// SPDX-License-Identifier: GPL-2.0
/*
* BlueZ - Bluetooth protocol stack for Linux
*
* Copyright (C) 2021 Intel Corporation
*/
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/mgmt.h>
#include "eir.h"
#define PNP_INFO_SVCLASS_ID 0x1200
u8 eir_append_local_name(struct hci_dev *hdev, u8 *ptr, u8 ad_len)
{
size_t short_len;
size_t complete_len;
/* no space left for name (+ type + len) */
if ((max_adv_len(hdev) - ad_len) < HCI_MAX_SHORT_NAME_LENGTH + 2)
return ad_len;
/* use complete name if present and fits */
complete_len = strnlen(hdev->dev_name, sizeof(hdev->dev_name));
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);
/* use short name if present */
short_len = strnlen(hdev->short_name, sizeof(hdev->short_name));
if (short_len)
return eir_append_data(ptr, ad_len, EIR_NAME_SHORT,
hdev->short_name,
short_len);
/* use shortened full name if present, we already know that name
* is longer then HCI_MAX_SHORT_NAME_LENGTH
*/
if (complete_len)
return eir_append_data(ptr, ad_len, EIR_NAME_SHORT,
hdev->dev_name,
HCI_MAX_SHORT_NAME_LENGTH);
return ad_len;
}
u8 eir_append_appearance(struct hci_dev *hdev, u8 *ptr, u8 ad_len)
{
return eir_append_le16(ptr, ad_len, EIR_APPEARANCE, hdev->appearance);
}
u8 eir_append_service_data(u8 *eir, u16 eir_len, u16 uuid, u8 *data,
u8 data_len)
{
eir[eir_len++] = sizeof(u8) + sizeof(uuid) + data_len;
eir[eir_len++] = EIR_SERVICE_DATA;
put_unaligned_le16(uuid, &eir[eir_len]);
eir_len += sizeof(uuid);
memcpy(&eir[eir_len], data, data_len);
eir_len += data_len;
return eir_len;
}
static u8 *create_uuid16_list(struct hci_dev *hdev, u8 *data, ptrdiff_t len)
{
u8 *ptr = data, *uuids_start = NULL;
struct bt_uuid *uuid;
if (len < 4)
return ptr;
list_for_each_entry(uuid, &hdev->uuids, list) {
u16 uuid16;
if (uuid->size != 16)
continue;
uuid16 = get_unaligned_le16(&uuid->uuid[12]);
if (uuid16 < 0x1100)
continue;
if (uuid16 == PNP_INFO_SVCLASS_ID)
continue;
if (!uuids_start) {
uuids_start = ptr;
uuids_start[0] = 1;
uuids_start[1] = EIR_UUID16_ALL;
ptr += 2;
}
/* Stop if not enough space to put next UUID */
if ((ptr - data) + sizeof(u16) > len) {
uuids_start[1] = EIR_UUID16_SOME;
break;
}
*ptr++ = (uuid16 & 0x00ff);
*ptr++ = (uuid16 & 0xff00) >> 8;
uuids_start[0] += sizeof(uuid16);
}
return ptr;
}
static u8 *create_uuid32_list(struct hci_dev *hdev, u8 *data, ptrdiff_t len)
{
u8 *ptr = data, *uuids_start = NULL;
struct bt_uuid *uuid;
if (len < 6)
return ptr;
list_for_each_entry(uuid, &hdev->uuids, list) {
if (uuid->size != 32)
continue;
if (!uuids_start) {
uuids_start = ptr;
uuids_start[0] = 1;
uuids_start[1] = EIR_UUID32_ALL;
ptr += 2;
}
/* Stop if not enough space to put next UUID */
if ((ptr - data) + sizeof(u32) > len) {
uuids_start[1] = EIR_UUID32_SOME;
break;
}
memcpy(ptr, &uuid->uuid[12], sizeof(u32));
ptr += sizeof(u32);
uuids_start[0] += sizeof(u32);
}
return ptr;
}
static u8 *create_uuid128_list(struct hci_dev *hdev, u8 *data, ptrdiff_t len)
{
u8 *ptr = data, *uuids_start = NULL;
struct bt_uuid *uuid;
if (len < 18)
return ptr;
list_for_each_entry(uuid, &hdev->uuids, list) {
if (uuid->size != 128)
continue;
if (!uuids_start) {
uuids_start = ptr;
uuids_start[0] = 1;
uuids_start[1] = EIR_UUID128_ALL;
ptr += 2;
}
/* Stop if not enough space to put next UUID */
if ((ptr - data) + 16 > len) {
uuids_start[1] = EIR_UUID128_SOME;
break;
}
memcpy(ptr, uuid->uuid, 16);
ptr += 16;
uuids_start[0] += 16;
}
return ptr;
}
void eir_create(struct hci_dev *hdev, u8 *data)
{
u8 *ptr = data;
size_t name_len;
name_len = strnlen(hdev->dev_name, sizeof(hdev->dev_name));
if (name_len > 0) {
/* EIR Data type */
if (name_len > 48) {
name_len = 48;
ptr[1] = EIR_NAME_SHORT;
} else {
ptr[1] = EIR_NAME_COMPLETE;
}
/* EIR Data length */
ptr[0] = name_len + 1;
memcpy(ptr + 2, hdev->dev_name, name_len);
ptr += (name_len + 2);
}
if (hdev->inq_tx_power != HCI_TX_POWER_INVALID) {
ptr[0] = 2;
ptr[1] = EIR_TX_POWER;
ptr[2] = (u8)hdev->inq_tx_power;
ptr += 3;
}
if (hdev->devid_source > 0) {
ptr[0] = 9;
ptr[1] = EIR_DEVICE_ID;
put_unaligned_le16(hdev->devid_source, ptr + 2);
put_unaligned_le16(hdev->devid_vendor, ptr + 4);
put_unaligned_le16(hdev->devid_product, ptr + 6);
put_unaligned_le16(hdev->devid_version, ptr + 8);
ptr += 10;
}
ptr = create_uuid16_list(hdev, ptr, HCI_MAX_EIR_LENGTH - (ptr - data));
ptr = create_uuid32_list(hdev, ptr, HCI_MAX_EIR_LENGTH - (ptr - data));
ptr = create_uuid128_list(hdev, ptr, HCI_MAX_EIR_LENGTH - (ptr - data));
}
u8 eir_create_per_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr)
{
struct adv_info *adv = NULL;
u8 ad_len = 0;
/* Return 0 when the current instance identifier is invalid. */
if (instance) {
adv = hci_find_adv_instance(hdev, instance);
if (!adv)
return 0;
}
if (adv) {
memcpy(ptr, adv->per_adv_data, adv->per_adv_data_len);
ad_len += adv->per_adv_data_len;
ptr += adv->per_adv_data_len;
}
return ad_len;
}
u8 eir_create_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr)
{
struct adv_info *adv = NULL;
u8 ad_len = 0, flags = 0;
u32 instance_flags;
/* Return 0 when the current instance identifier is invalid. */
if (instance) {
adv = hci_find_adv_instance(hdev, instance);
if (!adv)
return 0;
}
instance_flags = hci_adv_instance_flags(hdev, instance);
/* If instance already has the flags set skip adding it once
* again.
*/
if (adv && eir_get_data(adv->adv_data, adv->adv_data_len, EIR_FLAGS,
NULL))
goto skip_flags;
/* The Add Advertising command allows userspace to set both the general
* and limited discoverable flags.
*/
if (instance_flags & MGMT_ADV_FLAG_DISCOV)
flags |= LE_AD_GENERAL;
if (instance_flags & MGMT_ADV_FLAG_LIMITED_DISCOV)
flags |= LE_AD_LIMITED;
if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED))
flags |= LE_AD_NO_BREDR;
if (flags || (instance_flags & MGMT_ADV_FLAG_MANAGED_FLAGS)) {
/* If a discovery flag wasn't provided, simply use the global
* settings.
*/
if (!flags)
flags |= mgmt_get_adv_discov_flags(hdev);
/* If flags would still be empty, then there is no need to
* include the "Flags" AD field".
*/
if (flags) {
ptr[0] = 0x02;
ptr[1] = EIR_FLAGS;
ptr[2] = flags;
ad_len += 3;
ptr += 3;
}
}
skip_flags:
if (adv) {
memcpy(ptr, adv->adv_data, adv->adv_data_len);
ad_len += adv->adv_data_len;
ptr += adv->adv_data_len;
}
if (instance_flags & MGMT_ADV_FLAG_TX_POWER) {
s8 adv_tx_power;
if (ext_adv_capable(hdev)) {
if (adv)
adv_tx_power = adv->tx_power;
else
adv_tx_power = hdev->adv_tx_power;
} else {
adv_tx_power = hdev->adv_tx_power;
}
/* Provide Tx Power only if we can provide a valid value for it */
if (adv_tx_power != HCI_TX_POWER_INVALID) {
ptr[0] = 0x02;
ptr[1] = EIR_TX_POWER;
ptr[2] = (u8)adv_tx_power;
ad_len += 3;
ptr += 3;
}
}
return ad_len;
}
static u8 create_default_scan_rsp(struct hci_dev *hdev, u8 *ptr)
{
u8 scan_rsp_len = 0;
if (hdev->appearance)
scan_rsp_len = eir_append_appearance(hdev, ptr, scan_rsp_len);
return eir_append_local_name(hdev, ptr, scan_rsp_len);
}
u8 eir_create_scan_rsp(struct hci_dev *hdev, u8 instance, u8 *ptr)
{
struct adv_info *adv;
u8 scan_rsp_len = 0;
if (!instance)
return create_default_scan_rsp(hdev, ptr);
adv = hci_find_adv_instance(hdev, instance);
if (!adv)
return 0;
if ((adv->flags & MGMT_ADV_FLAG_APPEARANCE) && hdev->appearance)
scan_rsp_len = eir_append_appearance(hdev, ptr, scan_rsp_len);
memcpy(&ptr[scan_rsp_len], adv->scan_rsp_data, adv->scan_rsp_len);
scan_rsp_len += adv->scan_rsp_len;
if (adv->flags & MGMT_ADV_FLAG_LOCAL_NAME)
scan_rsp_len = eir_append_local_name(hdev, ptr, scan_rsp_len);
return scan_rsp_len;
}
void *eir_get_service_data(u8 *eir, size_t eir_len, u16 uuid, size_t *len)
{
while ((eir = eir_get_data(eir, eir_len, EIR_SERVICE_DATA, len))) {
u16 value = get_unaligned_le16(eir);
if (uuid == value) {
if (len)
*len -= 2;
return &eir[2];
}
eir += *len;
eir_len -= *len;
}
return NULL;
}
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