From f61851f64b171a684f5a1fa78325756dbbaadadc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micha=C5=82=20Narajowski?= Date: Wed, 19 Oct 2016 10:20:27 +0200 Subject: [PATCH] Bluetooth: Fix append max 11 bytes of name to scan rsp data MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Append maximum of 10 + 1 bytes of name to scan response data. Complete name is appended only if exists and is <= 10 characters. Else append short name if exists or shorten complete name if not. This makes sure name is consistent across multiple advertising instances. Signed-off-by: Michał Narajowski Signed-off-by: Marcel Holtmann --- net/bluetooth/hci_request.c | 51 +++++++++++++++++-------------------- net/bluetooth/hci_request.h | 2 ++ net/bluetooth/mgmt.c | 26 ++++++++++++------- 3 files changed, 43 insertions(+), 36 deletions(-) diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c index e2288421fe6b..1015d9c8d97d 100644 --- a/net/bluetooth/hci_request.c +++ b/net/bluetooth/hci_request.c @@ -969,41 +969,38 @@ void __hci_req_enable_advertising(struct hci_request *req) hci_req_add(req, HCI_OP_LE_SET_ADV_ENABLE, sizeof(enable), &enable); } -static u8 append_local_name(struct hci_dev *hdev, u8 *ptr, u8 ad_len) +u8 append_local_name(struct hci_dev *hdev, u8 *ptr, u8 ad_len) { - size_t complete_len; size_t short_len; - int max_len; + size_t complete_len; - max_len = HCI_MAX_AD_LENGTH - ad_len - 2; + /* no space left for name (+ NULL + type + len) */ + if ((HCI_MAX_AD_LENGTH - ad_len) < HCI_MAX_SHORT_NAME_LENGTH + 3) + return ad_len; + + /* use complete name if present and fits */ complete_len = strlen(hdev->dev_name); - short_len = strlen(hdev->short_name); - - /* no space left for name */ - if (max_len < 1) - return ad_len; - - /* no name set */ - if (!complete_len) - return ad_len; - - /* complete name fits and is eq to max short name len or smaller */ - if (complete_len <= max_len && - complete_len <= HCI_MAX_SHORT_NAME_LENGTH) { + if (complete_len && complete_len <= HCI_MAX_SHORT_NAME_LENGTH) return eir_append_data(ptr, ad_len, EIR_NAME_COMPLETE, - hdev->dev_name, complete_len); - } + hdev->dev_name, complete_len + 1); - /* short name set and fits */ - if (short_len && short_len <= max_len) { + /* use short name if present */ + short_len = strlen(hdev->short_name); + if (short_len) return eir_append_data(ptr, ad_len, EIR_NAME_SHORT, - hdev->short_name, short_len); - } + hdev->short_name, short_len + 1); - /* no short name set so shorten complete name */ - if (!short_len) { - return eir_append_data(ptr, ad_len, EIR_NAME_SHORT, - hdev->dev_name, max_len); + /* use shortened full name if present, we already know that name + * is longer then HCI_MAX_SHORT_NAME_LENGTH + */ + if (complete_len) { + u8 name[HCI_MAX_SHORT_NAME_LENGTH + 1]; + + memcpy(name, hdev->dev_name, HCI_MAX_SHORT_NAME_LENGTH); + name[HCI_MAX_SHORT_NAME_LENGTH] = '\0'; + + return eir_append_data(ptr, ad_len, EIR_NAME_SHORT, name, + sizeof(name)); } return ad_len; diff --git a/net/bluetooth/hci_request.h b/net/bluetooth/hci_request.h index 6b06629245a8..dde77bd59f91 100644 --- a/net/bluetooth/hci_request.h +++ b/net/bluetooth/hci_request.h @@ -106,6 +106,8 @@ static inline void hci_update_background_scan(struct hci_dev *hdev) void hci_request_setup(struct hci_dev *hdev); void hci_request_cancel_all(struct hci_dev *hdev); +u8 append_local_name(struct hci_dev *hdev, u8 *ptr, u8 ad_len); + static inline u16 eir_append_data(u8 *eir, u16 eir_len, u8 type, u8 *data, u8 data_len) { diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index 736038085feb..1fba2a03f8ae 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -6017,7 +6017,15 @@ static int read_adv_features(struct sock *sk, struct hci_dev *hdev, return err; } -static u8 tlv_data_max_len(u32 adv_flags, bool is_adv_data) +static u8 calculate_name_len(struct hci_dev *hdev) +{ + u8 buf[HCI_MAX_SHORT_NAME_LENGTH + 3]; + + return append_local_name(hdev, buf, 0); +} + +static u8 tlv_data_max_len(struct hci_dev *hdev, u32 adv_flags, + bool is_adv_data) { u8 max_len = HCI_MAX_AD_LENGTH; @@ -6030,9 +6038,8 @@ 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; + max_len -= calculate_name_len(hdev); if (adv_flags & (MGMT_ADV_FLAG_APPEARANCE)) max_len -= 4; @@ -6063,12 +6070,13 @@ static bool appearance_managed(u32 adv_flags) return adv_flags & MGMT_ADV_FLAG_APPEARANCE; } -static bool tlv_data_is_valid(u32 adv_flags, u8 *data, u8 len, bool is_adv_data) +static bool tlv_data_is_valid(struct hci_dev *hdev, u32 adv_flags, u8 *data, + u8 len, bool is_adv_data) { int i, cur_len; u8 max_len; - max_len = tlv_data_max_len(adv_flags, is_adv_data); + max_len = tlv_data_max_len(hdev, adv_flags, is_adv_data); if (len > max_len) return false; @@ -6215,8 +6223,8 @@ static int add_advertising(struct sock *sk, struct hci_dev *hdev, goto unlock; } - if (!tlv_data_is_valid(flags, cp->data, cp->adv_data_len, true) || - !tlv_data_is_valid(flags, cp->data + cp->adv_data_len, + if (!tlv_data_is_valid(hdev, flags, cp->data, cp->adv_data_len, true) || + !tlv_data_is_valid(hdev, flags, cp->data + cp->adv_data_len, cp->scan_rsp_len, false)) { err = mgmt_cmd_status(sk, hdev->id, MGMT_OP_ADD_ADVERTISING, MGMT_STATUS_INVALID_PARAMS); @@ -6429,8 +6437,8 @@ static int get_adv_size_info(struct sock *sk, struct hci_dev *hdev, 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); + rp.max_adv_data_len = tlv_data_max_len(hdev, flags, true); + rp.max_scan_rsp_len = tlv_data_max_len(hdev, flags, false); err = mgmt_cmd_complete(sk, hdev->id, MGMT_OP_GET_ADV_SIZE_INFO, MGMT_STATUS_SUCCESS, &rp, sizeof(rp));