diameter_tcp
(diameter)Diameter transport over TCP.
This module implements diameter transport over TCP using gen_tcp. It can be specified as the value of a transport_module option to diameter:add_transport/2 and implements the behaviour documented in diameter_transport(3). TLS security is supported, both as an upgrade following capabilities exchange as specified by RFC 3588 and at connection establishment as in the current draft standard.
Note that the ssl application is required for TLS and must be started before configuring TLS capability on diameter transports.
Functions
start({Type, Ref}, Svc, [Opt]) -> {ok, Pid, [LAddr]} | {error, Reason}
Type = connect | accept
Ref = reference()
Svc = #diameter_service{}
Opt = OwnOpt | SslOpt | OtherOpt
Pid = pid()
LAddr = ip_address()
Reason = term()
OwnOpt = {raddr, ip_address()} | {rport, integer()} | {port, integer()}
SslOpt = {ssl_options, true | list()}
OtherOpt = term()
The start function required by diameter_transport(3).
The only diameter_tcp-specific argument is the options list.
Options raddr
and rport
specify the remote address
and port for a connecting transport and are not valid for a listening
transport.
Option ssl_options
must be specified for a transport
that must be able to support TLS: a value of true
results in a
TLS handshake immediately upon connection establishment while
list() specifies options to be passed to ssl:connect/2 of ssl:ssl_accept/2
after capabilities exchange if TLS is negotiated.
Remaining options are any accepted by ssl:connect/3 or gen_tcp:connect/3 for
a connecting transport, or ssl:listen/3 or gen_tcp:listen/2 for
a listening transport, depending on whether or not {ssl_options, true}
has been specified.
Options binary
, packet
and active
cannot be specified.
Also, option port
can be specified for a listening transport
to specify the local listening port, the default being the standardized
3868 if unspecified.
Note that option ip
specifies the local address.
An ssl_options
list must be specified if and only if
the transport in question has specified an Inband-Security-Id
AVP with value TLS on the relevant call to
start_service/2 or
add_transport/2,
so that the transport process will receive notification of
whether or not to commence with a TLS handshake following capabilities
exchange.
Failing to specify an options list on a TLS-capable transport
for which TLS is negotiated will cause TLS handshake to fail.
Failing to specify TLS capability when ssl_options
has been
specified will cause the transport process to wait for a notification
that will not be forthcoming, which will eventually cause the RFC 3539
watchdog to take down the connection.
If the service specifies more than one Host-IP-Address and
option ip
is unspecified then then the
first of the service's addresses is used as the local address.
The returned local address list has length one.