1/* 2 * Copyright (c) 1982, 1986, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)tcp.h 8.1 (Berkeley) 6/10/93 30 * tcp.h,v 1.3 1994/08/21 05:27:34 paul Exp 31 */ 32 33#ifndef _TCP_H_ 34#define _TCP_H_ 35 36typedef u_int32_t tcp_seq; 37 38#define PR_SLOWHZ 2 /* 2 slow timeouts per second (approx) */ 39#define PR_FASTHZ 5 /* 5 fast timeouts per second (not important) */ 40 41extern struct socket *tcp_last_so; 42 43#define TCP_SNDSPACE 8192 44#define TCP_RCVSPACE 8192 45 46/* 47 * TCP header. 48 * Per RFC 793, September, 1981. 49 */ 50struct tcphdr { 51 u_int16_t th_sport; /* source port */ 52 u_int16_t th_dport; /* destination port */ 53 tcp_seq th_seq; /* sequence number */ 54 tcp_seq th_ack; /* acknowledgement number */ 55#ifdef HOST_WORDS_BIGENDIAN 56 u_int th_off:4, /* data offset */ 57 th_x2:4; /* (unused) */ 58#else 59 u_int th_x2:4, /* (unused) */ 60 th_off:4; /* data offset */ 61#endif 62 u_int8_t th_flags; 63#define TH_FIN 0x01 64#define TH_SYN 0x02 65#define TH_RST 0x04 66#define TH_PUSH 0x08 67#define TH_ACK 0x10 68#define TH_URG 0x20 69 u_int16_t th_win; /* window */ 70 u_int16_t th_sum; /* checksum */ 71 u_int16_t th_urp; /* urgent pointer */ 72}; 73 74#include "tcp_var.h" 75 76#define TCPOPT_EOL 0 77#define TCPOPT_NOP 1 78#define TCPOPT_MAXSEG 2 79#define TCPOLEN_MAXSEG 4 80#define TCPOPT_WINDOW 3 81#define TCPOLEN_WINDOW 3 82#define TCPOPT_SACK_PERMITTED 4 /* Experimental */ 83#define TCPOLEN_SACK_PERMITTED 2 84#define TCPOPT_SACK 5 /* Experimental */ 85#define TCPOPT_TIMESTAMP 8 86#define TCPOLEN_TIMESTAMP 10 87#define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 88 89#define TCPOPT_TSTAMP_HDR \ 90 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP) 91 92/* 93 * Default maximum segment size for TCP. 94 * With an IP MSS of 576, this is 536, 95 * but 512 is probably more convenient. 96 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)). 97 * 98 * We make this 1460 because we only care about Ethernet in the qemu context. 99 */ 100#define TCP_MSS 1460 101 102#define TCP_MAXWIN 65535 /* largest value for (unscaled) window */ 103 104#define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 105 106/* 107 * User-settable options (used with setsockopt). 108 * 109 * We don't use the system headers on unix because we have conflicting 110 * local structures. We can't avoid the system definitions on Windows, 111 * so we undefine them. 112 */ 113#undef TCP_NODELAY 114#define TCP_NODELAY 0x01 /* don't delay send to coalesce packets */ 115#undef TCP_MAXSEG 116/* #define TCP_MAXSEG 0x02 */ /* set maximum segment size */ 117 118/* 119 * TCP FSM state definitions. 120 * Per RFC793, September, 1981. 121 */ 122 123#define TCP_NSTATES 11 124 125#define TCPS_CLOSED 0 /* closed */ 126#define TCPS_LISTEN 1 /* listening for connection */ 127#define TCPS_SYN_SENT 2 /* active, have sent syn */ 128#define TCPS_SYN_RECEIVED 3 /* have send and received syn */ 129/* states < TCPS_ESTABLISHED are those where connections not established */ 130#define TCPS_ESTABLISHED 4 /* established */ 131#define TCPS_CLOSE_WAIT 5 /* rcvd fin, waiting for close */ 132/* states > TCPS_CLOSE_WAIT are those where user has closed */ 133#define TCPS_FIN_WAIT_1 6 /* have closed, sent fin */ 134#define TCPS_CLOSING 7 /* closed xchd FIN; await FIN ACK */ 135#define TCPS_LAST_ACK 8 /* had fin and close; await FIN ACK */ 136/* states > TCPS_CLOSE_WAIT && < TCPS_FIN_WAIT_2 await ACK of FIN */ 137#define TCPS_FIN_WAIT_2 9 /* have closed, fin is acked */ 138#define TCPS_TIME_WAIT 10 /* in 2*msl quiet wait after close */ 139 140#define TCPS_HAVERCVDSYN(s) ((s) >= TCPS_SYN_RECEIVED) 141#define TCPS_HAVEESTABLISHED(s) ((s) >= TCPS_ESTABLISHED) 142#define TCPS_HAVERCVDFIN(s) ((s) >= TCPS_TIME_WAIT) 143 144/* 145 * TCP sequence numbers are 32 bit integers operated 146 * on with modular arithmetic. These macros can be 147 * used to compare such integers. 148 */ 149#define SEQ_LT(a,b) ((int)((a)-(b)) < 0) 150#define SEQ_LEQ(a,b) ((int)((a)-(b)) <= 0) 151#define SEQ_GT(a,b) ((int)((a)-(b)) > 0) 152#define SEQ_GEQ(a,b) ((int)((a)-(b)) >= 0) 153 154/* 155 * Macros to initialize tcp sequence numbers for 156 * send and receive from initial send and receive 157 * sequence numbers. 158 */ 159#define tcp_rcvseqinit(tp) \ 160 (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1 161 162#define tcp_sendseqinit(tp) \ 163 (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = (tp)->iss 164 165#define TCP_ISSINCR (125*1024) /* increment for tcp_iss each second */ 166 167extern tcp_seq tcp_iss; /* tcp initial send seq # */ 168 169extern const char * const tcpstates[]; 170 171#endif 172