().size());
     EXPECT_EQ(
@@ -305,4 +314,11 @@ TEST_F(ICMPTest, ExtensionsParsingWithoutALengthField) {
         RawPDU::payload_type(encapsulated, encapsulated + sizeof(encapsulated)),
         raw->payload()
     );
+
+    PDU::serialization_type buffer = icmp.serialize();
+    EXPECT_EQ(sizeof(packet_with_extensions), buffer.size());
+    EXPECT_EQ(
+        buffer, 
+        PDU::serialization_type(packet_with_extensions, packet_with_extensions + sizeof(packet_with_extensions))
+    );
 }