/*************************************************************************** * RoutingHeader.cc -- The RoutingHeader Class represents an IPv6 Routing * * extension header. * ***********************IMPORTANT NMAP LICENSE TERMS************************ * * * The Nmap Security Scanner is (C) 1996-2019 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, we are happy to help. As mentioned above, we also * * offer an 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 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 "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){ /* 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() */