add flag to avoid delay of short packets (Nagle algorithm)

[unix-history] / usr / src / sys / netinet / tcp_var.h

diff --git a/usr/src/sys/netinet/tcp_var.h b/usr/src/sys/netinet/tcp_var.h
index 6eebe05..df54206 100644 (file)
--- a/usr/src/sys/netinet/tcp_var.h
+++ b/usr/src/sys/netinet/tcp_var.h
@@ -1,138 +1,78 @@
-/*     tcp_var.h       4.6     81/11/24        */
-

 /*
 /*

- * Kernel variables for tcp.
+ * Copyright (c) 1982 Regents of the University of California.
+ * All rights reserved.  The Berkeley software License Agreement
+ * specifies the terms and conditions for redistribution.
+ *
+ *     @(#)tcp_var.h   6.6 (Berkeley) %G%

  */
 
 /*
  */
 
 /*

- * Tcp+ip header, after ip options removed.
+ * Kernel variables for tcp.

  */
  */

-struct tcpiphdr {
-       struct  ipovly ti_i;            /* overlaid ip structure */
-       struct  tcphdr ti_t;            /* tcp header */
-};
-#define        ti_next         ti_i.ih_next
-#define        ti_prev         ti_i.ih_prev
-#define        ti_x1           ti_i.ih_x1
-#define        ti_pr           ti_i.ih_pr
-#define        ti_len          ti_i.ih_len
-#define        ti_src          ti_i.ih_src
-#define        ti_dst          ti_i.ih_dst
-#define        ti_sport        ti_t.th_sport
-#define        ti_dport        ti_t.th_dport
-#define        ti_seq          ti_t.th_seq
-#define        ti_ackno        ti_t.th_ackno
-#define        ti_x2           ti_t.th_x2
-#define        ti_off          ti_t.th_off
-#define        ti_flags        ti_t.th_flags
-#define        ti_win          ti_t.th_win
-#define        ti_sum          ti_t.th_sum
-#define        ti_urp          ti_t.th_urp

 
 /*
 
 /*

- * Tcp control block.
+ * Tcp control block, one per tcp; fields:

  */
 struct tcpcb {
  */
 struct tcpcb {

-       struct  tcpiphdr *seg_next,*seg_prev;   /* seq queue */
+       struct  tcpiphdr *seg_next;     /* sequencing queue */
+       struct  tcpiphdr *seg_prev;
+       short   t_state;                /* state of this connection */
+       short   t_timer[TCPT_NTIMERS];  /* tcp timers */
+       short   t_rxtshift;             /* log(2) of rexmt exp. backoff */
+       struct  mbuf *t_tcpopt;         /* tcp options */
+       short   t_maxseg;               /* maximum segment size */
+       char    t_force;                /* 1 if forcing out a byte */
+       u_char  t_flags;
+#define        TF_ACKNOW       0x01            /* ack peer immediately */
+#define        TF_DELACK       0x02            /* ack, but try to delay it */
+#define        TF_NODELAY      0x04            /* don't delay packets to coalesce */
+#define        TF_NOOPT        0x08            /* don't use tcp options */

        struct  tcpiphdr *t_template;   /* skeletal packet for transmit */
        struct  tcpiphdr *t_template;   /* skeletal packet for transmit */

-       struct  inpcb *t_inpcb;
-       seq_t   iss;                    /* initial send seq # */
-       seq_t   irs;                    /* initial recv seq # */
-       seq_t   rcv_urp;                /* rcv urgent pointer */
-       seq_t   rcv_nxt;                /* next seq # to rcv */
-       seq_t   rcv_end;                /* rcv eol pointer */
-       seq_t   snd_off;                /* seq # of first datum in send buf */
-       seq_t   seq_fin;                /* seq # of FIN sent */
-       seq_t   snd_end;                /* send eol pointer */
-       seq_t   snd_urp;                /* snd urgent pointer */
-       seq_t   snd_lst;                /* seq # of last sent datum */
-       seq_t   snd_nxt;                /* seq # of next datum to send */
-       seq_t   snd_una;                /* seq # of first unacked datum */
-       seq_t   snd_wl;                 /* seq # of last sent window */
-       seq_t   snd_hi;                 /* highest seq # sent */
-       seq_t   snd_wnd;                /* send window max */
-       seq_t   t_rexmt_val;            /* val saved in rexmt timer */
-       seq_t   t_rtl_val;              /* val saved in rexmt too long timer */
-       seq_t   t_xmt_val;              /* seq # sent when xmt timer started */
-       seq_t   rcv_adv;                /* advertised window */
-       struct  mbuf *seg_unack;        /* unacked message queue */
-       short   seqcnt;
-       u_short tc_flags;               /* flags and state; see below */
-       u_short t_options;
-#define        TO_EOL          0x01            /* eol mode */
-#define        TO_URG          0x02            /* urgent mode */
-       u_char  t_state;                /* state of this connection */
-       u_char  t_xmtime;               /* current rexmt time */
-/* timers... must be in order */
-       short   t_init;                 /* init */
-       short   t_rexmt;                /* retransmission */
-       short   t_rexmttl;              /* retransmit too long */
-       short   t_persist;              /* retransmit persistance */
-       short   t_finack;               /* fin acknowledged */
-       short   t_xmt;                  /* round trip transmission time */
-/* end timers */
-};
-
-/* tc_flags values */
-#define        TC_ACK_DUE      0x0001          /* must we send ACK */
-#define        TC_CANCELLED    0x0002          /* retransmit timer cancelled */
-#define        TC_FIN_RCVD     0x0004          /* FIN received */
-#define        TC_FORCE_ONE    0x0008          /* force sending of one byte */
-#define        TC_NEW_WINDOW   0x0010          /* received new window size */
-#define        TC_REXMT        0x0020          /* this msg is a retransmission */
-#define        TC_SND_FIN      0x0040          /* FIN should be sent */
-#define        TC_SND_RST      0x0080          /* RST should be sent */
-#define        TC_SND_URG      0x0100          /* urgent data to send */
-#define        TC_SYN_ACKED    0x0200          /* SYN has been ACKed */
-#define        TC_SYN_RCVD     0x0400          /* SYN has been received */
-#define        TC_USR_CLOSED   0x0800          /* user has closed connection */
-#define        TC_USR_ABORT    0x1000          /* user has closed and does not expect
-                                          to receive any more data */
+       struct  inpcb *t_inpcb;         /* back pointer to internet pcb */

 /*
 /*

- * TCP timers.
+ * The following fields are used as in the protocol specification.
+ * See RFC783, Dec. 1981, page 21.

  */
  */

-#define        TINIT           0
-#define        TREXMT          1
-#define        TREXMTTL        2
-#define        TPERSIST        3
-#define        TFINACK         4
-#define        TNTIMERS        5
-
-#define        intotcpcb(ip)   ((struct tcpcb *)(ip)->inp_ppcb)
-#define        sototcpcb(so)   (intotcpcb(sotoinpcb(so)))
-
+/* send sequence variables */
+       tcp_seq snd_una;                /* send unacknowledged */
+       tcp_seq snd_nxt;                /* send next */
+       tcp_seq snd_up;                 /* send urgent pointer */
+       tcp_seq snd_wl1;                /* window update seg seq number */
+       tcp_seq snd_wl2;                /* window update seg ack number */
+       tcp_seq iss;                    /* initial send sequence number */
+       u_short snd_wnd;                /* send window */
+/* receive sequence variables */
+       u_short rcv_wnd;                /* receive window */
+       tcp_seq rcv_nxt;                /* receive next */
+       tcp_seq rcv_up;                 /* receive urgent pointer */
+       tcp_seq irs;                    /* initial receive sequence number */

 /*
 /*

- * Tcp machine predicates
+ * Additional variables for this implementation.

  */
  */

-#define        ack_ok(x, y) \
-    (((y)->ti_flags&TH_ACK)==0 || \
-      ((x)->iss < (y)->ti_ackno && (y)->ti_ackno <= (x)->snd_hi))
-
-#define        syn_ok(x, y) \
-    ((y)->ti_flags&TH_SYN)
-
-#define        ack_fin(x, y) \
-    ((x)->seq_fin > (x)->iss && (y)->ti_ackno > (x)->seq_fin)
-
-#define        rcv_empty(x) \
-    (((x)->tc_flags&TC_USR_ABORT) || \
-      ((x)->t_inpcb->inp_socket->so_rcv.sb_mb == NULL && \
-       (x)->seg_next == (x)->seg_prev))
-
-#define        ISSINCR         128             /* increment for iss each second */
-#define        TCPSIZE         20              /* size of TCP leader (bytes) */
+/* receive variables */
+       tcp_seq rcv_adv;                /* advertised window */
+/* retransmit variables */
+       tcp_seq snd_max;                /* highest sequence number sent
+                                        * used to recognize retransmits
+                                        */
+/* congestion control (for source quench) */
+       u_short snd_cwnd;               /* congestion-controlled window */
+/* transmit timing stuff */
+       short   t_idle;                 /* inactivity time */
+       short   t_rtt;                  /* round trip time */
+       u_short max_rcvd;               /* most peer has sent into window */
+       tcp_seq t_rtseq;                /* sequence number being timed */
+       float   t_srtt;                 /* smoothed round-trip time */
+       u_short max_sndwnd;             /* largest window peer has offered */
+/* out-of-band data */
+       char    t_oobflags;             /* have some */
+       char    t_iobc;                 /* input character */
+#define        TCPOOB_HAVEDATA 0x01
+#define        TCPOOB_HADDATA  0x02
+};

 
 

-/*
- * THESE NEED TO BE JUSTIFIED!
- *
- * *2 here is because slow timeout routine called every 1/2 second.
- */
-#define        T_INIT          (30*2)
-#define        T_2ML           (10*2)          /* 2*maximum packet lifetime */
-#define        T_PERS          (5*2)           /* persist time */
-#define        T_REXMT         (1*2)           /* base for retransmission time */
-#define        T_REXMTTL       (30*2)          /* retransmit too long timeout */
-#define        T_REMAX         (30*2)          /* maximum retransmission time */
+#define        intotcpcb(ip)   ((struct tcpcb *)(ip)->inp_ppcb)
+#define        sototcpcb(so)   (intotcpcb(sotoinpcb(so)))

 
 struct tcpstat {
        int     tcps_badsum;
 
 struct tcpstat {
        int     tcps_badsum;


@@ -142,39 +82,10 @@ struct     tcpstat {
        int     tcps_unack;
 };
 
        int     tcps_unack;
 };
 

-#ifdef TCPDEBUG
-#define        TDBSIZE         50
-/*
- * Tcp debugging record.
- */
-struct tcp_debug {
-       long    td_tod;                 /* time of day */
-       struct  tcbcb *td_tcb;          /* -> tcb */
-       char    td_old;                 /* old state */
-       char    td_inp;                 /* input */
-       char    td_tim;                 /* timer id */
-       char    td_new;                 /* new state */
-       seq_t   td_sno;                 /* seq_t number */
-       seq_t   td_ano;                 /* acknowledgement */
-       u_short td_wno;                 /* window */
-       u_short td_lno;                 /* length */
-       u_char  td_flg;                 /* message flags */
-};
-#endif
-

 #ifdef KERNEL
 #ifdef KERNEL

-seq_t  tcp_iss;                        /* tcp initial send seq # */
-struct inpcb tcb;
-struct tcpstat tcpstat;
-#ifdef TCPDEBUG
-int    tcpconsdebug;                   /* set to 1 traces on console */
-struct tcp_debug tcp_debug[TDBSIZE];
-int    tdbx;                   /* rotating index into tcp_debug */
-#endif
+struct inpcb tcb;              /* head of queue of active tcpcb's */
+struct tcpstat tcpstat;        /* tcp statistics */

 struct tcpiphdr *tcp_template();
 struct tcpiphdr *tcp_template();

+struct tcpcb *tcp_close(), *tcp_drop();
+struct tcpcb *tcp_timers(), *tcp_disconnect(), *tcp_usrclosed();

 #endif
 #endif

-
-#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)