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Diffstat (limited to 'libnetutil/FragmentHeader.cc')
| -rw-r--r-- | libnetutil/FragmentHeader.cc | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/libnetutil/FragmentHeader.cc b/libnetutil/FragmentHeader.cc new file mode 100644 index 0000000..f89e00c --- /dev/null +++ b/libnetutil/FragmentHeader.cc @@ -0,0 +1,212 @@ +/*************************************************************************** + * FragmentHeader.cc -- The FragmentHeader Class represents an IPv6 * + * Hop-by-Hop extension header. * + ***********************IMPORTANT NMAP LICENSE TERMS************************ + * + * The Nmap Security Scanner is (C) 1996-2023 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 "FragmentHeader.h" +#include <assert.h> + +/******************************************************************************/ +/* CONTRUCTORS, DESTRUCTORS AND INITIALIZATION METHODS */ +/******************************************************************************/ +FragmentHeader::FragmentHeader() { + this->reset(); +} /* End of FragmentHeader constructor */ + + +FragmentHeader::~FragmentHeader() { + +} /* End of FragmentHeader destructor */ + + +/** Sets every attribute to its default value */ +void FragmentHeader::reset(){ + memset(&this->h, 0, sizeof(nping_ipv6_ext_fragment_hdr_t)); + this->length=8; +} /* 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 *FragmentHeader::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 FragmentHeader 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 FragmentHeader::storeRecvData(const u8 *buf, size_t len){ + if(buf==NULL || len<FRAGMENT_HEADER_LEN){ + this->length=0; + return OP_FAILURE; + }else{ + int stored_len = MIN(FRAGMENT_HEADER_LEN, len); + this->reset(); /* Re-init the object, just in case the caller had used it already */ + this->length=stored_len; + memcpy(&(this->h), buf, stored_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 FragmentHeader::protocol_id() const { + return HEADER_TYPE_IPv6_FRAG; +} /* 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 FragmentHeader::validate(){ + /* Check the object's length makes sense*/ + if(this->length != FRAGMENT_HEADER_LEN){ + return OP_FAILURE; + } + /* There is not much to check for here, since header fields may take any + * value. We could certainly check the NextHeader value, but let's leave + * that for the class user. */ + 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 FragmentHeader::print(FILE *output, int detail) const { + fprintf(output, "Fragment[%d, %d]", this->h.nh, this->h.id); + // 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 FragmentHeader::setNextHeader(u8 val){ + this->h.nh = val; + return OP_SUCCESS; +} /* End of setNextHeader() */ + + +/** Returns next header id */ +u8 FragmentHeader::getNextHeader(){ + return this->h.nh; +} /* End of getNextHeader() */ + + +/** Set Offset field */ +int FragmentHeader::setOffset(u16 val){ + this->h.off_res_flag[0]=(u8)(val >> 8); + this->h.off_res_flag[1]=(u8)((this->h.off_res_flag[1] & 0x7) | (val & ~0x7)); + return OP_SUCCESS; +} /* End of setOffset() */ + + +/** Returns fragment offset */ +u16 FragmentHeader::getOffset(){ + return ((this->h.off_res_flag[0] << 8) + this->h.off_res_flag[1]) & 0xfff8; +} /* End of getOffset() */ + + +/* Sets the "More Fragments" flag. */ +int FragmentHeader::setM(bool m_flag){ + if(m_flag) + this->h.off_res_flag[1]= (u8)((this->h.off_res_flag[1] & ~0x01) | 0x01); + else + this->h.off_res_flag[1]= (u8)((this->h.off_res_flag[1] & ~0x1)); + return OP_SUCCESS; +} /* End of setM() */ + + +/* Returns true if the "More Fragments" flag is set; false otherwise. */ +bool FragmentHeader::getM(){ + return (this->h.off_res_flag[1] & 0x01); +} /* End of getM() */ + + +/** Set the fragment identifier */ +int FragmentHeader::setIdentification(u32 val){ + this->h.id=htonl(val); + return OP_SUCCESS; +} /* End of setIdentification() */ + + +/** Returns the fragment identifier*/ +u32 FragmentHeader::getIdentification(){ + return ntohl(this->h.id); +} /* End of getIdentification.() */ |