/** Recursively unwraps the given locally stored attribute (in PROGMEM space), searching for UUIDs to match against
* the given UUID list. As matches are found, they are indicated in the UUIDMatch flag list.
*
* \param[in] UUIDList List of UUIDs which must be matched within the service attribute table
* \param[in] TotalUUIDs Total number of UUIDs stored in the UUID list
* \param[in, out] UUIDMatchFlags Array of flags indicating which UUIDs in the list have already been matched
* \param[in] CurrAttribute Pointer to the current attribute to search through
*
* \return True if all the UUIDs given in the UUID list appear in the given attribute table, false otherwise
*/
static void SDP_CheckUUIDMatch(uint8_t UUIDList[][UUID_SIZE_BYTES],
const uint8_t TotalUUIDs,
uint16_t* const UUIDMatchFlags,
const void* CurrAttribute)
{
uint8_t CurrAttributeType = (pgm_read_byte(CurrAttribute) & ~0x07);
/* Check the data type of the current attribute value - if UUID, compare, if Sequence, unwrap and recurse */
if (CurrAttributeType == SDP_DATATYPE_UUID)
{
uint16_t CurrUUIDMatchMask = (1 << 0);
/* Look for matches in the UUID list against the current attribute UUID value */
for (uint8_t i = 0; i < TotalUUIDs; i++)
{
/* Check if the current unmatched UUID is identical to the search UUID */
if (!(*UUIDMatchFlags & CurrUUIDMatchMask) && !(memcmp_P(UUIDList[i], (CurrAttribute + 1), UUID_SIZE_BYTES)))
{
/* Indicate match found for the current attribute UUID and early-abort */
*UUIDMatchFlags |= CurrUUIDMatchMask;
break;
}
CurrUUIDMatchMask <<= 1;
}
}
else if (CurrAttributeType == SDP_DATATYPE_Sequence)
{
uint8_t SequenceHeaderSize;
uint16_t SequenceSize = SDP_GetLocalAttributeContainerSize(CurrAttribute, &SequenceHeaderSize);
CurrAttribute += SequenceHeaderSize;
/* Recursively unwrap the sequence container, and re-search its contents for UUIDs */
while (SequenceSize)
{
uint8_t InnerHeaderSize;
uint16_t InnerSize = SDP_GetLocalAttributeContainerSize(CurrAttribute, &InnerHeaderSize);
/* Recursively search of the next element in the sequence, trying to match UUIDs with the UUID list */
SDP_CheckUUIDMatch(UUIDList, TotalUUIDs, UUIDMatchFlags, CurrAttribute);
/* Skip to the next element in the sequence */
SequenceSize -= InnerHeaderSize + InnerSize;
CurrAttribute += InnerHeaderSize + InnerSize;
}
}
}
/** Retrieves the Attribute table for the given UUID list if it exists.
*
* \param[in] ServiceEntry Pointer to the service entry whose attribute table is to be examined
* \param[in] UUIDList List of UUIDs which must be matched within the service attribute table
* \param[in] TotalUUIDs Total number of UUIDs stored in the UUID list
*
* \return True if all the UUIDs given in the UUID list appear in the given attribute table, false otherwise
*/
static bool SDP_SearchServiceTable(const SDP_ServiceEntry_t* const ServiceEntry,
uint8_t UUIDList[][UUID_SIZE_BYTES],
const uint8_t TotalUUIDs)
{
uint16_t UUIDMatchFlags = 0;
/* Search through the current attribute table, checking each attribute value for UUID matches */\
for (uint8_t i = 0; i < ServiceEntry->TotalTableAttributes; i++)
{
const void* CurrAttribute = pgm_read_ptr(&ServiceEntry->AttributeTable[i].Data);
SDP_CheckUUIDMatch(UUIDList, TotalUUIDs, &UUIDMatchFlags, CurrAttribute);
}
/* Determine how many UUID matches in the list we have found */
uint8_t UUIDMatches;
for (UUIDMatches = 0; UUIDMatchFlags; UUIDMatches++)
UUIDMatchFlags &= (UUIDMatchFlags - 1);
/* If all UUIDs have been matched to the current service, return true */
return (UUIDMatches == TotalUUIDs);
}
/** Retrieves the Attribute table for the given UUID list if it exists.
*
* \param[in] UUIDList List of UUIDs which must be matched within the service attribute table
* \param[in] TotalUUIDs Total number of UUIDs stored in the UUID list
* \param[in] CurrAttributeTable Pointer to the service attribute table to search through
*
* \return True if all the UUIDs given in the UUID list appear in the given attribute table, false otherwise
*/
static bool SDP_SearchServiceTable(uint8_t UUIDList[][UUID_SIZE_BYTES],
const uint8_t TotalUUIDs,
const ServiceAttributeTable_t* CurrAttributeTable)
{
const void* CurrAttribute;
uint16_t UUIDMatchFlags = 0;
/* Search through the current attribute table, checking each attribute value for UUID matches */
while ((CurrAttribute = pgm_read_ptr(&CurrAttributeTable->Data)) != NULL)
{
SDP_CheckUUIDMatch(UUIDList, TotalUUIDs, &UUIDMatchFlags, CurrAttribute);
CurrAttributeTable++;
}
/* Determine how many UUID matches in the list we have found */
uint8_t UUIDMatches;
for (UUIDMatches = 0; UUIDMatchFlags; UUIDMatches++)
UUIDMatchFlags &= (UUIDMatchFlags - 1);
/* If all UUIDs have been matched to the current service, return true */
return (UUIDMatches == TotalUUIDs);
}
