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nmap/libnetutil/IPv6Header.cc

577 lines
22 KiB
C++

/***************************************************************************
* IPv6Header.cc -- The IPv6Header Class represents an IPv4 datagram. 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) 1996-2017 Insecure.Com LLC ("The Nmap *
* Project"). Nmap is also a registered trademark of the Nmap Project. *
* 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@nmap.com). *
* Dozens of software vendors already license Nmap technology such as *
* host discovery, port scanning, OS detection, version detection, and *
* the Nmap Scripting Engine. *
* *
* Note that the GPL places important restrictions on "derivative works", *
* yet it does not provide a detailed definition of that term. To avoid *
* misunderstandings, we interpret that term as broadly as copyright law *
* 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 *
* results (as opposed to typical shell or execution-menu apps, which will *
* 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 *
* Nmap with other software in compressed or archival form does not *
* 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, the Nmap Project 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. *
* *
* The Nmap Project has permission to redistribute Npcap, a packet *
* capturing driver and library for the Microsoft Windows platform. *
* Npcap is a separate work with it's own license rather than this Nmap *
* license. Since the Npcap license does not permit redistribution *
* without special permission, our Nmap Windows binary packages which *
* contain Npcap may not be redistributed without special permission. *
* *
* 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 terms and conditions of this 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 *
* software. The terms, conditions, and exceptions of this license must *
* be included as well. This license is incompatible with some other open *
* source licenses as well. In some cases we can relicense portions of *
* Nmap or grant special permissions to use it in other open source *
* 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@nmap.com for further *
* information. *
* *
* If you have received a written license agreement or contract for *
* Covered Software stating terms other than these, you may choose to use *
* and redistribute Covered Software under those terms instead of these. *
* *
* 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 send your changes *
* to the dev@nmap.org mailing list for possible incorporation into the *
* main distribution. By sending these changes to Fyodor or one of the *
* Insecure.Org development mailing lists, or checking them into the Nmap *
* source code repository, it is understood (unless you specify *
* otherwise) that you are offering the Nmap Project the unlimited, *
* non-exclusive right to reuse, modify, and relicense the 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 "IPv6Header.h"
/******************************************************************************/
/* CONTRUCTORS, DESTRUCTORS AND INITIALIZATION METHODS */
/******************************************************************************/
IPv6Header::IPv6Header() {
this->reset();
} /* End of IPv6Header constructor */
IPv6Header::~IPv6Header() {
} /* End of IPv6Header destructor */
/** Sets every attribute to its default value */
void IPv6Header::reset(){
memset(&this->h, 0, sizeof(nping_ipv6_hdr_t));
this->length=IPv6_HEADER_LEN;
this->setVersion();
this->setTrafficClass(IPv6_DEFAULT_TCLASS);
this->setFlowLabel(IPv6_DEFAULT_FLABEL);
this->setHopLimit(IPv6_DEFAULT_HOPLIM);
this->setNextHeader(IPv6_DEFAULT_NXTHDR); /* No next header */
this->setPayloadLength(0);
} /* 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 *IPv6Header::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 IPv6Header class is able to hold a maximum of 40 bytes. If the
* supplied buffer is longer than that, only the first 40 bytes will be stored
* in the internal buffer.
* @warning Supplied len MUST be at least 40 bytes (IPv6 header length).
* @return OP_SUCCESS on success and OP_FAILURE in case of error */
int IPv6Header::storeRecvData(const u8 *buf, size_t len){
if(buf==NULL || len<IPv6_HEADER_LEN){
return OP_FAILURE;
}else{
this->reset(); /* Re-init the object, just in case the caller had used it already */
this->length=IPv6_HEADER_LEN;
memcpy(&(this->h), buf, IPv6_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 IPv6Header::protocol_id() const {
return HEADER_TYPE_IPv6;
} /* 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 IPv6Header::validate(){
if( this->length!=IPv6_HEADER_LEN)
return OP_FAILURE;
else
return IPv6_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 IPv6Header::print(FILE *output, int detail) const {
static char ipstring[256];
memset(ipstring, 0, 256);
struct in6_addr addr;
char ipinfo[512] = ""; /* Temp info about IP. */
fprintf(output, "IPv6[");
this->getSourceAddress(&addr);
inet_ntop(AF_INET6, &addr, ipstring, sizeof(ipstring));
fprintf(output, "%s", ipstring);
fprintf(output, " >");
this->getDestinationAddress(&addr);
inet_ntop(AF_INET6, &addr, ipstring, sizeof(ipstring));
fprintf(output, " %s", ipstring);
/* Create a string with information relevant to the specified level of detail */
if( detail == PRINT_DETAIL_LOW ){
Snprintf(ipinfo, sizeof(ipinfo), "hlim=%d", this->getHopLimit());
}else if( detail == PRINT_DETAIL_MED ){
Snprintf(ipinfo, sizeof(ipinfo), "hlim=%d tclass=%d flow=%d",
this->getHopLimit(), this->getTrafficClass(), this->getFlowLabel() );
}else if( detail>=PRINT_DETAIL_HIGH ){
Snprintf(ipinfo, sizeof(ipinfo), "ver=%d hlim=%d tclass=%d flow=%d plen=%d nh=%d",
this->getVersion(), this->getHopLimit(), this->getTrafficClass(),
this->getFlowLabel(), this->getPayloadLength(), this->getNextHeader() );
}
fprintf(output, " %s]", ipinfo);
if(this->next!=NULL){
print_separator(output, detail);
next->print(output, detail);
}
return OP_SUCCESS;
} /* End of print() */
/******************************************************************************/
/* PROTOCOL-SPECIFIC METHODS */
/******************************************************************************/
/** Set Version field (4 bits). */
int IPv6Header::setVersion(u8 val){
union{
struct firstbyte{
#if WORDS_BIGENDIAN
u8 ver:4;
u8 tclass:4;
#else
u8 tclass:4;
u8 ver:4;
#endif
}halfbyte;
u8 fullbyte;
}header1stbyte;
header1stbyte.fullbyte = h.ip6_start[0];
header1stbyte.halfbyte.ver=val;
h.ip6_start[0]=header1stbyte.fullbyte;
return OP_SUCCESS;
} /* End of setVersion() */
/** Set Version field to value 6. */
int IPv6Header::setVersion(){
this->setVersion(6);
return OP_SUCCESS;
} /* End of setVersion() */
/** Returns an 8bit number containing the value of the Version field. */
u8 IPv6Header::getVersion() const {
union{
struct firstbyte{
#if WORDS_BIGENDIAN
u8 ver:4;
u8 tclass:4;
#else
u8 tclass:4;
u8 ver:4;
#endif
}halfbyte;
u8 fullbyte;
}header1stbyte;
header1stbyte.fullbyte = h.ip6_start[0];
return (u8)header1stbyte.halfbyte.ver;
} /* End of getVersion() */
int IPv6Header::setTrafficClass(u8 val){
union{
struct firstbyte{
#if WORDS_BIGENDIAN
u8 ver:4;
u8 tclass1:4;
#else
u8 tclass1:4;
u8 ver:4;
#endif
}halfbyte;
u8 fullbyte;
}header1stbyte;
union{
struct firstbyte{
#if WORDS_BIGENDIAN
u8 tclass2:4;
u8 flow:4;
#else
u8 flow:4;
u8 tclass2:4;
#endif
}halfbyte;
u8 fullbyte;
}header2ndbyte;
/* Store old contents */
header1stbyte.fullbyte = h.ip6_start[0];
header2ndbyte.fullbyte = h.ip6_start[1];
/* Fill the two 4bit halves */
header1stbyte.halfbyte.tclass1=val>>4;
header2ndbyte.halfbyte.tclass2=val;
/* Write the bytes back to the header */
h.ip6_start[0]=header1stbyte.fullbyte;
h.ip6_start[1]=header2ndbyte.fullbyte;
return OP_SUCCESS;
} /* End of setTrafficClass() */
u8 IPv6Header::getTrafficClass() const {
union{
struct firstbyte{
#if WORDS_BIGENDIAN
u8 ver:4;
u8 tclass1:4;
#else
u8 tclass1:4;
u8 ver:4;
#endif
}halfbyte;
u8 fullbyte;
}header1stbyte;
union{
struct firstbyte{
#if WORDS_BIGENDIAN
u8 tclass2:4;
u8 flow:4;
#else
u8 flow:4;
u8 tclass2:4;
#endif
}halfbyte;
u8 fullbyte;
}header2ndbyte;
union{
struct firstbyte{
#if WORDS_BIGENDIAN
u8 tclass1:4;
u8 tclass2:4;
#else
u8 tclass2:4;
u8 tclass1:4;
#endif
}halfbyte;
u8 fullbyte;
}finalbyte;
header1stbyte.fullbyte = h.ip6_start[0];
header2ndbyte.fullbyte = h.ip6_start[1];
finalbyte.halfbyte.tclass1=header1stbyte.halfbyte.tclass1;
finalbyte.halfbyte.tclass2=header2ndbyte.halfbyte.tclass2;
return finalbyte.fullbyte;
} /* End of getTrafficClass() */
int IPv6Header::setFlowLabel(u32 val){
u32 netbyte = htonl(val);
u8 *pnt=(u8*)&netbyte;
union{
struct firstbyte{
#if WORDS_BIGENDIAN
u8 tclass2:4;
u8 flow:4;
#else
u8 flow:4;
u8 tclass2:4;
#endif
}halfbyte;
u8 fullbyte;
}header2ndbyte;
header2ndbyte.fullbyte = h.ip6_start[1];
header2ndbyte.halfbyte.flow=pnt[1];
h.ip6_start[1]=header2ndbyte.fullbyte;
h.ip6_start[2]=pnt[2];
h.ip6_start[3]=pnt[3];
return OP_SUCCESS;
} /* End of setFlowLabel() */
u32 IPv6Header::getFlowLabel() const {
u32 hostbyte=0;
u8 *pnt=(u8*)&hostbyte;
union{
struct firstbyte{
#if WORDS_BIGENDIAN
u8 tclass2:4;
u8 flow:4;
#else
u8 flow:4;
u8 tclass2:4;
#endif
}halfbyte;
u8 fullbyte;
}header2ndbyte;
header2ndbyte.fullbyte = h.ip6_start[1];
pnt[0]=0;
pnt[1]=header2ndbyte.halfbyte.flow;
pnt[2]=h.ip6_start[2];
pnt[3]=h.ip6_start[3];
hostbyte=ntohl(hostbyte);
return hostbyte;
} /* End of getFlowLabel() */
int IPv6Header::setPayloadLength(u16 val){
this->h.ip6_len = htons(val);
return OP_SUCCESS;
} /* End of setPayloadLength() */
int IPv6Header::setPayloadLength(){
int otherslen=0;
if (next!=NULL)
otherslen=next->getLen();
setPayloadLength( otherslen );
return OP_SUCCESS;
} /* End of setTotalLength() */
u16 IPv6Header::getPayloadLength() const {
return ntohs(this->h.ip6_len);
} /* End of getPayloadLength() */
int IPv6Header::setNextHeader(u8 val){
this->h.ip6_nh = val;
return OP_SUCCESS;
} /* End of setNextHeader() */
u8 IPv6Header::getNextHeader() const {
return this->h.ip6_nh;
} /* End of getNextHeader() */
/** Sets field "next header" to the number that corresponds to the supplied
* protocol name. Currently onyl TCP, UDP and ICMP are supported. Any
* help to extend this functionality would be appreciated. For a list of all
* proto names and numbers check:
* http://www.iana.org/assignments/protocol-numbers/ */
int IPv6Header::setNextHeader(const char *p){
if (p==NULL){
printf("setNextProto(): NULL pointer supplied\n");
return OP_FAILURE;
}
if( !strcasecmp(p, "TCP") )
setNextHeader(6); /* 6=IANA number for proto TCP */
else if( !strcasecmp(p, "UDP") )
setNextHeader(17); /* 17=IANA number for proto UDP */
else if( !strcasecmp(p, "ICMPv6"))
setNextHeader(58); /* 58=IANA number for proto ICMPv6 */
else
netutil_fatal("setNextProto(): Invalid protocol number\n");
return OP_SUCCESS;
} /* End of setNextHeader() */
int IPv6Header::setHopLimit(u8 val){
this->h.ip6_hopl = val;
return OP_SUCCESS;
} /* End of setHopLimit() */
u8 IPv6Header::getHopLimit() const {
return this->h.ip6_hopl;
} /* End of getHopLimit() */
int IPv6Header::setSourceAddress(u8 *val){
if(val==NULL)
netutil_fatal("setSourceAddress(): NULL value supplied.");
memcpy(this->h.ip6_src, val, 16);
return OP_SUCCESS;
} /* End of setSourceAddress() */
int IPv6Header::setSourceAddress(struct in6_addr val){
memcpy(this->h.ip6_src, val.s6_addr, 16);
return OP_SUCCESS;
} /* End of setSourceAddress() */
const u8 *IPv6Header::getSourceAddress() const {
return this->h.ip6_src;
} /* End of getSourceAddress() */
/** Returns source IPv6 address
* @warning Returned value is in NETWORK byte order. */
struct in6_addr IPv6Header::getSourceAddress(struct in6_addr *result) const {
struct in6_addr myaddr;
memset(&myaddr, 0, sizeof(myaddr));
memcpy(myaddr.s6_addr, this->h.ip6_src, 16);
if(result!=NULL)
*result=myaddr;
return myaddr;
} /* End of getSourceAddress() */
int IPv6Header::setDestinationAddress(u8 *val){
if(val==NULL)
netutil_fatal("setDestinationAddress(): NULL value supplied.");
memcpy(this->h.ip6_dst, val, 16);
return OP_SUCCESS;
} /* End of setDestinationAddress() */
int IPv6Header::setDestinationAddress(struct in6_addr val){
memcpy(this->h.ip6_dst, val.s6_addr, 16);
return OP_SUCCESS;
} /* End of setDestinationAddress() */
/** Returns destination IPv6 address. */
const u8 *IPv6Header::getDestinationAddress() const {
return this->h.ip6_dst;
} /* End of getDestinationAddress() */
/** Returns destination IPv6 address
* @warning Returned value is in NETWORK byte order. */
struct in6_addr IPv6Header::getDestinationAddress(struct in6_addr *result) const {
struct in6_addr myaddr;
memset(&myaddr, 0, sizeof(myaddr));
memcpy(myaddr.s6_addr, this->h.ip6_dst, 16);
if(result!=NULL)
*result=myaddr;
return myaddr;
} /* End of getDestinationAddress() */
/** Returns the length of an IPv4 address. */
u16 IPv6Header::getAddressLength() const {
return 16;
} /* End of getAddressLength()*/