extmod/bluetooth: Add gap_unpair() for all BLE backends.

docs/library/bluetooth.rst

@@ -733,6 +733,19 @@ Pairing and bonding
 
     On successful pairing, the ``_IRQ_ENCRYPTION_UPDATE`` event will be raised.
 
+.. method:: BLE.gap_unpair([addr_type, addr, /])
+
+    Remove bond information from persistent storage. If *addr_type* and *addr*
+    are provided, removes the bond for that specific peer. If called with no
+    arguments, removes all bonds. The address can be obtained from the
+    ``_IRQ_CENTRAL_CONNECT`` or ``_IRQ_PERIPHERAL_CONNECT`` events.
+
+    When removing a specific peer, raises ``OSError(ENOENT)`` if no matching
+    bond exists.
+
+    **Note:** The peer should be disconnected before calling ``gap_unpair``.
+    Behaviour when the peer is still connected is backend-dependent.
+
 .. method:: BLE.gap_passkey(conn_handle, action, passkey, /)
 
     Respond to a ``_IRQ_PASSKEY_ACTION`` event for the specified *conn_handle*

extmod/btstack/modbluetooth_btstack.c

@@ -1265,6 +1265,27 @@ int mp_bluetooth_gap_pair(uint16_t conn_handle) {
     return 0;
 }
 
+int mp_bluetooth_gap_unpair(uint8_t addr_type, const uint8_t *addr) {
+    DEBUG_printf("mp_bluetooth_gap_unpair: addr=%p\n", addr);
+    int count = le_device_db_max_count();
+    for (int i = 0; i < count; i++) {
+        int entry_type;
+        bd_addr_t entry_addr;
+        sm_key_t irk;
+        le_device_db_info(i, &entry_type, entry_addr, irk);
+        if (entry_type == (int)BD_ADDR_TYPE_UNKNOWN) {
+            continue;
+        }
+        if (addr == NULL || ((int)addr_type == entry_type && memcmp(addr, entry_addr, BD_ADDR_LEN) == 0)) {
+            le_device_db_remove(i);
+            if (addr != NULL) {
+                return 0;
+            }
+        }
+    }
+    return (addr == NULL) ? 0 : MP_ENOENT;
+}
+
 int mp_bluetooth_gap_passkey(uint16_t conn_handle, uint8_t action, mp_int_t passkey) {
     DEBUG_printf("mp_bluetooth_gap_passkey: conn_handle=%d action=%d passkey=%d\n", conn_handle, action, (int)passkey);
     return MP_EOPNOTSUPP;

extmod/modbluetooth.c

@@ -51,6 +51,19 @@
 #error pairing and bonding require synchronous modbluetooth events
 #endif
 
+// Ensure QSTRs for pairing/bonding features are always extracted even when feature is disabled.
+// These are used in config() and method tables when MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING=1.
+// Force QSTR extraction for conditional features - must be outside #ifndef NO_QSTR
+static inline void __attribute__((unused)) _force_qstr_extraction(void) {
+    (void)MP_QSTR_bond;
+    (void)MP_QSTR_mitm;
+    (void)MP_QSTR_io;
+    (void)MP_QSTR_le_secure;
+    (void)MP_QSTR_gap_pair;
+    (void)MP_QSTR_gap_passkey;
+    (void)MP_QSTR_gap_unpair;
+}
+
 // NimBLE can have fragmented data for GATTC events, so requires reassembly.
 #define MICROPY_PY_BLUETOOTH_USE_GATTC_EVENT_DATA_REASSEMBLY MICROPY_BLUETOOTH_NIMBLE
 
@@ -717,6 +730,23 @@ static mp_obj_t bluetooth_ble_gap_pair(mp_obj_t self_in, mp_obj_t conn_handle_in
 }
 static MP_DEFINE_CONST_FUN_OBJ_2(bluetooth_ble_gap_pair_obj, bluetooth_ble_gap_pair);
 
+static mp_obj_t bluetooth_ble_gap_unpair(size_t n_args, const mp_obj_t *args) {
+    (void)args[0]; // self
+    if (n_args == 1) {
+        // No args: clear all bonds.
+        return bluetooth_handle_errno(mp_bluetooth_gap_unpair(0, NULL));
+    }
+    // Two args: addr_type, addr.
+    uint8_t addr_type = mp_obj_get_int(args[1]);
+    mp_buffer_info_t bufinfo = {0};
+    mp_get_buffer_raise(args[2], &bufinfo, MP_BUFFER_READ);
+    if (bufinfo.len != 6) {
+        mp_raise_ValueError(MP_ERROR_TEXT("invalid addr"));
+    }
+    return bluetooth_handle_errno(mp_bluetooth_gap_unpair(addr_type, bufinfo.buf));
+}
+static MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bluetooth_ble_gap_unpair_obj, 1, 3, bluetooth_ble_gap_unpair);
+
 static mp_obj_t bluetooth_ble_gap_passkey(size_t n_args, const mp_obj_t *args) {
     uint16_t conn_handle = mp_obj_get_int(args[1]);
     uint8_t action = mp_obj_get_int(args[2]);
@@ -945,6 +975,7 @@ static const mp_rom_map_elem_t bluetooth_ble_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_gap_disconnect), MP_ROM_PTR(&bluetooth_ble_gap_disconnect_obj) },
     #if MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
     { MP_ROM_QSTR(MP_QSTR_gap_pair), MP_ROM_PTR(&bluetooth_ble_gap_pair_obj) },
+    { MP_ROM_QSTR(MP_QSTR_gap_unpair), MP_ROM_PTR(&bluetooth_ble_gap_unpair_obj) },
     { MP_ROM_QSTR(MP_QSTR_gap_passkey), MP_ROM_PTR(&bluetooth_ble_gap_passkey_obj) },
     #endif
     // GATT Server

extmod/modbluetooth.h

@@ -360,6 +360,9 @@ int mp_bluetooth_gap_pair(uint16_t conn_handle);
 
 // Respond to a pairing request.
 int mp_bluetooth_gap_passkey(uint16_t conn_handle, uint8_t action, mp_int_t passkey);
+
+// Remove bond for addr, or all bonds if addr is NULL.
+int mp_bluetooth_gap_unpair(uint8_t addr_type, const uint8_t *addr);
 #endif // MICROPY_PY_BLUETOOTH_ENABLE_PAIRING_BONDING
 
 #if MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE

extmod/nimble/modbluetooth_nimble.c

@@ -1111,6 +1111,45 @@ int mp_bluetooth_gap_pair(uint16_t conn_handle) {
     return ble_hs_err_to_errno(ble_gap_security_initiate(conn_handle));
 }
 
+int mp_bluetooth_gap_unpair(uint8_t addr_type, const uint8_t *addr) {
+    DEBUG_printf("mp_bluetooth_gap_unpair: addr=%p\n", addr);
+
+    // Cannot use ble_gap_unpair(), ble_store_util_delete_peer(), or
+    // ble_store_clear() directly:
+    //
+    // All of these ultimately call ble_store_util_delete_all() which loops
+    // calling store_delete_cb until it returns non-zero. Our callback invokes
+    // the Python _IRQ_SET_SECRET handler which returns True (success)
+    // unconditionally — NimBLE has no internal store to deplete, so the loop
+    // never terminates if a Python IRQ handler is registered.
+    //
+    // Instead, notify the Python handler directly to delete bond data,
+    // bypassing ble_store_util_delete_all's broken loop.
+
+    if (addr == NULL) {
+        // Use a zeroed address (BLE_ADDR_ANY) to signal "delete all" to the
+        // Python handler.
+        ble_addr_t any = {0};
+        mp_bluetooth_gap_on_set_secret(BLE_STORE_OBJ_TYPE_OUR_SEC, (const uint8_t *)&any, sizeof(ble_addr_t), NULL, 0);
+        mp_bluetooth_gap_on_set_secret(BLE_STORE_OBJ_TYPE_PEER_SEC, (const uint8_t *)&any, sizeof(ble_addr_t), NULL, 0);
+        return 0;
+    }
+
+    ble_addr_t ble_addr;
+    ble_addr.type = addr_type;
+    memcpy(ble_addr.val, addr, 6);
+
+    // Remove from controller resolving list (best-effort, ignore errors).
+    ble_hs_pvcy_remove_entry(addr_type, addr);
+
+    // Notify Python handler to delete persistent bond data.
+    // Track whether either secret type had a matching bond.
+    bool deleted = false;
+    deleted |= mp_bluetooth_gap_on_set_secret(BLE_STORE_OBJ_TYPE_OUR_SEC, (const uint8_t *)&ble_addr, sizeof(ble_addr_t), NULL, 0);
+    deleted |= mp_bluetooth_gap_on_set_secret(BLE_STORE_OBJ_TYPE_PEER_SEC, (const uint8_t *)&ble_addr, sizeof(ble_addr_t), NULL, 0);
+    return deleted ? 0 : MP_ENOENT;
+}
+
 int mp_bluetooth_gap_passkey(uint16_t conn_handle, uint8_t action, mp_int_t passkey) {
     struct ble_sm_io io = {0};
 

tests/multi_bluetooth/ble_gap_pair.py

@@ -130,4 +130,5 @@ def instance1():
 ble = bluetooth.BLE()
 ble.config(mitm=True, le_secure=True, bond=False)
 ble.active(1)
+ble.gap_unpair()  # Clear stale bonds/CCC from persistent storage
 ble.irq(irq)

tests/multi_bluetooth/ble_gap_pair_bond.py

@@ -135,4 +135,5 @@ def instance1():
 ble = bluetooth.BLE()
 ble.config(mitm=True, le_secure=True, bond=True)
 ble.active(1)
+ble.gap_unpair()  # Clear stale bonds/CCC from persistent storage
 ble.irq(irq)

tests/multi_bluetooth/ble_gap_unpair.py

@@ -0,0 +1,140 @@
+# Test BLE gap_unpair: clear-all (no args) and per-address bond removal.
+#
+# Both instances call gap_unpair() with no args at startup to clear all bonds,
+# then pair with bonding, disconnect, and unpair the specific peer by address.
+
+from micropython import const
+import time, machine, bluetooth
+
+if not hasattr(bluetooth.BLE, "gap_unpair"):
+    print("SKIP")
+    raise SystemExit
+
+TIMEOUT_MS = 5000
+
+_IRQ_CENTRAL_CONNECT = const(1)
+_IRQ_CENTRAL_DISCONNECT = const(2)
+_IRQ_GATTS_READ_REQUEST = const(4)
+_IRQ_PERIPHERAL_CONNECT = const(7)
+_IRQ_PERIPHERAL_DISCONNECT = const(8)
+_IRQ_GATTC_CHARACTERISTIC_RESULT = const(11)
+_IRQ_GATTC_CHARACTERISTIC_DONE = const(12)
+_IRQ_GATTC_READ_RESULT = const(15)
+_IRQ_ENCRYPTION_UPDATE = const(28)
+_IRQ_SET_SECRET = const(30)
+
+_FLAG_READ = const(0x0002)
+_FLAG_READ_ENCRYPTED = const(0x0200)
+
+SERVICE_UUID = bluetooth.UUID("A5A5A5A5-FFFF-9999-1111-5A5A5A5A5A5A")
+CHAR_UUID = bluetooth.UUID("00000000-1111-2222-3333-444444444444")
+CHAR = (CHAR_UUID, _FLAG_READ | _FLAG_READ_ENCRYPTED)
+SERVICE = (SERVICE_UUID, (CHAR,))
+
+waiting_events = {}
+
+
+def irq(event, data):
+    if event == _IRQ_CENTRAL_CONNECT:
+        print("_IRQ_CENTRAL_CONNECT")
+        waiting_events[event] = (data[0], data[1], bytes(data[2]))
+    elif event == _IRQ_CENTRAL_DISCONNECT:
+        print("_IRQ_CENTRAL_DISCONNECT")
+    elif event == _IRQ_GATTS_READ_REQUEST:
+        # Don't print here - print after wait_for_event for consistent ordering.
+        pass
+    elif event == _IRQ_PERIPHERAL_CONNECT:
+        print("_IRQ_PERIPHERAL_CONNECT")
+        waiting_events[event] = (data[0], data[1], bytes(data[2]))
+    elif event == _IRQ_PERIPHERAL_DISCONNECT:
+        print("_IRQ_PERIPHERAL_DISCONNECT")
+    elif event == _IRQ_GATTC_CHARACTERISTIC_RESULT:
+        if data[-1] == CHAR_UUID:
+            print("_IRQ_GATTC_CHARACTERISTIC_RESULT", data[-1])
+            waiting_events[event] = data[2]
+        else:
+            return
+    elif event == _IRQ_GATTC_CHARACTERISTIC_DONE:
+        print("_IRQ_GATTC_CHARACTERISTIC_DONE")
+    elif event == _IRQ_GATTC_READ_RESULT:
+        print("_IRQ_GATTC_READ_RESULT", bytes(data[-1]))
+    elif event == _IRQ_ENCRYPTION_UPDATE:
+        print("_IRQ_ENCRYPTION_UPDATE", data[1], data[2], data[3])
+    elif event == _IRQ_SET_SECRET:
+        return True
+
+    if event not in waiting_events:
+        waiting_events[event] = None
+
+
+def wait_for_event(event, timeout_ms):
+    t0 = time.ticks_ms()
+    while time.ticks_diff(time.ticks_ms(), t0) < timeout_ms:
+        if event in waiting_events:
+            return waiting_events.pop(event)
+        machine.idle()
+    raise ValueError("Timeout waiting for {}".format(event))
+
+
+# Acting in peripheral role.
+def instance0():
+    multitest.globals(BDADDR=ble.config("mac"))
+    ((char_handle,),) = ble.gatts_register_services((SERVICE,))
+    ble.gatts_write(char_handle, "encrypted")
+
+    print("gap_advertise")
+    ble.gap_advertise(20_000, b"\x02\x01\x06\x04\xffMPY")
+    multitest.next()
+    try:
+        # Wait for central to connect and pair.
+        conn_handle, addr_type, addr = wait_for_event(_IRQ_CENTRAL_CONNECT, TIMEOUT_MS)
+        wait_for_event(_IRQ_ENCRYPTION_UPDATE, TIMEOUT_MS)
+        wait_for_event(_IRQ_GATTS_READ_REQUEST, TIMEOUT_MS)
+        print("_IRQ_GATTS_READ_REQUEST")
+        wait_for_event(_IRQ_CENTRAL_DISCONNECT, TIMEOUT_MS)
+
+        # Unpair the central by address (tests per-address removal).
+        print("gap_unpair_addr")
+        ble.gap_unpair(addr_type, addr)
+        print("gap_unpair_addr done")
+    finally:
+        ble.active(0)
+
+
+# Acting in central role.
+def instance1():
+    multitest.next()
+    try:
+        # Connect, pair, read encrypted char, disconnect.
+        print("gap_connect")
+        ble.gap_connect(*BDADDR)
+        conn_handle, addr_type, addr = wait_for_event(_IRQ_PERIPHERAL_CONNECT, TIMEOUT_MS)
+
+        ble.gattc_discover_characteristics(conn_handle, 1, 65535)
+        value_handle = wait_for_event(_IRQ_GATTC_CHARACTERISTIC_RESULT, TIMEOUT_MS)
+        wait_for_event(_IRQ_GATTC_CHARACTERISTIC_DONE, TIMEOUT_MS)
+
+        print("gap_pair")
+        ble.gap_pair(conn_handle)
+        wait_for_event(_IRQ_ENCRYPTION_UPDATE, TIMEOUT_MS)
+
+        print("gattc_read")
+        ble.gattc_read(conn_handle, value_handle)
+        wait_for_event(_IRQ_GATTC_READ_RESULT, TIMEOUT_MS)
+
+        print("gap_disconnect:", ble.gap_disconnect(conn_handle))
+        wait_for_event(_IRQ_PERIPHERAL_DISCONNECT, TIMEOUT_MS)
+
+        # Unpair the peripheral by address (tests per-address removal on central).
+        print("gap_unpair_addr")
+        ble.gap_unpair(addr_type, addr)
+        print("gap_unpair_addr done")
+    finally:
+        ble.active(0)
+
+
+ble = bluetooth.BLE()
+ble.config(mitm=True, le_secure=True, bond=True)
+ble.active(1)
+ble.gap_unpair()  # Clear all bonds at start (tests no-arg form).
+ble.irq(irq)

tests/multi_bluetooth/ble_gap_unpair.py.exp

@@ -0,0 +1,21 @@
+--- instance0 ---
+gap_advertise
+_IRQ_CENTRAL_CONNECT
+_IRQ_ENCRYPTION_UPDATE 1 0 1
+_IRQ_GATTS_READ_REQUEST
+_IRQ_CENTRAL_DISCONNECT
+gap_unpair_addr
+gap_unpair_addr done
+--- instance1 ---
+gap_connect
+_IRQ_PERIPHERAL_CONNECT
+_IRQ_GATTC_CHARACTERISTIC_RESULT UUID('00000000-1111-2222-3333-444444444444')
+_IRQ_GATTC_CHARACTERISTIC_DONE
+gap_pair
+_IRQ_ENCRYPTION_UPDATE 1 0 1
+gattc_read
+_IRQ_GATTC_READ_RESULT b'encrypted'
+gap_disconnect: True
+_IRQ_PERIPHERAL_DISCONNECT
+gap_unpair_addr
+gap_unpair_addr done

tests/multi_bluetooth/ble_subscribe.py

@@ -243,4 +243,5 @@ def instance1():
 
 ble = bluetooth.BLE()
 ble.active(1)
+ble.gap_unpair()  # Clear stale bonds/CCC from persistent storage
 ble.irq(irq)