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Diffstat (limited to 'libnetutil/TCPHeader.h')
| -rw-r--r-- | libnetutil/TCPHeader.h | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/libnetutil/TCPHeader.h b/libnetutil/TCPHeader.h new file mode 100644 index 0000000..6178be2 --- /dev/null +++ b/libnetutil/TCPHeader.h @@ -0,0 +1,259 @@ +/*************************************************************************** + * TCPHeader.h -- The TCPHeader Class represents a TCP packet. It contains * + * methods to set the different header fields. These methods tipically * + * perform the necessary error checks and byte order conversions. * + * * + ***********************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 __TCPHEADER_H__ +#define __TCPHEADER_H__ 1 + +#include "TransportLayerElement.h" + +/* TCP FLAGS */ +#define TH_FIN 0x01 +#define TH_SYN 0x02 +#define TH_RST 0x04 +#define TH_PSH 0x08 +#define TH_ACK 0x10 +#define TH_URG 0x20 +#define TH_ECN 0x40 +#define TH_CWR 0x80 + +/* TCP OPTIONS */ +#define TCPOPT_EOL 0 /* End of Option List (RFC793) */ +#define TCPOPT_NOOP 1 /* No-Operation (RFC793) */ +#define TCPOPT_MSS 2 /* Maximum Segment Size (RFC793) */ +#define TCPOPT_WSCALE 3 /* WSOPT - Window Scale (RFC1323) */ +#define TCPOPT_SACKOK 4 /* SACK Permitted (RFC2018) */ +#define TCPOPT_SACK 5 /* SACK (RFC2018) */ +#define TCPOPT_ECHOREQ 6 /* Echo (obsolete) (RFC1072)(RFC6247) */ +#define TCPOPT_ECHOREP 7 /* Echo Reply (obsolete) (RFC1072)(RFC6247) */ +#define TCPOPT_TSTAMP 8 /* TSOPT - Time Stamp Option (RFC1323) */ +#define TCPOPT_POCP 9 /* Partial Order Connection Permitted (obsol.) */ +#define TCPOPT_POSP 10 /* Partial Order Service Profile (obsolete) */ +#define TCPOPT_CC 11 /* CC (obsolete) (RFC1644)(RFC6247) */ +#define TCPOPT_CCNEW 12 /* CC.NEW (obsolete) (RFC1644)(RFC6247) */ +#define TCPOPT_CCECHO 13 /* CC.ECHO (obsolete) (RFC1644)(RFC6247) */ +#define TCPOPT_ALTCSUMREQ 14 /* TCP Alternate Checksum Request (obsolete) */ +#define TCPOPT_ALTCSUMDATA 15 /* TCP Alternate Checksum Data (obsolete) */ +#define TCPOPT_MD5 19 /* MD5 Signature Option (obsolete) (RFC2385) */ +#define TCPOPT_SCPS 20 /* SCPS Capabilities */ +#define TCPOPT_SNACK 21 /* Selective Negative Acknowledgements */ +#define TCPOPT_QSRES 27 /* Quick-Start Response (RFC4782) */ +#define TCPOPT_UTO 28 /* User Timeout Option (RFC5482) */ +#define TCPOPT_AO 29 /* TCP Authentication Option (RFC5925) */ + +/* Internal constants */ +#define TCP_HEADER_LEN 20 +#define MAX_TCP_OPTIONS_LEN 40 +#define MAX_TCP_PAYLOAD_LEN 65495 /**< Max len of a TCP packet */ + +/* Default header values */ +#define TCP_DEFAULT_SPORT 20 +#define TCP_DEFAULT_DPORT 80 +#define TCP_DEFAULT_SEQ 0 +#define TCP_DEFAULT_ACK 0 +#define TCP_DEFAULT_FLAGS 0x02 +#define TCP_DEFAULT_WIN 8192 +#define TCP_DEFAULT_URP 0 + + + +/* ++--------+--------+---------+--------... +| Type | Len | Value ++--------+--------+---------+--------... +*/ +struct nping_tcp_opt { + u8 type; /* Option type code. */ + u8 len; /* Option length. */ + u8 *value; /* Option value */ +}__attribute__((__packed__)); +typedef struct nping_tcp_opt nping_tcp_opt_t; + + +class TCPHeader : public TransportLayerElement { + + 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 + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Source Port | Destination Port | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Sequence Number | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Acknowledgment Number | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Offset| Res. |C|E|U|A|P|R|S|F| Window | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Checksum | Urgent Pointer | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Options | Padding | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + */ + struct nping_tcp_hdr { + u16 th_sport; /* Source port */ + u16 th_dport; /* Destination port */ + u32 th_seq; /* Sequence number */ + u32 th_ack; /* Acknowledgement number */ + #if WORDS_BIGENDIAN + u8 th_off:4; /* Data offset */ + u8 th_x2:4; /* Reserved */ + #else + u8 th_x2:4; /* Reserved */ + u8 th_off:4; /* Data offset */ + #endif + u8 th_flags; /* Flags */ + u16 th_win; /* Window size */ + u16 th_sum; /* Checksum */ + u16 th_urp; /* Urgent pointer */ + + u8 options[MAX_TCP_OPTIONS_LEN ]; /* Space for TCP Options */ + }__attribute__((__packed__)); + + typedef struct nping_tcp_hdr nping_tcp_hdr_t; + + nping_tcp_hdr_t h; + + int tcpoptlen; /**< Length of TCP options */ + + void __tcppacketoptinfo(const u8 *optp, int len, char *result, int bufsize) const; + + public: + + TCPHeader(); + ~TCPHeader(); + 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; + + int setSourcePort(u16 p); + u16 getSourcePort() const; + + int setDestinationPort(u16 p); + u16 getDestinationPort() const; + + int setSeq(u32 p); + u32 getSeq() const; + + int setAck(u32 p); + u32 getAck() const; + + int setOffset(u8 o); + int setOffset(); + u8 getOffset() const; + + int setReserved(u8 r); + u8 getReserved() const; + + int setFlags(u8 f); + u8 getFlags() const; + u16 getFlags16() const; + bool setCWR(); + bool unsetCWR(); + bool getCWR() const; + bool setECE(); + bool unsetECE(); + bool getECE() const; + bool setECN(); + bool unsetECN(); + bool getECN() const; + bool setURG(); + bool unsetURG(); + bool getURG() const; + bool setACK(); + bool unsetACK(); + bool getACK() const; + bool setPSH(); + bool unsetPSH(); + bool getPSH() const; + bool setRST(); + bool unsetRST(); + bool getRST() const; + bool setSYN(); + bool unsetSYN(); + bool getSYN() const; + bool setFIN(); + bool unsetFIN(); + bool getFIN() const; + + int setWindow(u16 p); + u16 getWindow() const; + + int setUrgPointer(u16 l); + u16 getUrgPointer() const; + + int setSum(u16 s); + int setSum(struct in_addr source, struct in_addr destination); + int setSum(); + int setSumRandom(); + int setSumRandom(struct in_addr source, struct in_addr destination); + u16 getSum() const; + + int setOptions(const u8 *optsbuff, size_t optslen); + const u8 *getOptions(size_t *optslen) const; + nping_tcp_opt_t getOption(unsigned int index) const; + static const char *optcode2str(u8 optcode); + +}; /* End of class TCPHeader */ + +#endif /* __TCPHEADER_H__ */ |