Add MPLS PDU and hook it up with ICMP extensions

include/tins/constants.h

@@ -78,6 +78,7 @@ namespace Tins {
                 SPRITE = 0x0500,  /* Sprite */
                 IP = 0x0800,      /* IP */
                 ARP = 0x0806,     /* Address resolution */
+                MPLS = 0x8847,    /* MPLS */
                 REVARP = 0x8035,  /* Reverse ARP */
                 AT = 0x809B,      /* AppleTalk protocol */
                 AARP = 0x80F3,    /* AppleTalk ARP */

include/tins/icmp_extension.h

@@ -10,6 +10,8 @@
 
 namespace Tins {
 
+class MPLS;
+
 /**
  * \brief Class that represents an ICMP extension object
  */
@@ -207,10 +209,20 @@ public:
     /**
      * \brief Adds an extension to this structure
      *
-     * \param extension The extension to be added;
+     * \param extension The extension to be added
      */
     void add_extension(const ICMPExtension& extension);
 
+    /**
+     * \brief Adds an MPLS extension to this structure
+     *
+     * This will construct an extension using the provided MPLS packet as
+     * its payload. The class and type fields will be set appropriately.
+     *
+     * \param extension The MPLS payload to be used for the new extension
+     */
+    void add_extension(MPLS& mpls);
+
     /**
      * \brief Gets the size of this ICMP extensions structure
      *

include/tins/memory_helpers.h

@@ -4,6 +4,7 @@
 #include <stdint.h>
 #include <cstring>
 #include <algorithm>
+#include <vector>
 #include "exceptions.h"
 #include "ip_address.h"
 #include "ipv6_address.h"
@@ -36,6 +37,10 @@ public:
     : buffer_(buffer), size_(total_sz) {
     }
 
+    InputMemoryStream(const std::vector<uint8_t>& data)
+    : buffer_(&data[0]), size_(data.size()) {
+    }
+
     void skip(uint32_t size) {
         buffer_ += size;
         size_ -= size;

include/tins/mpls.h

@@ -0,0 +1,154 @@
+/*
+ * Copyright (c) 2014, Matias Fontanini
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following disclaimer
+ *   in the documentation and/or other materials provided with the
+ *   distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef TINS_MPLS_H
+#define TINS_MPLS_H
+
+#include "pdu.h"
+#include "endianness.h"
+#include "macros.h"
+#include "small_uint.h"
+
+namespace Tins {
+
+class ICMPExtension;
+
+/**
+ * \brief Represents an MPLS PDU
+ */
+class MPLS : public PDU {
+public:
+    /**
+     * \brief This PDU's flag.
+     */
+    static const PDU::PDUType pdu_flag = PDU::MPLS;
+
+    /**
+     * \brief Default constructor
+     */
+    MPLS();
+
+    /**
+     * \brief Construct an MPLS layer from an ICMP extension
+     *
+     * This will use the extension's payload to build this packet. 
+     * The extension's class and type are not checked.
+     *
+     */
+    MPLS(const ICMPExtension& extension);
+
+    /**
+     * \brief Constructor from buffer
+     */
+    MPLS(const uint8_t* buffer, uint32_t total_sz);
+
+    /**
+     * \brief Getter for the label field.
+     */
+    small_uint<20> label() const {
+        return (Endian::be_to_host(header_.label_high) << 4) | 
+               ((header_.label_low_and_bottom >> 4) & 0xf);
+    }
+
+    /**
+     * \brief Getter for the bottom of the stack field.
+     */
+    small_uint<1> bottom_of_stack() const {
+        return header_.label_low_and_bottom & 0x1;
+    }
+
+    /**
+     * \brief Getter for the ttl field.
+     */
+    uint8_t ttl() const {
+        return header_.ttl;
+    }
+
+    /**
+     * \brief Setter for the label field
+     *
+     * \param value The new label field value
+     */
+    void label(small_uint<20> value);
+
+    /**
+     * \brief Setter for the bottom of the stack field
+     *
+     * Note that if this MPLS layer is somewhere between an Ethernet and IP
+     * layers, the bottom of the stack field will be overriden and set 
+     * automatically. You should only set this field when constructing ICMP
+     * extensions.
+     *
+     * \param value The new bottom of the stack field value
+     */
+    void bottom_of_stack(small_uint<1> value);
+
+    /**
+     * \brief Setter for the ttl field
+     *
+     * \param value The new ttl field value
+     */
+    void ttl(uint8_t value);
+
+    /**
+     * \brief Returns the MPLS frame's header length.
+     *
+     * \return The header's size.
+     * \sa PDU::header_size()
+     */
+    uint32_t header_size() const;
+
+    /**
+     * \brief Getter for the PDU's type.
+     * \sa PDU::pdu_type
+     */
+    PDUType pdu_type() const { return pdu_flag; }
+
+    /**
+     * \sa PDU::clone
+     */
+    MPLS *clone() const {
+        return new MPLS(*this);
+    }
+private:
+    TINS_BEGIN_PACK
+    struct mpls_header {
+        uint16_t label_high;
+        uint8_t label_low_and_bottom;
+        uint8_t ttl;
+    } TINS_END_PACK;
+
+    void write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent);
+
+    mpls_header header_;
+};
+
+} // Tins
+
+#endif // TINS_MPLS_H

include/tins/pdu.h

@@ -129,6 +129,7 @@ namespace Tins {
             RAW,
             ETHERNET_II,
             IEEE802_3,
+            DOT3 = IEEE802_3,
             RADIOTAP,
             DOT11,
             DOT11_ACK,
@@ -177,6 +178,7 @@ namespace Tins {
             IPSEC_AH,
             IPSEC_ESP,
             PKTAP,
+            MPLS,
             USER_DEFINED_PDU = 1000
         };
         

include/tins/tins.h

@@ -45,6 +45,7 @@
 #include "dot3.h"
 #include "ip.h"
 #include "ipv6.h"
+#include "mpls.h"
 #include "packet_sender.h"
 #include "packet_writer.h"
 #include "pdu.h"