186 lines
5.5 KiB
Groff
186 lines
5.5 KiB
Groff
.\" Copyright (c) 1985, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the University of
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.\" California, Berkeley and its contributors.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)idp.4 8.1 (Berkeley) 6/5/93
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.\"
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.Dd June 5, 1993
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.Dt IDP 4
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.Os BSD 4.3
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.Sh NAME
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.Nm idp
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.Nd Xerox Internet Datagram Protocol
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.Sh SYNOPSIS
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.Fd #include <sys/socket.h>
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.Fd #include <netns/ns.h>
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.Fd #include <netns/idp.h>
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.Ft int
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.Fn socket AF_NS SOCK_DGRAM 0
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.Sh DESCRIPTION
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.Tn IDP
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is a simple, unreliable datagram protocol which is used
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to support the
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.Dv SOCK_DGRAM
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abstraction for the Internet
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protocol family.
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.Tn IDP
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sockets are connectionless, and are
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normally used with the
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.Xr sendto
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and
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.Xr recvfrom
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calls, though the
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.Xr connect 2
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call may also be used to fix the destination for future
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packets (in which case the
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.Xr recv 2
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or
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.Xr read 2
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and
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.Xr send 2
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or
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.Xr write 2
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system calls may be used).
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.Pp
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Xerox protocols are built vertically on top of
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.Tn IDP .
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Thus,
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.Tn IDP
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address formats are identical to those used by
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.Tn SPP .
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Note that the
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.Tn IDP
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port
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space is the same as the
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.Tn SPP
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port space (i.e. a
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.Tn IDP
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port
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may be
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.Dq connected
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to a
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.Tn SPP
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port, with certain
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options enabled below).
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In addition broadcast packets may be sent
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(assuming the underlying network supports
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this) by using a reserved
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.Dq broadcast address ;
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this address
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is network interface dependent.
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.Sh DIAGNOSTICS
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A socket operation may fail with one of the following errors returned:
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.Bl -tag -width [EADDRNOTAVAIL]
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.It Bq Er EISCONN
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when trying to establish a connection on a socket which
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already has one, or when trying to send a datagram with the destination
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address specified and the socket is already connected;
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.It Bq Er ENOTCONN
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when trying to send a datagram, but
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no destination address is specified, and the socket hasn't been
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connected;
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.It Bq Er ENOBUFS
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when the system runs out of memory for
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an internal data structure;
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.It Bq Er EADDRINUSE
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when an attempt
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is made to create a socket with a port which has already been
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allocated;
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.It Bq Er EADDRNOTAVAIL
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when an attempt is made to create a
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socket with a network address for which no network interface
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exists.
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.El
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.Sh SOCKET OPTIONS
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.Bl -tag -width [SO_HEADERS_ON_OUTPUT]
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.It Bq Dv SO_ALL_PACKETS
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When set, this option defeats automatic processing of Error packets,
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and Sequence Protocol packets.
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.It Bq Dv SO_DEFAULT_HEADERS
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The user provides the kernel an
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.Tn IDP
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header, from which
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it gleans the Packet Type.
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When requested, the kernel will provide an
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.Tn IDP
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header, showing
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the default packet type, and local and foreign addresses, if
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connected.
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.It Bq Dv SO_HEADERS_ON_INPUT
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When set, the first 30 bytes of any data returned from a read
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or recv from will be the initial 30 bytes of the
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.Tn IDP
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packet,
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as described by
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.Bd -literal -offset indent
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struct idp {
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u_short idp_sum;
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u_short idp_len;
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u_char idp_tc;
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u_char idp_pt;
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struct ns_addr idp_dna;
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struct ns_addr idp_sna;
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};
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.Ed
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.Pp
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This allows the user to determine the packet type, and whether
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the packet was a multi-cast packet or directed specifically at
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the local host.
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When requested, gives the current state of the option,
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.Pf ( Dv NSP_RAWIN
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or 0).
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.It Bq Dv SO_HEADERS_ON_OUTPUT
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When set, the first 30 bytes of any data sent
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will be the initial 30 bytes of the
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.Tn IDP
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packet.
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This allows the user to determine the packet type, and whether
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the packet should be multi-cast packet or directed specifically at
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the local host.
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You can also misrepresent the sender of the packet.
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When requested, gives the current state of the option.
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.Pf ( Dv NSP_RAWOUT
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or 0).
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.It Bq Dv SO_SEQNO
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When requested, this returns a sequence number which is not likely
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to be repeated until the machine crashes or a very long time has passed.
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It is useful in constructing Packet Exchange Protocol packets.
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.El
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.Sh SEE ALSO
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.Xr send 2 ,
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.Xr recv 2 ,
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.Xr intro 4 ,
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.Xr ns 4
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.Sh HISTORY
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The
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.Nm
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protocol appeared in
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.Bx 4.3 .
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