Bluetooth: Add support for Get Advertising Size Information command

The Get Advertising Size Information command allows to retrieve size
information for advertising data and scan response data fields depending
on the selected flags. This is useful if applications want to know the
available size ahead of time.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h
index b831242d48a4b8ce420661c9d56bd3e047f79bd6..af17774c9416c0040eb04f51c05c0fb77e890adc 100644 (file)
--- a/include/net/bluetooth/mgmt.h
+++ b/include/net/bluetooth/mgmt.h
@@ -571,6 +571,19 @@ struct mgmt_rp_remove_advertising {
        __u8    instance;
 } __packed;
 
+#define MGMT_OP_GET_ADV_SIZE_INFO      0x0040
+struct mgmt_cp_get_adv_size_info {
+       __u8    instance;
+       __le32  flags;
+} __packed;
+#define MGMT_GET_ADV_SIZE_INFO_SIZE    5
+struct mgmt_rp_get_adv_size_info {
+       __u8    instance;
+       __le32  flags;
+       __u8    max_adv_data_len;
+       __u8    max_scan_rsp_len;
+} __packed;
+
 #define MGMT_EV_CMD_COMPLETE           0x0001
 struct mgmt_ev_cmd_complete {
        __le16  opcode;

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 05370e76feb0db84aba98c4995277ffcbcc97fa1..dc8e428050d93e353ddcfbf5e8e0cd92669537f7 100644 (file)
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -102,6 +102,7 @@ static const u16 mgmt_commands[] = {
        MGMT_OP_READ_ADV_FEATURES,
        MGMT_OP_ADD_ADVERTISING,
        MGMT_OP_REMOVE_ADVERTISING,
+       MGMT_OP_GET_ADV_SIZE_INFO,
 };
 
 static const u16 mgmt_events[] = {
@@ -7059,6 +7060,62 @@ unlock:
        return err;
 }
 
+static u8 tlv_data_max_len(u32 adv_flags, bool is_adv_data)
+{
+       u8 max_len = HCI_MAX_AD_LENGTH;
+
+       if (is_adv_data) {
+               if (adv_flags & (MGMT_ADV_FLAG_DISCOV |
+                                MGMT_ADV_FLAG_LIMITED_DISCOV |
+                                MGMT_ADV_FLAG_MANAGED_FLAGS))
+                       max_len -= 3;
+
+               if (adv_flags & MGMT_ADV_FLAG_TX_POWER)
+                       max_len -= 3;
+       }
+
+       return max_len;
+}
+
+static int get_adv_size_info(struct sock *sk, struct hci_dev *hdev,
+                            void *data, u16 data_len)
+{
+       struct mgmt_cp_get_adv_size_info *cp = data;
+       struct mgmt_rp_get_adv_size_info rp;
+       u32 flags, supported_flags;
+       int err;
+
+       BT_DBG("%s", hdev->name);
+
+       if (!lmp_le_capable(hdev))
+               return mgmt_cmd_status(sk, hdev->id, MGMT_OP_GET_ADV_SIZE_INFO,
+                                      MGMT_STATUS_REJECTED);
+
+       if (cp->instance < 1 || cp->instance > HCI_MAX_ADV_INSTANCES)
+               return mgmt_cmd_status(sk, hdev->id, MGMT_OP_GET_ADV_SIZE_INFO,
+                                      MGMT_STATUS_INVALID_PARAMS);
+
+       flags = __le32_to_cpu(cp->flags);
+
+       /* The current implementation only supports a subset of the specified
+        * flags.
+        */
+       supported_flags = get_supported_adv_flags(hdev);
+       if (flags & ~supported_flags)
+               return mgmt_cmd_status(sk, hdev->id, MGMT_OP_GET_ADV_SIZE_INFO,
+                                      MGMT_STATUS_INVALID_PARAMS);
+
+       rp.instance = cp->instance;
+       rp.flags = cp->flags;
+       rp.max_adv_data_len = tlv_data_max_len(flags, true);
+       rp.max_scan_rsp_len = tlv_data_max_len(flags, false);
+
+       err = mgmt_cmd_complete(sk, hdev->id, MGMT_OP_GET_ADV_SIZE_INFO,
+                               MGMT_STATUS_SUCCESS, &rp, sizeof(rp));
+
+       return err;
+}
+
 static const struct hci_mgmt_handler mgmt_handlers[] = {
        { NULL }, /* 0x0000 (no command) */
        { read_version,            MGMT_READ_VERSION_SIZE,
@@ -7146,6 +7203,7 @@ static const struct hci_mgmt_handler mgmt_handlers[] = {
        { add_advertising,         MGMT_ADD_ADVERTISING_SIZE,
                                                HCI_MGMT_VAR_LEN },
        { remove_advertising,      MGMT_REMOVE_ADVERTISING_SIZE },
+       { get_adv_size_info,       MGMT_GET_ADV_SIZE_INFO_SIZE },
 };
 
 void mgmt_index_added(struct hci_dev *hdev)