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 #include <glib.h>
  37
  38 typedef uint32_t tcp_seq;
  39
  40 #define      PR_SLOWHZ       2               /* 2 slow timeouts per second (approx) */
  41 #define      PR_FASTHZ       5               /* 5 fast timeouts per second (not important) */
  42
  43 #define TCP_SNDSPACE 8192
  44 #define TCP_RCVSPACE 8192
  45
  46 /*
  47  * TCP header.
  48  * Per RFC 793, September, 1981.
  49  */
  50 #define tcphdr slirp_tcphdr
  51 struct tcphdr {
  52         uint16_t th_sport;              /* source port */
  53         uint16_t th_dport;              /* destination port */
  54         tcp_seq th_seq;                 /* sequence number */
  55         tcp_seq th_ack;                 /* acknowledgement number */
  56 #if G_BYTE_ORDER == G_BIG_ENDIAN
  57         uint8_t th_off:4,               /* data offset */
  58                 th_x2:4;                /* (unused) */
  59 #else
  60         uint8_t th_x2:4,                /* (unused) */
  61                 th_off:4;               /* data offset */
  62 #endif
  63         uint8_t th_flags;
  64         uint16_t th_win;                /* window */
  65         uint16_t th_sum;                /* checksum */
  66         uint16_t th_urp;                /* urgent pointer */
  67 };
  68
  69 #include "tcp_var.h"
  70
  71 #ifndef TH_FIN
  72 #define TH_FIN  0x01
  73 #define TH_SYN  0x02
  74 #define TH_RST  0x04
  75 #define TH_PUSH 0x08
  76 #define TH_ACK  0x10
  77 #define TH_URG  0x20
  78 #endif
  79
  80 #ifndef TCPOPT_EOL
  81 #define TCPOPT_EOL              0
  82 #define TCPOPT_NOP              1
  83 #define TCPOPT_MAXSEG           2
  84 #define TCPOPT_WINDOW           3
  85 #define TCPOPT_SACK_PERMITTED   4               /* Experimental */
  86 #define TCPOPT_SACK             5               /* Experimental */
  87 #define TCPOPT_TIMESTAMP        8
  88
  89 #define TCPOPT_TSTAMP_HDR       \
  90     (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)
  91 #endif
  92
  93 #ifndef TCPOLEN_MAXSEG
  94 #define    TCPOLEN_MAXSEG               4
  95 #define    TCPOLEN_WINDOW               3
  96 #define    TCPOLEN_SACK_PERMITTED       2
  97 #define    TCPOLEN_TIMESTAMP            10
  98 #define    TCPOLEN_TSTAMP_APPA          (TCPOLEN_TIMESTAMP+2) /* appendix A */
  99 #endif
 100
 101 /*
 102  * Default maximum segment size for TCP.
 103  * With an IP MSS of 576, this is 536,
 104  * but 512 is probably more convenient.
 105  * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
 106  *
 107  * We make this 1460 because we only care about Ethernet in the qemu context.
 108  */
 109 #undef TCP_MSS
 110 #define TCP_MSS 1460
 111 #undef TCP6_MSS
 112 #define TCP6_MSS 1440
 113
 114 #undef TCP_MAXWIN
 115 #define TCP_MAXWIN      65535   /* largest value for (unscaled) window */
 116
 117 #undef TCP_MAX_WINSHIFT
 118 #define TCP_MAX_WINSHIFT        14      /* maximum window shift */
 119
 120 /*
 121  * User-settable options (used with setsockopt).
 122  *
 123  * We don't use the system headers on unix because we have conflicting
 124  * local structures. We can't avoid the system definitions on Windows,
 125  * so we undefine them.
 126  */
 127 #undef TCP_NODELAY
 128 #define TCP_NODELAY     0x01    /* don't delay send to coalesce packets */
 129 #undef TCP_MAXSEG
 130
 131 /*
 132  * TCP FSM state definitions.
 133  * Per RFC793, September, 1981.
 134  */
 135
 136 #define TCP_NSTATES     11
 137
 138 #define TCPS_CLOSED             0       /* closed */
 139 #define TCPS_LISTEN             1       /* listening for connection */
 140 #define TCPS_SYN_SENT           2       /* active, have sent syn */
 141 #define TCPS_SYN_RECEIVED       3       /* have send and received syn */
 142 /* states < TCPS_ESTABLISHED are those where connections not established */
 143 #define TCPS_ESTABLISHED        4       /* established */
 144 #define TCPS_CLOSE_WAIT         5       /* rcvd fin, waiting for close */
 145 /* states > TCPS_CLOSE_WAIT are those where user has closed */
 146 #define TCPS_FIN_WAIT_1         6       /* have closed, sent fin */
 147 #define TCPS_CLOSING            7       /* closed xchd FIN; await FIN ACK */
 148 #define TCPS_LAST_ACK           8       /* had fin and close; await FIN ACK */
 149 /* states > TCPS_CLOSE_WAIT && < TCPS_FIN_WAIT_2 await ACK of FIN */
 150 #define TCPS_FIN_WAIT_2         9       /* have closed, fin is acked */
 151 #define TCPS_TIME_WAIT          10      /* in 2*msl quiet wait after close */
 152
 153 #define TCPS_HAVERCVDSYN(s)     ((s) >= TCPS_SYN_RECEIVED)
 154 #define TCPS_HAVEESTABLISHED(s) ((s) >= TCPS_ESTABLISHED)
 155 #define TCPS_HAVERCVDFIN(s)     ((s) >= TCPS_TIME_WAIT)
 156
 157 /*
 158  * TCP sequence numbers are 32 bit integers operated
 159  * on with modular arithmetic.  These macros can be
 160  * used to compare such integers.
 161  */
 162 #define SEQ_LT(a,b)     ((int)((a)-(b)) < 0)
 163 #define SEQ_LEQ(a,b)    ((int)((a)-(b)) <= 0)
 164 #define SEQ_GT(a,b)     ((int)((a)-(b)) > 0)
 165 #define SEQ_GEQ(a,b)    ((int)((a)-(b)) >= 0)
 166
 167 /*
 168  * Macros to initialize tcp sequence numbers for
 169  * send and receive from initial send and receive
 170  * sequence numbers.
 171  */
 172 #define tcp_rcvseqinit(tp) \
 173      (tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
 174
 175 #define tcp_sendseqinit(tp) \
 176     (tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = (tp)->iss
 177
 178 #define TCP_ISSINCR     (125*1024)      /* increment for tcp_iss each second */
 179
 180 #endif