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fix(ndef): flesh out ble oob ndef record
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* Add public address type to mac address field
* Add flags EIR and update eir to handle flags field
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finger563 committed Oct 10, 2023
1 parent 975b537 commit 442e5e6
Showing 1 changed file with 20 additions and 17 deletions.
37 changes: 20 additions & 17 deletions components/ndef/include/ndef.hpp
Original file line number Diff line number Diff line change
Expand Up @@ -502,26 +502,19 @@ class Ndef {
// https://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf
// for examples

// optional local name (0x09)
// TODO: making this the first field ensures android displays it
if (name.size() > 0) {
add_bt_eir(data, BtEir::LONG_LOCAL_NAME, name);
}

// (mandatory 0x1B) LE device address in reverse order. According to section
// 3.3.1 of NFCForum-AD-BTSSP_1_1.pdf, the data value consists of 7 octets,
// with the 6 least significant octets being the MAC address in reverse
// order. The least significant bit in the most significant octet is the
// random address bit.
uint8_t mac_addr_bytes[] = {
(uint8_t)(mac_addr >> 0 & 0xFF), (uint8_t)(mac_addr >> 8 & 0xFF),
(uint8_t)(mac_addr >> 16 & 0xFF), (uint8_t)(mac_addr >> 24 & 0xFF),
(uint8_t)(mac_addr >> 32 & 0xFF), (uint8_t)(mac_addr >> 40 & 0xFF),
// NOTE: according to the doc (see above) the
// mac address field examples contain an
// extra byte, but adding it causes
// android to fail to parse this
// (uint8_t)(0x01)
(uint8_t)(mac_addr >> 0 & 0xFF),
(uint8_t)(mac_addr >> 8 & 0xFF),
(uint8_t)(mac_addr >> 16 & 0xFF),
(uint8_t)(mac_addr >> 24 & 0xFF),
(uint8_t)(mac_addr >> 32 & 0xFF),
(uint8_t)(mac_addr >> 40 & 0xFF),
(uint8_t)(0x00) // Public address type
};
add_bt_eir(data, BtEir::MAC,
std::string_view{(const char *)&mac_addr_bytes[0], sizeof(mac_addr_bytes)});
Expand Down Expand Up @@ -553,10 +546,17 @@ class Ndef {
add_bt_eir(data, BtEir::APPEARANCE,
std::string_view{(const char *)&appearance_bytes[0], sizeof(appearance_bytes)});

// optional local name (0x09)
if (name.size() > 0) {
add_bt_eir(data, BtEir::LONG_LOCAL_NAME, name);
}

// optional Flags (0x01)
// uint8_t flags_bytes[] = {0x06}; // BR/EDR not supported, LE supported, Simultaneous LE/BT to
// same device capable (controller) add_bt_eir(data, BtEir::FLAGS, std::string_view{(const
// char*)&flags_bytes[0], sizeof(flags_bytes)});
// 0x06: BR/EDR not supported, LE supported, Simultaneous LE/BT to same
// device capable (controller)
uint8_t flags_bytes[] = {0x06};
add_bt_eir(data, BtEir::FLAGS,
std::string_view{(const char *)&flags_bytes[0], sizeof(flags_bytes)});

auto sv_data = std::string_view{(const char *)data.data(), data.size()};
return Ndef(TNF::MIME_MEDIA, "application/vnd.bluetooth.le.oob", sv_data);
Expand Down Expand Up @@ -715,6 +715,9 @@ class Ndef {
case BtEir::UUIDS_128_BIT_COMPLETE:
num_eir_bytes = payload.size();
break;
case BtEir::FLAGS:
num_eir_bytes = 1;
break;
case BtEir::SHORT_LOCAL_NAME:
case BtEir::LONG_LOCAL_NAME:
num_eir_bytes = payload.size();
Expand Down

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