IDP
Section: Devices and Network Interfaces (4)
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BSD mandoc
BSD 4.3
NAME
idp
- Xerox Internet Datagram Protocol
SYNOPSIS
Fd #include <sys/socket.h>
Fd #include <netns/ns.h>
Fd #include <netns/idp.h>
Ft int
Fn socket AF_NS SOCK_DGRAM 0
DESCRIPTION
IDP
is a simple, unreliable datagram protocol which is used
to support the
SOCK_DGRAM
abstraction for the Internet
protocol family.
IDP
sockets are connectionless, and are
normally used with the
sendto
and
recvfrom
calls, though the
connect(2)
call may also be used to fix the destination for future
packets (in which case the
recv(2)
or
read(2)
and
send(2)
or
write(2)
system calls may be used).
Xerox protocols are built vertically on top of
IDP
Thus,
IDP
address formats are identical to those used by
SPP
Note that the
IDP
port
space is the same as the
SPP
port space (i.e. a
IDP
port
may be
``connected''
to a
SPP
port, with certain
options enabled below).
In addition broadcast packets may be sent
(assuming the underlying network supports
this) by using a reserved
``broadcast address''
this address
is network interface dependent.
DIAGNOSTICS
A socket operation may fail with one of the following errors returned:
- Bq Er EISCONN
-
when trying to establish a connection on a socket which
already has one, or when trying to send a datagram with the destination
address specified and the socket is already connected;
- Bq Er ENOTCONN
-
when trying to send a datagram, but
no destination address is specified, and the socket hasn't been
connected;
- Bq Er ENOBUFS
-
when the system runs out of memory for
an internal data structure;
- Bq Er EADDRINUSE
-
when an attempt
is made to create a socket with a port which has already been
allocated;
- Bq Er EADDRNOTAVAIL
-
when an attempt is made to create a
socket with a network address for which no network interface
exists.
SOCKET OPTIONS
- Bq SO_ALL_PACKETS
-
When set, this option defeats automatic processing of Error packets,
and Sequence Protocol packets.
- Bq SO_DEFAULT_HEADERS
-
The user provides the kernel an
IDP
header, from which
it gleans the Packet Type.
When requested, the kernel will provide an
IDP
header, showing
the default packet type, and local and foreign addresses, if
connected.
- Bq SO_HEADERS_ON_INPUT
-
When set, the first 30 bytes of any data returned from a read
or recv from will be the initial 30 bytes of the
IDP
packet,
as described by
struct idp {
u_short idp_sum;
u_short idp_len;
u_char idp_tc;
u_char idp_pt;
struct ns_addr idp_dna;
struct ns_addr idp_sna;
};
This allows the user to determine the packet type, and whether
the packet was a multi-cast packet or directed specifically at
the local host.
When requested, gives the current state of the option,
( NSP_RAWIN
or 0).
- Bq SO_HEADERS_ON_OUTPUT
-
When set, the first 30 bytes of any data sent
will be the initial 30 bytes of the
IDP
packet.
This allows the user to determine the packet type, and whether
the packet should be multi-cast packet or directed specifically at
the local host.
You can also misrepresent the sender of the packet.
When requested, gives the current state of the option.
( NSP_RAWOUT
or 0).
- Bq SO_SEQNO
-
When requested, this returns a sequence number which is not likely
to be repeated until the machine crashes or a very long time has passed.
It is useful in constructing Packet Exchange Protocol packets.
SEE ALSO
send(2),
recv(2),
intro(4),
ns(4)
HISTORY
The
protocol appeared in
BSD 4.3
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- DIAGNOSTICS
-
- SOCKET OPTIONS
-
- SEE ALSO
-
- HISTORY
-
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Time: 06:48:52 GMT, May 19, 2025