/* SPDX-License-Identifier: GPL-2.0 */
/*
 * BlueZ - Bluetooth protocol stack for Linux
 *
 * Copyright (C) 2021 Intel Corporation
 */

#include <linux/unaligned.h>

void eir_create(struct hci_dev *hdev, u8 *data);

u8 eir_create_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr, u8 size);
u8 eir_create_scan_rsp(struct hci_dev *hdev, u8 instance, u8 *ptr);
u8 eir_create_per_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr);

u8 eir_append_local_name(struct hci_dev *hdev, u8 *eir, u8 ad_len);
u8 eir_append_appearance(struct hci_dev *hdev, u8 *ptr, u8 ad_len);
u8 eir_append_service_data(u8 *eir, u16 eir_len, u16 uuid, u8 *data,
                           u8 data_len);

static inline u16 eir_precalc_len(u8 data_len)
{
        return sizeof(u8) * 2 + data_len;
}

static inline u16 eir_append_data(u8 *eir, u16 eir_len, u8 type,
                                  u8 *data, u8 data_len)
{
        eir[eir_len++] = sizeof(type) + data_len;
        eir[eir_len++] = type;
        memcpy(&eir[eir_len], data, data_len);
        eir_len += data_len;

        return eir_len;
}

static inline u16 eir_append_le16(u8 *eir, u16 eir_len, u8 type, u16 data)
{
        eir[eir_len++] = sizeof(type) + sizeof(data);
        eir[eir_len++] = type;
        put_unaligned_le16(data, &eir[eir_len]);
        eir_len += sizeof(data);

        return eir_len;
}

static inline u16 eir_skb_put_data(struct sk_buff *skb, u8 type, u8 *data, u8 data_len)
{
        u8 *eir;
        u16 eir_len;

        eir_len = eir_precalc_len(data_len);
        eir = skb_put(skb, eir_len);
        WARN_ON(sizeof(type) + data_len > U8_MAX);
        eir[0] = sizeof(type) + data_len;
        eir[1] = type;
        memcpy(&eir[2], data, data_len);

        return eir_len;
}

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;
}

void *eir_get_service_data(u8 *eir, size_t eir_len, u16 uuid, size_t *len);