slirp/tcp.h

   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
  36 typedef uint32_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
  41 #define TCP_SNDSPACE 8192
  42 #define TCP_RCVSPACE 8192
  43
  44 /*
  45  * TCP header.
  46  * Per RFC 793, September, 1981.
  47  */
  48 #define tcphdr slirp_tcphdr
  49 struct tcphdr {
  50         uint16_t th_sport;              /* source port */
  51         uint16_t th_dport;              /* destination port */
  52         tcp_seq th_seq;                 /* sequence number */
  53         tcp_seq th_ack;                 /* acknowledgement number */
  54 #ifdef HOST_WORDS_BIGENDIAN
  55         uint8_t th_off:4,               /* data offset */
  56                 th_x2:4;                /* (unused) */
  57 #else
  58         uint8_t th_x2:4,                /* (unused) */
  59                 th_off:4;               /* data offset */
  60 #endif
  61         uint8_t th_flags;
  62         uint16_t th_win;                /* window */
  63         uint16_t th_sum;                /* checksum */
  64         uint16_t th_urp;                /* urgent pointer */
  65 };
  66
  67 #include "tcp_var.h"
  68
  69 #ifndef TH_FIN
  70 #define TH_FIN  0x01
  71 #define TH_SYN  0x02
  72 #define TH_RST  0x04
  73 #define TH_PUSH 0x08
  74 #define TH_ACK  0x10
  75 #define TH_URG  0x20
  76 #endif
  77
  78 #ifndef TCPOPT_EOL
  79 #define TCPOPT_EOL              0
  80 #define TCPOPT_NOP              1
  81 #define TCPOPT_MAXSEG           2
  82 #define TCPOPT_WINDOW           3
  83 #define TCPOPT_SACK_PERMITTED   4               /* Experimental */
  84 #define TCPOPT_SACK             5               /* Experimental */
  85 #define TCPOPT_TIMESTAMP        8
  86
  87 #define TCPOPT_TSTAMP_HDR       \
  88     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
  89 #endif
  90
  91 #ifndef TCPOLEN_MAXSEG
  92 #define    TCPOLEN_MAXSEG               4
  93 #define    TCPOLEN_WINDOW               3
  94 #define    TCPOLEN_SACK_PERMITTED       2
  95 #define    TCPOLEN_TIMESTAMP            10
  96 #define    TCPOLEN_TSTAMP_APPA          (TCPOLEN_TIMESTAMP+2) /* appendix A */
  97 #endif
  98
  99 /*
 100  * Default maximum segment size for TCP.
 101  * With an IP MSS of 576, this is 536,
 102  * but 512 is probably more convenient.
 103  * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
 104  *
 105  * We make this 1460 because we only care about Ethernet in the qemu context.
 106  */
 107 #undef TCP_MSS
 108 #define TCP_MSS 1460
 109
 110 #undef TCP_MAXWIN
 111 #define TCP_MAXWIN      65535   /* largest value for (unscaled) window */
 112
 113 #undef TCP_MAX_WINSHIFT
 114 #define TCP_MAX_WINSHIFT        14      /* maximum window shift */
 115
 116 /*
 117  * User-settable options (used with setsockopt).
 118  *
 119  * We don't use the system headers on unix because we have conflicting
 120  * local structures. We can't avoid the system definitions on Windows,
 121  * so we undefine them.
 122  */
 123 #undef TCP_NODELAY
 124 #define TCP_NODELAY     0x01    /* don't delay send to coalesce packets */
 125 #undef TCP_MAXSEG
 126
 127 /*
 128  * TCP FSM state definitions.
 129  * Per RFC793, September, 1981.
 130  */
 131
 132 #define TCP_NSTATES     11
 133
 134 #define TCPS_CLOSED             0       /* closed */
 135 #define TCPS_LISTEN             1       /* listening for connection */
 136 #define TCPS_SYN_SENT           2       /* active, have sent syn */
 137 #define TCPS_SYN_RECEIVED       3       /* have send and received syn */
 138 /* states < TCPS_ESTABLISHED are those where connections not established */
 139 #define TCPS_ESTABLISHED        4       /* established */
 140 #define TCPS_CLOSE_WAIT         5       /* rcvd fin, waiting for close */
 141 /* states > TCPS_CLOSE_WAIT are those where user has closed */
 142 #define TCPS_FIN_WAIT_1         6       /* have closed, sent fin */
 143 #define TCPS_CLOSING            7       /* closed xchd FIN; await FIN ACK */
 144 #define TCPS_LAST_ACK           8       /* had fin and close; await FIN ACK */
 145 /* states > TCPS_CLOSE_WAIT && < TCPS_FIN_WAIT_2 await ACK of FIN */
 146 #define TCPS_FIN_WAIT_2         9       /* have closed, fin is acked */
 147 #define TCPS_TIME_WAIT          10      /* in 2*msl quiet wait after close */
 148
 149 #define TCPS_HAVERCVDSYN(s)     ((s) >= TCPS_SYN_RECEIVED)
 150 #define TCPS_HAVEESTABLISHED(s) ((s) >= TCPS_ESTABLISHED)
 151 #define TCPS_HAVERCVDFIN(s)     ((s) >= TCPS_TIME_WAIT)
 152
 153 /*
 154  * TCP sequence numbers are 32 bit integers operated
 155  * on with modular arithmetic.  These macros can be
 156  * used to compare such integers.
 157  */
 158 #define SEQ_LT(a,b)     ((int)((a)-(b)) < 0)
 159 #define SEQ_LEQ(a,b)    ((int)((a)-(b)) <= 0)
 160 #define SEQ_GT(a,b)     ((int)((a)-(b)) > 0)
 161 #define SEQ_GEQ(a,b)    ((int)((a)-(b)) >= 0)
 162
 163 /*
 164  * Macros to initialize tcp sequence numbers for
 165  * send and receive from initial send and receive
 166  * sequence numbers.
 167  */
 168 #define tcp_rcvseqinit(tp) \
 169      (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
 170
 171 #define tcp_sendseqinit(tp) \
 172     (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = (tp)->iss
 173
 174 #define TCP_ISSINCR     (125*1024)      /* increment for tcp_iss each second */
 175
 176 #endif