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/* $Id$ */
/** @file
* NAT - TCP.
*/
/*
* Copyright (C) 2006-2022 Oracle and/or its affiliates.
*
* This file is part of VirtualBox base platform packages, as
* available from https://www.virtualbox.org.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, in version 3 of the
* License.
*
* 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 GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses>.
*
* SPDX-License-Identifier: GPL-3.0-only
*/
/*
* This code is based on:
*
* Copyright (c) 1982, 1986, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)tcp.h 8.1 (Berkeley) 6/10/93
* tcp.h,v 1.3 1994/08/21 05:27:34 paul Exp
*/
#ifndef _TCP_H_
#define _TCP_H_
typedef uint32_t tcp_seq;
#define PR_SLOWHZ 2 /* 2 slow timeouts per second (approx) */
#define PR_FASTHZ 5 /* 5 fast timeouts per second (not important) */
extern int tcp_rcvspace;
extern int tcp_sndspace;
extern struct socket *tcp_last_so;
#define TCP_SNDSPACE 8192
#define TCP_RCVSPACE 8192
/*
* TCP header.
* Per RFC 793, September, 1981.
*/
struct tcphdr
{
uint16_t th_sport; /* source port */
uint16_t th_dport; /* destination port */
tcp_seq th_seq; /* sequence number */
tcp_seq th_ack; /* acknowledgement number */
#ifdef WORDS_BIGENDIAN
# ifdef _MSC_VER
uint8_t th_off:4; /* data offset */
uint8_t th_x2:4; /* (unused) */
# else
unsigned th_off:4; /* data offset */
unsigned th_x2:4; /* (unused) */
# endif
#else
# ifdef _MSC_VER
uint8_t th_x2:4; /* (unused) */
uint8_t th_off:4; /* data offset */
# else
unsigned th_x2:4; /* (unused) */
unsigned th_off:4; /* data offset */
# endif
#endif
uint8_t th_flags;
#define TH_FIN 0x01
#define TH_SYN 0x02
#define TH_RST 0x04
#define TH_PUSH 0x08
#define TH_ACK 0x10
#define TH_URG 0x20
uint16_t th_win; /* window */
uint16_t th_sum; /* checksum */
uint16_t th_urp; /* urgent pointer */
};
AssertCompileSize(struct tcphdr, 20);
#include "tcp_var.h"
#define TCPOPT_EOL 0
#define TCPOPT_NOP 1
#define TCPOPT_MAXSEG 2
#define TCPOLEN_MAXSEG 4
#define TCPOPT_WINDOW 3
#define TCPOLEN_WINDOW 3
#define TCPOPT_SACK_PERMITTED 4 /* Experimental */
#define TCPOLEN_SACK_PERMITTED 2
#define TCPOPT_SACK 5 /* Experimental */
#define TCPOPT_TIMESTAMP 8
#define TCPOLEN_TIMESTAMP 10
#define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */
#define TCPOPT_TSTAMP_HDR \
(TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
/*
* Default maximum segment size for TCP.
* With an IP MSS of 576, this is 536,
* but 512 is probably more convenient.
* This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
*
* We make this 1460 because we only care about Ethernet in the qemu context.
*/
#define TCP_MSS (if_mtu - 80)
#define TCP_MAXWIN 65535 /* largest value for (unscaled) window */
#define TCP_MAX_WINSHIFT 14 /* maximum window shift */
/*
* User-settable options (used with setsockopt).
*
* We don't use the system headers on unix because we have conflicting
* local structures. We can't avoid the system definitions on Windows,
* so we undefine them.
*/
#undef TCP_NODELAY
#define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */
#undef TCP_MAXSEG
/* #define TCP_MAXSEG 0x02 */ /* set maximum segment size */
/*
* TCP FSM state definitions.
* Per RFC793, September, 1981.
*/
#define TCP_NSTATES 11
#define TCPS_CLOSED 0 /* closed */
#define TCPS_LISTEN 1 /* listening for connection */
#define TCPS_SYN_SENT 2 /* active, have sent syn */
#define TCPS_SYN_RECEIVED 3 /* have send and received syn */
/* states < TCPS_ESTABLISHED are those where connections not established */
#define TCPS_ESTABLISHED 4 /* established */
#define TCPS_CLOSE_WAIT 5 /* rcvd fin, waiting for close */
/* states > TCPS_CLOSE_WAIT are those where user has closed */
#define TCPS_FIN_WAIT_1 6 /* have closed, sent fin */
#define TCPS_CLOSING 7 /* closed xchd FIN; await FIN ACK */
#define TCPS_LAST_ACK 8 /* had fin and close; await FIN ACK */
/* states > TCPS_CLOSE_WAIT && < TCPS_FIN_WAIT_2 await ACK of FIN */
#define TCPS_FIN_WAIT_2 9 /* have closed, fin is acked */
#define TCPS_TIME_WAIT 10 /* in 2*msl quiet wait after close */
#define TCPS_HAVERCVDSYN(s) ((s) >= TCPS_SYN_RECEIVED)
#define TCPS_HAVEESTABLISHED(s) ((s) >= TCPS_ESTABLISHED)
#define TCPS_HAVERCVDFIN(s) ((s) >= TCPS_TIME_WAIT)
/*
* TCP sequence numbers are 32 bit integers operated on with modular arithmetic.
* These macros can be used to compare such integers.
*/
#define SEQ_LT(a,b) ((int)((a)-(b)) < 0)
#define SEQ_LEQ(a,b) ((int)((a)-(b)) <= 0)
#define SEQ_GT(a,b) ((int)((a)-(b)) > 0)
#define SEQ_GEQ(a,b) ((int)((a)-(b)) >= 0)
/*
* Macros to initialize tcp sequence numbers for
* send and receive from initial send and receive
* sequence numbers.
*/
#define tcp_rcvseqinit(tp) \
(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
#define tcp_sendseqinit(tp) \
(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = (tp)->iss
#define TCP_ISSINCR (125*1024) /* increment for tcp_iss each second */
extern const char * const tcpstates[];
#endif
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