— Netgraph node type that is also
an H4 line discipline
node type is both a persistent Netgraph node type and a
H4 line discipline. It implements a Bluetooth HCI UART transport layer as per
chapter H4 of the Bluetooth Specification Book v1.1. A new node is created
when the corresponding line discipline,
registered on a tty device (see tty(4)
The node has a single hook called
. Incoming bytes
received on the tty device are re-assembled into HCI frames (according to the
length). Full HCI frames are sent out on the hook. HCI frames received on
are transmitted out on the tty device. No
modification to the data is performed in either direction. While the line
discipline is installed on a tty, the normal read and write operations are
Information about the node is available via the netgraph
command returns a struct nodeinfo
similar to the
This node type supports the following hooks:
- single HCI frame contained in single
This node type supports the generic control messages, plus the following:
- Reset the node.
- Returns current receiving state for the node.
- Returns an integer containing the current debug level for
- This command takes an integer argument and sets current
debug level for the node.
- Returns current length of outgoing queue for the node.
- This command takes an integer argument and sets maximum
length of outgoing queue for the node.
- Returns various statistic information for the node, such
as: number of bytes (frames) sent, number of bytes (frames) received and
number of input (output) errors.
- Reset all statistic counters to zero.
This node shuts down when the corresponding device is closed (or the line
discipline is uninstalled on the device).
node type was implemented in FreeBSD
This node still uses spltty(9)
to lock tty layer. This is