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Defined HCI_INCOMING_PRE_BUFFER_SIZE

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(14 Bytes = 2 * sizeof(bd_addr_t) + sizeof(uint16_t))
This avoids extra copying of the ethernet frame into a static buffer

bnep.c implements two solutions with and without HCI_INCOMING_PRE_BUFFER_SIZE
defined
This commit is contained in:
ole.reinhardt@googlemail.com 2014-11-12 00:12:23 +00:00
parent c24894aa88
commit cf7827865f
2 changed files with 22 additions and 4 deletions
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2
example/libusb/btstack-config.h
View File

@ -16,7 +16,7 @@
#define SDP_DES_DUMP
#define ENABLE_LOG_INFO
#define ENABLE_LOG_ERROR
//#define HCI_ACL_PAYLOAD_SIZE 1021
#define HCI_INCOMING_PRE_BUFFER_SIZE 14 // sizeof benep heade, avoid memcpy
#define HCI_ACL_PAYLOAD_SIZE (1691 + 4)
#define HAVE_HCI_DUMP
#define SDP_DES_DUMP

24
src/bnep.c
View File

@ -794,8 +794,25 @@ static int bnep_handle_multi_addr_response(bnep_channel_t *channel, uint8_t *pac
static int bnep_handle_ethernet_packet(bnep_channel_t *channel, bd_addr_t addr_dest, bd_addr_t addr_source, uint16_t network_protocol_type, uint8_t *payload, uint16_t size)
{
uint8_t ethernet_packet[BNEP_MTU_MIN];
uint16_t pos = 0;
#if (HCI_INCOMING_PRE_BUFFER_SIZE) && (HCI_INCOMING_PRE_BUFFER_SIZE >= 14 - 8) // 2 * sizeof(bd_addr_t) + sizeof(uint16_t) - L2CAP Header (4) - ACL Header (4)
/* In-place modify the package and add the ethernet header in front of the payload.
* WARNING: This modifies the data in front of the payload and may overwrite 14 bytes there!
*/
uint8_t *ethernet_packet = payload - 2 * sizeof(bd_addr_t) - sizeof(uint16_t);
/* Restore the ethernet packet header */
BD_ADDR_COPY(ethernet_packet + pos, addr_dest);
pos += sizeof(bd_addr_t);
BD_ADDR_COPY(ethernet_packet + pos, addr_source);
pos += sizeof(bd_addr_t);
bt_store_16(ethernet_packet, pos, network_protocol_type);
/* Payload is just in place... */
#else
/* Copy ethernet frame to statically allocated buffer. This solution is more
* save, but needs an extra copy and more stack!
*/
uint8_t ethernet_packet[BNEP_MTU_MIN];
/* Restore the ethernet packet header */
BD_ADDR_COPY(ethernet_packet + pos, addr_dest);
@ -805,11 +822,12 @@ static int bnep_handle_ethernet_packet(bnep_channel_t *channel, bd_addr_t addr_d
bt_store_16(ethernet_packet, pos, network_protocol_type);
pos += 2;
memcpy(ethernet_packet + pos, payload, size);
#endif
/* Notify application layer and deliver the ethernet packet */
(*app_packet_handler)(channel->connection, BNEP_DATA_PACKET, channel->uuid_source,
ethernet_packet, size + sizeof(uint16_t) + 2 * sizeof(bd_addr_t));
return size;
}