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1 | \ ========== Copyright Header Begin ========================================== |
2 | \ | |
3 | \ Hypervisor Software File: tcp.fth | |
4 | \ | |
5 | \ Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved. | |
6 | \ | |
7 | \ - Do no alter or remove copyright notices | |
8 | \ | |
9 | \ - Redistribution and use of this software in source and binary forms, with | |
10 | \ or without modification, are permitted provided that the following | |
11 | \ conditions are met: | |
12 | \ | |
13 | \ - Redistribution of source code must retain the above copyright notice, | |
14 | \ this list of conditions and the following disclaimer. | |
15 | \ | |
16 | \ - Redistribution in binary form must reproduce the above copyright notice, | |
17 | \ this list of conditions and the following disclaimer in the | |
18 | \ documentation and/or other materials provided with the distribution. | |
19 | \ | |
20 | \ Neither the name of Sun Microsystems, Inc. or the names of contributors | |
21 | \ may be used to endorse or promote products derived from this software | |
22 | \ without specific prior written permission. | |
23 | \ | |
24 | \ This software is provided "AS IS," without a warranty of any kind. | |
25 | \ ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, | |
26 | \ INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A | |
27 | \ PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN | |
28 | \ MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR | |
29 | \ ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR | |
30 | \ DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN | |
31 | \ OR ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR | |
32 | \ FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE | |
33 | \ DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, | |
34 | \ ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF | |
35 | \ SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. | |
36 | \ | |
37 | \ You acknowledge that this software is not designed, licensed or | |
38 | \ intended for use in the design, construction, operation or maintenance of | |
39 | \ any nuclear facility. | |
40 | \ | |
41 | \ ========== Copyright Header End ============================================ | |
42 | id: @(#)tcp.fth 1.1 04/09/07 | |
43 | purpose: TCP support | |
44 | copyright: Copyright 2004 Sun Microsystems, Inc. All Rights Reserved | |
45 | copyright: Use is subject to license terms. | |
46 | ||
47 | \ RFC 793: Transmission Control Protocol | |
48 | ||
49 | fload ${BP}/pkg/netinet/tcp-h.fth | |
50 | fload ${BP}/pkg/netinet/tcpbuf.fth | |
51 | fload ${BP}/pkg/netinet/tcb.fth | |
52 | fload ${BP}/pkg/netinet/tcp-trace.fth | |
53 | ||
54 | headerless | |
55 | ||
56 | /queue-head instance buffer: tcp-inpcb-list \ Head of TCP's INPCB list | |
57 | ||
58 | : tcp-init ( -- ) | |
59 | tcp-inpcb-list queue-init | |
60 | [ifdef] DEBUG | |
61 | tcptrace-init | |
62 | [then] | |
63 | ; | |
64 | ||
65 | : tcp-close ( -- ) ; | |
66 | ||
67 | \ Compute TCP packet checksum. | |
68 | : tcp-checksum ( ip-pkt -- chksum ) | |
69 | IPPROTO_TCP over >ip-src /ip-addr (in-cksum) | |
70 | over >ip-dest /ip-addr (in-cksum) | |
71 | swap ippkt>payload rot over + -rot in-cksum | |
72 | ; | |
73 | ||
74 | \ ISN selection. This must be a reasonably random number. | |
75 | : tcp-iss ( -- iss ) random ; | |
76 | ||
77 | \ Initialize TCP send sequence variables. | |
78 | : tcp-sendseq-init ( tcb -- ) | |
79 | tcp-iss swap 2dup snd-una! 2dup snd-nxt! 2dup snd-wl2! snd-max! | |
80 | ; | |
81 | ||
82 | \ Estimating mean round trip time and variance. Use the "fast algorithm | |
83 | \ for RTT mean and variation" from "Congestion Avoidance and Control", | |
84 | \ Jacobson, V. and M. Karels, Nov 1988. | |
85 | \ | |
86 | \ SRTT and RTTVAR are stored as fixed point numbers with scaling factors | |
87 | \ of 8 and 4 respectively. On the first RTT measurement (SRTT = 0), the | |
88 | \ values stored in SRTT and RTTVAR reflect their scaling factors. For | |
89 | \ subsequent measurements, the code becomes | |
90 | \ | |
91 | \ error = measurement - (average >> 3); | |
92 | \ average = average + error; | |
93 | \ if (error < 0) | |
94 | \ error = -error; | |
95 | \ error = error - (variance >> 2); | |
96 | \ variance = variance + error; | |
97 | \ RTO = (average >> 3) + variance; | |
98 | \ | |
99 | \ reflecting alpha = 1/8, beta = 1/4, and RTO = A + 4D. | |
100 | ||
101 | \ Set next retransmission timeout interval, enforcing lower and upper | |
102 | \ bounds for the timeout. | |
103 | : tcp-set-rto ( tcb rto -- ) d# 1000 max d# 60000 min swap tcb-rto! ; | |
104 | ||
105 | \ Update RTT estimators and compute RTO, enforcing lower and upper | |
106 | \ bounds for the timeout | |
107 | : tcp-update-rto ( tcb rtt -- ) | |
108 | 2dup swap >tcb-rtt l! ( tcb rtt ) | |
109 | over tcb-srtt@ 0<> if ( tcb rtt ) | |
110 | over tcb-srtt@ 3 rshift - ( tcb error ) | |
111 | 2dup over tcb-srtt@ + swap tcb-srtt! ( tcb error ) | |
112 | abs over tcb-rttvar@ 2 rshift - ( tcb error' ) | |
113 | over tcb-rttvar@ + over tcb-rttvar! ( tcb ) | |
114 | else ( tcb rtt ) | |
115 | 2dup 3 lshift swap tcb-srtt! ( tcb rtt ) | |
116 | 1 lshift over tcb-rttvar! ( tcb ) | |
117 | then ( tcb ) | |
118 | dup tcb-srtt@ 3 rshift over tcb-rttvar@ + ( tcb rto ) | |
119 | tcp-set-rto ( ) | |
120 | ; | |
121 | ||
122 | \ Back off the timer on retransmissions. | |
123 | : tcp-backoff ( tcb -- ) dup tcb-rto@ 2* tcp-set-rto ; | |
124 | ||
125 | headers | |
126 | ||
127 | fload ${BP}/pkg/netinet/tcp-output.fth | |
128 | fload ${BP}/pkg/netinet/tcp-timer.fth | |
129 | fload ${BP}/pkg/netinet/tcp-input.fth | |
130 | ||
131 | headerless | |
132 | ||
133 | : tcp-connected? ( tcb -- flag ) | |
134 | tcb-state@ TCPS_ESTABLISHED = | |
135 | ; | |
136 | ||
137 | : tcp-disconnected? ( tcb -- flag ) | |
138 | tcb-state@ dup TCPS_CLOSED = swap TCPS_TIME_WAIT = or | |
139 | ; | |
140 | ||
141 | \ Process packets until desired state is reached or an error is seen. | |
142 | : tcp-state-wait ( tcb acf -- ) | |
143 | begin ( tcb acf ) | |
144 | 2dup execute 0= 2 pick tcb-error@ 0= and ( tcb acf flag ) | |
145 | while ( tcb acf ) | |
146 | tcp-poll ( tcb acf ) | |
147 | repeat 2drop ( ) | |
148 | ; | |
149 | ||
150 | \ Pushed data can be delivered if we have received all data up through | |
151 | \ the recorded push sequence. | |
152 | ||
153 | : tcp-pushdata? ( tcb -- flag ) | |
154 | dup tcb-flags@ TF_PUSH and if ( tcb ) | |
155 | dup rcv-nxt@ swap >tcb-pushseq l@ seq>= ( flag ) | |
156 | else ( tcb ) | |
157 | drop false ( false ) | |
158 | then ( flag ) | |
159 | ; | |
160 | ||
161 | \ Check if the read request can be satisfied. Data in the receive | |
162 | \ buffer can be read if we have enough data, or we are not expecting | |
163 | \ any more data, or data is being pushed. | |
164 | ||
165 | : tcp-cangetdata? ( tcb len -- cangetdata? ) | |
166 | over tcb-error@ 0= if ( tcb len ) | |
167 | over tcb>rcvbuf tcpbuf-count@ <= ( tcb flag ) | |
168 | over tcp-pushdata? or ( tcb flag' ) | |
169 | swap tcp-receive-done? or ( cangetdata? ) | |
170 | else ( tcb len ) | |
171 | 2drop false ( false ) | |
172 | then ( cangetdata? ) | |
173 | ; | |
174 | ||
175 | \ Copy data from TCP receive buffer to an user buffer. If the window can | |
176 | \ now be opened up at least 50% of the maximum window we ever advertised, | |
177 | \ send a window update. | |
178 | ||
179 | : tcp-getdata ( tcb adr len -- nread ) | |
180 | rot >r ( adr len ) ( r: tcb ) | |
181 | ||
182 | \ Read data from the receive buffer | |
183 | r@ tcb>rcvbuf dup 2swap 0 -rot tcpbuf-read ( buf nread ) | |
184 | 2dup tcpbuf-drop ( buf nread ) | |
185 | ||
186 | \ Clear PUSH state if all outstanding data has been | |
187 | \ delivered to the application. | |
188 | over tcpbuf-count@ 0= if ( buf nread ) | |
189 | r@ TF_PUSH tcb-clear-flags ( buf nread ) | |
190 | then ( buf nread ) | |
191 | ||
192 | \ Schedule a window update if one can be sent. | |
193 | over tcpbuf-space@ r@ rcv-wnd@ - ( buf nread incr ) | |
194 | rot tcpbuf-size@ 2/ >= if ( nread ) | |
195 | r@ TF_ACKNOW tcb-set-flags ( nread ) | |
196 | then ( nread ) | |
197 | ||
198 | r> tcp-output ( nread ) ( r: ) | |
199 | ; | |
200 | ||
201 | \ Check if we can accept a send request. | |
202 | : tcp-canputdata? ( tcb len -- flag ) | |
203 | over tcb-error@ 0= if ( tcb len ) | |
204 | swap tcb>sndbuf tcpbuf-space@ <= ( flag ) | |
205 | else ( tcb len ) | |
206 | 2drop false ( false ) | |
207 | then ( flag ) | |
208 | ; | |
209 | ||
210 | \ Copy data from an user buffer to the end of the send buffer. | |
211 | : tcp-putdata ( tcb adr len -- len' ) | |
212 | rot tcb>sndbuf dup >r ( adr len buf ) ( r: buf ) | |
213 | dup tcpbuf-count@ 2swap tcpbuf-write ( len' ) | |
214 | r> over tcpbuf-count+! ( len' ) ( r: ) | |
215 | ; | |
216 | ||
217 | \ Initiate a connection. | |
218 | : tcp-open-connection ( tcb -- 0 | error ) | |
219 | tcp-start-timers ( tcb ) | |
220 | dup tcp-sendseq-init ( tcb ) | |
221 | dup >tcbt-connect TCP_CONN_TIMEOUT set-timer ( tcb ) | |
222 | TCPS_SYN_SENT over tcb-state! ( tcb ) | |
223 | dup tcp-output ( tcb ) | |
224 | dup ['] tcp-connected? tcp-state-wait ( tcb ) | |
225 | dup >tcbt-connect clear-timer drop ( tcb ) | |
226 | tcb-error@ ( result ) | |
227 | ; | |
228 | ||
229 | \ Accept incoming connections. | |
230 | : tcp-accept-connection ( tcb -- 0 | error# ) | |
231 | tcp-start-timers ( tcb ) | |
232 | dup ['] tcp-connected? tcp-state-wait ( tcb ) | |
233 | tcb-error@ ( result ) | |
234 | ; | |
235 | ||
236 | \ Initiate a TCP disconnect. | |
237 | : tcp-disconnect ( tcb -- ) | |
238 | dup tcb-state@ case | |
239 | TCPS_SYN_RCVD of TCPS_FIN_WAIT_1 over tcb-state! endof | |
240 | TCPS_ESTABLISHED of TCPS_FIN_WAIT_1 over tcb-state! endof | |
241 | TCPS_CLOSE_WAIT of TCPS_LAST_ACK over tcb-state! endof | |
242 | endcase | |
243 | tcp-output | |
244 | ; | |
245 | ||
246 | \ Close a connection. | |
247 | : tcp-close-connection ( tcb -- ) | |
248 | tcp-drain-input ( tcb ) | |
249 | dup tcb-state@ TCPS_SYN_SENT <= if ( tcb ) | |
250 | TCPS_CLOSED swap tcb-state! ( ) | |
251 | else ( tcb ) | |
252 | dup tcb>rcvbuf tcpbuf-count@ 0<> if ( tcb ) | |
253 | TCPS_CLOSED over tcb-state! tcp-output ( ) | |
254 | tcp-drain-input ( ) | |
255 | else ( tcb ) | |
256 | dup tcp-disconnect ( tcb ) | |
257 | ['] tcp-disconnected? tcp-state-wait ( ) | |
258 | then ( ) | |
259 | then ( ) | |
260 | ; | |
261 | ||
262 | fload ${BP}/pkg/netinet/tcp-debug.fth \ Post-mortem debugging routines | |
263 | ||
264 | headers |