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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)tcp.h 8.1 (Berkeley) 6/10/93 34 * tcp.h,v 1.3 1994/08/21 05:27:34 paul Exp 35 */ 36 37 #ifndef _TCP_H_ 38 #define _TCP_H_ 39 40 #ifdef __FreeBSD__ 41 #include <sys/endian.h> 42 43 #if !defined(__BYTE_ORDER) 44 #if defined(_BYTE_ORDER) 45 #define __BYTE_ORDER _BYTE_ORDER 46 #elif defined(BYTE_ORDER) 47 #define __BYTE_ORDER BYTE_ORDER 48 #else 49 #error BYTE_ORDER not defined 50 #endif 51 #endif /* !defined(__BYTE_ORDER) */ 52 53 #if !defined(__BIG_ENDIAN) 54 #if defined(_BIG_ENDIAN) 55 #define __BIG_ENDIAN _BIG_ENDIAN 56 #elif defined(BIG_ENDIAN) 57 #define __BIG_ENDIAN BIG_ENDIAN 58 #else 59 #error BIG_ENDIAN not defined 60 #endif 61 #endif /* !defined(__BIG_ENDIAN) */ 62 63 #endif /* __FreeBSD__ */ 64 65 typedef u_int32_t tcp_seq; 66 67 #define PR_SLOWHZ 2 /* 2 slow timeouts per second (approx) */ 68 #define PR_FASTHZ 5 /* 5 fast timeouts per second (not important) */ 69 70 extern int tcp_rcvspace; 71 extern int tcp_sndspace; 72 extern struct socket *tcp_last_so; 73 74 #define TCP_SNDSPACE 8192 75 #define TCP_RCVSPACE 8192 76 77 /* 78 * TCP header. 79 * Per RFC 793, September, 1981. 80 */ 81 struct tcphdr { 82 u_int16_t th_sport; /* source port */ 83 u_int16_t th_dport; /* destination port */ 84 tcp_seq th_seq; /* sequence number */ 85 tcp_seq th_ack; /* acknowledgement number */ 86 #if __BYTE_ORDER == __BIG_ENDIAN 87 u_int th_off:4, /* data offset */ 88 th_x2:4; /* (unused) */ 89 #else 90 u_int th_x2:4, /* (unused) */ 91 th_off:4; /* data offset */ 92 #endif 93 u_int8_t th_flags; 94 #define TH_FIN 0x01 95 #define TH_SYN 0x02 96 #define TH_RST 0x04 97 #define TH_PUSH 0x08 98 #define TH_ACK 0x10 99 #define TH_URG 0x20 100 u_int16_t th_win; /* window */ 101 u_int16_t th_sum; /* checksum */ 102 u_int16_t th_urp; /* urgent pointer */ 103 }; 104 105 #include "tcp_var.h" 106 107 #define TCPOPT_EOL 0 108 #define TCPOPT_NOP 1 109 #define TCPOPT_MAXSEG 2 110 #define TCPOLEN_MAXSEG 4 111 #define TCPOPT_WINDOW 3 112 #define TCPOLEN_WINDOW 3 113 #define TCPOPT_SACK_PERMITTED 4 /* Experimental */ 114 #define TCPOLEN_SACK_PERMITTED 2 115 #define TCPOPT_SACK 5 /* Experimental */ 116 #define TCPOPT_TIMESTAMP 8 117 #define TCPOLEN_TIMESTAMP 10 118 #define TCPOLEN_TSTAMP_APPA (TCPOLEN_TIMESTAMP+2) /* appendix A */ 119 120 #define TCPOPT_TSTAMP_HDR \ 121 (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP) 122 123 /* 124 * Default maximum segment size for TCP. 125 * With an IP MSS of 576, this is 536, 126 * but 512 is probably more convenient. 127 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)). 128 */ 129 #define TCP_MSS 512 130 131 #define TCP_MAXWIN 65535 /* largest value for (unscaled) window */ 132 133 #define TCP_MAX_WINSHIFT 14 /* maximum window shift */ 134 135 /* 136 * User-settable options (used with setsockopt). 137 */ 138 /* #define TCP_NODELAY 0x01 */ /* don't delay send to coalesce packets */ 139 /* #define TCP_MAXSEG 0x02 */ /* set maximum segment size */ 140 141 /* 142 * TCP FSM state definitions. 143 * Per RFC793, September, 1981. 144 */ 145 146 #define TCP_NSTATES 11 147 148 #define TCPS_CLOSED 0 /* closed */ 149 #define TCPS_LISTEN 1 /* listening for connection */ 150 #define TCPS_SYN_SENT 2 /* active, have sent syn */ 151 #define TCPS_SYN_RECEIVED 3 /* have send and received syn */ 152 /* states < TCPS_ESTABLISHED are those where connections not established */ 153 #define TCPS_ESTABLISHED 4 /* established */ 154 #define TCPS_CLOSE_WAIT 5 /* rcvd fin, waiting for close */ 155 /* states > TCPS_CLOSE_WAIT are those where user has closed */ 156 #define TCPS_FIN_WAIT_1 6 /* have closed, sent fin */ 157 #define TCPS_CLOSING 7 /* closed xchd FIN; await FIN ACK */ 158 #define TCPS_LAST_ACK 8 /* had fin and close; await FIN ACK */ 159 /* states > TCPS_CLOSE_WAIT && < TCPS_FIN_WAIT_2 await ACK of FIN */ 160 #define TCPS_FIN_WAIT_2 9 /* have closed, fin is acked */ 161 #define TCPS_TIME_WAIT 10 /* in 2*msl quiet wait after close */ 162 163 #define TCPS_HAVERCVDSYN(s) ((s) >= TCPS_SYN_RECEIVED) 164 #define TCPS_HAVEESTABLISHED(s) ((s) >= TCPS_ESTABLISHED) 165 #define TCPS_HAVERCVDFIN(s) ((s) >= TCPS_TIME_WAIT) 166 167 /* 168 * TCP sequence numbers are 32 bit integers operated 169 * on with modular arithmetic. These macros can be 170 * used to compare such integers. 171 */ 172 #define SEQ_LT(a,b) ((int)((a)-(b)) < 0) 173 #define SEQ_LEQ(a,b) ((int)((a)-(b)) <= 0) 174 #define SEQ_GT(a,b) ((int)((a)-(b)) > 0) 175 #define SEQ_GEQ(a,b) ((int)((a)-(b)) >= 0) 176 177 /* 178 * Macros to initialize tcp sequence numbers for 179 * send and receive from initial send and receive 180 * sequence numbers. 181 */ 182 #define tcp_rcvseqinit(tp) \ 183 (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1 184 185 #define tcp_sendseqinit(tp) \ 186 (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = (tp)->iss 187 188 #define TCP_ISSINCR (125*1024) /* increment for tcp_iss each second */ 189 190 extern tcp_seq tcp_iss; /* tcp initial send seq # */ 191 192 extern char *tcpstates[]; 193 194 #endif 195