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).