/***************************************************************************
* EthernetHeader.cc -- The EthernetHeader Class represents an Ethernet *
* header and footer. It contains methods to set the different header *
* fields. These methods tipically perform the necessary error checks and *
* byte order conversions. *
* *
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***************************************************************************/
/* This code was originally part of the Nping tool. */
#include "EthernetHeader.h"
/******************************************************************************/
/* CONTRUCTORS, DESTRUCTORS AND INITIALIZATION METHODS */
/******************************************************************************/
EthernetHeader::EthernetHeader(){
this->reset();
} /* End of EthernetHeader constructor */
EthernetHeader::~EthernetHeader(){
} /* End of EthernetHeader destructor */
/** Sets every attribute to its default value */
void EthernetHeader::reset(){
memset(&this->h, 0, sizeof(nping_eth_hdr_t));
this->length=ETH_HEADER_LEN;
} /* End of reset() */
/** @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 * EthernetHeader::getBufferPointer(){
return (u8*)(&h);
} /* End of getBufferPointer() */
/******************************************************************************/
/* PacketElement:: OVERWRITTEN METHODS */
/******************************************************************************/
/** Stores supplied packet in the internal buffer so the information
* can be accessed using the standard get & set methods.
* @warning The EthernetHeader class is able to hold a maximum of 14 bytes.
* If the supplied buffer is longer than that, only the first 14 bytes will be
* stored in the internal buffer.
* @warning Supplied len MUST be at least 14 bytes (Ethernet header length).
* @return OP_SUCCESS on success and OP_FAILURE in case of error */
int EthernetHeader::storeRecvData(const u8 *buf, size_t len){
if(buf==NULL || len<ETH_HEADER_LEN){
return OP_FAILURE;
}else{
this->reset(); /* Re-init the object, just in case the caller had used it already */
this->length=ETH_HEADER_LEN;
memcpy(&(this->h), buf, ETH_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 EthernetHeader::protocol_id() const {
return HEADER_TYPE_ETHERNET;
} /* 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 EthernetHeader::validate(){
if( this->length!=ETH_HEADER_LEN)
return OP_FAILURE;
else
return ETH_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 EthernetHeader::print(FILE *output, int detail) const {
fprintf(output, "Eth[");
for(int i=0; i<6; i++){
fprintf(output, "%02x", this->h.eth_smac[i]);
if(i<5)
fprintf(output, ":");
}
fprintf(output, " > ");
for(int i=0; i<6; i++){
fprintf(output, "%02x", this->h.eth_dmac[i]);
if(i<5)
fprintf(output, ":");
}
if(detail>=PRINT_DETAIL_MED)
fprintf(output, " Type=%04x", this->getEtherType());
fprintf(output, "]");
if(this->next!=NULL){
print_separator(output, detail);
next->print(output, detail);
}
return OP_SUCCESS;
} /* End of print() */
/******************************************************************************/
/* PROTOCOL-SPECIFIC METHODS */
/******************************************************************************/
/** Sets Source MAC address
* @warning Supplied buffer must contain at least 6 bytes */
int EthernetHeader::setSrcMAC(const u8 *m){
if(m==NULL)
netutil_fatal("EthernetHeader::setSrcMAC(u8*): NULL value supplied ");
memcpy(h.eth_smac, m, 6);
return OP_SUCCESS;
} /* End of setSrcMAC() */
/** Returns source port in HOST byte order
* @warning Returned pointer points directly to a Class internal buffer. If
* contents are changed, the instance of the class will be affected. */
const u8* EthernetHeader::getSrcMAC() const {
return this->h.eth_smac;
} /* End of getSrcMAC() */
/** Sets Destination MAC address
* @warning Supplied buffer must contain at least 6 bytes */
int EthernetHeader::setDstMAC(u8 *m){
if(m==NULL)
netutil_fatal("EthernetHeader::setDstMAC(u8 *): NULL value supplied ");
memcpy(h.eth_dmac, m, 6);
return OP_SUCCESS;
} /* End of setDstMAC() */
/** Returns destination port in HOST byte order */
const u8 *EthernetHeader::getDstMAC() const {
return this->h.eth_dmac;
} /* End of getDstMAC() */
int EthernetHeader::setEtherType(u16 val){
h.eth_type=htons(val);
return OP_SUCCESS;
} /* End of setEtherType() */
/** Returns destination port in HOST byte order */
const u16 EthernetHeader::getEtherType() const {
return ntohs(this->h.eth_type);
} /* End of getEtherType() */