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ng_atm(4)

NAME

     ng_atm -- netgraph ATM node type

SYNOPSIS

     #include <net/if_atm.h>
     #include <netgraph/ng_atm.h>

DESCRIPTION

     The atm netgraph node type allows natm(4) ATM drivers to be connected to
     the netgraph(4) networking subsystem.  When the ng_atm module is loaded a
     node is automatically created for each natm(4) ATM interface.  The nodes
     are named with the same name as the interface.  Nodes are also created if
     a driver for an ATM card is loaded after ng_atm was loaded.

     The atm nodes are persistent.  They are removed when the interface is
     removed.  NGM_SHUTDOWN messages are ignored by the node.

HOOKS

     Four special hooks with fixed names and an unlimited number of hooks with
     user defined names are supported.	Three of the fixed hooks are attached
     to strategic points in the information flow in the natm(4) system and
     support only reading.  The fourth fixed hook behaves like the other user
     hooks, but a number of management messages are sent along the hook.  The
     other hooks can be attached to VCIs dynamically by means of control mes-
     sages to the atm node and can be written and read.

     The four fixed hooks are:

     input    This is a connection to the raw input stream from the network.
	      If this hook is connected, all incoming packets are delivered
	      out to this hook.  Note that this redirects ALL input.  Neither
	      natm(4) nor the user hooks will see any input if input is con-
	      nected.  An atm_pseudohdr (see natm(4)) is prepended to the
	      actual data.

     output   This is a connection to the raw output stream to the network
	      device.  If this hook is connected, all outgoing packets are
	      handed over to the netgraph system and delivered to the hook
	      instead of being delivered to the ATM driver.  An atm_pseudohdr
	      (see natm(4)) is prepended to the actual data.

     orphans  This hook receives all packets that are unrecognized, i.e., do
	      not belong to either a natm(4) socket, a ng_atm VCI or natm(4)
	      IP.  Because ATM is connection oriented and packets are received
	      on a given VCI only when someone initiates this VCI, packets
	      should never be orphaned.  There is however one exception: if
	      you use natm(4) IP with LLC/SNAP encapsulation packets with do
	      not have the IP protocol indicated in the packet header are
	      delivered out of this hook.  An atm_pseudohdr (see natm(4)) is
	      prepended to the actual data send out to the hook.

     manage   This hook behaves exactly like a normal user hook (see below)
	      except that the node at the other hand will receive management
	      messages.

     Hooks for dynamically initiated VCIs can have whatever name is allowed by
     netgraph(4) as long as the name does not collide with one of the three

CONTROL MESSAGES

     This node type supports the generic messages plus the following:

     NGM_ATM_GET_IFNAME
	   Return the name of the interface as a NUL-terminated string.  This
	   is normally the same name as that of the node.

     NGM_ATM_GET_CONFIG
	   Returns a structure defining the configuration of the interface:

	   struct ng_atm_config {
		   uint32_t	   pcr; 	   /* peak cell rate */
		   uint32_t	   maxvpi;	   /* maximum vpi */
		   uint32_t	   maxvci;	   /* maximum vci */
		   uint32_t	   max_vpcs;	   /* maximum number of VPCs */
		   uint32_t	   max_vccs;	   /* maximum number of VCCs */
	   };

     NGM_ATM_GET_VCCS
	   Returns the table of open VCCs from the driver.  This table con-
	   sists of a header and a variable sized array of entries, one for
	   each open VCC:

	   struct atmio_vcctable {
		   uint32_t	   count;	   /* number of vccs */
		   struct atmio_vcc vccs[0];	   /* array of VCCs */
	   };
	   struct atmio_vcc {
		   uint16_t	   flags;	   /* flags */
		   uint16_t	   vpi; 	   /* VPI */
		   uint16_t	   vci; 	   /* VCI */
		   uint16_t	   rmtu;	   /* Receive maximum CPCS size */
		   uint16_t	   tmtu;	   /* Transmit maximum CPCS size */
		   uint8_t	   aal; 	   /* aal type */
		   uint8_t	   traffic;	   /* traffic type */
		   struct atmio_tparam tparam;	   /* traffic parameters */
	   };
	   struct atmio_tparam {
		   uint32_t	   pcr;    /* 24bit: Peak Cell Rate */
		   uint32_t	   scr;    /* 24bit: VBR Sustainable Cell Rate */
		   uint32_t	   mbs;    /* 24bit: VBR Maximum burst size */
		   uint32_t	   mcr;    /* 24bit: MCR */
		   uint32_t	   icr;    /* 24bit: ABR ICR */
		   uint32_t	   tbe;    /* 24bit: ABR TBE (1...2^24-1) */
		   uint8_t	   nrm;    /*  3bit: ABR Nrm */
		   uint8_t	   trm;    /*  3bit: ABR Trm */
		   uint16_t	   adtf;   /* 10bit: ABR ADTF */
		   uint8_t	   rif;    /*  4bit: ABR RIF */
		   uint8_t	   rdf;    /*  4bit: ABR RDF */
		   uint8_t	   cdf;    /*  3bit: ABR CDF */
	   };

	   Note that this is the driver's table, so all VCCs opened via
	   natm(4) sockets and IP are also shown.  They can, however, be dis-
	   tinguished by their flags.  The flags field contains the following
	   flags:

		 ATM_PH_AAL5	 use AAL5 instead of AAL0
	   meaningful information.

	   The aal field contains one of the following values:

		 ATMIO_AAL_0	 AAL 0 (raw cells)
		 ATMIO_AAL_34	 AAL 3 or AAL 4
		 ATMIO_AAL_5	 AAL 5
		 ATMIO_AAL_RAW	 device specific raw cells

	   The traffic field can have one of the following values (not all
	   drivers support all traffic types however):

		 ATMIO_TRAFFIC_UBR
		 ATMIO_TRAFFIC_CBR
		 ATMIO_TRAFFIC_ABR
		 ATMIO_TRAFFIC_VBR

     NGM_ATM_CPCS_INIT
	   Initialize a VCC for sending and receiving.	The argument is a
	   structure:

	   struct ng_atm_cpcs_init {
		   char 	   name[NG_HOOKSIZ];
		   uint32_t	   flags;	   /* flags. (if_natmio.h) */
		   uint16_t	   vci; 	   /* VCI to open */
		   uint16_t	   vpi; 	   /* VPI to open */
		   uint16_t	   rmtu;	   /* receive maximum PDU */
		   uint16_t	   tmtu;	   /* transmit maximum PDU */
		   uint8_t	   aal; 	   /* AAL type (if_natmio.h) */
		   uint8_t	   traffic;	   /* traffic type (if_natmio.h) */
		   uint32_t	   pcr; 	   /* Peak cell rate */
		   uint32_t	   scr; 	   /* Sustainable cell rate */
		   uint32_t	   mbs; 	   /* Maximum burst size */
		   uint32_t	   mcr; 	   /* Minimum cell rate */
		   uint32_t	   icr; 	   /* ABR: Initial cell rate */
		   uint32_t	   tbe; 	   /* ABR: Transmit buffer exposure */
		   uint8_t	   nrm; 	   /* ABR: Nrm */
		   uint8_t	   trm; 	   /* ABR: Trm */
		   uint16_t	   adtf;	   /* ABR: ADTF */
		   uint8_t	   rif; 	   /* ABR: RIF */
		   uint8_t	   rdf; 	   /* ABR: RDF */
		   uint8_t	   cdf; 	   /* ABR: CDF */
	   };

	   The name field is the name of the hook for which sending and
	   receiving should be enabled.  This hook must already be connected.
	   The vpi and vci fields are the respective VPI and VCI values to use
	   for the ATM cells.  They must be within the range, given by the
	   maxvpi and maxvci fields of the ng_atm_config structure.  The flags
	   field contains the flags (see above) and the other fields describe
	   the type of traffic.

     NGM_ATM_CPCS_TERM
	   Stop sending and receiving on the indicated hook.  The argument is
	   a

	   struct ng_atm_cpcs_term {
		   char 	   name[NG_HOOKSIZ];

	   message has the following structure:

	   struct ng_atm_carrier_change {
		   uint32_t	   node;
		   uint32_t	   state;
	   };

	   The node field is the node ID of the ATM node.  This can be used by
	   the managing entity (for example ilmid(8)) to manage several inter-
	   faces at the same time through the same node.  The state field is 1
	   if the carrier was detected, and 0 if it was lost.

     NGM_ATM_VCC_CHANGE
	   A permanent VCC has been added, deleted or changed.	This is used
	   by ilmid(8) to generate the appropriate ILMI traps.	The structure
	   of the message is:

	   struct ng_atm_vcc_change {
		   uint32_t	   node;
		   uint16_t	   vci;
		   uint8_t	   vpi;
		   uint8_t	   state;
	   };
	   Where state is 0 if the PVC was deleted, and 1 if it was added or
	   modified.

FLOW CONTROL

     If the hardware driver supports it, the node can emit flow control mes-
     sages along a user hook.  The format of these messages is described in
     <netgraph/ng_message.h>.  The atm node may generate NGM_HIGH_WATER_PASSED
     and NGM_LOW_WATER_PASSED messages.  The first one indicates that the
     hardware driver has stopped output on the channel and drops new packets,
     the second one reports that output was reenabled.	Currently, the struc-
     tures are not filled with information.

SHUTDOWN

     The nodes are persistent as long as the corresponding interface exists.
     Upon receipt of a NGM_SHUTDOWN messages, all hooks are disconnected and
     the node is reinitialized.  All VCCs opened via netgraph(4) are closed.
     When the ATM interface is unloaded, the node disappears.  If the node is
     compiled with NGATM_DEBUG there is a sysctl net.graph.atm.allow_shutdown
     which, when set to a non-zero value, allows the nodes to shut down.  Note
     that this is intended for development only and may lead to kernel panics
     if set.

SEE ALSO

     natm(4), netgraph(4), ng_ether(4), ngctl(8)

AUTHORS

     Harti Brandt <harti@FreeBSD.org>

FreeBSD 5.4			 June 24, 2003			   FreeBSD 5.4

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