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/***************************************************************************
* IPv4Header.h -- The IPv4Header Class represents an IPv4 datagram. It *
* contains methods to set any header field. In general, these methods do *
* error checkings and byte order conversion. *
* *
***********************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. */
#ifndef IPV4HEADER_H
#define IPV4HEADER_H 1
#include "NetworkLayerElement.h"
#define IP_RF 0x8000 /* Reserved fragment flag */
#define IP_DF 0x4000 /* Don't fragment flag */
#define IP_MF 0x2000 /* More fragments flag */
#define IP_OFFMASK 0x1fff /* Mask for fragmenting bits */
#define IP_HEADER_LEN 20 /* Length of the standard header */
#define MAX_IP_OPTIONS_LEN 40 /* Max Length for IP Options */
/* Default header values */
#define IPv4_DEFAULT_TOS 0
#define IPv4_DEFAULT_ID 0
#define IPv4_DEFAULT_TTL 64
#define IPv4_DEFAULT_PROTO 6 /* TCP */
class IPv4Header : public NetworkLayerElement {
private:
/*
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| IHL |Type of Service| Total Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identification |Flags| Fragment Offset |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Time to Live | Protocol | Header Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Options | Padding |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
struct nping_ipv4_hdr {
#if WORDS_BIGENDIAN
u8 ip_v:4; /* Version */
u8 ip_hl:4; /* Header length */
#else
u8 ip_hl:4; /* Header length */
u8 ip_v:4; /* Version */
#endif
u8 ip_tos; /* Type of service */
u16 ip_len; /* Total length */
u16 ip_id; /* Identification */
u16 ip_off; /* Fragment offset field */
u8 ip_ttl; /* Time to live */
u8 ip_p; /* Protocol */
u16 ip_sum; /* Checksum */
struct in_addr ip_src; /* Source IP address */
struct in_addr ip_dst; /* Destination IP address */
u8 options[MAX_IP_OPTIONS_LEN]; /* IP Options */
}__attribute__((__packed__));
typedef struct nping_ipv4_hdr nping_ipv4_hdr_t;
nping_ipv4_hdr_t h;
int ipoptlen; /**< Length of IP options */
public:
/* Misc */
IPv4Header();
~IPv4Header();
void reset();
u8 *getBufferPointer();
int storeRecvData(const u8 *buf, size_t len);
int protocol_id() const;
int validate();
int print(FILE *output, int detail) const;
/* IP version */
int setVersion();
u8 getVersion() const;
/* Header Length */
int setHeaderLength();
int setHeaderLength(u8 l);
u8 getHeaderLength() const;
/* Type of Service */
int setTOS(u8 v);
u8 getTOS() const;
/* Total length of the datagram */
int setTotalLength();
int setTotalLength(u16 l);
u16 getTotalLength() const;
/* Identification value */
int setIdentification();
int setIdentification(u16 i);
u16 getIdentification() const;
/* Fragment Offset */
int setFragOffset();
int setFragOffset(u16 f);
u16 getFragOffset() const;
/* Flags */
int setRF();
int unsetRF();
bool getRF() const;
int setDF();
int unsetDF();
bool getDF() const;
int setMF();
int unsetMF();
bool getMF() const;
/* Time to live */
int setTTL();
int setTTL(u8 t);
u8 getTTL() const;
/* Next protocol */
int setNextProto(u8 p);
int setNextProto(const char *p);
u8 getNextProto() const;
int setNextHeader(u8 val);
u8 getNextHeader() const;
/* Checksum */
int setSum();
int setSum(u16 s);
int setSumRandom();
u16 getSum() const;
/* Destination IP */
int setDestinationAddress(u32 d);
int setDestinationAddress(struct in_addr d);
const u8 *getDestinationAddress() const;
struct in_addr getDestinationAddress(struct in_addr *result) const;
/* Source IP */
int setSourceAddress(u32 d);
int setSourceAddress(struct in_addr d);
const u8 *getSourceAddress() const;
struct in_addr getSourceAddress(struct in_addr *result) const;
u16 getAddressLength() const;
/* IP Options */
int setOpts(const char *txt);
int setOpts(u8 *opts_buff, u32 opts_len);
const u8 *getOpts() const;
const u8 *getOpts(int *len) const;
int printOptions() const;
const char *getOptionsString() const;
}; /* End of class IPv4Header */
#endif
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