Bluetooth: eir: Move EIR/Adv Data functions to its own file

This moves functions manipulating EIR/Adv Data to its own file so it
can be reused by other files.

Signed-off-by: Luiz Augusto von Dentz <[email protected]>
Signed-off-by: Marcel Holtmann <[email protected]>

Author: Vudentz

include/net/bluetooth/hci_core.h

@@ -1380,6 +1380,8 @@ int hci_set_adv_instance_data(struct hci_dev *hdev, u8 instance,
 			 u16 scan_rsp_len, u8 *scan_rsp_data);
 int hci_remove_adv_instance(struct hci_dev *hdev, u8 instance);
 void hci_adv_instances_set_rpa_expired(struct hci_dev *hdev, bool rpa_expired);
+u32 hci_adv_instance_flags(struct hci_dev *hdev, u8 instance);
+bool hci_adv_instance_is_scannable(struct hci_dev *hdev, u8 instance);
 
 void hci_adv_monitors_clear(struct hci_dev *hdev);
 void hci_free_adv_monitor(struct hci_dev *hdev, struct adv_monitor *monitor);
@@ -1632,43 +1634,6 @@ static inline void hci_role_switch_cfm(struct hci_conn *conn, __u8 status,
 	mutex_unlock(&hci_cb_list_lock);
 }
 
-static inline void *eir_get_data(u8 *eir, size_t eir_len, u8 type,
-				 size_t *data_len)
-{
-	size_t parsed = 0;
-
-	if (eir_len < 2)
-		return NULL;
-
-	while (parsed < eir_len - 1) {
-		u8 field_len = eir[0];
-
-		if (field_len == 0)
-			break;
-
-		parsed += field_len + 1;
-
-		if (parsed > eir_len)
-			break;
-
-		if (eir[1] != type) {
-			eir += field_len + 1;
-			continue;
-		}
-
-		/* Zero length data */
-		if (field_len == 1)
-			return NULL;
-
-		if (data_len)
-			*data_len = field_len - 1;
-
-		return &eir[2];
-	}
-
-	return NULL;
-}
-
 static inline bool hci_bdaddr_is_rpa(bdaddr_t *bdaddr, u8 addr_type)
 {
 	if (addr_type != ADDR_LE_DEV_RANDOM)

net/bluetooth/Makefile

@@ -14,7 +14,8 @@ bluetooth_6lowpan-y := 6lowpan.o
 
 bluetooth-y := af_bluetooth.o hci_core.o hci_conn.o hci_event.o mgmt.o \
 	hci_sock.o hci_sysfs.o l2cap_core.o l2cap_sock.o smp.o lib.o \
-	ecdh_helper.o hci_request.o mgmt_util.o mgmt_config.o hci_codec.o
+	ecdh_helper.o hci_request.o mgmt_util.o mgmt_config.o hci_codec.o \
+	eir.o
 
 bluetooth-$(CONFIG_BT_BREDR) += sco.o
 bluetooth-$(CONFIG_BT_HS) += a2mp.o amp.o

net/bluetooth/eir.c

@@ -0,0 +1,335 @@
+// 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 (+ 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);
+	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 + 1);
+
+	/* 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 + 1);
+
+	/* 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;
+}
+
+u8 eir_append_appearance(struct hci_dev *hdev, u8 *ptr, u8 ad_len)
+{
+	return eir_append_le16(ptr, ad_len, EIR_APPEARANCE, hdev->appearance);
+}
+
+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 = strlen(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_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;
+}