ng_btsocket (4)
Leading comments
Copyright (c) 2001-2002 Maksim Yevmenkin <m_evmenkin@yahoo.com> All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in t...
NAME
ng_btsocket - Bluetooth sockets layerSYNOPSIS
In sys/types.h In sys/socket.h In sys/bitstring.h In netgraph/bluetooth/include/ng_hci.h In netgraph/bluetooth/include/ng_l2cap.h In netgraph/bluetooth/include/ng_btsocket.hDESCRIPTION
The ifconfig module implements three Netgraph node types. Each type in its turn implements one protocol within PF_BLUETOOTH domain.BLUETOOTH_PROTO_HCI
protocol
SOCK_RAW
HCI sockets
Implemented by
btsock_hci_raw
Netgraph type.
Raw HCI sockets allow sending of raw HCI command datagrams
only to correspondents named in
send(2)
calls.
Raw HCI datagrams (HCI commands, events and data) are generally received with
recvfrom(2),
which returns the next datagram with its return address.
Raw HCI sockets can also be used to control HCI nodes.
The Bluetooth raw HCI socket address is defined as follows:
/* Bluetooth version of struct sockaddr for raw HCI sockets */
struct sockaddr_hci {
u_char hci_len; /* total length */
u_char hci_family; /* address family */
char hci_node[32]; /* address (size == NG_NODESIZ ) */
};
Raw HCI sockets support a number of ioctl(2) requests such as:
- SIOC_HCI_RAW_NODE_GET_STATE
- Returns current state for the HCI node.
- SIOC_HCI_RAW_NODE_INIT
- Turn on ``inited'' bit for the HCI node.
- SIOC_HCI_RAW_NODE_GET_DEBUG
- Returns current debug level for the HCI node.
- SIOC_HCI_RAW_NODE_SET_DEBUG
- Sets current debug level for the HCI node.
- SIOC_HCI_RAW_NODE_GET_BUFFER
- Returns current state of data buffers for the HCI node.
- SIOC_HCI_RAW_NODE_GET_BDADDR
- Returns BD_ADDR for the HCI node.
- SIOC_HCI_RAW_NODE_GET_FEATURES
- Returns the list of features supported by hardware for the HCI node.
- SIOC_HCI_RAW_NODE_GET_STAT
- Returns various statistic counters for the HCI node.
- SIOC_HCI_RAW_NODE_RESET_STAT
- Resets all statistic counters for the HCI node to zero.
- SIOC_HCI_RAW_NODE_FLUSH_NEIGHBOR_CACHE
- Remove all neighbor cache entries for the HCI node.
- SIOC_HCI_RAW_NODE_GET_NEIGHBOR_CACHE
- Returns content of the neighbor cache for the HCI node.
- SIOC_HCI_RAW_NODE_GET_CON_LIST
- Returns list of active baseband connections (i.e., ACL and SCO links) for the HCI node.
- SIOC_HCI_RAW_NODE_GET_LINK_POLICY_MASK
- Returns current link policy settings mask for the HCI node.
- SIOC_HCI_RAW_NODE_SET_LINK_POLICY_MASK
- Sets current link policy settings mask for the HCI node.
- SIOC_HCI_RAW_NODE_GET_PACKET_MASK
- Returns current packet mask for the HCI node.
- SIOC_HCI_RAW_NODE_SET_PACKET_MASK
- Sets current packet mask for the HCI node.
- SIOC_HCI_RAW_NODE_GET_ROLE_SWITCH
- Returns current value of the role switch parameter for the HCI node.
- SIOC_HCI_RAW_NODE_SET_ROLE_SWITCH
- Sets new value of the role switch parameter for the HCI node.
The net.bluetooth.hci.sockets.raw.ioctl_timeout variable, that can be examined and set via sysctl(8), controls the control request timeout (in seconds) for raw HCI sockets.
Raw HCI sockets support filters. The application can filter certain HCI datagram types. For HCI event datagrams the application can set additional filter. The raw HCI socket filter defined as follows:
/*
* Raw HCI socket filter.
*
* For packet mask use (1 << (HCI packet indicator - 1))
* For event mask use (1 << (Event - 1))
*/
struct ng_btsocket_hci_raw_filter {
bitstr_t bit_decl(packet_mask, 32);
bitstr_t bit_decl(event_mask, (NG_HCI_EVENT_MASK_SIZE * 8));
};
The SO_HCI_RAW_FILTER option defined at SOL_HCI_RAW level can be used to obtain via getsockopt(2) or change via setsockopt(2) raw HCI socket's filter.
BLUETOOTH_PROTO_L2CAP
protocol
The Bluetooth L2CAP socket address is defined as follows:
/* Bluetooth version of struct sockaddr for L2CAP sockets */
struct sockaddr_l2cap {
u_char l2cap_len; /* total length */
u_char l2cap_family; /* address family */
uint16_t l2cap_psm; /* Protocol/Service Multiplexor */
bdaddr_t l2cap_bdaddr; /* address */
};
SOCK_RAW
L2CAP sockets
Implemented by
btsock_l2c_raw
Netgraph type.
Raw L2CAP sockets do not provide access to raw L2CAP datagrams.
These
sockets used to control L2CAP nodes and to issue special L2CAP requests
such as
ECHO_REQUEST
and
GET_INFO
request.
Raw L2CAP sockets support number of ioctl(2) requests such as:
- SIOC_L2CAP_NODE_GET_FLAGS
- Returns current state for the L2CAP node.
- SIOC_L2CAP_NODE_GET_DEBUG
- Returns current debug level for the L2CAP node.
- SIOC_L2CAP_NODE_SET_DEBUG
- Sets current debug level for the L2CAP node.
- SIOC_L2CAP_NODE_GET_CON_LIST
- Returns list of active baseband connections (i.e., ACL links) for the L2CAP node.
- SIOC_L2CAP_NODE_GET_CHAN_LIST
- Returns list of active channels for the L2CAP node.
- SIOC_L2CAP_NODE_GET_AUTO_DISCON_TIMO
- Returns current value of the auto disconnect timeout for the L2CAP node.
- SIOC_L2CAP_NODE_SET_AUTO_DISCON_TIMO
- Sets current value of the auto disconnect timeout for the L2CAP node.
- SIOC_L2CAP_L2CA_PING
- Issues L2CAP ECHO_REQUEST
- SIOC_L2CAP_L2CA_GET_INFO
- Issues L2CAP GET_INFO request.
The net.bluetooth.l2cap.sockets.raw.ioctl_timeout variable, that can be examined and set via sysctl(8), controls the control request timeout (in seconds) for raw L2CAP sockets.
SOCK_SEQPACKET
L2CAP sockets
Implemented by
btsock_l2c
Netgraph type.
L2CAP sockets are either
``active''
or
``passive''
Active sockets initiate connections to passive sockets.
By default, L2CAP sockets are created active; to create a passive socket, the
listen(2)
system call must be used after binding the socket with the
bind(2)
system call.
Only passive sockets may use the
accept(2)
call to accept incoming connections.
Only active sockets may use the
connect(2)
call to initiate connections.
L2CAP sockets support ``wildcard addressing'' In this case, socket must be bound to NG_HCI_BDADDR_ANY address. Note that PSM (Protocol/Service Multiplexor) field is always required. Once a connection has been established, the socket's address is fixed by the peer entity's location. The address assigned to the socket is the address associated with the Bluetooth device through which packets are being transmitted and received, and PSM (Protocol/Service Multiplexor).
L2CAP sockets support number of options defined at SOL_L2CAP level which can be set with setsockopt(2) and tested with getsockopt(2):
- SO_L2CAP_IMTU
- Get (set) maximum payload size the local socket is capable of accepting.
- SO_L2CAP_OMTU
- Get maximum payload size the remote socket is capable of accepting.
- SO_L2CAP_IFLOW
- Get incoming flow specification for the socket. Bf -emphasis Not implemented. Ef
- SO_L2CAP_OFLOW
- Get (set) outgoing flow specification for the socket. Bf -emphasis Not implemented. Ef
- SO_L2CAP_FLUSH
- Get (set) value of the flush timeout. Bf -emphasis Not implemented. Ef
BLUETOOTH_PROTO_RFCOMM
protocol
The Bluetooth RFCOMM socket address is defined as follows:
/* Bluetooth version of struct sockaddr for RFCOMM sockets */
struct sockaddr_rfcomm {
u_char rfcomm_len; /* total length */
u_char rfcomm_family; /* address family */
bdaddr_t rfcomm_bdaddr; /* address */
uint8_t rfcomm_channel; /* channel */
};
SOCK_STREAM
RFCOMM sockets
Note that RFCOMM sockets do not have associated Netgraph node type.
RFCOMM sockets are implemented as additional layer on top of L2CAP sockets.
RFCOMM sockets are either
``active''
or
``passive''
Active sockets initiate connections to passive sockets.
By default, RFCOMM sockets are created active; to create a passive socket, the
listen(2)
system call must be used after binding the socket with the
bind(2)
system call.
Only passive sockets may use the
accept(2)
call to accept incoming connections.
Only active sockets may use the
connect(2)
call to initiate connections.
RFCOMM sockets support ``wildcard addressing'' In this case, socket must be bound to NG_HCI_BDADDR_ANY address. Note that RFCOMM channel field is always required. Once a connection has been established, the socket's address is fixed by the peer entity's location. The address assigned to the socket is the address associated with the Bluetooth device through which packets are being transmitted and received, and RFCOMM channel.
The following options, which can be tested with getsockopt(2) call, are defined at SOL_RFCOMM level for RFCOMM sockets:
- SO_RFCOMM_MTU
- Returns the maximum transfer unit size (in bytes) for the underlying RFCOMM channel. Note that application still can write/read bigger chunks to/from the socket.
- SO_RFCOMM_FC_INFO
- Return the flow control information for the underlying RFCOMM channel.
The net.bluetooth.rfcomm.sockets.stream.timeout variable, that can be examined and set via sysctl(8), controls the connection timeout (in seconds) for RFCOMM sockets.