xref: /btstack/src/mesh/pb_gatt.c (revision 77ba3d3f9fd2c90e975cda31e3c706784e95d43a)
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 #define __BTSTACK_FILE__ "pb_gatt.c"
39 
40 #include <stdlib.h>
41 #include <string.h>
42 #include "btstack_util.h"
43 #include "btstack_debug.h"
44 #include "btstack_event.h"
45 #include "mesh/pb_gatt.h"
46 #include "ble/gatt-service/mesh_provisioning_service_server.h"
47 #include "provisioning.h"
48 #include "ble/att_server.h"
49 
50 /************** PB GATT Mesh Provisioning ********************/
51 
52 // share buffer for reassembly and segmentation - protocol is half-duplex
53 static union {
54     uint8_t  reassembly_buffer[MESH_PROV_MAX_PROXY_PDU];
55     uint8_t  segmentation_buffer[MESH_PROV_MAX_PROXY_PDU];
56 } sar_buffer;
57 
58 static const uint8_t * pb_gatt_own_device_uuid;
59 static const uint8_t * proxy_pdu;
60 static uint16_t proxy_pdu_size;
61 
62 static uint16_t reassembly_offset;
63 static uint16_t segmentation_offset;
64 static mesh_msg_sar_field_t segmentation_state;
65 static uint16_t pb_gatt_mtu;
66 
67 static btstack_packet_handler_t pb_gatt_packet_handler;
68 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
69 
70 static void pb_gatt_emit_pdu_sent(uint8_t status){
71     uint8_t event[] = {HCI_EVENT_MESH_META, 2, MESH_SUBEVENT_PB_TRANSPORT_PDU_SENT, status};
72     pb_gatt_packet_handler(HCI_EVENT_PACKET, 0, event, sizeof(event));
73 }
74 
75 static void packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
76     UNUSED(channel);
77     UNUSED(size);
78     mesh_msg_sar_field_t msg_sar_field;
79     mesh_msg_type_t msg_type;
80     int pdu_segment_len;
81     int pos;
82     hci_con_handle_t con_handle;
83 
84     switch (packet_type) {
85         case PROVISIONING_DATA_PACKET:
86             pos = 0;
87             // on provisioning PDU call packet handler with PROVISIONG_DATA type
88             msg_sar_field = packet[pos] >> 6;
89             msg_type = packet[pos] & 0x3F;
90             pos++;
91             if (msg_type != MESH_MSG_TYPE_PROVISIONING_PDU) return;
92             if (!pb_gatt_packet_handler) return;
93 
94             pdu_segment_len = size - pos;
95 
96             if (sizeof(sar_buffer.reassembly_buffer) - reassembly_offset < pdu_segment_len) {
97                 log_error("sar buffer too small left %d, new to store %d", MESH_PROV_MAX_PROXY_PDU - reassembly_offset, pdu_segment_len);
98                 break;
99             }
100 
101             // update mtu if incoming packet is larger than default
102             if (size > (ATT_DEFAULT_MTU - 1)){
103                 log_info("Remote uses larger MTU, enable long PDUs");
104                 pb_gatt_mtu = att_server_get_mtu(channel);
105             }
106 
107             switch (msg_sar_field){
108                 case MESH_MSG_SAR_FIELD_FIRST_SEGMENT:
109                     memset(sar_buffer.reassembly_buffer, 0, sizeof(sar_buffer.reassembly_buffer));
110                     memcpy(sar_buffer.reassembly_buffer, packet+pos, pdu_segment_len);
111                     reassembly_offset = pdu_segment_len;
112                     return;
113                 case MESH_MSG_SAR_FIELD_CONTINUE:
114                     memcpy(sar_buffer.reassembly_buffer + reassembly_offset, packet+pos, pdu_segment_len);
115                     reassembly_offset += pdu_segment_len;
116                     return;
117                 case MESH_MSG_SAR_FIELD_LAST_SEGMENT:
118                     memcpy(sar_buffer.reassembly_buffer + reassembly_offset, packet+pos, pdu_segment_len);
119                     reassembly_offset += pdu_segment_len;
120                     // send to provisioning device
121                     pb_gatt_packet_handler(PROVISIONING_DATA_PACKET, 0, sar_buffer.reassembly_buffer, reassembly_offset);
122                     reassembly_offset = 0;
123                     break;
124                 case MESH_MSG_SAR_FIELD_COMPLETE_MSG:
125                     // send to provisioning device
126                     pb_gatt_packet_handler(PROVISIONING_DATA_PACKET, 0, packet+pos, pdu_segment_len);
127                     break;
128             }
129             break;
130 
131         case HCI_EVENT_PACKET:
132             switch (hci_event_packet_get_type(packet)) {
133                 case HCI_EVENT_MESH_META:
134                     switch (hci_event_mesh_meta_get_subevent_code(packet)){
135                         case MESH_SUBEVENT_PB_TRANSPORT_LINK_OPEN:
136                         case MESH_SUBEVENT_PB_TRANSPORT_LINK_CLOSED:
137                             // Forward link open/close
138                             pb_gatt_mtu = ATT_DEFAULT_MTU;
139                             pb_gatt_packet_handler(HCI_EVENT_PACKET, 0, packet, size);
140                             break;
141                         case MESH_SUBEVENT_CAN_SEND_NOW:
142                             con_handle = little_endian_read_16(packet, 3);
143                             if (con_handle == HCI_CON_HANDLE_INVALID) return;
144 
145                             sar_buffer.segmentation_buffer[0] = (segmentation_state << 6) | MESH_MSG_TYPE_PROVISIONING_PDU;
146                             pdu_segment_len = btstack_min(proxy_pdu_size - segmentation_offset, pb_gatt_mtu - 1);
147                             memcpy(&sar_buffer.segmentation_buffer[1], &proxy_pdu[segmentation_offset], pdu_segment_len);
148                             segmentation_offset += pdu_segment_len;
149 
150                             mesh_provisioning_service_server_send_proxy_pdu(con_handle, sar_buffer.segmentation_buffer, pdu_segment_len + 1);
151 
152                             switch (segmentation_state){
153                                 case MESH_MSG_SAR_FIELD_COMPLETE_MSG:
154                                 case MESH_MSG_SAR_FIELD_LAST_SEGMENT:
155                                     pb_gatt_emit_pdu_sent(0);
156                                     break;
157                                 case MESH_MSG_SAR_FIELD_CONTINUE:
158                                 case MESH_MSG_SAR_FIELD_FIRST_SEGMENT:
159                                     if ((proxy_pdu_size - segmentation_offset) > (pb_gatt_mtu - 1)){
160                                         segmentation_state = MESH_MSG_SAR_FIELD_CONTINUE;
161                                     } else {
162                                         segmentation_state = MESH_MSG_SAR_FIELD_LAST_SEGMENT;
163                                     }
164                                     mesh_provisioning_service_server_request_can_send_now(con_handle);
165                                     break;
166                             }
167                             break;
168                         default:
169                             break;
170                     }
171             }
172             break;
173         default:
174             break;
175     }
176 }
177 
178 /**
179  * Setup mesh provisioning service
180  * @param device_uuid
181  */
182 void pb_gatt_init(const uint8_t * device_uuid){
183     pb_gatt_own_device_uuid = device_uuid;
184     // setup mesh provisioning service
185     mesh_provisioning_service_server_init();
186     mesh_provisioning_service_server_register_packet_handler(packet_handler);
187 }
188 
189 /**
190  * Register listener for Provisioning PDUs
191  */
192 void pb_gatt_register_packet_handler(btstack_packet_handler_t _packet_handler){
193     pb_gatt_packet_handler = _packet_handler;
194 }
195 
196 /**
197  * Send pdu
198  * @param con_handle
199  * @param pdu
200  * @param pdu_size
201  */
202 void pb_gatt_send_pdu(uint16_t con_handle, const uint8_t * pdu, uint16_t size){
203     if (!pdu || size <= 0) return;
204     if (con_handle == HCI_CON_HANDLE_INVALID) return;
205     // store pdu, request to send
206     proxy_pdu = pdu;
207     proxy_pdu_size = size;
208     segmentation_offset = 0;
209 
210     // check if segmentation is necessary
211     if (proxy_pdu_size > (pb_gatt_mtu - 1)){
212         segmentation_state = MESH_MSG_SAR_FIELD_FIRST_SEGMENT;
213     } else {
214         segmentation_state = MESH_MSG_SAR_FIELD_COMPLETE_MSG;
215     }
216     mesh_provisioning_service_server_request_can_send_now(con_handle);
217 }
218 /**
219  * Close Link
220  * @param con_handle
221  * @param reason 0 = success, 1 = timeout, 2 = fail
222  */
223 void pb_gatt_close_link(hci_con_handle_t con_handle, uint8_t reason){
224 }
225 
226 /**
227  * Setup Link with unprovisioned device
228  * @param device_uuid
229  * @returns con_handle or HCI_CON_HANDLE_INVALID
230  */
231 uint16_t pb_gatt_create_link(const uint8_t * device_uuid){
232     return HCI_CON_HANDLE_INVALID;
233 }
234