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Diffstat (limited to 'tcp.h')
| -rw-r--r-- | tcp.h | 170 |
1 files changed, 170 insertions, 0 deletions
@@ -0,0 +1,170 @@ +/* + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. 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 u_int32_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 { + u_int16_t th_sport; /* source port */ + u_int16_t th_dport; /* destination port */ + tcp_seq th_seq; /* sequence number */ + tcp_seq th_ack; /* acknowledgement number */ +#ifdef WORDS_BIGENDIAN + u_int th_off : 4, /* data offset */ + th_x2 : 4; /* (unused) */ +#else + u_int th_x2 : 4, /* (unused) */ + th_off : 4; /* data offset */ +#endif + u_int8_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 + u_int16_t th_win; /* window */ + u_int16_t th_sum; /* checksum */ + u_int16_t th_urp; /* urgent pointer */ +}; + +#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)). + */ +#define TCP_MSS 512 + +#define TCP_MAXWIN 65535 /* largest value for (unscaled) window */ + +#define TCP_MAX_WINSHIFT 14 /* maximum window shift */ + +/* + * User-settable options (used with setsockopt). + */ +/* #define TCP_NODELAY 0x01 */ /* don't delay send to coalesce packets + */ +/* #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 tcp_seq tcp_iss; /* tcp initial send seq # */ + +extern char *tcpstates[]; + +#endif |