NS
Section: Devices and Network Interfaces (4)
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BSD mandoc
BSD 4.3
NAME
ns
- Xerox Network Systems(tm) protocol family
SYNOPSIS
options NS
options NSIP
pseudo-device ns
DESCRIPTION
The
NS
protocol family is a collection of protocols
layered atop the
Internet Datagram Protocol
(IDP
)
transport layer, and using the Xerox
NS
address formats.
The
NS
family provides protocol support for the
SOCK_STREAM , SOCK_DGRAM , SOCK_SEQPACKET
and
SOCK_RAW
socket types; the
SOCK_RAW
interface is a debugging tool, allowing you to trace all packets
entering, (or with toggling kernel variable, additionally leaving) the local
host.
ADDRESSING
NS
addresses are 12 byte quantities, consisting of a
4 byte Network number, a 6 byte Host number and a 2 byte port number,
all stored in network standard format.
(on the
VAX
these are word and byte reversed; on the
Sun
they are not
reversed). The include file
Aq Pa netns/ns.h
defines the
NS
address as a structure containing unions (for quicker
comparisons).
Sockets in the Internet protocol family use the following
addressing structure:
struct sockaddr_ns {
short sns_family;
struct ns_addr sns_addr;
char sns_zero[2];
};
where an
ns_addr
is composed as follows:
union ns_host {
u_char c_host[6];
u_short s_host[3];
};
union ns_net {
u_char c_net[4];
u_short s_net[2];
};
struct ns_addr {
union ns_net x_net;
union ns_host x_host;
u_short x_port;
};
Sockets may be created with an address of all zeroes to effect
``wildcard''
matching on incoming messages.
The local port address specified in a
bind(2)
call is restricted to be greater than
NSPORT_RESERVED
(=3000, in
Aq Pa netns/ns.h )
unless the creating process is running
as the super-user, providing a space of protected port numbers.
PROTOCOLS
The
NS
protocol family supported by the operating system
is comprised of
the Internet Datagram Protocol
(IDP
)
idp(4),
Error Protocol (available through
IDP )
and
Sequenced Packet Protocol
(SPP
)
spp(4).
SPP
is used to support the
SOCK_STREAM
and
SOCK_SEQPACKET
abstraction,
while
IDP
is used to support the
SOCK_DGRAM
abstraction.
The Error protocol is responded to by the kernel
to handle and report errors in protocol processing;
it is, however,
only accessible to user programs through heroic actions.
SEE ALSO
intro(3),
byteorder(3),
gethostbyname(3),
getnetent(3),
getprotoent(3),
getservent(3),
ns(3),
intro(4),
spp(4),
idp(4),
nsip(4)
-
"Internet Transport Protocols"
Xerox Corporation document XSIS
028112
-
"An Advanced 4.3 BSD Interprocess Communication Tutorial"
HISTORY
The
options NS
protocol family
appeared in
BSD 4.3
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- ADDRESSING
-
- PROTOCOLS
-
- SEE ALSO
-
- HISTORY
-
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Time: 06:48:30 GMT, May 19, 2025