Return-Path: Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Subject: Re: [PATCH v2 1/6] Bluetooth: Add support for local name in scan rsp From: Marcel Holtmann In-Reply-To: <1474195807-12310-1-git-send-email-szymon.janc@codecoup.pl> Date: Sun, 18 Sep 2016 16:28:11 +0200 Cc: linux-bluetooth@vger.kernel.org, =?utf-8?Q?Micha=C5=82_Narajowski?= Message-Id: References: <1474195807-12310-1-git-send-email-szymon.janc@codecoup.pl> To: Szymon Janc Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Szymon, > This patch enables appending local name to scan response data. If > currently advertised instance has name flag set it is expired > immediately. > > Signed-off-by: Michał Narajowski > Signed-off-by: Szymon Janc > --- > net/bluetooth/hci_request.c | 28 +++++++++++++++++++-------- > net/bluetooth/mgmt.c | 46 +++++++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 64 insertions(+), 10 deletions(-) > > diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c > index 9566ff8..0ce6cdd 100644 > --- a/net/bluetooth/hci_request.c > +++ b/net/bluetooth/hci_request.c > @@ -971,14 +971,14 @@ void __hci_req_enable_advertising(struct hci_request *req) > hci_req_add(req, HCI_OP_LE_SET_ADV_ENABLE, sizeof(enable), &enable); > } > > -static u8 create_default_scan_rsp_data(struct hci_dev *hdev, u8 *ptr) > +static u8 append_local_name(struct hci_dev *hdev, u8 *ptr, u8 ad_len) > { > - u8 ad_len = 0; > size_t name_len; > + int max_len; > > + max_len = HCI_MAX_AD_LENGTH - ad_len - 2; > name_len = strlen(hdev->dev_name); > - if (name_len > 0) { > - size_t max_len = HCI_MAX_AD_LENGTH - ad_len - 2; > + if (name_len > 0 && max_len > 0) { > > if (name_len > max_len) { > name_len = max_len; > @@ -997,22 +997,34 @@ static u8 create_default_scan_rsp_data(struct hci_dev *hdev, u8 *ptr) > return ad_len; > } > > +static u8 create_default_scan_rsp_data(struct hci_dev *hdev, u8 *ptr) > +{ > + return append_local_name(hdev, ptr, 0); > +} > + > static u8 create_instance_scan_rsp_data(struct hci_dev *hdev, u8 instance, > u8 *ptr) > { > struct adv_info *adv_instance; > + u32 instance_flags; > + u8 scan_rsp_len = 0; > > adv_instance = hci_find_adv_instance(hdev, instance); > if (!adv_instance) > return 0; > > - /* TODO: Set the appropriate entries based on advertising instance flags > - * here once flags other than 0 are supported. > - */ > + instance_flags = adv_instance->flags; > + > memcpy(ptr, adv_instance->scan_rsp_data, > adv_instance->scan_rsp_len); > > - return adv_instance->scan_rsp_len; > + scan_rsp_len += adv_instance->scan_rsp_len; > + ptr += adv_instance->scan_rsp_len; > + > + if (instance_flags & MGMT_ADV_FLAG_LOCAL_NAME) > + scan_rsp_len = append_local_name(hdev, ptr, scan_rsp_len); > + > + return scan_rsp_len; > } > > void __hci_req_update_scan_rsp_data(struct hci_request *req, u8 instance) > diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c > index 74179b9..fa1f1c7 100644 > --- a/net/bluetooth/mgmt.c > +++ b/net/bluetooth/mgmt.c > @@ -3014,6 +3014,35 @@ static int user_passkey_neg_reply(struct sock *sk, struct hci_dev *hdev, > HCI_OP_USER_PASSKEY_NEG_REPLY, 0); > } > > +static void adv_expire(struct hci_dev *hdev, u32 flags) > +{ > + struct adv_info *adv_instance; > + struct hci_request req; > + int err; > + > + adv_instance = hci_find_adv_instance(hdev, hdev->cur_adv_instance); > + if (!adv_instance) > + return; > + > + /* stop if current instance doesn't need to be changed */ > + if (!(adv_instance->flags & flags)) > + return; are you sure this is correct? Isn't this !(current_flags ^ new_flags) what you are looking for. Also we should really have mgmt-tester test cases for this. We want to make sure that this works for active instances and also the default instance 0 (aka Set Advertising). > + > + cancel_adv_timeout(hdev); > + > + adv_instance = hci_get_next_instance(hdev, adv_instance->instance); > + if (!adv_instance) > + return; > + > + hci_req_init(&req, hdev); > + err = __hci_req_schedule_adv_instance(&req, adv_instance->instance, > + true); > + if (err) > + return; > + > + hci_req_run(&req, NULL); > +} > + > static void set_name_complete(struct hci_dev *hdev, u8 status, u16 opcode) > { > struct mgmt_cp_set_local_name *cp; > @@ -3029,13 +3058,17 @@ static void set_name_complete(struct hci_dev *hdev, u8 status, u16 opcode) > > cp = cmd->param; > > - if (status) > + if (status) { > mgmt_cmd_status(cmd->sk, hdev->id, MGMT_OP_SET_LOCAL_NAME, > mgmt_status(status)); > - else > + } else { > mgmt_cmd_complete(cmd->sk, hdev->id, MGMT_OP_SET_LOCAL_NAME, 0, > cp, sizeof(*cp)); > > + if (hci_dev_test_flag(hdev, HCI_LE_ADV)) > + adv_expire(hdev, MGMT_ADV_FLAG_LOCAL_NAME); > + } > + > mgmt_pending_remove(cmd); > > unlock: > @@ -5887,6 +5920,7 @@ static u32 get_supported_adv_flags(struct hci_dev *hdev) > flags |= MGMT_ADV_FLAG_DISCOV; > flags |= MGMT_ADV_FLAG_LIMITED_DISCOV; > flags |= MGMT_ADV_FLAG_MANAGED_FLAGS; > + flags |= MGMT_ADV_FLAG_LOCAL_NAME; > > if (hdev->adv_tx_power != HCI_TX_POWER_INVALID) > flags |= MGMT_ADV_FLAG_TX_POWER; > @@ -5963,6 +5997,10 @@ static bool tlv_data_is_valid(struct hci_dev *hdev, u32 adv_flags, u8 *data, > tx_power_managed = true; > max_len -= 3; > } > + } else { > + /* at least 1 byte of name should fit in */ > + if (adv_flags & MGMT_ADV_FLAG_LOCAL_NAME) > + max_len -= 3; > } > > if (len > max_len) > @@ -6295,6 +6333,10 @@ static u8 tlv_data_max_len(u32 adv_flags, bool is_adv_data) > > if (adv_flags & MGMT_ADV_FLAG_TX_POWER) > max_len -= 3; > + } else { > + /* at least 1 byte of name should fit in */ > + if (adv_flags & MGMT_ADV_FLAG_LOCAL_NAME) > + max_len -= 3; > } So I do not get the math here. Either the short name will fit or the long name. Especially the Get Advertising Size Information command should return the accurate leftover size. I mean if the name utilizes all the space, then this should return 0. Also the short name is maximal 11 + 2 octets. Meaning it will always fit together with appearance no matter what. So if long name is too large, then we pick the short name and return the leftover space. Regards Marcel