/*************************************************************************** * RoutingHeader.cc -- The RoutingHeader Class represents an IPv6 Routing * * extension header. * ***********************IMPORTANT NMAP LICENSE TERMS************************ * * The Nmap Security Scanner is (C) 1996-2024 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 "RoutingHeader.h" #include /******************************************************************************/ /* 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 || lenlength=0; return OP_FAILURE; }else{ /* Store the first 4 bytes, so we can access length and routing type */ memcpy(&(this->h), buf, 4); /* Our behaviour is different depending on the routing type. */ switch(this->h.type){ // No checks against ROUTING_HEADER_MAX_LEN because h.len cannot get that large: // h.len is u8, max value 0xff, so (0xff+1)*8 = 0x800 // but ROUTING_HEADER_MAX_LEN is 8+256*8 = 0x808 /* 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->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(lenlength=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->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){ 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){ 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() */