net/bluetooth/eir.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * BlueZ - Bluetooth protocol stack for Linux
   4  *
   5  * Copyright (C) 2021 Intel Corporation
   6  */
   7
   8 #include <asm/unaligned.h>
   9
  10 void eir_create(struct hci_dev *hdev, u8 *data);
  11
  12 u8 eir_create_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr);
  13 u8 eir_create_scan_rsp(struct hci_dev *hdev, u8 instance, u8 *ptr);
  14 u8 eir_create_per_adv_data(struct hci_dev *hdev, u8 instance, u8 *ptr);
  15
  16 u8 eir_append_local_name(struct hci_dev *hdev, u8 *eir, u8 ad_len);
  17 u8 eir_append_appearance(struct hci_dev *hdev, u8 *ptr, u8 ad_len);
  18 u8 eir_append_service_data(u8 *eir, u16 eir_len, u16 uuid, u8 *data,
  19                            u8 data_len);
  20
  21 static inline u16 eir_precalc_len(u8 data_len)
  22 {
  23         return sizeof(u8) * 2 + data_len;
  24 }
  25
  26 static inline u16 eir_append_data(u8 *eir, u16 eir_len, u8 type,
  27                                   u8 *data, u8 data_len)
  28 {
  29         eir[eir_len++] = sizeof(type) + data_len;
  30         eir[eir_len++] = type;
  31         memcpy(&eir[eir_len], data, data_len);
  32         eir_len += data_len;
  33
  34         return eir_len;
  35 }
  36
  37 static inline u16 eir_append_le16(u8 *eir, u16 eir_len, u8 type, u16 data)
  38 {
  39         eir[eir_len++] = sizeof(type) + sizeof(data);
  40         eir[eir_len++] = type;
  41         put_unaligned_le16(data, &eir[eir_len]);
  42         eir_len += sizeof(data);
  43
  44         return eir_len;
  45 }
  46
  47 static inline u16 eir_skb_put_data(struct sk_buff *skb, u8 type, u8 *data, u8 data_len)
  48 {
  49         u8 *eir;
  50         u16 eir_len;
  51
  52         eir_len = eir_precalc_len(data_len);
  53         eir = skb_put(skb, eir_len);
  54         WARN_ON(sizeof(type) + data_len > U8_MAX);
  55         eir[0] = sizeof(type) + data_len;
  56         eir[1] = type;
  57         memcpy(&eir[2], data, data_len);
  58
  59         return eir_len;
  60 }
  61
  62 static inline void *eir_get_data(u8 *eir, size_t eir_len, u8 type,
  63                                  size_t *data_len)
  64 {
  65         size_t parsed = 0;
  66
  67         if (eir_len < 2)
  68                 return NULL;
  69
  70         while (parsed < eir_len - 1) {
  71                 u8 field_len = eir[0];
  72
  73                 if (field_len == 0)
  74                         break;
  75
  76                 parsed += field_len + 1;
  77
  78                 if (parsed > eir_len)
  79                         break;
  80
  81                 if (eir[1] != type) {
  82                         eir += field_len + 1;
  83                         continue;
  84                 }
  85
  86                 /* Zero length data */
  87                 if (field_len == 1)
  88                         return NULL;
  89
  90                 if (data_len)
  91                         *data_len = field_len - 1;
  92
  93                 return &eir[2];
  94         }
  95
  96         return NULL;
  97 }
  98
  99 void *eir_get_service_data(u8 *eir, size_t eir_len, u16 uuid, size_t *len);