/*************************************************************************** * RoutingHeader.cc -- The RoutingHeader Class represents an IPv6 Routing * * extension header. * ***********************IMPORTANT NMAP LICENSE TERMS************************ * * * The Nmap Security Scanner is (C) 1996-2012 Insecure.Com LLC. Nmap is * * also a registered trademark of Insecure.Com LLC. 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 with the clarifications and exceptions described * * below. 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@insecure.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 "derived 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: * * o Integrates source code from Nmap * * o Reads or includes Nmap copyrighted data files, such as * * nmap-os-db or nmap-service-probes. * * o Executes Nmap and parses the results (as opposed to typical shell or * * execution-menu apps, which simply display raw Nmap output and so are * * not derivative works.) * * o Integrates/includes/aggregates Nmap into a proprietary executable * * installer, such as those produced by InstallShield. * * o Links to a library or executes a program that does any of the above * * * * The term "Nmap" should be taken to also include any portions or derived * * works of Nmap, as well as other software we distribute under this * * license such as Zenmap, Ncat, and Nping. This list is not exclusive, * * but is meant to clarify our interpretation of derived works with some * * common examples. Our interpretation applies only to Nmap--we don't * * speak for other people's GPL works. * * * * If you have any questions about the GPL licensing restrictions on using * * Nmap in non-GPL works, we would be 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@insecure.com for * * further information. * * * * As a special exception to the GPL terms, Insecure.Com LLC 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. You must obey the GNU GPL in all * * respects for all of the code used other than OpenSSL. If you modify * * this file, you may extend this exception to your version of the file, * * but you are not obligated to do so. * * * * If you received these files with a written license agreement or * * contract stating terms other than the terms above, then that * * alternative license agreement takes precedence over these comments. * * * * 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 (none * * have been found so far). * * * * 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 nmap-dev@insecure.org 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 (Insecure.Com LLC) 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 GNU * * General Public License v2.0 for more details at * * http://www.gnu.org/licenses/gpl-2.0.html , or in the COPYING file * * included with Nmap. * * * ***************************************************************************/ /* 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 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(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->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() */