xref: /btstack/src/ble/att_dispatch.c (revision b3fcedb9c9ccbcc9680da165cd86f394be5d84a8)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 
39 /**
40  * Dispatcher for independent implementation of ATT client and server
41  */
42 
43 #include "att_dispatch.h"
44 #include "ble/core.h"
45 #include "btstack_debug.h"
46 #include "l2cap.h"
47 
48 static btstack_packet_handler_t att_client_handler;
49 static btstack_packet_handler_t att_server_handler;
50 
51 static uint8_t att_client_waiting_for_can_send;
52 static uint8_t att_server_waiting_for_can_send;
53 
54 static void att_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size){
55 	switch (packet_type){
56 		case ATT_DATA_PACKET:
57 			// log_info("att_data_packet with opcode 0x%x", packet[0]);
58 			if (packet[0] & 1){
59 				// odd PDUs are sent from server to client
60 				if (!att_client_handler) return;
61 				att_client_handler(packet_type, handle, packet, size);
62 			} else {
63 				// even PDUs are sent from client to server
64 				if (!att_server_handler) return;
65 				att_server_handler(packet_type, handle, packet, size);
66 			}
67 		case HCI_EVENT_PACKET:
68 			if (packet[0] != L2CAP_EVENT_CAN_SEND_NOW) break;
69 			if (att_server_handler && att_server_waiting_for_can_send){
70 				att_server_waiting_for_can_send = 0;
71 				att_server_handler(packet_type, handle, packet, size);
72 				// stop if client cannot send anymore
73 				if (!hci_can_send_acl_le_packet_now()) break;
74 			}
75 			if (att_client_handler && att_client_waiting_for_can_send){
76 				att_client_waiting_for_can_send = 0;
77 				att_client_handler(packet_type, handle, packet, size);
78 			}
79 			break;
80 		default:
81 			break;
82 	}
83 }
84 
85 /**
86  * @brief reset att dispatchter
87  * @param packet_hander for ATT client packets
88  */
89 void att_dispatch_register_client(btstack_packet_handler_t packet_handler){
90 	att_client_handler = packet_handler;
91 	l2cap_register_fixed_channel(att_packet_handler, L2CAP_CID_ATTRIBUTE_PROTOCOL);
92 }
93 
94 /**
95  * @brief reset att dispatchter
96  * @param packet_hander for ATT server packets
97  */
98 void att_dispatch_register_server(btstack_packet_handler_t packet_handler){
99 	att_server_handler = packet_handler;
100 	l2cap_register_fixed_channel(att_packet_handler, L2CAP_CID_ATTRIBUTE_PROTOCOL);
101 }
102 
103 /**
104  * @brief can send packet for client
105  * @param handle
106  */
107 int att_dispatch_client_can_send_now(hci_con_handle_t con_handle){
108 	return l2cap_can_send_fixed_channel_packet_now(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL);
109 }
110 
111 /**
112  * @brief can send packet for server
113  * @param handle
114  */
115 int att_dispatch_server_can_send_now(hci_con_handle_t con_handle){
116 	return l2cap_can_send_fixed_channel_packet_now(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL);
117 }
118 
119 /**
120  * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible for client
121  * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function
122  *       so packet handler should be ready to handle it
123  * @param con_handle
124  */
125 void att_dispatch_client_request_can_send_now_event(hci_con_handle_t con_handle){
126 	att_client_waiting_for_can_send = 1;
127 	l2cap_request_can_send_fix_channel_now_event(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL);
128 }
129 
130 /**
131  * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible for server
132  * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function
133  *       so packet handler should be ready to handle it
134  * @param con_handle
135  */
136 void att_dispatch_server_request_can_send_now_event(hci_con_handle_t con_handle){
137 	att_server_waiting_for_can_send = 1;
138 	l2cap_request_can_send_fix_channel_now_event(con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL);
139 }
140