mirror of
https://github.com/nmap/nmap.git
synced 2025-12-06 04:31:29 +00:00
390 lines
16 KiB
C++
390 lines
16 KiB
C++
/***************************************************************************
|
|
* HopByHopHeader.cc -- The HopByHopHeader Class represents an IPv6 *
|
|
* Hop-by-Hop extension header. *
|
|
***********************IMPORTANT NMAP LICENSE TERMS************************
|
|
*
|
|
* The Nmap Security Scanner is (C) 1996-2025 Nmap Software LLC ("The Nmap
|
|
* Project"). Nmap is also a registered trademark of the Nmap Project.
|
|
*
|
|
* This program is distributed under the terms of the Nmap Public Source
|
|
* License (NPSL). The exact license text applying to a particular Nmap
|
|
* release or source code control revision is contained in the LICENSE
|
|
* file distributed with that version of Nmap or source code control
|
|
* revision. More Nmap copyright/legal information is available from
|
|
* https://nmap.org/book/man-legal.html, and further information on the
|
|
* NPSL license itself can be found at https://nmap.org/npsl/ . This
|
|
* header summarizes some key points from the Nmap license, but is no
|
|
* substitute for the actual license text.
|
|
*
|
|
* Nmap is generally free for end users to download and use themselves,
|
|
* including commercial use. It is available from https://nmap.org.
|
|
*
|
|
* The Nmap license generally prohibits companies from using and
|
|
* redistributing Nmap in commercial products, but we sell a special Nmap
|
|
* OEM Edition with a more permissive license and special features for
|
|
* this purpose. See https://nmap.org/oem/
|
|
*
|
|
* If you have received a written Nmap license agreement or contract
|
|
* stating terms other than these (such as an Nmap OEM license), you may
|
|
* choose to use and redistribute Nmap under those terms instead.
|
|
*
|
|
* The official Nmap Windows builds include the Npcap software
|
|
* (https://npcap.com) for packet capture and transmission. It is under
|
|
* separate license terms which forbid redistribution without special
|
|
* permission. So the official Nmap Windows builds may not be redistributed
|
|
* without special permission (such as an Nmap OEM license).
|
|
*
|
|
* 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.
|
|
*
|
|
* Source code also allows you to port Nmap to new platforms, fix bugs, and
|
|
* add new features. You are highly encouraged to submit your changes as a
|
|
* Github PR or by email to the dev@nmap.org mailing list for possible
|
|
* incorporation into the main distribution. Unless you specify otherwise, it
|
|
* is understood that you are offering us very broad rights to use your
|
|
* submissions as described in the Nmap Public Source License Contributor
|
|
* Agreement. This is important because we fund the project by selling licenses
|
|
* with various terms, and also because the inability to relicense code has
|
|
* caused devastating problems for other Free Software projects (such as KDE
|
|
* and NASM).
|
|
*
|
|
* The free version of Nmap 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. Warranties,
|
|
* indemnification and commercial support are all available through the
|
|
* Npcap OEM program--see https://nmap.org/oem/
|
|
*
|
|
***************************************************************************/
|
|
/* This code was originally part of the Nping tool. */
|
|
|
|
#include "HopByHopHeader.h"
|
|
#include <assert.h>
|
|
|
|
/******************************************************************************/
|
|
/* CONTRUCTORS, DESTRUCTORS AND INITIALIZATION METHODS */
|
|
/******************************************************************************/
|
|
HopByHopHeader::HopByHopHeader() {
|
|
this->reset();
|
|
} /* End of HopByHopHeader constructor */
|
|
|
|
|
|
HopByHopHeader::~HopByHopHeader() {
|
|
|
|
} /* End of HopByHopHeader destructor */
|
|
|
|
|
|
/** Sets every attribute to its default value */
|
|
void HopByHopHeader::reset(){
|
|
memset(&this->h, 0, sizeof(nping_ipv6_ext_hopbyhop_hdr_t));
|
|
curr_option=(u8*)this->h.options;
|
|
this->length=2;
|
|
this->addOption(EXTOPT_PADN, 4, (const u8*)"\x00\x00\x00\x00");
|
|
} /* 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 *HopByHopHeader::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 HopByHopHeader 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 HopByHopHeader::storeRecvData(const u8 *buf, size_t len){
|
|
if(buf==NULL || len<HOPBYHOP_MIN_HEADER_LEN){
|
|
this->length=0;
|
|
return OP_FAILURE;
|
|
}else{
|
|
/* Store the first 4 bytes, so we can access the HdrExtLen field. */
|
|
memcpy(&(this->h), buf, 4);
|
|
|
|
/* Check that the HdrExtLen field makes sense:
|
|
* 1) Check that it carries as many octets as it claims
|
|
* 2) Check that we don't exceed our internal storage space. */
|
|
// h.len cannot exceed 0xff, so max is (0xff+1)*8, but HOPBYHOP_MAX_HEADER_LEN is 8 + 0x100*8
|
|
if( ((unsigned int)(this->h.len+1))*8 > len){
|
|
this->length=0;
|
|
return OP_FAILURE;
|
|
}else{
|
|
int mylen=(this->h.len+1)*8;
|
|
this->reset();
|
|
this->length=mylen;
|
|
memcpy(&(this->h), buf, this->length);
|
|
return OP_SUCCESS;
|
|
}
|
|
}
|
|
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 HopByHopHeader::protocol_id() const {
|
|
return HEADER_TYPE_IPv6_HOPOPT;
|
|
} /* 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 HopByHopHeader::validate(){
|
|
nping_ipv6_ext_hopbyhop_opt_t *curr_opt=NULL;
|
|
u8 *curr_pnt=(u8 *)this->h.options;
|
|
int bytes_left=this->length-2;
|
|
|
|
/* Check the object's length makes sense*/
|
|
if(this->length%8!=0 || this->length < HOPBYHOP_MIN_HEADER_LEN || this->length > HOPBYHOP_MAX_HEADER_LEN){
|
|
return OP_FAILURE;
|
|
}
|
|
/* Check the header's length field. It should match the object's length */
|
|
if( (this->h.len+1)*8 != this->length){
|
|
return OP_FAILURE;
|
|
}
|
|
|
|
/* Now validate the TLV-encoded options. */
|
|
while(bytes_left>0){
|
|
/* Use the opts structure as a template to access current option */
|
|
curr_opt=(nping_ipv6_ext_hopbyhop_opt_t *)curr_pnt;
|
|
|
|
/* Let's see what we have. */
|
|
switch(curr_opt->type){
|
|
|
|
/* Pad1
|
|
+-+-+-+-+-+-+-+-+
|
|
| 0 |
|
|
+-+-+-+-+-+-+-+-+ */
|
|
case EXTOPT_PAD1:
|
|
curr_pnt++; /* Skip one octet */
|
|
bytes_left--;
|
|
break;
|
|
|
|
/* PadN
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
|
|
| 1 | Padding Len | Padding
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - - */
|
|
case EXTOPT_PADN:
|
|
/* Check we have as many octets as the option advertises */
|
|
if(bytes_left<2+curr_opt->len)
|
|
return OP_FAILURE;
|
|
curr_pnt+=2+curr_opt->len;
|
|
bytes_left-=2+curr_opt->len;
|
|
break;
|
|
|
|
/* Jumbo Payload Option (RFC 2675).
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| Option Type | Opt Data Len |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| Jumbo Payload Length |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */
|
|
case EXTOPT_JUMBO:
|
|
/* Jumbo has a fixed length of 4 octets (plus 2). */
|
|
if(curr_opt->len!=4)
|
|
return OP_FAILURE;
|
|
/* Check if we actually have all the octets */
|
|
if(bytes_left<2+4)
|
|
return OP_FAILURE;
|
|
curr_pnt+=6;
|
|
bytes_left-=6;
|
|
break;
|
|
|
|
/* Tunnel Encapsulation limit (RFC 2473).
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| Option Type | 1 | Tun Encap Lim |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */
|
|
case EXTOPT_TUNENCAPLIM:
|
|
/* This one also has a fixed length. */
|
|
if(curr_opt->len!=1)
|
|
return OP_FAILURE;
|
|
/* Check if we actually have all the octets */
|
|
if(bytes_left<2+1)
|
|
return OP_FAILURE;
|
|
curr_pnt+=3;
|
|
bytes_left-=3;
|
|
break;
|
|
|
|
/* Router Alert (RFC 2711).
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| Option Type | 2 | Value (2 octets) |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */
|
|
case EXTOPT_ROUTERALERT:
|
|
/* Fixed length (two octets)*/
|
|
if(curr_opt->len!=2)
|
|
return OP_FAILURE;
|
|
/* Check that we actually have all the octets */
|
|
if(bytes_left<2+2)
|
|
return OP_FAILURE;
|
|
curr_pnt+=4;
|
|
bytes_left-=4;
|
|
break;
|
|
|
|
/* Quick-Start (RFC 4782).
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| Option | Length=6 | Func. | Rate | Not Used |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| QS Nonce | R |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */
|
|
case EXTOPT_QUICKSTART:
|
|
/* Fixed length (two octets)*/
|
|
if(curr_opt->len!=6)
|
|
return OP_FAILURE;
|
|
/* Check that we actually have all the octets */
|
|
if(bytes_left<2+6)
|
|
return OP_FAILURE;
|
|
curr_pnt+=8;
|
|
bytes_left-=8;
|
|
break;
|
|
|
|
/* CALIPSO (RFC 5570).
|
|
+----------------------------+
|
|
| Option Type | Option Length|
|
|
+-------------+---------------+-------------+--------------+
|
|
| CALIPSO Domain of Interpretation |
|
|
+-------------+---------------+-------------+--------------+
|
|
| Cmpt Length | Sens Level | Checksum (CRC-16) |
|
|
+-------------+---------------+-------------+--------------+
|
|
| Compartment Bitmap (Optional; variable length) |
|
|
+-------------+---------------+-------------+--------------+ */
|
|
case EXTOPT_CALIPSO:
|
|
/* The length of the CALIPSO option is variable because the
|
|
* Compartment Bitmap is not mandatory. However, the length
|
|
* must be at least 8. */
|
|
if(curr_opt->len<8)
|
|
return OP_FAILURE;
|
|
/* Check that we actually have all the octets */
|
|
if(bytes_left<2+curr_opt->len)
|
|
return OP_FAILURE;
|
|
curr_pnt+=2+curr_opt->len;
|
|
bytes_left-=2+curr_opt->len;
|
|
break;
|
|
|
|
|
|
/* Home Address (RFC 6275).
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| Option Type | Option Length |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
| |
|
|
+ +
|
|
| |
|
|
+ Home Address +
|
|
| |
|
|
+ +
|
|
| |
|
|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+*/
|
|
case EXTOPT_HOMEADDR:
|
|
/* Fixed length of 16 */
|
|
if(curr_opt->len!=16)
|
|
return OP_FAILURE;
|
|
/* Check if we actually have all the octets */
|
|
if(bytes_left<2+16)
|
|
return OP_FAILURE;
|
|
curr_pnt+=18;
|
|
bytes_left-=18;
|
|
break;
|
|
|
|
/* Option Type Unknown */
|
|
default:
|
|
/* If we don't know the option, we can still try to validate it,
|
|
* checking if the OptionLength contains something reasonable. */
|
|
/* Fixed length of 16 */
|
|
if(bytes_left<2+curr_opt->len)
|
|
return OP_FAILURE;
|
|
curr_pnt+=2+curr_opt->len;
|
|
bytes_left-=2+curr_opt->len;
|
|
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 HopByHopHeader::print(FILE *output, int detail) const {
|
|
fprintf(output, "HopByHop[%d,%d]", this->h.nh, this->h.len);
|
|
// 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 HopByHopHeader::setNextHeader(u8 val){
|
|
this->h.nh = val;
|
|
return OP_SUCCESS;
|
|
} /* End of setNextHeader() */
|
|
|
|
|
|
/** Returns next header id */
|
|
u8 HopByHopHeader::getNextHeader(){
|
|
return this->h.nh;
|
|
} /* End of getNextHeader() */
|
|
|
|
|
|
/* Add TLV encoded option */
|
|
int HopByHopHeader::addOption(u8 type, u8 len, const u8 *data){
|
|
/* Make sure we don't screw up due to buffer length issues */
|
|
if(data==NULL)
|
|
return OP_FAILURE;
|
|
if ( (this->length+len+2) > HOPBYHOP_MAX_HEADER_LEN ) /* No space for more */
|
|
return OP_FAILURE;
|
|
|
|
/* Store the option */
|
|
curr_option[0]=type;
|
|
curr_option[1]=len;
|
|
memcpy(curr_option+2, data, len);
|
|
/* Update internal option offset and object's length */
|
|
curr_option+=(len+2);
|
|
this->length+=(len+2);
|
|
this->addPadding();
|
|
return OP_SUCCESS;
|
|
|
|
} /* End of addOption() */
|
|
|
|
|
|
/* If the current length of the extension header is not a multiple of 8 octets,
|
|
* this method adds the necessary padding (either PadN or Pad1 options)*/
|
|
int HopByHopHeader::addPadding(){
|
|
u8 zeroes[8]={0,0,0,0,0,0,0,0};
|
|
// required_octets in range [0,7]
|
|
int required_octets=(8 - (this->length % 8)) % 8;
|
|
|
|
/* Make sure we have enough space for the padding. */
|
|
if ( (this->length+required_octets) > HOPBYHOP_MAX_HEADER_LEN )
|
|
return OP_FAILURE;
|
|
|
|
/* Insert Pad1 or PadN to fill the necessary octets */
|
|
if (required_octets == 1) {
|
|
curr_option[0]=EXTOPT_PAD1;
|
|
curr_option++;
|
|
this->length++;
|
|
}
|
|
else if (required_octets > 0) {
|
|
this->addOption(EXTOPT_PADN, required_octets-2, zeroes );
|
|
}
|
|
assert(this->length%8==0);
|
|
this->h.len=(this->length/8)-1;
|
|
return OP_SUCCESS;
|
|
} /* End of addPadding() */
|