
/***************************************************************************
 * ARPHeader.cc -- The ARPHeader Class represents an ARP packet. It        *
 * contains methods to set any header field. In general, these methods do  *
 * error checkings and byte order conversion.                              *
 *                                                                         *
 ***********************IMPORTANT NMAP LICENSE TERMS************************
 *                                                                         *
 * The Nmap Security Scanner is (C) 1996-2013 Insecure.Com LLC. Nmap is    *
 * also a registered trademark of Insecure.Com LLC.  This program is free  *
 * software; you may redistribute and/or modify it under the terms of the  *
 * GNU General Public License as published by the Free Software            *
 * Foundation; Version 2 ("GPL"), BUT ONLY WITH ALL OF THE CLARIFICATIONS  *
 * AND EXCEPTIONS DESCRIBED HEREIN.  This guarantees your right to use,    *
 * modify, and redistribute this software under certain conditions.  If    *
 * you wish to embed Nmap technology into proprietary software, we sell    *
 * alternative licenses (contact sales@insecure.com).  Dozens of software  *
 * vendors already license Nmap technology such as host discovery, port    *
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 * Engine.                                                                 *
 *                                                                         *
 * Note that the GPL places important restrictions on "derivative works",  *
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 * allows.  For example, we consider an application to constitute a        *
 * derivative work for the purpose of this license if it does any of the   *
 * following with any software or content covered by this license          *
 * ("Covered Software"):                                                   *
 *                                                                         *
 * o Integrates source code from Covered Software.                         *
 *                                                                         *
 * o Reads or includes copyrighted data files, such as Nmap's nmap-os-db   *
 * or nmap-service-probes.                                                 *
 *                                                                         *
 * o Is designed specifically to execute Covered Software and parse the    *
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 * execute anything you tell them to).                                     *
 *                                                                         *
 * o Includes Covered Software in a proprietary executable installer.  The *
 * installers produced by InstallShield are an example of this.  Including *
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 * trigger this provision, provided appropriate open source decompression  *
 * or de-archiving software is widely available for no charge.  For the    *
 * purposes of this license, an installer is considered to include Covered *
 * Software even if it actually retrieves a copy of Covered Software from  *
 * another source during runtime (such as by downloading it from the       *
 * Internet).                                                              *
 *                                                                         *
 * o Links (statically or dynamically) to a library which does any of the  *
 * above.                                                                  *
 *                                                                         *
 * o Executes a helper program, module, or script to do any of the above.  *
 *                                                                         *
 * This list is not exclusive, but is meant to clarify our interpretation  *
 * of derived works with some common examples.  Other people may interpret *
 * the plain GPL differently, so we consider this a special exception to   *
 * the GPL that we apply to Covered Software.  Works which meet any of     *
 * these conditions must conform to all of the terms of this license,      *
 * particularly including the GPL Section 3 requirements of providing      *
 * source code and allowing free redistribution of the work as a whole.    *
 *                                                                         *
 * As another special exception to the GPL terms, Insecure.Com LLC grants  *
 * permission to link the code of this program with any version of the     *
 * OpenSSL library which is distributed under a license identical to that  *
 * listed in the included docs/licenses/OpenSSL.txt file, and distribute   *
 * linked combinations including the two.                                  *
 *                                                                         *
 * Any redistribution of Covered Software, including any derived works,    *
 * must obey and carry forward all of the terms of this license, including *
 * obeying all GPL rules and restrictions.  For example, source code of    *
 * the whole work must be provided and free redistribution must be         *
 * allowed.  All GPL references to "this License", are to be treated as    *
 * including the special and conditions of the license text as well.       *
 *                                                                         *
 * Because this license imposes special exceptions to the GPL, Covered     *
 * Work may not be combined (even as part of a larger work) with plain GPL *
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 * be included as well.  This license is incompatible with some other open *
 * source licenses as well.  In some cases we can relicense portions of    *
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 * software.  Please contact fyodor@nmap.org with any such requests.       *
 * Similarly, we don't incorporate incompatible open source software into  *
 * Covered Software without special permission from the copyright holders. *
 *                                                                         *
 * If you have any questions about the licensing restrictions on using     *
 * Nmap in other works, are happy to help.  As mentioned above, we also    *
 * offer alternative license to integrate Nmap into proprietary            *
 * applications and appliances.  These contracts have been sold to dozens  *
 * of software vendors, and generally include a perpetual license as well  *
 * as providing for priority support and updates.  They also fund the      *
 * continued development of Nmap.  Please email sales@insecure.com for     *
 * further information.                                                    *
 *                                                                         *
 * If you received these files with a written license agreement or         *
 * contract stating terms other than the terms above, then that            *
 * alternative license agreement takes precedence over these comments.     *
 *                                                                         *
 * Source is provided to this software because we believe users have a     *
 * right to know exactly what a program is going to do before they run it. *
 * This also allows you to audit the software for security holes (none     *
 * have been found so far).                                                *
 *                                                                         *
 * Source code also allows you to port Nmap to new platforms, fix bugs,    *
 * and add new features.  You are highly encouraged to send your changes   *
 * to the dev@nmap.org mailing list for possible incorporation into the    *
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 * Insecure.Org development mailing lists, or checking them into the Nmap  *
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 * code.  Nmap will always be available Open Source, but this is important *
 * because the inability to relicense code has caused devastating problems *
 * for other Free Software projects (such as KDE and NASM).  We also       *
 * occasionally relicense the code to third parties as discussed above.    *
 * If you wish to specify special license conditions of your               *
 * contributions, just say so when you send them.                          *
 *                                                                         *
 * This program is distributed in the hope that it will be useful, but     *
 * WITHOUT ANY WARRANTY; without even the implied warranty of              *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the Nmap      *
 * license file for more details (it's in a COPYING file included with     *
 * Nmap, and also available from https://svn.nmap.org/nmap/COPYING         *
 *                                                                         *
 ***************************************************************************/
/* This code was originally part of the Nping tool.                        */

#include "ARPHeader.h"

/******************************************************************************/
/* CONTRUCTORS, DESTRUCTORS AND INITIALIZATION METHODS                        */
/******************************************************************************/
ARPHeader::ARPHeader() {
  this->reset();
} /* End of ARPHeader constructor */


ARPHeader::~ARPHeader() {

} /* End of ARPHeader destructor */


/** Sets every attribute to its default value */
void ARPHeader::reset(){
  memset (&this->h, 0, sizeof(nping_arp_hdr_t));
  this->length=ARP_HEADER_LEN;
} /* End of reset() */


/******************************************************************************/
/* PacketElement:: OVERWRITTEN METHODS                                        */
/******************************************************************************/

/** @warning This method is essential for the superclass getBinaryBuffer()
 *  method to work. Do NOT change a thing unless you know what you're doing  */
u8 *ARPHeader::getBufferPointer(){
  return (u8*)(&h);
} /* End of getBufferPointer() */


/** Stores supplied packet in the internal buffer so the information
  * can be accessed using the standard get & set methods.
  * @warning  The ARPHeader class is able to hold a maximum of 28 bytes.
  * If the supplied buffer is longer than that, only the first 28 bytes will be
  * stored in the internal buffer.
  * @warning Supplied len MUST be at least 28 bytes (ARP header length).
  * @return OP_SUCCESS on success and OP_FAILURE in case of error */
int ARPHeader::storeRecvData(const u8 *buf, size_t len){
  if(buf==NULL || len<ARP_HEADER_LEN){
    return OP_FAILURE;
  }else{
    this->reset(); /* Re-init the object, just in case the caller had used it already */
    this->length=ARP_HEADER_LEN;
    memcpy(&(this->h), buf, ARP_HEADER_LEN);
  }
 return OP_SUCCESS;
} /* End of storeRecvData() */


/* Returns a protocol identifier. This is used by packet parsing funtions
 * that return linked lists of PacketElement objects, to determine the protocol
 * the object represents. */
int ARPHeader::protocol_id() const {
    return HEADER_TYPE_ARP;
} /* End of protocol_id() */


/** Determines if the data stored in the object after an storeRecvData() call
  * is valid and safe to use. This mainly checks the length of the data but may
  * also test the value of certain protocol fields to ensure their correctness.
  * @return the length, in bytes, of the header, if its found to be valid or
  * OP_FAILURE (-1) otherwise. */
int ARPHeader::validate(){
  if( this->length!=ARP_HEADER_LEN)
    return OP_FAILURE;
  else
    return ARP_HEADER_LEN;
} /* End of validate() */


/** Prints the contents of the header and calls print() on the next protocol
  * header in the chain (if there is any).
  * @return OP_SUCCESS on success and OP_FAILURE in case of error. */
int ARPHeader::print(FILE *output, int detail) const {
  fprintf(output, "ARP[]");
  if(this->next!=NULL){
    print_separator(output, detail);
    next->print(output, detail);
  }
  return OP_SUCCESS;
} /* End of print() */


/******************************************************************************/
/* PROTOCOL-SPECIFIC METHODS                                                  */
/******************************************************************************/

/** Sets HardwareType.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setHardwareType(u16 val){
  this->h.ar_hrd=htons(val);
  return OP_SUCCESS;
} /* End of setHardwareType() */


/** Sets HardwareType to ETHERNET.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setHardwareType(){
  this->h.ar_hrd=htons(HDR_ETH10MB);
  return OP_SUCCESS;
} /* End of setHardwareType() */


/** Returns value of attribute h.ar_hrd */
u16 ARPHeader::getHardwareType(){
  return ntohs(this->h.ar_hrd);
} /* End of getHardwareType() */


/** Sets ProtocolType.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setProtocolType(u16 val){
  this->h.ar_pro=htons(val);
  return OP_SUCCESS;
} /* End of setProtocolType() */


/** Sets ProtocolType.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setProtocolType(){
  this->h.ar_pro=htons(0x0800); /* DEFAULT: IPv4 */
  return OP_SUCCESS;
} /* End of setProtocolType() */


/** Returns value of attribute h.ar_pro */
u16 ARPHeader::getProtocolType(){
  return ntohs(this->h.ar_pro);
} /* End of getProtocolType() */


/** Sets HwAddrLen.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setHwAddrLen(u8 val){
  this->h.ar_hln=val;
  return OP_SUCCESS;
} /* End of setHwAddrLen() */


/** Sets HwAddrLen.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setHwAddrLen(){
  this->h.ar_hln=ETH_ADDRESS_LEN;
  return OP_SUCCESS;
} /* End of setHwAddrLen() */


/** Returns value of attribute h.ar_hln */
u8 ARPHeader::getHwAddrLen(){
  return this->h.ar_hln;
} /* End of getHwAddrLen() */


/** Sets ProtoAddrLen.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setProtoAddrLen(u8 val){
  this->h.ar_pln=val;
  return OP_SUCCESS;
} /* End of setProtoAddrLen() */


/** Sets ProtoAddrLen.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setProtoAddrLen(){
  this->h.ar_pln=IPv4_ADDRESS_LEN; /* DEFAULT: IPv4 */
  return OP_SUCCESS;
} /* End of setProtoAddrLen() */


/** Returns value of attribute h.ar_pln */
u8 ARPHeader::getProtoAddrLen(){
  return this->h.ar_pln;
} /* End of getProtoAddrLen() */


/** Sets OpCode.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setOpCode(u16 val){
  this->h.ar_op=htons(val);
  return OP_SUCCESS;
} /* End of setOpCode() */


/** Returns value of attribute h.ar_op */
u16 ARPHeader::getOpCode(){
  return ntohs(this->h.ar_op);
} /* End of getOpCode() */


/** Sets SenderMAC.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setSenderMAC(const u8 * val){
  if(val==NULL)
    return OP_FAILURE;
  memcpy(this->h.data, val, ETH_ADDRESS_LEN);
  return OP_SUCCESS;
} /* End of setSenderMAC() */


/** Returns value of attribute h.ar_sha */
u8 * ARPHeader::getSenderMAC(){
  return this->h.data;
} /* End of getSenderMAC() */


/** Sets SenderIP.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setSenderIP(struct in_addr val){
  memcpy(this->h.data+6, &val.s_addr, 4);
  return OP_SUCCESS;
} /* End of setSenderIP() */


/** Returns value of attribute h.ar_sip */
u32 ARPHeader::getSenderIP(){
  u32 *p = (u32 *)(this->h.data+6);
  return *p;
} /* End of getSenderIP() */


/** Sets TargetMAC.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setTargetMAC(u8 * val){
  if(val==NULL)
    return OP_FAILURE;
  memcpy(this->h.data+10, val, ETH_ADDRESS_LEN);
  return OP_SUCCESS;
} /* End of setTargetMAC() */


/** Returns value of attribute h.ar_tha */
u8 * ARPHeader::getTargetMAC(){
  return this->h.data+10;
} /* End of getTargetMAC() */


/** Sets TargetIP.
 *  @return OP_SUCCESS on success and OP_FAILURE in case of error.           */
int ARPHeader::setTargetIP(struct in_addr val){
  memcpy(this->h.data+16, &val.s_addr, 4);
  return OP_SUCCESS;
} /* End of setTargetIP() */


/** Returns value of attribute h.ar_tip */
u32 ARPHeader::getTargetIP(){
  u32 *p = (u32 *)(this->h.data+16);
  return *p;
} /* End of getTargetIP() */
