(By Sklower) checkpoint the current state of Cherenson's work.

[unix-history] / usr / src / sys / netinet / tcp_output.c

diff --git a/usr/src/sys/netinet/tcp_output.c b/usr/src/sys/netinet/tcp_output.c
index 2078ca1..c946f2b 100644 (file)
--- a/usr/src/sys/netinet/tcp_output.c
+++ b/usr/src/sys/netinet/tcp_output.c
@@ -4,7 +4,7 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)tcp_output.c        7.24 (Berkeley) %G%
+ *     @(#)tcp_output.c        7.25 (Berkeley) %G%

  */
 
 #include <sys/param.h>
  */
 
 #include <sys/param.h>


@@ -36,10 +36,8 @@
 extern struct mbuf *m_copypack();
 #endif
 
 extern struct mbuf *m_copypack();
 #endif
 

-/*
- * Initial options.
- */
-u_char tcp_initopt[4] = { TCPOPT_MAXSEG, 4, 0x0, 0x0, };
+
+#define MAX_TCPOPTLEN  32      /* max # bytes that go in options */

 
 /*
  * Tcp output routine: figure out what should be sent and send it.
 
 /*
  * Tcp output routine: figure out what should be sent and send it.


@@ -52,7 +50,7 @@ tcp_output(tp)
        int off, flags, error;
        register struct mbuf *m;
        register struct tcpiphdr *ti;
        int off, flags, error;
        register struct mbuf *m;
        register struct tcpiphdr *ti;

-       u_char *opt;
+       u_char opt[MAX_TCPOPTLEN];

        unsigned optlen, hdrlen;
        int idle, sendalot;
 
        unsigned optlen, hdrlen;
        int idle, sendalot;
 


@@ -151,7 +149,13 @@ again:
         * window, then want to send a window update to peer.
         */
        if (win > 0) {
         * window, then want to send a window update to peer.
         */
        if (win > 0) {

-               long adv = win - (tp->rcv_adv - tp->rcv_nxt);
+               /* 
+                * "adv" is the amount we can increase the window,
+                * taking into account that we are limited by
+                * TCP_MAXWIN << tp->rcv_scale.
+                */
+               long adv = min(win, (long)TCP_MAXWIN << tp->rcv_scale) -
+                       (tp->rcv_adv - tp->rcv_nxt);

 
                if (adv >= (long) (2 * tp->t_maxseg))
                        goto send;
 
                if (adv >= (long) (2 * tp->t_maxseg))
                        goto send;


@@ -224,16 +228,119 @@ send:
        if (flags & TH_SYN && (tp->t_flags & TF_NOOPT) == 0) {
                u_short mss;
 
        if (flags & TH_SYN && (tp->t_flags & TF_NOOPT) == 0) {
                u_short mss;
 

-               opt = tcp_initopt;
-               optlen = sizeof (tcp_initopt);
-               hdrlen += sizeof (tcp_initopt);
+               opt[0] = TCPOPT_MAXSEG;
+               opt[1] = 4;

                mss = htons((u_short) tcp_mss(tp, 0));
                bcopy((caddr_t)&mss, (caddr_t)(opt + 2), sizeof(mss));
                mss = htons((u_short) tcp_mss(tp, 0));
                bcopy((caddr_t)&mss, (caddr_t)(opt + 2), sizeof(mss));

+               optlen = 4;
+ 
+               if ((tp->t_flags & TF_REQ_SCALE) &&
+                   ((flags & TH_ACK) == 0 || (tp->t_flags & TF_RCVD_SCALE))) {
+                       *((u_long *) (opt + optlen)) = htonl(
+                               TCPOPT_NOP<<24 |
+                               TCPOPT_WINDOW<<16 |
+                               TCPOLEN_WINDOW<<8 |
+                               tp->request_r_scale);
+                       optlen += 4;
+               }
+ 
+#ifdef DO_SACK
+               /* Send a SACK_PERMITTED option in the SYN segment. */
+               *((u_long *) (opt + optlen)) = htonl(
+                               TCPOPT_NOP<<24 |
+                               TCPOPT_NOP<<16 |
+                               TCPOPT_SACK_PERMITTED<<8 |
+                               TCPOLEN_SACK_PERMITTED);
+               optlen += 4;
+#endif
+       }
+ 
+       /*
+        * Send a timestamp and echo-reply if this is a SYN and our side 
+        * wants to use timestamps (TF_REQ_TSTMP is set) or both our side
+        * and our peer have sent timestamps in our SYN's.
+        */
+       if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP &&
+            (flags & TH_RST) == 0 &&
+           ((flags & (TH_SYN|TH_ACK)) == TH_SYN ||
+            (tp->t_flags & TF_RCVD_TSTMP))) {
+               u_long *lp = (u_long *)(opt + optlen);
+ 
+               /* Form timestamp option as shown in appendix A of RFC 1323. */
+               *lp++ = htonl(TCPOPT_TSTAMP_HDR);
+               *lp++ = htonl(tcp_now);
+               *lp   = htonl(tp->ts_recent);
+               optlen += TCPOLEN_TSTAMP_APPA;
+       }
+ 
+#ifdef DO_SACK
+       /* Send SACK if needed. Don't tack a SACK onto a non-empty segment. */
+       if (tp->seg_next != (struct tcpiphdr *)tp && len == 0 &&
+           (tp->t_flags & (TF_SACK_PERMIT|TF_NOOPT)) == TF_SACK_PERMIT) {
+ 
+               register struct tcpiphdr *q = tp->seg_next;
+               register u_long *optl = (u_long *)(opt + optlen) + 1;
+               tcp_seq block_start;
+               u_long  block_size;
+               int sack_len = 2;
+ 
+               /*
+                * Use these to gather runs of received segments.
+                * The first segment in the queue becomes the initial run.
+                */
+               block_start = q->ti_seq;
+               block_size = q->ti_len;
+ 
+               do {
+                       q = (struct tcpiphdr *) q->ti_next;
+                       if (q == (struct tcpiphdr *) tp ||
+                               block_start + block_size != q->ti_seq) {
+                               
+                               /*
+                                * Stick the relative origin and block size
+                                * in the SACK option.
+                                */
+                               *optl++ = htonl(block_start-tp->rcv_nxt);
+                               *optl++ = htonl(block_size);
+                               sack_len += 8;
+ 
+                               /* If no more will fit into options, quit. */
+                               if (sack_len + optlen > MAX_TCPOPTLEN - 8)
+                                       break;
+ 
+                               if (q != (struct tcpiphdr *) tp) {
+                                       block_start = q->ti_seq;
+                                       block_size = q->ti_len;
+                               }
+                       } else {
+                               /* 
+                                * This segment just accumulates into previous
+                                * run.
+                                */
+                               block_size += q->ti_len;
+                       }
+               } while (q != (struct tcpiphdr *) tp);
+ 
+               *((u_long *) (opt + optlen)) = htonl(TCPOPT_NOP << 24 |
+                       TCPOPT_NOP << 16 | TCPOPT_SACK << 8 | sack_len);
+               optlen += sack_len + 2;
+       }
+#endif
+       hdrlen += optlen;
+       /*
+        * Adjust data length if insertion of options will
+        * bump the packet length beyond the t_maxseg length.
+        */
+        if (len > tp->t_maxseg - optlen) {
+               len = tp->t_maxseg - optlen;
+               sendalot = 1;
+        }
+
+

 #ifdef DIAGNOSTIC
 #ifdef DIAGNOSTIC

-               if (max_linkhdr + hdrlen > MHLEN)
-                       panic("tcphdr too big");
+       if (max_linkhdr + hdrlen > MHLEN)
+               panic("tcphdr too big");

 #endif
 #endif

-       }

 
        /*
         * Grab a header mbuf, attaching a copy of data to
 
        /*
         * Grab a header mbuf, attaching a copy of data to


@@ -327,13 +434,13 @@ send:
         */
        if (win < (long)(so->so_rcv.sb_hiwat / 4) && win < (long)tp->t_maxseg)
                win = 0;
         */
        if (win < (long)(so->so_rcv.sb_hiwat / 4) && win < (long)tp->t_maxseg)
                win = 0;

-       if (win > TCP_MAXWIN)
-               win = TCP_MAXWIN;
+       if (win > (long)TCP_MAXWIN << tp->rcv_scale)
+               win = (long)TCP_MAXWIN << tp->rcv_scale;

        if (win < (long)(tp->rcv_adv - tp->rcv_nxt))
                win = (long)(tp->rcv_adv - tp->rcv_nxt);
        if (win > IP_MAXPACKET)
                win = IP_MAXPACKET;
        if (win < (long)(tp->rcv_adv - tp->rcv_nxt))
                win = (long)(tp->rcv_adv - tp->rcv_nxt);
        if (win > IP_MAXPACKET)
                win = IP_MAXPACKET;

-       ti->ti_win = htons((u_short)win);
+       ti->ti_win = htons((u_short) (win>>tp->rcv_scale));

        if (SEQ_GT(tp->snd_up, tp->snd_nxt)) {
                ti->ti_urp = htons((u_short)(tp->snd_up - tp->snd_nxt));
                ti->ti_flags |= TH_URG;
        if (SEQ_GT(tp->snd_up, tp->snd_nxt)) {
                ti->ti_urp = htons((u_short)(tp->snd_up - tp->snd_nxt));
                ti->ti_flags |= TH_URG;


@@ -426,7 +533,7 @@ send:
 #if BSD >= 43
 #if BSD>=43
        error = ip_output(m, tp->t_inpcb->inp_options, &tp->t_inpcb->inp_route,
 #if BSD >= 43
 #if BSD>=43
        error = ip_output(m, tp->t_inpcb->inp_options, &tp->t_inpcb->inp_route,

-           so->so_options & SO_DONTROUTE);
+           so->so_options & SO_DONTROUTE, 0);

 #else
        error = ip_output(m, (struct mbuf *)0, &tp->t_inpcb->inp_route, 
            so->so_options & SO_DONTROUTE);
 #else
        error = ip_output(m, (struct mbuf *)0, &tp->t_inpcb->inp_route, 
            so->so_options & SO_DONTROUTE);


@@ -458,6 +565,7 @@ out:
         */
        if (win > 0 && SEQ_GT(tp->rcv_nxt+win, tp->rcv_adv))
                tp->rcv_adv = tp->rcv_nxt + win;
         */
        if (win > 0 && SEQ_GT(tp->rcv_nxt+win, tp->rcv_adv))
                tp->rcv_adv = tp->rcv_nxt + win;

+       tp->last_ack_sent = tp->rcv_nxt;

        tp->t_flags &= ~(TF_ACKNOW|TF_DELACK);
        if (sendalot)
                goto again;
        tp->t_flags &= ~(TF_ACKNOW|TF_DELACK);
        if (sendalot)
                goto again;