/***************************************************************************
* RoutingHeader.cc -- The RoutingHeader Class represents an IPv6 Routing *
* extension header. *
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/* This code was originally part of the Nping tool. */
#include "RoutingHeader.h"
#include <assert.h>
/******************************************************************************/
/* CONTRUCTORS, DESTRUCTORS AND INITIALIZATION METHODS */
/******************************************************************************/
RoutingHeader::RoutingHeader() {
this->reset();
} /* End of RoutingHeader constructor */
RoutingHeader::~RoutingHeader() {
} /* End of RoutingHeader destructor */
/** Sets every attribute to its default value */
void RoutingHeader::reset(){
memset(&this->h, 0, sizeof(nping_ipv6_ext_routing_hdr_t));
this->length=ROUTING_HEADER_MIN_LEN;
this->curr_addr=(u8 *)this->h.data;
} /* 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 *RoutingHeader::getBufferPointer(){
return (u8*)(&this->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 RoutingHeader class is able to hold a maximum of
* sizeof(nping_icmpv6_hdr_t) bytes. If the supplied buffer is longer than
* that, only the first 1508 bytes will be stored in the internal buffer.
* @warning Supplied len MUST be at least 8 bytes (min ICMPv6 header length).
* @return OP_SUCCESS on success and OP_FAILURE in case of error */
int RoutingHeader::storeRecvData(const u8 *buf, size_t len){
if(buf==NULL || len<ROUTING_HEADER_MIN_LEN){
this->length=0;
return OP_FAILURE;
}else{
/* Store the first 4 bytes, so we can access lenght and routing type */
memcpy(&(this->h), buf, 4);
/* Our behaviour is different depending on the routing type. */
switch(this->h.type){
/* Routing Type 0 (deprecated by RFC 5095)*/
case 0:
/* Type 0 has a variable length, but the value of its HdrExtLen
* field must be even (because it must be a multiple of the
* IPv6 address size). We also make sure that the received buffer
* has as many bytes as the HdrExtLen field says it has, and
* that it doesn't exceed the maximum number of octets we
* can store in this object. */
if(this->h.len%2==1 || ((unsigned int)(this->h.len+1))*8 > len || (this->h.len+1)*8 > ROUTING_HEADER_MAX_LEN){
this->length=0;
return OP_FAILURE;
}else{
int pkt_len=(this->h.len+1)*8;
this->reset();
this->length=pkt_len;
memcpy(&(this->h), buf, this->length);
return OP_SUCCESS;
}
break;
/* Routing Type 2 (For IPv6 Mobility. See RFC 6275) */
case 2:
/* Type 2 has a fixed length. If we have that many octets, store
* them. We'll perform validation later in validate(). */
if(len<ROUTING_TYPE_2_HEADER_LEN){
this->length=0;
return OP_FAILURE;
}else{
this->reset();
memcpy(&(this->h), buf, ROUTING_TYPE_2_HEADER_LEN);
this->length=ROUTING_TYPE_2_HEADER_LEN;
return OP_SUCCESS;
}
break;
/* Unknown routing type */
default:
/* If this is some routing type that we don't know about, we'll have
* to store as much data as the header says it has. Obvioulsy, we
* check that we received as much data as the HdrExtLen advertises,
* and that we don't exceed our own internal limit. */
if( ((unsigned int)(this->h.len+1))*8 > len || (this->h.len+1)*8 > ROUTING_HEADER_MAX_LEN){
this->length=0;
return OP_FAILURE;
}else{
this->reset();
this->length=(this->h.len+1)*8;
memcpy(&(this->h), buf, this->length);
return OP_SUCCESS;
}
break;
}
}
return OP_FAILURE;
} /* 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 RoutingHeader::protocol_id() const {
return HEADER_TYPE_IPv6_ROUTE;
} /* 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 RoutingHeader::validate(){
/* Check the object's length makes sense*/
if(this->length < ROUTING_HEADER_MIN_LEN || this->length%8!=0) {
return OP_FAILURE;
}
switch(this->h.type){
/* Routing Type 0 (deprecated by RFC 5095)*/
case 0:
/* Here we check that:
* 1) The length in HdrExtLen is even.
* 2) The length in HdrExtLen matches the octects stored in this object.
* 3) The length in HdrExtLen does not exceed our internal limit. */
if(this->h.len%2==1 || (this->h.len+1)*8 != this->length || (this->h.len+1)*8 > ROUTING_HEADER_MAX_LEN){
return OP_FAILURE;
}
/* Also, for Type 0, the value in the SegmentsLeft field should be less
* than or equal to the number of addresses in the packet. We verify
* that using the value of the HDrExtLen field which, divided by two,
* yields the number of addresses in the packet. It certainly doesn't
* make sense for the packet to say there are 5 hops left when we
* have less than 5 IPv6 addresses. We allow it to be less than
* the number of addresses present in the packet because the RFC 2460
* only talkes about segleft being greater than HDrExtLen/2, not less. */
if(this->h.segleft > this->h.len/2){
return OP_FAILURE;
}
break;
/* Routing Type 2 (For IPv6 Mobility. See RFC 6275) */
case 2:
/* Check that we have the exact number of octets we expect. */
if(this->length!= ROUTING_TYPE_2_HEADER_LEN){
return OP_FAILURE;
}
/* Also check that the HdrExtLen and SegmentsLeft fields have the
* value that RFC 6275 dictates. */
if(this->h.segleft!=1 || this->h.len!=2){
return OP_FAILURE;
}
break;
/* Unknown routing type */
default:
/* If this is some routing type that we don't know about, we just
* check that the length makes sense because we cannot make assumptions
* about the semantics of other fields. */
if( this->length!=(this->h.len+1)*8 || (this->h.len+1)*8>ROUTING_HEADER_MAX_LEN){
return OP_FAILURE;
}
break;
}
return this->length;
} /* 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 RoutingHeader::print(FILE *output, int detail) const {
fprintf(output, "Routing[nh=%d len=%d type=%d segleft=%d]", this->h.nh, this->h.len, this->h.type, this->h.segleft);
// TODO: @todo : Implement this
if(this->next!=NULL){
print_separator(output, detail);
next->print(output, detail);
}
return OP_SUCCESS;
} /* End of print() */
/******************************************************************************/
/* PROTOCOL-SPECIFIC METHODS */
/******************************************************************************/
/** Set Next Header field */
int RoutingHeader::setNextHeader(u8 val){
this->h.nh = val;
return OP_SUCCESS;
} /* End of setNextHeader() */
/** Returns next header id */
u8 RoutingHeader::getNextHeader(){
return this->h.nh;
} /* End of getNextHeader() */
/** Set routing type */
int RoutingHeader::setRoutingType(u8 val){
this->h.type = val;
return OP_SUCCESS;
} /* End of setRoutingType() */
/** Returns the routing type */
u8 RoutingHeader::getRoutingType(){
return this->h.type;
} /* End of getRoutingType() */
/** Set number of segments left */
int RoutingHeader::setSegmentsLeft(u8 val){
this->h.segleft = val;
return OP_SUCCESS;
} /* End of setSegmentsLeft() */
/** Returns the number of segments left */
u8 RoutingHeader::getSegmentsLeft(){
return this->h.segleft;
} /* End of getSegmentsLeft() */
/** Set number of segments left */
int RoutingHeader::addAddress(struct in6_addr val){
/* Check we don't exceed max length */
if((this->length + 16)>ROUTING_HEADER_MAX_LEN)
return OP_FAILURE;
memcpy(this->curr_addr, val.s6_addr, 16);
this->curr_addr+=16;
this->h.len+=2;
this->length+=16;
return OP_SUCCESS;
} /* End of setSegmentsLeft() */