Bluetooth: Change MGMT security info CMD to be more generic

For advertising, we wish to know the LE tx power capabilities of the
controller in userspace, so this patch edits the Security Info MGMT
command to be more generic, such that other various controller
capabilities can be included in the EIR data. This change also includes
the LE min and max tx power into this newly-named command.

The change was tested by manually verifying that the MGMT command
returns the tx power range as expected in userspace.

Reviewed-by: Sonny Sasaka <sonnysasaka@chromium.org>
Signed-off-by: Daniel Winkler <danielwinkler@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

1 files changed, 29 insertions, 14 deletions

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 668a62c8181e..754489e4e065 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -110,7 +110,7 @@ static const u16 mgmt_commands[] = {
 	MGMT_OP_SET_APPEARANCE,
 	MGMT_OP_SET_BLOCKED_KEYS,
 	MGMT_OP_SET_WIDEBAND_SPEECH,
-	MGMT_OP_READ_SECURITY_INFO,
+	MGMT_OP_READ_CONTROLLER_CAP,
 	MGMT_OP_READ_EXP_FEATURES_INFO,
 	MGMT_OP_SET_EXP_FEATURE,
 	MGMT_OP_READ_DEF_SYSTEM_CONFIG,
@@ -176,7 +176,7 @@ static const u16 mgmt_untrusted_commands[] = {
 	MGMT_OP_READ_CONFIG_INFO,
 	MGMT_OP_READ_EXT_INDEX_LIST,
 	MGMT_OP_READ_EXT_INFO,
-	MGMT_OP_READ_SECURITY_INFO,
+	MGMT_OP_READ_CONTROLLER_CAP,
 	MGMT_OP_READ_EXP_FEATURES_INFO,
 	MGMT_OP_READ_DEF_SYSTEM_CONFIG,
 	MGMT_OP_READ_DEF_RUNTIME_CONFIG,
@@ -3710,13 +3710,14 @@ unlock:
 	return err;
 }
 
-static int read_security_info(struct sock *sk, struct hci_dev *hdev,
-			      void *data, u16 data_len)
+static int read_controller_cap(struct sock *sk, struct hci_dev *hdev,
+			       void *data, u16 data_len)
 {
-	char buf[16];
-	struct mgmt_rp_read_security_info *rp = (void *)buf;
-	u16 sec_len = 0;
+	char buf[20];
+	struct mgmt_rp_read_controller_cap *rp = (void *)buf;
+	u16 cap_len = 0;
 	u8 flags = 0;
+	u8 tx_power_range[2];
 
 	bt_dev_dbg(hdev, "sock %p", sk);
 
@@ -3740,23 +3741,37 @@ static int read_security_info(struct sock *sk, struct hci_dev *hdev,
 
 	flags |= 0x08;		/* Encryption key size enforcement (LE) */
 
-	sec_len = eir_append_data(rp->sec, sec_len, 0x01, &flags, 1);
+	cap_len = eir_append_data(rp->cap, cap_len, MGMT_CAP_SEC_FLAGS,
+				  &flags, 1);
 
 	/* When the Read Simple Pairing Options command is supported, then
 	 * also max encryption key size information is provided.
 	 */
 	if (hdev->commands[41] & 0x08)
-		sec_len = eir_append_le16(rp->sec, sec_len, 0x02,
+		cap_len = eir_append_le16(rp->cap, cap_len,
+					  MGMT_CAP_MAX_ENC_KEY_SIZE,
 					  hdev->max_enc_key_size);
 
-	sec_len = eir_append_le16(rp->sec, sec_len, 0x03, SMP_MAX_ENC_KEY_SIZE);
+	cap_len = eir_append_le16(rp->cap, cap_len,
+				  MGMT_CAP_SMP_MAX_ENC_KEY_SIZE,
+				  SMP_MAX_ENC_KEY_SIZE);
+
+	/* Append the min/max LE tx power parameters if we were able to fetch
+	 * it from the controller
+	 */
+	if (hdev->commands[38] & 0x80) {
+		memcpy(&tx_power_range[0], &hdev->min_le_tx_power, 1);
+		memcpy(&tx_power_range[1], &hdev->max_le_tx_power, 1);
+		cap_len = eir_append_data(rp->cap, cap_len, MGMT_CAP_LE_TX_PWR,
+					  tx_power_range, 2);
+	}
 
-	rp->sec_len = cpu_to_le16(sec_len);
+	rp->cap_len = cpu_to_le16(cap_len);
 
 	hci_dev_unlock(hdev);
 
-	return mgmt_cmd_complete(sk, hdev->id, MGMT_OP_READ_SECURITY_INFO, 0,
-				 rp, sizeof(*rp) + sec_len);
+	return mgmt_cmd_complete(sk, hdev->id, MGMT_OP_READ_CONTROLLER_CAP, 0,
+				 rp, sizeof(*rp) + cap_len);
 }
 
 #ifdef CONFIG_BT_FEATURE_DEBUG
@@ -8193,7 +8208,7 @@ static const struct hci_mgmt_handler mgmt_handlers[] = {
 	{ set_blocked_keys,	   MGMT_OP_SET_BLOCKED_KEYS_SIZE,
 						HCI_MGMT_VAR_LEN },
 	{ set_wideband_speech,	   MGMT_SETTING_SIZE },
-	{ read_security_info,      MGMT_READ_SECURITY_INFO_SIZE,
+	{ read_controller_cap,     MGMT_READ_CONTROLLER_CAP_SIZE,
 						HCI_MGMT_UNTRUSTED },
 	{ read_exp_features_info,  MGMT_READ_EXP_FEATURES_INFO_SIZE,
 						HCI_MGMT_UNTRUSTED |