use buffers of size 1021 to fit 3-DH5 ACL packets, check buffer for SDP responses

src/btstack.c

@@ -48,7 +48,8 @@
 #include <stdarg.h>
 #include <stdio.h>
 
-static uint8_t hci_cmd_buffer[3+255];
+// static uint8_t hci_cmd_buffer[3+255]; // HCI Command Header + max payload
+static uint8_t hci_cmd_buffer[HCI_ACL_3DH5_SIZE]; // BTstack command packets are not size restricted
 
 static connection_t *btstack_connection = NULL;
 

src/hci.h

@@ -53,6 +53,10 @@
 #define HCI_SCO_DATA_PKT_HDR	  0x03
 #define HCI_EVENT_PKT_HDR         0x02
 
+// packet sizes
+#define HCI_ACL_3DH5_SIZE         1021
+#define HCI_ACL_DH5_SIZE           339
+
 // OGFs
 #define OGF_LINK_CONTROL          0x01
 #define OGF_LINK_POLICY           0x02

src/hci_transport_h4.c

@@ -73,7 +73,7 @@ static  H4_STATE h4_state;
 static int bytes_to_read;
 static int read_pos;
 // static uint8_t hci_event_buffer[255+2]; // maximal payload + 2 bytes header
-static uint8_t hci_packet[400]; // bigger than largest packet
+static uint8_t hci_packet[HCI_ACL_3DH5_SIZE]; // bigger than largest packet
 
 #ifdef TEST_LONG_INVALID_REMOTE_NAME
 // test event with remote name of 255 bytes length

src/hci_transport_h5.c

@@ -64,7 +64,7 @@ typedef enum {
 typedef struct h5_slip {
 	state_t state;
 	uint16_t length;
-	uint8_t data[400];
+	uint8_t data[HCI_ACL_3DH5_SIZE];
 } h5_slip_t;
 
 // Global State

src/hci_transport_usb.c

@@ -77,9 +77,9 @@ static hci_transport_t * hci_transport_usb = NULL;
 
 static  void (*packet_handler)(uint8_t *packet, int size) = dummy_handler;
 
-static uint8_t hci_cmd_out[400];      // bigger than largest packet
-static uint8_t hci_event_buffer[400]; // bigger than largest packet
-static uint8_t hci_acl_in[400];       // bigger than largest packet
+static uint8_t hci_cmd_out[HCI_ACL_3DH5_SIZE];      // bigger than largest packet
+static uint8_t hci_event_buffer[HCI_ACL_3DH5_SIZE]; // bigger than largest packet
+static uint8_t hci_acl_in[HCI_ACL_3DH5_SIZE];       // bigger than largest packet
 
 // libusb
 static struct libusb_device_descriptor desc;
@@ -278,7 +278,7 @@ static int usb_open(void *transport_config){
 	
 
     // bulk in (= ACL packets) handler
-	libusb_fill_bulk_transfer(bulk_in_transfer, handle, 0x82, hci_acl_in, 400, bulk_in_callback, NULL, 3000) ;	
+	libusb_fill_bulk_transfer(bulk_in_transfer, handle, 0x82, hci_acl_in, HCI_ACL_3DH5_SIZE, bulk_in_callback, NULL, 3000) ;	
 	// bulk_in_transfer->flags = LIBUSB_TRANSFER_SHORT_NOT_OK;
 	r = libusb_submit_transfer(bulk_in_transfer);
 	if (r) {

src/l2cap.c

@@ -72,8 +72,7 @@ static uint8_t config_options[] = { 1, 2, 150, 0}; // mtu = 48
 
 void l2cap_init(){
     sig_buffer = malloc( L2CAP_MINIMAL_MTU );
-    // acl_buffer = malloc( 255 + 8 ); 
-    acl_buffer = malloc( 400 + 8 ); 
+    acl_buffer = malloc( HCI_ACL_3DH5_SIZE); 
 
     // 
     // register callback with HCI

src/sdp.c

@@ -70,6 +70,10 @@ static uint32_t sdp_next_service_record_handle = maxReservedServiceRecordHandle
 // AttributeIDList used to remove ServiceRecordHandle
 const uint8_t removeServiceRecordHandleAttributeIDList[] = { 0x36, 0x00, 0x05, 0x0A, 0x00, 0x01, 0xFF, 0xFF };
 
+#define SDP_RESPONSE_BUFFER_SIZE HCI_ACL_3DH5_SIZE
+static uint8_t sdp_response_buffer[SDP_RESPONSE_BUFFER_SIZE];
+
+
 void sdp_init(){
     // register with l2cap psm sevices
     l2cap_register_service_internal(NULL, sdp_packet_handler, PSM_SDP, 250);
@@ -195,8 +199,6 @@ void sdp_unregister_services_for_connection(void *connection){
 // PDU
 // PDU ID (1), Transaction ID (2), Param Length (2), Param 1, Param 2, ..
 
-static uint8_t sdp_response_buffer[400];
-
 int sdp_create_error_response(uint16_t transaction_id, uint16_t error_code){
     sdp_response_buffer[0] = SDP_ErrorResponse;
     net_store_16(sdp_response_buffer, 1, transaction_id);
@@ -445,6 +447,11 @@ static void sdp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *p
             transaction_id = READ_NET_16(packet, 1);
             param_len = READ_NET_16(packet, 3);
             remote_mtu = l2cap_get_remote_mtu_for_local_cid(channel);
+            // account for our buffer
+            if (remote_mtu > SDP_RESPONSE_BUFFER_SIZE){
+                remote_mtu = SDP_RESPONSE_BUFFER_SIZE;
+            }
+            
             // printf("SDP Request: type %u, transaction id %u, len %u, mtu %u\n", pdu_id, transaction_id, param_len, remote_mtu);
             switch (pdu_id){
                     

src/socket_connection.c

@@ -88,7 +88,7 @@ struct connection {
     SOCKET_STATE state;
     uint16_t bytes_read;
     uint16_t bytes_to_read;
-    uint8_t  buffer[360]; // packet_header(6) + max packet: DH5 = header(4) + payload (339)
+    uint8_t  buffer[6+HCI_ACL_3DH5_SIZE]; // packet_header(6) + max packet: 3-DH5 = header(6) + payload (1021)
 };
 
 /** list of socket connections */