/*************************************************************************** * PacketElement.h -- The PacketElement Class is a generic class that * * represents a protocol header or a part of a network packet. Many other * * classes inherit from it (NetworkLayerElement, TransportLayerElement, * * etc). * * * ***********************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. */ #ifndef PACKETELEMENT_H #define PACKETELEMENT_H 1 #include "nbase.h" #include "netutil.h" #define HEADER_TYPE_IPv6_HOPOPT 0 /* IPv6 Hop-by-Hop Option */ #define HEADER_TYPE_ICMPv4 1 /* ICMP Internet Control Message */ #define HEADER_TYPE_IGMP 2 /* IGMP Internet Group Management */ #define HEADER_TYPE_IPv4 4 /* IPv4 IPv4 encapsulation */ #define HEADER_TYPE_TCP 6 /* TCP Transmission Control */ #define HEADER_TYPE_EGP 8 /* EGP Exterior Gateway Protocol */ #define HEADER_TYPE_UDP 17 /* UDP User Datagram */ #define HEADER_TYPE_IPv6 41 /* IPv6 IPv6 encapsulation */ #define HEADER_TYPE_IPv6_ROUTE 43 /* IPv6-Route Routing Header for IPv6 */ #define HEADER_TYPE_IPv6_FRAG 44 /* IPv6-Frag Fragment Header for IPv6 */ #define HEADER_TYPE_GRE 47 /* GRE General Routing Encapsulation */ #define HEADER_TYPE_ESP 50 /* ESP Encap Security Payload */ #define HEADER_TYPE_AH 51 /* AH Authentication Header */ #define HEADER_TYPE_ICMPv6 58 /* IPv6-ICMP ICMP for IPv6 */ #define HEADER_TYPE_IPv6_NONXT 59 /* IPv6-NoNxt No Next Header for IPv6 */ #define HEADER_TYPE_IPv6_OPTS 60 /* IPv6-Opts IPv6 Destination Options */ #define HEADER_TYPE_EIGRP 88 /* EIGRP */ #define HEADER_TYPE_ETHERNET 97 /* Ethernet */ #define HEADER_TYPE_L2TP 115 /* L2TP Layer Two Tunneling Protocol */ #define HEADER_TYPE_SCTP 132 /* SCTP Stream Control Transmission P. */ #define HEADER_TYPE_IPv6_MOBILE 135 /* Mobility Header */ #define HEADER_TYPE_MPLS_IN_IP 137 /* MPLS-in-IP */ #define HEADER_TYPE_ARP 2054 /* ARP Address Resolution Protocol */ #define HEADER_TYPE_ICMPv6_OPTION 9997 /* ICMPv6 option */ #define HEADER_TYPE_NEP 9998 /* Nping Echo Protocol */ #define HEADER_TYPE_RAW_DATA 9999 /* Raw unknown data */ #define PRINT_DETAIL_LOW 1 #define PRINT_DETAIL_MED 2 #define PRINT_DETAIL_HIGH 3 #define DEFAULT_PRINT_DETAIL (PRINT_DETAIL_LOW) #define DEFAULT_PRINT_DESCRIPTOR stdout class PacketElement { protected: int length; PacketElement *next; /**< Next PacketElement (next proto header) */ PacketElement *prev; /**< Prev PacketElement (previous proto header) */ public: PacketElement(); virtual ~PacketElement(){ } /* End of PacketElement destructor */ /** This function MUST be overwritten on ANY class that inherits from * this one. Otherwise getBinaryBuffer will fail */ virtual u8 * getBufferPointer(){ netutil_fatal("getBufferPointer(): Attempting to use superclass PacketElement method.\n"); return NULL; } /* End of getBufferPointer() */ /** Returns a buffer that contains the header of the packet + all the * lower level headers and payload. Returned buffer should be ok to be * passes to a send() call to be transferred trough a socket. * @return a pointer to a free()able buffer that contains packet's binary * data. * @warning If there are linked elements, their getBinaryBuffer() method * will be called recursively and the buffers that they return WILL be * free()d as soon as we copy the data in our own allocated buffer. * @warning Calls to this method may not ve very efficient since they * always involved a few malloc()s and free()s. If you want efficiency * use dumpToBinaryBuffer(); */ virtual u8 * getBinaryBuffer(){ u8 *ourbuff=NULL; u8 *othersbuff=NULL; u8 *totalbuff=NULL; long otherslen=0; /* Get our own buffer address */ if ( (ourbuff=getBufferPointer()) == NULL ){ netutil_fatal("getBinaryBuffer(): Couldn't get own data pointer\n"); } if( next != NULL ){ /* There is some other packet element */ othersbuff = next->getBinaryBuffer(); otherslen=next->getLen(); totalbuff=(u8 *)safe_zalloc(otherslen + length); memcpy(totalbuff, ourbuff, length); memcpy(totalbuff+length, othersbuff, otherslen); free(othersbuff); }else{ totalbuff=(u8 *)safe_zalloc(length); memcpy(totalbuff, ourbuff, length); } return totalbuff; } /* End of getBinaryBuffer() */ virtual int dumpToBinaryBuffer(u8* dst, int maxlen){ u8 *ourbuff=NULL; long ourlength=0; /* Get our own buffer address and length */ if ( (ourbuff=getBufferPointer()) == NULL || (ourlength=this->length) < 0 ) netutil_fatal("getBinaryBuffer(): Couldn't get own data pointer\n"); /* Copy our part of the buffer */ if ( maxlen < ourlength ) netutil_fatal("getBinaryBuffer(): Packet exceeds maximum length %d\n", maxlen); memcpy( dst, ourbuff, ourlength); /* If there are more elements, tell them to copy their part */ if( next!= NULL ){ next->dumpToBinaryBuffer(dst+ourlength, maxlen-ourlength); } return this->getLen(); } /* End of dumpToBinaryBuffer() */ /** Does the same as the previous one but it stores the length of the * return buffer on the memory pointed by the supplied int pointer. */ virtual u8 * getBinaryBuffer(int *len){ u8 *buff = getBinaryBuffer(); if( len != NULL ) *len = getLen(); return buff; } /* End of getBinaryBuffer() */ /** Returns the length of this PacketElement + the length of all the * PacketElements that are next to it (are linked trough the "next" * attribute). So for example, if we have IPv4Header p1, linked to * a TCPHeader p2, representing a simple TCP SYN with no options, * a call to p1.getLen() will return 20 (IP header with no options) + 20 * (TCP header with no options) = 40 bytes. */ int getLen() const { /* If we have some other packet element linked, get its length */ if (next!=NULL) return length + next->getLen(); else return length; } /* End of getLen() */ /** Returns the address of the next PacketElement that is linked to this */ virtual PacketElement *getNextElement() const { return next; } /* End of getNextElement() */ /** Links current object with the next header in the protocol chain. Note * that this method also links the next element with this one, calling * setPrevElement(). */ virtual int setNextElement(PacketElement *n){ next=n; if(next!=NULL) next->setPrevElement(this); return OP_SUCCESS; } /* End of setNextElement() */ /** Sets attribute prev with the supplied pointer value. * @warning Supplied pointer must point to a PacketElement object or * an object that inherits from it. */ virtual int setPrevElement(PacketElement *n){ this->prev=n; return OP_SUCCESS; } /* End of setPrevElement() */ /** Returns the address of the previous PacketElement that is linked to * this one. * @warning In many cases this function will return NULL since there is * a high probability that the user of this class does not link * PacketElements in both directions. Normally one would set attribute * "next" of an IPHeader object to the TCPHeader that follows it, but * not the other way around. */ virtual PacketElement *getPrevElement(){ return prev; } /* End of getPrevElement() */ /** This method should be overwritten by any class that inherits from * PacketElement. It should print the object contents and then call * this->next->print(), providing this->next!=NULL */ virtual int print(FILE *output, int detail) const { if(this->next!=NULL) this->next->print(output, detail); return OP_SUCCESS; } /* End of printf() */ virtual int print() const { return print(DEFAULT_PRINT_DESCRIPTOR, DEFAULT_PRINT_DETAIL); } virtual int print(int detail) const { return print(DEFAULT_PRINT_DESCRIPTOR, detail); } virtual void print_separator(FILE *output, int detail) const { fprintf(output, " "); } /* Returns the type of protocol an object represents. This method MUST * be overwritten by all children. */ virtual int protocol_id() const = 0; }; #endif