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root/cebix/BasiliskII/src/slirp/tcp_timer.h
Revision: 1.2
Committed: 2012-03-30T01:10:28Z (12 years, 2 months ago) by asvitkine
Content type: text/plain
Branch: MAIN
CVS Tags: HEAD
Changes since 1.1: +1 -5 lines
Log Message: 
Switch slirp to 3-clause BSD license. This change went in upstream to QEMU's
version of slirp (where this code comes from), with the following checkin:

commit 2f5f89963186d42a7ded253bc6cf5b32abb45cec
Author: aliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>
Date:   Mon Jan 26 19:37:41 2009 +0000

    Remove the advertising clause from the slirp license

    According to the FSF, the 4-clause BSD license, which slirp is covered under,
    is not compatible with the GPL or LGPL[1].

    [1] http://www.fsf.org/licensing/licenses/index_html#GPLIncompatibleLicenses

    There are three declared copyright holders in slirp that use the 4-clause
    BSD license, the Regents of UC Berkley, Danny Gasparovski, and Kelly Price.
    Below are the appropriate permissions to remove the advertise clause from slirp
    from each party.

    Special thanks go to Richard Fontana from Red Hat for contacting all of the
    necessary authors to resolve this issue!

    Regents of UC Berkley:
    From ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change

    July 22, 1999

    To All Licensees, Distributors of Any Version of BSD:

    As you know, certain of the Berkeley Software Distribution ("BSD") source
    code files require that further distributions of products containing all or
    portions of the software, acknowledge within their advertising materials
    that such products contain software developed by UC Berkeley and its
    contributors.

    Specifically, the provision reads:

    "     * 3. All advertising materials mentioning features or use of this software
          *    must display the following acknowledgement:
          *    This product includes software developed by the University of
          *    California, Berkeley and its contributors."

    Effective immediately, licensees and distributors are no longer required to
    include the acknowledgement within advertising materials.  Accordingly, the
    foregoing paragraph of those BSD Unix files containing it is hereby deleted
    in its entirety.

    William Hoskins
    Director, Office of Technology Licensing
    University of California, Berkeley

    Danny Gasparovski:

    Subject: RE: Slirp license
    Date: Thu, 8 Jan 2009 10:51:00 +1100
    From: "Gasparovski, Daniel" <Daniel.Gasparovski@ato.gov.au>
    To: "Richard Fontana" <rfontana@redhat.com>

    Hi Richard,

    I have no objection to having Slirp code in QEMU be licensed under the
    3-clause BSD license.

    Thanks for taking the effort to consult me about this.


    Dan ...

    Kelly Price:

    Date: Thu, 8 Jan 2009 19:38:56 -0500
    From: "Kelly Price" <strredwolf@gmail.com>
    To: "Richard Fontana" <rfontana@redhat.com>
    Subject: Re: Slirp license

    Thanks for contacting me, Richard.  I'm glad you were able to find
    Dan, as I've been "keeping the light on" for Slirp.  I have no use for
    it now, and I have little time for it (now holding onto Keenspot's
    Comic Genesis and having a regular US state government position). If
    Dan would like to return to the project, I'd love to give it back to
    him.

    As for copyright, I don't own all of it.  Dan does, so I will defer to
    him.  Any of my patches I will gladly license to the 3-part BSD
    license.  My interest in re-licensing was because we didn't have ready
    info to contact Dan.  If Dan would like to port Slirp back out of
    QEMU, a lot of us 64-bit users would be grateful.

    Feel free to share this email address with Dan.  I will be glad to
    effect a transfer of the project to him and Mr. Bellard of the QEMU
    project.

    Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


    git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6451 c046a42c-6fe2-441c-8c8c-71466251a162

File Contents

# Content
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_timer.h 8.1 (Berkeley) 6/10/93
30 * tcp_timer.h,v 1.4 1994/08/21 05:27:38 paul Exp
31 */
32
33 #ifndef _TCP_TIMER_H_
34 #define _TCP_TIMER_H_
35
36 /*
37 * Definitions of the TCP timers. These timers are counted
38 * down PR_SLOWHZ times a second.
39 */
40 #define TCPT_NTIMERS 4
41
42 #define TCPT_REXMT 0 /* retransmit */
43 #define TCPT_PERSIST 1 /* retransmit persistence */
44 #define TCPT_KEEP 2 /* keep alive */
45 #define TCPT_2MSL 3 /* 2*msl quiet time timer */
46
47 /*
48 * The TCPT_REXMT timer is used to force retransmissions.
49 * The TCP has the TCPT_REXMT timer set whenever segments
50 * have been sent for which ACKs are expected but not yet
51 * received. If an ACK is received which advances tp->snd_una,
52 * then the retransmit timer is cleared (if there are no more
53 * outstanding segments) or reset to the base value (if there
54 * are more ACKs expected). Whenever the retransmit timer goes off,
55 * we retransmit one unacknowledged segment, and do a backoff
56 * on the retransmit timer.
57 *
58 * The TCPT_PERSIST timer is used to keep window size information
59 * flowing even if the window goes shut. If all previous transmissions
60 * have been acknowledged (so that there are no retransmissions in progress),
61 * and the window is too small to bother sending anything, then we start
62 * the TCPT_PERSIST timer. When it expires, if the window is nonzero,
63 * we go to transmit state. Otherwise, at intervals send a single byte
64 * into the peer's window to force him to update our window information.
65 * We do this at most as often as TCPT_PERSMIN time intervals,
66 * but no more frequently than the current estimate of round-trip
67 * packet time. The TCPT_PERSIST timer is cleared whenever we receive
68 * a window update from the peer.
69 *
70 * The TCPT_KEEP timer is used to keep connections alive. If an
71 * connection is idle (no segments received) for TCPTV_KEEP_INIT amount of time,
72 * but not yet established, then we drop the connection. Once the connection
73 * is established, if the connection is idle for TCPTV_KEEP_IDLE time
74 * (and keepalives have been enabled on the socket), we begin to probe
75 * the connection. We force the peer to send us a segment by sending:
76 * <SEQ=SND.UNA-1><ACK=RCV.NXT><CTL=ACK>
77 * This segment is (deliberately) outside the window, and should elicit
78 * an ack segment in response from the peer. If, despite the TCPT_KEEP
79 * initiated segments we cannot elicit a response from a peer in TCPT_MAXIDLE
80 * amount of time probing, then we drop the connection.
81 */
82
83 /*
84 * Time constants.
85 */
86 #define TCPTV_MSL ( 5*PR_SLOWHZ) /* max seg lifetime (hah!) */
87
88 #define TCPTV_SRTTBASE 0 /* base roundtrip time;
89 if 0, no idea yet */
90 #define TCPTV_SRTTDFLT ( 3*PR_SLOWHZ) /* assumed RTT if no info */
91
92 #define TCPTV_PERSMIN ( 5*PR_SLOWHZ) /* retransmit persistence */
93 #define TCPTV_PERSMAX ( 60*PR_SLOWHZ) /* maximum persist interval */
94
95 #define TCPTV_KEEP_INIT ( 75*PR_SLOWHZ) /* initial connect keep alive */
96 #define TCPTV_KEEP_IDLE (120*60*PR_SLOWHZ) /* dflt time before probing */
97 #define TCPTV_KEEPINTVL ( 75*PR_SLOWHZ) /* default probe interval */
98 #define TCPTV_KEEPCNT 8 /* max probes before drop */
99
100 #define TCPTV_MIN ( 1*PR_SLOWHZ) /* minimum allowable value */
101 /* #define TCPTV_REXMTMAX ( 64*PR_SLOWHZ) */ /* max allowable REXMT value */
102 #define TCPTV_REXMTMAX ( 12*PR_SLOWHZ) /* max allowable REXMT value */
103
104 #define TCP_LINGERTIME 120 /* linger at most 2 minutes */
105
106 #define TCP_MAXRXTSHIFT 12 /* maximum retransmits */
107
108
109 #ifdef TCPTIMERS
110 char *tcptimers[] =
111 { "REXMT", "PERSIST", "KEEP", "2MSL" };
112 #endif
113
114 /*
115 * Force a time value to be in a certain range.
116 */
117 #define TCPT_RANGESET(tv, value, tvmin, tvmax) { \
118 (tv) = (value); \
119 if ((tv) < (tvmin)) \
120 (tv) = (tvmin); \
121 else if ((tv) > (tvmax)) \
122 (tv) = (tvmax); \
123 }
124
125 extern int tcp_keepidle; /* time before keepalive probes begin */
126 extern int tcp_keepintvl; /* time between keepalive probes */
127 extern int tcp_maxidle; /* time to drop after starting probes */
128 extern int tcp_ttl; /* time to live for TCP segs */
129 extern int tcp_backoff[];
130
131 struct tcpcb;
132
133 void tcp_fasttimo _P((void));
134 void tcp_slowtimo _P((void));
135 void tcp_canceltimers _P((struct tcpcb *));
136 struct tcpcb * tcp_timers _P((register struct tcpcb *, int));
137
138 #endif