/*************************************************************************** * 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) 1996-2022 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 "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 || lenreset(); /* 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 only 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()*/