1NS(4F) NS(4F)
2
6 ns - Xerox Network Systems(tm) protocol family
7
9 Not currently supported under 2.11BSD
10
12 The NS protocol family is a collection of protocols layered atop the
13 Internet Datagram Protocol (IDP) transport layer, and using the Xerox
14 NS address formats. The NS family provides protocol support for the
15 SOCK_STREAM, SOCK_DGRAM, SOCK_SEQPACKET, and SOCK_RAW socket types; the
16 SOCK_RAW interface is a debugging tool, allowing you to trace all pack‐
17 ets entering, (or with toggling kernel variable, additionally leaving)
18 the local host.
19
21 NS addresses are 12 byte quantities, consisting of a 4 byte Network
22 number, a 6 byte Host number and a 2 byte port number, all stored in
23 network standard format. (on the VAX these are word and byte reversed;
24 on the Sun they are not reversed). The include file <netns/ns.h>
25 defines the NS address as a structure containing unions (for quicker
26 comparisons).
27 Sockets in the Internet protocol family use the following addressing
29 structure:
30 struct sockaddr_ns {
32 short sns_family;
33 struct ns_addr sns_addr;
34 char sns_zero[2];
35 };
36 where an ns_addr is composed as follows:
38 union ns_host {
40 u_char c_host[6];
41 u_short s_host[3];
42 };
43 union ns_net {
45 u_char c_net[4];
46 u_short s_net[2];
47 };
48 struct ns_addr {
50 union ns_net x_net;
51 union ns_host x_host;
52 u_short x_port;
53 };
54 Sockets may be created with an address of all zeroes to effect ``wild‐
56 card'' matching on incoming messages. The local port address specified
57 in a bind(2) call is restricted to be greater than NSPORT_RESERVED
58 (=3000, in <netns/ns.h>) unless the creating process is running as the
59 super-user, providing a space of protected port numbers.
60
62 The NS protocol family supported by the operating system is comprised
63 of the Internet Datagram Protocol (IDP) idp(4P), Error Protocol (avail‐
64 able through IDP), and Sequenced Packet Protocol (SPP) spp(4P).
65 SPP is used to support the SOCK_STREAM and SOCK_SEQPACKET abstraction,
67 while IDP is used to support the SOCK_DGRAM abstraction. The Error
68 protocol is responded to by the kernel to handle and report errors in
69 protocol processing; it is, however, only accessible to user programs
70 through heroic actions.
71
73 intro(3), byteorder(3N), gethostbyname(3N), getnetent(3N), getpro‐
74 toent(3N), getservent(3N), ns(3N), intro(4N), spp(4P), idp(4P), nsip(4)
75 Internet Transport Protocols, Xerox Corporation document XSIS-028112
76 An Advanced 4.3BSD Interprocess Communication Tutorial
773rd Berkeley Distribution January 27, 1996 NS(4F)