\ ========== Copyright Header Begin ========================================== \ \ Hypervisor Software File: tcp.fth \ \ Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved. \ \ - Do no alter or remove copyright notices \ \ - Redistribution and use of this software in source and binary forms, with \ or without modification, are permitted provided that the following \ conditions are met: \ \ - Redistribution of source code must retain the above copyright notice, \ this list of conditions and the following disclaimer. \ \ - Redistribution 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. \ \ Neither the name of Sun Microsystems, Inc. or the names of contributors \ may be used to endorse or promote products derived from this software \ without specific prior written permission. \ \ This software is provided "AS IS," without a warranty of any kind. \ ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, \ INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A \ PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN \ MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR \ ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR \ DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN \ OR ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR \ FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE \ DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, \ ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF \ SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. \ \ You acknowledge that this software is not designed, licensed or \ intended for use in the design, construction, operation or maintenance of \ any nuclear facility. \ \ ========== Copyright Header End ============================================ id: @(#)tcp.fth 1.1 04/09/07 purpose: TCP support copyright: Copyright 2004 Sun Microsystems, Inc. All Rights Reserved copyright: Use is subject to license terms. \ RFC 793: Transmission Control Protocol fload ${BP}/pkg/netinet/tcp-h.fth fload ${BP}/pkg/netinet/tcpbuf.fth fload ${BP}/pkg/netinet/tcb.fth fload ${BP}/pkg/netinet/tcp-trace.fth headerless /queue-head instance buffer: tcp-inpcb-list \ Head of TCP's INPCB list : tcp-init ( -- ) tcp-inpcb-list queue-init [ifdef] DEBUG tcptrace-init [then] ; : tcp-close ( -- ) ; \ Compute TCP packet checksum. : tcp-checksum ( ip-pkt -- chksum ) IPPROTO_TCP over >ip-src /ip-addr (in-cksum) over >ip-dest /ip-addr (in-cksum) swap ippkt>payload rot over + -rot in-cksum ; \ ISN selection. This must be a reasonably random number. : tcp-iss ( -- iss ) random ; \ Initialize TCP send sequence variables. : tcp-sendseq-init ( tcb -- ) tcp-iss swap 2dup snd-una! 2dup snd-nxt! 2dup snd-wl2! snd-max! ; \ Estimating mean round trip time and variance. Use the "fast algorithm \ for RTT mean and variation" from "Congestion Avoidance and Control", \ Jacobson, V. and M. Karels, Nov 1988. \ \ SRTT and RTTVAR are stored as fixed point numbers with scaling factors \ of 8 and 4 respectively. On the first RTT measurement (SRTT = 0), the \ values stored in SRTT and RTTVAR reflect their scaling factors. For \ subsequent measurements, the code becomes \ \ error = measurement - (average >> 3); \ average = average + error; \ if (error < 0) \ error = -error; \ error = error - (variance >> 2); \ variance = variance + error; \ RTO = (average >> 3) + variance; \ \ reflecting alpha = 1/8, beta = 1/4, and RTO = A + 4D. \ Set next retransmission timeout interval, enforcing lower and upper \ bounds for the timeout. : tcp-set-rto ( tcb rto -- ) d# 1000 max d# 60000 min swap tcb-rto! ; \ Update RTT estimators and compute RTO, enforcing lower and upper \ bounds for the timeout : tcp-update-rto ( tcb rtt -- ) 2dup swap >tcb-rtt l! ( tcb rtt ) over tcb-srtt@ 0<> if ( tcb rtt ) over tcb-srtt@ 3 rshift - ( tcb error ) 2dup over tcb-srtt@ + swap tcb-srtt! ( tcb error ) abs over tcb-rttvar@ 2 rshift - ( tcb error' ) over tcb-rttvar@ + over tcb-rttvar! ( tcb ) else ( tcb rtt ) 2dup 3 lshift swap tcb-srtt! ( tcb rtt ) 1 lshift over tcb-rttvar! ( tcb ) then ( tcb ) dup tcb-srtt@ 3 rshift over tcb-rttvar@ + ( tcb rto ) tcp-set-rto ( ) ; \ Back off the timer on retransmissions. : tcp-backoff ( tcb -- ) dup tcb-rto@ 2* tcp-set-rto ; headers fload ${BP}/pkg/netinet/tcp-output.fth fload ${BP}/pkg/netinet/tcp-timer.fth fload ${BP}/pkg/netinet/tcp-input.fth headerless : tcp-connected? ( tcb -- flag ) tcb-state@ TCPS_ESTABLISHED = ; : tcp-disconnected? ( tcb -- flag ) tcb-state@ dup TCPS_CLOSED = swap TCPS_TIME_WAIT = or ; \ Process packets until desired state is reached or an error is seen. : tcp-state-wait ( tcb acf -- ) begin ( tcb acf ) 2dup execute 0= 2 pick tcb-error@ 0= and ( tcb acf flag ) while ( tcb acf ) tcp-poll ( tcb acf ) repeat 2drop ( ) ; \ Pushed data can be delivered if we have received all data up through \ the recorded push sequence. : tcp-pushdata? ( tcb -- flag ) dup tcb-flags@ TF_PUSH and if ( tcb ) dup rcv-nxt@ swap >tcb-pushseq l@ seq>= ( flag ) else ( tcb ) drop false ( false ) then ( flag ) ; \ Check if the read request can be satisfied. Data in the receive \ buffer can be read if we have enough data, or we are not expecting \ any more data, or data is being pushed. : tcp-cangetdata? ( tcb len -- cangetdata? ) over tcb-error@ 0= if ( tcb len ) over tcb>rcvbuf tcpbuf-count@ <= ( tcb flag ) over tcp-pushdata? or ( tcb flag' ) swap tcp-receive-done? or ( cangetdata? ) else ( tcb len ) 2drop false ( false ) then ( cangetdata? ) ; \ Copy data from TCP receive buffer to an user buffer. If the window can \ now be opened up at least 50% of the maximum window we ever advertised, \ send a window update. : tcp-getdata ( tcb adr len -- nread ) rot >r ( adr len ) ( r: tcb ) \ Read data from the receive buffer r@ tcb>rcvbuf dup 2swap 0 -rot tcpbuf-read ( buf nread ) 2dup tcpbuf-drop ( buf nread ) \ Clear PUSH state if all outstanding data has been \ delivered to the application. over tcpbuf-count@ 0= if ( buf nread ) r@ TF_PUSH tcb-clear-flags ( buf nread ) then ( buf nread ) \ Schedule a window update if one can be sent. over tcpbuf-space@ r@ rcv-wnd@ - ( buf nread incr ) rot tcpbuf-size@ 2/ >= if ( nread ) r@ TF_ACKNOW tcb-set-flags ( nread ) then ( nread ) r> tcp-output ( nread ) ( r: ) ; \ Check if we can accept a send request. : tcp-canputdata? ( tcb len -- flag ) over tcb-error@ 0= if ( tcb len ) swap tcb>sndbuf tcpbuf-space@ <= ( flag ) else ( tcb len ) 2drop false ( false ) then ( flag ) ; \ Copy data from an user buffer to the end of the send buffer. : tcp-putdata ( tcb adr len -- len' ) rot tcb>sndbuf dup >r ( adr len buf ) ( r: buf ) dup tcpbuf-count@ 2swap tcpbuf-write ( len' ) r> over tcpbuf-count+! ( len' ) ( r: ) ; \ Initiate a connection. : tcp-open-connection ( tcb -- 0 | error ) tcp-start-timers ( tcb ) dup tcp-sendseq-init ( tcb ) dup >tcbt-connect TCP_CONN_TIMEOUT set-timer ( tcb ) TCPS_SYN_SENT over tcb-state! ( tcb ) dup tcp-output ( tcb ) dup ['] tcp-connected? tcp-state-wait ( tcb ) dup >tcbt-connect clear-timer drop ( tcb ) tcb-error@ ( result ) ; \ Accept incoming connections. : tcp-accept-connection ( tcb -- 0 | error# ) tcp-start-timers ( tcb ) dup ['] tcp-connected? tcp-state-wait ( tcb ) tcb-error@ ( result ) ; \ Initiate a TCP disconnect. : tcp-disconnect ( tcb -- ) dup tcb-state@ case TCPS_SYN_RCVD of TCPS_FIN_WAIT_1 over tcb-state! endof TCPS_ESTABLISHED of TCPS_FIN_WAIT_1 over tcb-state! endof TCPS_CLOSE_WAIT of TCPS_LAST_ACK over tcb-state! endof endcase tcp-output ; \ Close a connection. : tcp-close-connection ( tcb -- ) tcp-drain-input ( tcb ) dup tcb-state@ TCPS_SYN_SENT <= if ( tcb ) TCPS_CLOSED swap tcb-state! ( ) else ( tcb ) dup tcb>rcvbuf tcpbuf-count@ 0<> if ( tcb ) TCPS_CLOSED over tcb-state! tcp-output ( ) tcp-drain-input ( ) else ( tcb ) dup tcp-disconnect ( tcb ) ['] tcp-disconnected? tcp-state-wait ( ) then ( ) then ( ) ; fload ${BP}/pkg/netinet/tcp-debug.fth \ Post-mortem debugging routines headers