ng_uni -- netgraph UNI node type
#include <netnatm/sig/unidef.h>
#include <netgraph/atm/ng_uni.h>
The ng_uni netgraph node implements ATM Forum signalling 4.0.
After creation of the node, the UNI instance must be created by sending
an enable message to the node. If the node is enabled, the UNI parameters
can be retrieved and modified and the protocol can be started.
The node is shutdown either by a NGM_SHUTDOWN message or when all hooks
are disconnected.
Each ng_uni node has three hooks with fixed names:
lower
This hook is the interface of the UNI protocol to the transport
layer of the ATM control plane. The node expectes the interface
exported by ng_sscfu(4) at this hook.
upper
This hook is the `user' interface of the UNI protocol. Because
there is no standardized interface at this point, this implementation
follows more or less the interface specified by the SDL diagrams
in ITU-T recommendations Q.2931 and Q.2971. Normally either a
ng_ccatm(4) or a switch CAC should be stacked at this interface.
The message format at the upper hook is described below. Because is
functional, it makes sometimes sense to switch this hook to queueing
mode from the peer node upon connection.
The upper interface of the ng_uni node is loosely modelled after the
interface specified in the ITU-T signalling standards. There is however
one derivation from this: normally there exists four kinds of signals:
requests, responses, indications and confirmations. These signals are
usually triggered either by external events (receiving a message) or
internal events (a timer or another signal). This scheme works fine for
user APIs that are entirely asynchronuous and in cases, where error handling
is not taken into account. With synchronuous APIs and error handling,
however there is a problem. If, for example, the application
issues a request to setup a connection. It may do it by sending a
SETUP.request signal to the UNI. Normally the UNI stack will send a SETUP
message and receive a message from the switch (a RELEASE, CONNECT,
CALL PROCEEDING or ALERTING) or a timer in the UNI stack will time out.
In any of these cases the UNI stack is supposed to report an event back
to the application and the application will unblock (in the case of a
synchronuous API) and handle the event. The problem occurs, when an
error happens. Suppose there is no memory to send the SETUP message and
to start the timer. In this case the application will block forever,
because no received message and no timer will wake it up. For this reason
this implementation uses an additional message: for each signal sent
from the application to the stack, the stack will respond with an error
code. If this code is zero, the stack has accepted the signal and the
application may block, if the code is non-zero, the signal is effectivly
ignored and the code describes, what was wrong. This system makes it
very easy to make a blocking interface out of the message based netgraph
interface.
The upper interface uses the following structure:
struct uni_arg {
uint32_t sig;
uint32_t cookie;
u_char data[];
};
The sig field contains the actual signal that is sent from the user to
UNI or the UNI to the user. The cookie can be used by the user to correlate
requests with events and responses. If an error response, a confirmation
or an indication was triggered by a request or response, the
cookie from that request or response is carried in the message from the
stack to the user. The cookie field is followed by the actual data for
the signal.
The signal is one of the following:
enum uni_sig {
UNIAPI_ERROR, /* UNI -> API */
UNIAPI_CALL_CREATED, /* UNI -> API */
UNIAPI_CALL_DESTROYED, /* UNI -> API */
UNIAPI_PARTY_CREATED, /* UNI -> API */
UNIAPI_PARTY_DESTROYED, /* UNI -> API */
UNIAPI_LINK_ESTABLISH_request, /* API -> UNI */
UNIAPI_LINK_ESTABLISH_confirm, /* UNI -> API */
UNIAPI_LINK_RELEASE_request, /* API -> UNI */
UNIAPI_LINK_RELEASE_confirm, /* UNI -> API */
UNIAPI_RESET_request, /* API -> UNI */
UNIAPI_RESET_confirm, /* UNI -> API */
UNIAPI_RESET_indication, /* UNI -> API */
UNIAPI_RESET_ERROR_indication, /* UNI -> API */
UNIAPI_RESET_response, /* API -> UNI */
UNIAPI_RESET_ERROR_response, /* API -> UNI */
UNIAPI_RESET_STATUS_indication, /* UNI -> API */
UNIAPI_SETUP_request, /* API -> UNI */
UNIAPI_SETUP_indication, /* UNI -> API */
UNIAPI_SETUP_response, /* API -> UNI */
UNIAPI_SETUP_confirm, /* UNI -> API */
UNIAPI_SETUP_COMPLETE_indication, /* UNI -> API */
UNIAPI_ALERTING_request, /* API -> UNI */
UNIAPI_ALERTING_indication, /* UNI -> API */
UNIAPI_PROCEEDING_request, /* API -> UNI */
UNIAPI_PROCEEDING_indication, /* UNI -> API */
UNIAPI_RELEASE_request, /* API -> UNI */
UNIAPI_RELEASE_indication, /* UNI -> API */
UNIAPI_RELEASE_response, /* API -> UNI */
UNIAPI_RELEASE_confirm, /* UNI -> API */
UNIAPI_NOTIFY_request, /* API -> UNI */
UNIAPI_NOTIFY_indication, /* UNI -> API */
UNIAPI_STATUS_indication, /* UNI -> API */
UNIAPI_STATUS_ENQUIRY_request, /* API -> UNI */
UNIAPI_ADD_PARTY_request, /* API -> UNI */
UNIAPI_ADD_PARTY_indication, /* UNI -> API */
UNIAPI_PARTY_ALERTING_request, /* API -> UNI */
UNIAPI_PARTY_ALERTING_indication, /* UNI -> API */
UNIAPI_ADD_PARTY_ACK_request, /* API -> UNI */
UNIAPI_ADD_PARTY_ACK_indication, /* UNI -> API */
UNIAPI_ADD_PARTY_REJ_request, /* API -> UNI */
UNIAPI_ADD_PARTY_REJ_indication, /* UNI -> API */
UNIAPI_DROP_PARTY_request, /* API -> UNI */
UNIAPI_DROP_PARTY_indication, /* UNI -> API */
UNIAPI_DROP_PARTY_ACK_request, /* API -> UNI */
UNIAPI_DROP_PARTY_ACK_indication, /* UNI -> API */
UNIAPI_ABORT_CALL_request, /* API -> UNI */
UNIAPI_MAXSIG
};
The meaning of most of the signals can be deduced from the ITU-T SDLs. A
number of signals, however, is unique to this implementation:
UNIAPI_ERROR
This is the error response, mentioned earlier. It carries an error
code or zero, if the signal was accepted by the stack.
UNIAPI_CALL_CREATED
The UNI stack has created a call instance either from an incoming
SETUP or from the user requesting an outgoing SETUP. This may be
used to synchronize the creation and destroying of call data between
the UNI stack and the user.
UNIAPI_CALL_DESTROYED
An call instance has been destroyed and all resources have been
freed.
UNIAPI_PARTY_CREATED
A new party has been created for an existing point-to-multipoint
call. This may be used to synchronize the creation and destroying
of party data between the UNI stack and the user.
UNIAPI_PARTY_DESTROYED
A party has been destroyed and all resources have been freed.
UNIAPI_ABORT_CALL_request
The requests the stack to destroy the call instance and free all
it's resources without sending any messages to the network.
UNIAPI_MAXSIG
This is not a signal, but rather a definition to get the number of
defined signals.
Each of the signals is followed by a fixed size structure defined in
unidef.h.
The ng_uni node understands the standard control messages plus the following:
NGM_UNI_SETDEBUG
Set debugging facility levels. The UNI stack defines a number of
debugging facilities, each one associated with a debugging level.
If the debugging level of a facility is non-zero, text output will
be generated to the console. The message uses the following structure:
struct ngm_uni_debug {
uint32_t level[UNI_MAXFACILITY];
};
NGM_UNI_SETDEBUG
Get debugging facility levels. This returns a ngm_uni_debug structure.
NGM_UNI_GET_CONFIG
Retrieve the current configuration of the UNI instance. This message
returns a uni_config structure:
struct uni_config {
uint32_t proto; /* which protocol */
uint32_t popt; /* protocol option */
uint32_t option; /* other options */
uint32_t timer301; /* T301 */
uint32_t timer303; /* T303 */
uint32_t init303; /* T303 retransmission count */
uint32_t timer308; /* T308 */
uint32_t init308; /* T308 retransmission count */
uint32_t timer309; /* T309 */
uint32_t timer310; /* T310 */
uint32_t timer313; /* T313 */
uint32_t timer316; /* T316 */
uint32_t init316; /* T316 retransmission count */
uint32_t timer317; /* T317 */
uint32_t timer322; /* T322 */
uint32_t init322; /* T322 retransmission count */
uint32_t timer397; /* T397 */
uint32_t timer398; /* T398 */
uint32_t timer399; /* T399 */
};
The field proto specifies one of the following protocols:
enum uni_proto {
UNIPROTO_UNI40U, /* UNI4.0 user side */
UNIPROTO_UNI40N, /* UNI4.0 network side */
UNIPROTO_PNNI10, /* PNNI1.0 */
};
Some protocols may have options which can be set in popt:
enum uni_popt {
UNIPROTO_GFP, /* enable GFP */
};
The option field controls parsing and checking of messages:
enum uni_option {
UNIOPT_GIT_HARD, /* harder check of GIT IE */
UNIOPT_BEARER_HARD, /* harder check of BEARER IE */
UNIOPT_CAUSE_HARD, /* harder check of CAUSE IE */
};
All timer values are given in milliseconds. Note, however, that the
actual resolution of the timers depend on system configuration (see
timeout(9) ).
NGM_UNI_SET_CONFIG
Change the UNI configuration. This takes a
struct ngm_uni_set_config {
struct uni_config config;
struct ngm_uni_config_mask mask;
};
struct ngm_uni_config_mask {
uint32_t mask;
uint32_t popt_mask;
uint32_t option_mask;
};
The fields of the ngm_uni_config_mask specify which configuration
parameter to change. The mask field contains bit definitions for
all timers, retransmission counters and the proto field, popt_mask
selects which of the protocol options to change and option_mask
specifies which options should be changed. The following bits are
defined:
enum uni_config_mask {
UNICFG_PROTO,
UNICFG_TIMER301,
UNICFG_TIMER303,
UNICFG_INIT303,
UNICFG_TIMER308,
UNICFG_INIT308,
UNICFG_TIMER309,
UNICFG_TIMER310,
UNICFG_TIMER313,
UNICFG_TIMER316,
UNICFG_INIT316,
UNICFG_TIMER317,
UNICFG_TIMER322,
UNICFG_INIT322,
UNICFG_TIMER397,
UNICFG_TIMER398,
UNICFG_TIMER399,
};
For the popt_mask and option_mask the definitions from enum uni_popt
and enum uni_option should be used.
NGM_UNI_ENABLE
Create the UNI instance and enable processing. Before the UNI is
enabled parameters cannot be retrieved or set.
NGM_UNI_DISABLE
Destroy the UNI instance and free all resources. Note, that connections
are not released.
netgraph(4), ng_atm(4), ng_sscfu(4), ng_sscop(4), ngctl(8)
+o LIJ (leaf-initiated-join) is not implemented yet.
+o GFP (generic functional protocol, Q.2932.1) is not yet implemented.
+o More testing needed.
+o PNNI not yet implemented.
+o Need to implement connection modification and the Q.2931 amandements.
The ng_uni netgraph node and this manual page was written by Harti Brandt
<harti@freebsd.org>
FreeBSD October 6, 2003 FreeBSD
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