NAME

       hci - Bluetooth HCI protocol

SYNOPSIS

          #include <sys/socket.h>
          #include <bluetooth/bluetooth.h>
          #include <bluetooth/hci.h>

          hci_socket = socket(PF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);

DESCRIPTION

       Bluetooth  Host  Controller  Interface  (HCI)  is  the  standard  protocol  to communicate with Bluetooth
       adapters. HCI protocol provides a uniform command method for the Host to access  Controller  capabilities
       and to control connections to other Controllers.

SOCKET ADDRESS

          struct sockaddr_hci {
              sa_family_t    hci_family;
              unsigned short hci_dev;
              unsigned short hci_channel;
          };

       Possible values for hci_channel:
                            ┌─────────────────────┬───────┬──────────────────────────────┐
                            │ Define              │ Value │ Description                  │
                            ├─────────────────────┼───────┼──────────────────────────────┤
                            │ HCI_CHANNEL_RAW     │ 0x00  │ Raw  channel  - Used for raw │
                            │                     │       │ HCI communication            │
                            ├─────────────────────┼───────┼──────────────────────────────┤
                            │ HCI_CHANNEL_USER    │ 0x01  │ User  channel  -  Used   for │
                            │                     │       │ userspace  HCI communication │
                            │                     │       │ (disables kernel processing) │
                            ├─────────────────────┼───────┼──────────────────────────────┤
                            │ HCI_CHANNEL_MONITOR │ 0x02  │ Monitor channel -  Used  for │
                            │                     │       │ monitoring    HCI    traffic │
                            │                     │       │ (btmon(1))                   │
                            ├─────────────────────┼───────┼──────────────────────────────┤
                            │ HCI_CHANNEL_CONTROL │ 0x03  │ Control channel  -  Used  to │
                            │                     │       │ manage     local    adapters │
                            │                     │       │ (bluetoothd(7))              │
                            ├─────────────────────┼───────┼──────────────────────────────┤
                            │ HCI_CHANNEL_LOGGING │ 0x04  │ Logging channel  -  Used  to │
                            │                     │       │ inject    logging   messages │
                            │                     │       │ (bluetoothd(7))              │
                            └─────────────────────┴───────┴──────────────────────────────┘

       Example:

          struct sockaddr_hci addr;

          memset(&addr, 0, sizeof(addr));
          addr.hci_family = AF_BLUETOOTH;
          addr.hci_dev = HCI_DEV_NONE;
          addr.hci_channel = HCI_CHANNEL_CONTROL;

SOCKET OPTIONS

       The socket options listed below can be set by using setsockopt(2) and read with  getsockopt(2)  with  the
       socket level set to SOL_BLUETOOTH or SOL_HCI (HCI_FILTER).

   HCI_FILTER (since Linux 2.6)
       Filter by HCI events, requires hci_channel to be set to HCI_CHANNEL_RAW, possible values:

          struct hci_filter {
              uint32_t type_mask;
              uint32_t event_mask[2];
              uint16_t opcode;
          };

       Example:

          struct hci_filter flt;

          memset(&flt, 0, sizeof(flt));
          flt.type_mask = 1 << BT_H4_EVT_PKT;
          flt.event_mask[0] = 0xffffffff;
          flt.event_mask[1] = 0xffffffff;

          setsockopt(fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt));

   BT_SNDBUF (since Linux 5.16)
       Set  send  buffer  size,  requires  hci_channel  to be set to HCI_CHANNEL_MONITOR, HCI_CHANNEL_CONTROL or
       HCI_CHANNEL_LOGGING.

       Default value is 1028.

       Example:

          uint16_t mtu = UINT16_MAX;
          int err;

          err = setsockopt(fd, SOL_BLUETOOTH, BT_SNDMTU, &mtu, sizeof(mtu));

   BT_RCVBUF (since Linux 5.16)
       Set receive buffer size, requires hci_channel to be set to  HCI_CHANNEL_MONITOR,  HCI_CHANNEL_CONTROL  or
       HCI_CHANNEL_LOGGING.

       Default value is 1028.

       Example:

          uint16_t mtu;
          socklen_t len;
          int err;

          len = sizeof(mtu);
          err = getsockopt(sock, SOL_BLUETOOTH, BT_RCVMTU, mtu, &len);

RESOURCES

        <http://www.bluez.org>

REPORTING BUGS

        <linux-bluetooth@vger.kernel.org>

SEE ALSO

       socket(7)

COPYRIGHT

       Free use of this software is granted under ther terms of the GNU Lesser General Public Licenses (LGPL).

BlueZ                                             October 2024                                            HCI(7)