tp.4p

早期freebsd实现

.TH TP 4P "9 December 1988"
.ds ]W Wisconsin ARGO 1.0
.UC 4
.SH NAME
TP \- ISO Transport Protocol
.SH SYNOPSIS
.nf
\fB#include <sys/socket.h>\fR
\fB#include <netargo/iso_errno.h>\fR
\fB#include <netargo/tp_param.h>\fR
\fB#include <netargo/tp_user.h>\fR
.PP
\fBs = socket( [ AF_INET, AF_ISO ] , SOCK_SEQPACKET, 0);\fR
.SH DESCRIPTION
.PP
The ISO Transport Protocol implemented for AOS R2
at the University of Wisconsin - Madison
includes classes 0 and 4 
of the ISO transport protocols
as specified in
the September 1984 version of DIS 8073.
Class 4 of the protocol provides reliable, sequenced,
flow-controlled, two-way
transmission of data packets with an alternate stop-and-wait data path called
the "expedited data" service.
Class 0 is essentially a null transport protocol, which is used
when the underlying network service provides reliable, sequenced,
flow-controlled, two-way data transmission.
Class 0 does not provide the expedited data service.
The protocols are implemented as a single transport layer entity 
that coexists with the Internet protocol suite.
Class 0 may be used only in the ISO domain.
Class 4 may be used in the Internet domain as well as in the ISO domain.
.PP
The user interface to this protocol is the Berkeley interprocess communication
interface (see \fIsocket(2)\fR.)
Two new system calls for sending and receiving
were added to this interface to
to permit the support the end-of-transport-service-data-unit (EOTSDU)
indication. 
See \fIsendv(2)\fR and \fIrecvv(2)\fR.
If the EOTSDU is not needed, the Berkeley 4.3BSD interface
can be used. 
See \fIsend(2)\fR and \fIrecv(2)\fR.
.PP
Through the 
\fIgetsockopt\fR and \fIsetsockopt\fR
system calls,
TP supports several options 
to control such things as negotiable options
in the protocol and protocol strategies.
.\"These system calls are used
.\"to submit data for inclusion on connect and disconnect TPDUs. 
The options are defined in \fB<netargo/tp_user.h>\fR,
and are described below.
.\".PP
.\"The options marked with a percent sign ( \fB%\fR )
.\"are limited to use by the super-user.
.PP
In the tables below,
the options marked with a pound sign ( \fB#\fR )
may be used 
with \fIsetsockopt()\fR
after a connection is established.
Others must be used before the connection
is established, in other words,
before calling
\fIconnect()\fR or 
\fIaccept()\fR.
All options may be used 
with \fIgetsockopt()\fR
before or
after a connection is established.
.\"
.\" .PP
.\" The options marked with an exclamation point ( \fB!\fR )
.\" may be used after a connection is released,
.\" but before 
.\" the TP reference timer (which generally
.\" has a value in minutes) expires, and before
.\" a \fIclose()\fR system call.
.\" In other words, these commands may be used when the peer closes
.\" a connection (possibly causing a disconnect indication), as long as the command
.\" is issued "soon" after the disconnection occurred.  
.\" Disconnect data may be sent by the side initiating the close
.\" but not by the passive side ("passive" with respect to the closing
.\" of the connection), so there is no need to read disconnect data
.\" after calling \fIclose()\fR.
.\" .PP
.\" The implementation of data on connect and disconnect is incomplete
.\" and is not supported.
.sp 1
.TP 25
\fBName\fR
\fBValue [default]\fR
.IP
\fBDescription\fR
.\".TP 25
.\"TPOPT_CONN_DATA
.\"(char *) [none]
.\".IP
.\"Data to send on \fIconnect()\fR.
.\".TP 25
.\"TPOPT_DISC_DATA\fB # !\fR
.\"(char *) [none]
.\".IP
.\"Data to send on \fIclose()\fR.
.\".TP 25
.\"TPOPT_CDDATA_CLEAR\fB #\fR
.\"No associated value.
.\".IP
.\"Erase outgoing connect or disconnect data.
.TP 25
TPOPT_MY_TSEL\fB \fR
1-64 bytes.
.IP
An "extended" transport selector (tsel) for this socket.
This option is used to set or get the local tsel.
When this option is used to set a tsel, 
the default the 2-byte tsel
that may have been allocated by \fIbind()\fR
is retained, but this "extended" tsel is the
tsel that is transmitted in a connection request
When this option is used to get a tsel, 
it will return whatever transport tsel exists;
if no "extended" tsel was given to this socket,
the 2-byte tsel is returned.
.TP 25
TPOPT_PEER_TSEL\fB \fR
1-64 bytes.
.IP
An "extended" transport selector (tsel) for the
peer transport entity.
This option is used to get the peer's tsel after
a connection is established. 
When used before a connection
is established, this option can set the tsel that
will be transmitted as the "called" tsel
in a connection request.
.TP 25
TPOPT_PERF_MEAS\fB #\fR
Boolean.
.IP
When \fBtrue\fR, performance measurements will be kept
for this connection.  
When set before a connection is established, the
active side will use a locally defined parameter on the
connect request packet; if the peer is another ARGO
implementation, this will cause performance measurement to be
turned on 
on the passive side as well.
See \fItpperf(8)\fR.
.TP 25
TPOPT_PSTATISTICS\fB\fR
No associated value on input.
On output, struct tp_pmeas.
.IP
This command is used to read the performance statistics accumulated
during a connection's lifetime.
It can only be used with \fIgetsockopt()\fR.
The structure it returns is described in \fB<netargo/tp_stat.h>\fR.
See \fItpperf(8)\fR.
.TP 25
TPOPT_FLAGS
unsigned integer. [ 0x0 ]
.IP
This command can only be used with \fIgetsockopt()\fR.
See the description of the flags below.
.TP 25
TPOPT_PARAMS\fB\fR
struct tp_conn_param.
.IP
Used to get or set a group parameters for a connection.
The struct tp_conn_param is the argument used with the
\fIgetsockopt()\fR or \fIsetsockopt()\fR system call. 
It is described in 
\fB<netargo/tp_user.h>\fR.
.PP
The fields of the \fItp_conn_param\fR structure are
described below.
.nf
.sp 1
\fIValues for TPOPT_PARAMS:\fR
.fi
.TP 25
\fBField\fR
\fBValue [default]\fR
.IP
\fBDescription\fR
.\" ******************8
.TP 25
p_Nretrans
nonzero short integer [ 1 ]
.IP
Number of times a TPDU will be retransmitted before the
local TP entity closes a connection.
.\" ******************8
.TP 25
p_dr_ticks
nonzero short integer [ various ]
.IP
Number of clock ticks between retransmissions of disconnect request TPDUs.
.\" ******************8
.TP 25
p_dt_ticks
nonzero short integer [ various ]
.IP
Number of clock ticks between retransmissions of data TPDUs.
This parameter applies only to class 4.
.\" ******************8
.TP 25
p_cr_ticks
nonzero short integer [ various ]
.IP
Number of clock ticks between retransmissions of connection request TPDUs.
.\" ******************8
.TP 25
p_cc_ticks
nonzero short integer [ various ]
.IP
Number of clock ticks between retransmissions of connection confirm TPDUs.
This parameter applies only to class 4.
.\" ******************8
.TP 25
p_x_ticks
nonzero short integer [ various ]
.IP
Number of clock ticks between retransmissions of expedited data TPDUs.
This parameter applies only to class 4.
.\" ******************8
.TP 25
p_sendack_ticks
nonzero short integer [ various ]
.IP
Number of clock ticks that the local TP entity
will wait before sending an acknowledgment for normal data
(not applicable if the acknowlegement strategy is TPACK_EACH).
This parameter applies only to class 4.
.\" ******************8
.TP 25
p_ref_ticks
nonzero short integer [ various ]
.IP
Number of clock ticks for which a reference will
be considered frozen after the connection to which
it applied is closed.
This parameter applies to classes 4 and 0 in the 
ARGO implementation, despite the fact that
the frozen reference function is required only for
class 4.
.\" ******************8
.TP 25
p_inact_ticks
nonzero short integer [ various ]
.IP
Number of clock ticks without an incoming packet from the peer after which 
TP close the connection.
This parameter applies only to class 4.
.\" ******************8
.TP 25
p_keepalive_ticks
nonzero short integer [ various ]
.IP
nonzero short integer [ various ]
Number of clock ticks between acknowledgments that are sent
to keep an inactive connection open (to prevent the peer's
inactivity control function from closing the connection).
This parameter applies only to class 4.
.\" ******************8
.TP 25
p_winsize
short integer between 128 and 16384. [4096 bytes]
.IP
The buffer space limits in bytes for incoming and outgoing data.
There is no way to specify different limits for incoming and outgoing
paths.
The actual window size at any time
during the lifetime of a connection
is a function of the buffer size limit, the negotiated
maximum TPDU size, and the 
rate at which the user program receives data.
This parameter applies only to class 4.
.\" ******************8
.TP 25
p_tpdusize
unsigned char between 0x7 and 0xd. 
[ 0xc for class 4 ] [ 0xb for class 0 ]
.IP
Log 2 of the maximum TPDU size to be negotiated.
The TP standard (ISO 8473) gives an upper bound of 
0xd for class 4 and 0xb for class 0.
The ARGO implementation places upper bounds of
0xc on class 4 and 0xb on class 0.
.\" ******************8
.TP 25
p_ack_strat
TPACK_EACH or TPACK_WINDOW.  [ TPACK_WINDOW ]
.IP
This parameter applies only to class 4.
Two acknowledgment strategies are supported:
.IP
TPACK_EACH means that each data TPDU is acknowledged
with an AK TPDU.
.IP
TPACK_WINDOW