The
netconfig
file defines a list of
"transport names",
describing their semantics and protocol.
In
FreeBSD ,
this file is only used by the RPC library code.
Entries have the following format:
network_id semantics flags family protoname device libraries
Entries consist of the following fields:
|
| network_id
|
| |
The name of the transport described.
|
| semantics
|
Describes the semantics of the transport.
This can be one of:
|
|
| tpi_clts
|
Connectionless transport.
|
| tpi_cots
|
Connection-oriented transport
|
| tpi_cots_ord
|
| |
Connection-oriented, ordered transport.
|
| tpi_raw
|
A raw connection.
|
|
| flags
|
This field is either blank (specified by
"-"),
or contains one or more of the following characters:
|
|
| b
|
The network represented by this entry is broadcast capable.
This flag is meaningless in
FreeBSD .
|
| v
|
The entry may be returned by the
getnetpath(3)
function.
|
|
| family
|
| |
The protocol family of the transport.
This is currently one of:
|
|
| inet6
|
The IPv6
( PF_INET6)
family of protocols.
|
| inet
|
The IPv4
( PF_INET)
family of protocols.
|
| loopback
|
| |
The
PF_LOCAL
protocol family.
|
|
| protoname
|
| |
The name of the protocol used for this transport.
Can currently be either
udp,
tcp
or empty.
|
| device
|
This field is always empty in
FreeBSD .
|
| libraries
|
| |
This field is always empty in
FreeBSD .
|
|
The order of entries in this file will determine which transport will
be preferred by the RPC library code, given a match on a specified
network type.
For example, if a sample network config file would look like this:
udp6 tpi_clts v inet6 udp - -
tcp6 tpi_cots_ord v inet6 tcp - -
udp tpi_clts v inet udp - -
tcp tpi_cots_ord v inet tcp - -
rawip tpi_raw - inet - - -
local tpi_cots_ord - loopback - - -
then using the network type
udp
in calls to the RPC library function (see
rpc(3))
will make the code first try
udp6,
and then
udp.
getnetconfig(3)
and associated functions will parse this file and return structures of
the following format:
struct netconfig {
char *nc_netid; /* Network ID */
unsigned long nc_semantics; /* Semantics */
unsigned long nc_flag; /* Flags */
char *nc_protofmly; /* Protocol family */
char *nc_proto; /* Protocol name */
char *nc_device; /* Network device pathname (unused) */
unsigned long nc_nlookups; /* Number of lookup libs (unused) */
char **nc_lookups; /* Names of the libraries (unused) */
unsigned long nc_unused[9]; /* reserved */
};
