The
node implements the API specified by the ATM Forum for access to ATM services
(see ATM-Forum document
af-saa-0108 )
This document specifies the semantics
of the API, not the exact language binding.
For this reason, it is expected that
this implementation is neither compile-time nor binary compatible with
other implementations of this API.
It should, however, be fairly straightforward
to convert between different API implementations.
This node is usually stacked on top of one or more UNI nodes (see
ng_uni4).
Each of these hooks appears as a
``port''
to the user of the node.
It also has one hook connected to the ILMI daemon for management purposes.
The node is removed when it receives a
NGM_SHUTDOWN
messages or when all hooks are disconnected.
HOOKS
The node understands a number of hooks with predefined names and an
unlimited number of hooks for user connections.
The predefined names are:
uni NNN
These hooks stack the
node on top of a UNI stack.
The node expects the interface on these hooks
to conform to the upper interface specified in
ng_uni4.
These hooks are forced into queuing mode, so that there are no circular
calls from call control to UNI and UNI back to call control.
The
NNN
in the hook name is the decimal port number and should not be zero.
The port number is a 32-bit unsigned integer.
manage
This hook should be connected to the ILMI daemon.
No data is ever sent on this hook and all received data is discarded.
The hook is used to send control messages along.
dump
On receipt of a
NGM_CCATM_DUMP
command a textual description of the current state of the node is sent
out of this hook.
This text is sent as one large message consisting of more
than one
Vt mbuf .
All other hook names are taken to be user hooks and correspond to an
ATM endpoint as specified in the ATM Forum document.
The interface on these hooks is defined in
#include <atmapi.h>
and uses a structure
These codes correspond directly to the operations specified in the ATM
Forum document with the following exceptions:
ATMOP_RESP
As discussed in
ng_uni4,
this is used to
``synchronify''
the interface.
The argument is a
struct atm_resp {
int32_t resp;
uint32_t data; /* type of attached data */
};
If the response code
resp
is zero, the node has accepted the user request.
If something goes wrong,
resp
contains an error code.
For requests that return data,
data
contains a code describing the type of data and the data itself
starts immediately after the structure.
ATMOP_QUERY_CONNECTION_ATTRIBUTES_X
This is the same as
ATMOP_QUERY_CONNECTION_ATTRIBUTES
except that it allows to query several attributes
within one request.
ATMOP_SET_CONNECTION_ATTRIBUTES_X
This is the same as
ATMOP_SET_CONNECTION_ATTRIBUTES
except that it allows to set several attributes
within one request.
The list of attributes is followed directly by the attributes in the same
order as they appear in the list.
If a user hook is disconnected, an active connection on that hook is released.
Incoming connections waiting to be accepted are reoffered to other
listening hooks or rejected.
CONTROL MESSAGES
Besides the generic messages the node understands the following special
messages:
NGM_CCATM_DUMP
This causes the internal state of the node to be dumped in ASCII to the
dump
hook.
NGM_CCATM_STOP
This message causes all connections on that port to be aborted (not released!)
and all ATM endpoints which are bound to that port to be closed.
It stops processing of all messages from the UNI stack on that port UNI stack.
The argument is a
struct ngm_ccatm_port {
uint32_t port;
};
NGM_CCATM_START
Start processing on the port.
The argument is a
Vt ngm_ccatm_port
structure.
NGM_CCATM_CLEAR
This message takes a
Vt ngm_ccatm_port
structure and clears all prefixes and addresses on that port.
If the port number is zero, all ports are cleared.
NGM_CCATM_GET_ADDRESSES
Get the list of all registered addresses on the given port.
The argument is a
Vt ngm_ccatm_port
structure and the result is a
Vt ngm_ccatm_get_addresses
structure:
If the
port
field is zero in the request, all addresses on all ports
are returned.
If it is not zero, only the addresses on that port are reported.
The number of addresses is returned in the
count
field.
NGM_CCATM_ADDRESS_REGISTERED
This message is used by ILMI to inform the
node that a previous address registration request was successful.
This causes the node to activate that address.
The argument to the message is a
Vt ngm_ccatm_address_req
structure.
NGM_CCATM_ADDRESS_UNREGISTERED
This message is used by ILMI to inform the
node that an address has been unregistered.
The node clears that address from its tables.
The argument is a
Vt ngm_ccatm_address_req
structure.
NGM_CCATM_SET_PORT_PARAM
This request sets the parameters on the given port.
The argument is a
struct ngm_ccatm_atm_port {
uint32_t port; /* port for which to set parameters */
uint32_t pcr; /* port peak cell rate */
uint32_t max_vpi_bits;
uint32_t max_vci_bits;
uint32_t max_svpc_vpi;
uint32_t max_svcc_vpi;
uint32_t min_svcc_vci;
uint8_t esi[6];
uint32_t num_addr;
};
This should be used only by ILMI and when that port is stopped and the
address and prefix tables of that port are empty.
The
num_addr
field is ignored.
NGM_CCATM_GET_PORT_PARAM
Retrieve the parameters of the given port.
The argument is a
Vt ngm_ccatm_port
and the result a
Vt ngm_ccatm_atm_port .
NGM_CCATM_GET_PORTLIST
Get a list of all available ports on that node.
This is returned as a
Return the state of a port.
The argument is a
Vt struct ngm_ccatm_port
and the return values as a
Vt uint32_t .
NGM_CCATM_SETLOG
This requests sets a new logging level and returns the previous one.
The argument is either a
Vt uint32_t
in which case it specifies the new logging level, or may be empty
in which case just the old level is returned as a
Vt uint32_t .
NGM_CCATM_RESET
Reset the node.
This is allowed only if the number of user hooks and connected UNI stacks is
zero.
