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__ "l2cap.c" 39 40 /* 41 * l2cap.c 42 * 43 * Logical Link Control and Adaption Protocl (L2CAP) 44 * 45 * Created by Matthias Ringwald on 5/16/09. 46 */ 47 48 #include "l2cap.h" 49 #include "hci.h" 50 #include "hci_dump.h" 51 #include "bluetooth_sdp.h" 52 #include "btstack_debug.h" 53 #include "btstack_event.h" 54 #include "btstack_memory.h" 55 56 #ifdef ENABLE_LE_DATA_CHANNELS 57 #include "ble/sm.h" 58 #endif 59 60 #include <stdarg.h> 61 #include <string.h> 62 63 #include <stdio.h> 64 65 // nr of buffered acl packets in outgoing queue to get max performance 66 #define NR_BUFFERED_ACL_PACKETS 3 67 68 // used to cache l2cap rejects, echo, and informational requests 69 #define NR_PENDING_SIGNALING_RESPONSES 3 70 71 // nr of credits provided to remote if credits fall below watermark 72 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 73 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 74 75 // offsets for L2CAP SIGNALING COMMANDS 76 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 77 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 78 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 79 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 80 81 // internal table 82 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 83 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 84 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 85 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) 86 87 #if defined(ENABLE_LE_DATA_CHANNELS) || defined(ENABLE_CLASSIC) 88 #define L2CAP_USES_CHANNELS 89 #endif 90 91 // prototypes 92 static void l2cap_run(void); 93 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 94 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 95 static void l2cap_notify_channel_can_send(void); 96 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 97 #ifdef ENABLE_CLASSIC 98 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 99 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 100 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 101 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 102 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel); 103 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 104 #endif 105 #ifdef ENABLE_LE_DATA_CHANNELS 106 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status); 107 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel); 108 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid); 109 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel); 110 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 111 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 112 #endif 113 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 114 static int l2cap_ertm_num_unacknowledged_tx_packets(l2cap_channel_t * channel); 115 #endif 116 117 typedef struct l2cap_fixed_channel { 118 btstack_packet_handler_t callback; 119 uint8_t waiting_for_can_send_now; 120 } l2cap_fixed_channel_t; 121 122 #ifdef ENABLE_CLASSIC 123 static btstack_linked_list_t l2cap_channels; 124 static btstack_linked_list_t l2cap_services; 125 static uint8_t require_security_level2_for_outgoing_sdp; 126 #endif 127 128 #ifdef ENABLE_LE_DATA_CHANNELS 129 static btstack_linked_list_t l2cap_le_channels; 130 static btstack_linked_list_t l2cap_le_services; 131 #endif 132 133 // used to cache l2cap rejects, echo, and informational requests 134 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 135 static int signaling_responses_pending; 136 137 static btstack_packet_callback_registration_t hci_event_callback_registration; 138 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 139 140 #ifdef ENABLE_BLE 141 // only used for connection parameter update events 142 static btstack_packet_handler_t l2cap_event_packet_handler; 143 #endif 144 145 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 146 147 /* 148 * CRC lookup table for generator polynom D^16 + D^15 + D^2 + 1 149 */ 150 static const uint16_t crc16_table[256] = { 151 0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241, 0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440, 152 0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40, 0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841, 153 0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40, 0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41, 154 0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641, 0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040, 155 0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240, 0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441, 156 0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41, 0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840, 157 0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41, 0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40, 158 0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640, 0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041, 159 0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240, 0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441, 160 0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41, 0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840, 161 0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41, 0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40, 162 0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640, 0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041, 163 0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241, 0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440, 164 0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40, 0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841, 165 0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40, 0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41, 166 0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641, 0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040, 167 }; 168 169 static uint16_t crc16_calc(uint8_t * data, uint16_t len){ 170 uint16_t crc = 0; // initial value = 0 171 while (len--){ 172 crc = (crc >> 8) ^ crc16_table[ (crc ^ ((uint16_t) *data++)) & 0x00FF ]; 173 } 174 return crc; 175 } 176 177 #endif 178 179 180 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 181 switch (index){ 182 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 183 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 184 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 185 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 186 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 187 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 188 default: 189 return 0; 190 } 191 } 192 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 193 switch (channel_id){ 194 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 195 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 196 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 197 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 198 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 199 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 200 default: 201 return -1; 202 } 203 } 204 205 static int l2cap_fixed_channel_table_index_is_le(int index){ 206 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 207 return 1; 208 } 209 210 void l2cap_init(void){ 211 signaling_responses_pending = 0; 212 213 uint8_t test[] = {0x0E, 0x00, 0x40, 0x00, 0x02, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09 }; 214 printf("crc16: %04x\n", crc16_calc(test, sizeof(test))); 215 216 #ifdef ENABLE_CLASSIC 217 l2cap_channels = NULL; 218 l2cap_services = NULL; 219 require_security_level2_for_outgoing_sdp = 0; 220 #endif 221 222 #ifdef ENABLE_LE_DATA_CHANNELS 223 l2cap_le_services = NULL; 224 l2cap_le_channels = NULL; 225 #endif 226 227 #ifdef ENABLE_BLE 228 l2cap_event_packet_handler = NULL; 229 #endif 230 memset(fixed_channels, 0, sizeof(fixed_channels)); 231 232 // 233 // register callback with HCI 234 // 235 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 236 hci_add_event_handler(&hci_event_callback_registration); 237 238 hci_register_acl_packet_handler(&l2cap_acl_handler); 239 240 #ifdef ENABLE_CLASSIC 241 gap_connectable_control(0); // no services yet 242 #endif 243 } 244 245 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 246 #ifdef ENABLE_BLE 247 l2cap_event_packet_handler = handler; 248 #else 249 UNUSED(handler); 250 #endif 251 } 252 253 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 254 UNUSED(con_handle); 255 256 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 257 if (index < 0) return; 258 fixed_channels[index].waiting_for_can_send_now = 1; 259 l2cap_notify_channel_can_send(); 260 } 261 262 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 263 UNUSED(channel_id); 264 265 return hci_can_send_acl_packet_now(con_handle); 266 } 267 268 uint8_t *l2cap_get_outgoing_buffer(void){ 269 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 270 } 271 272 int l2cap_reserve_packet_buffer(void){ 273 return hci_reserve_packet_buffer(); 274 } 275 276 void l2cap_release_packet_buffer(void){ 277 hci_release_packet_buffer(); 278 } 279 280 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint8_t packet_boundary, uint16_t remote_cid, uint16_t len){ 281 // 0 - Connection handle : PB=pb : BC=00 282 little_endian_store_16(acl_buffer, 0, con_handle | (packet_boundary << 12) | (0 << 14)); 283 // 2 - ACL length 284 little_endian_store_16(acl_buffer, 2, len + 4); 285 // 4 - L2CAP packet length 286 little_endian_store_16(acl_buffer, 4, len + 0); 287 // 6 - L2CAP channel DEST 288 little_endian_store_16(acl_buffer, 6, remote_cid); 289 } 290 291 // assumption - only on LE connections 292 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 293 294 if (!hci_is_packet_buffer_reserved()){ 295 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 296 return BTSTACK_ACL_BUFFERS_FULL; 297 } 298 299 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 300 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 301 return BTSTACK_ACL_BUFFERS_FULL; 302 } 303 304 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 305 306 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 307 l2cap_setup_header(acl_buffer, con_handle, 0, cid, len); 308 // send 309 return hci_send_acl_packet_buffer(len+8); 310 } 311 312 // assumption - only on LE connections 313 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 314 315 if (!hci_can_send_acl_packet_now(con_handle)){ 316 log_info("l2cap_send cid 0x%02x, cannot send", cid); 317 return BTSTACK_ACL_BUFFERS_FULL; 318 } 319 320 hci_reserve_packet_buffer(); 321 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 322 323 memcpy(&acl_buffer[8], data, len); 324 325 return l2cap_send_prepared_connectionless(con_handle, cid, len); 326 } 327 328 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 329 log_debug("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 330 uint8_t event[4]; 331 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 332 event[1] = sizeof(event) - 2; 333 little_endian_store_16(event, 2, channel); 334 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 335 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 336 } 337 338 #ifdef L2CAP_USES_CHANNELS 339 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 340 (* (channel->packet_handler))(type, channel->local_cid, data, size); 341 } 342 343 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 344 uint8_t event[4]; 345 event[0] = event_code; 346 event[1] = sizeof(event) - 2; 347 little_endian_store_16(event, 2, channel->local_cid); 348 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 349 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 350 } 351 #endif 352 353 #ifdef ENABLE_CLASSIC 354 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 355 log_info("L2CAP_EVENT_CHANNEL_OPENED status 0x%x addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u, flush_timeout %u", 356 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 357 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 358 uint8_t event[24]; 359 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 360 event[1] = sizeof(event) - 2; 361 event[2] = status; 362 reverse_bd_addr(channel->address, &event[3]); 363 little_endian_store_16(event, 9, channel->con_handle); 364 little_endian_store_16(event, 11, channel->psm); 365 little_endian_store_16(event, 13, channel->local_cid); 366 little_endian_store_16(event, 15, channel->remote_cid); 367 little_endian_store_16(event, 17, channel->local_mtu); 368 little_endian_store_16(event, 19, channel->remote_mtu); 369 little_endian_store_16(event, 21, channel->flush_timeout); 370 event[23] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 371 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 372 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 373 } 374 375 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 376 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 377 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 378 } 379 380 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 381 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 382 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 383 uint8_t event[16]; 384 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 385 event[1] = sizeof(event) - 2; 386 reverse_bd_addr(channel->address, &event[2]); 387 little_endian_store_16(event, 8, channel->con_handle); 388 little_endian_store_16(event, 10, channel->psm); 389 little_endian_store_16(event, 12, channel->local_cid); 390 little_endian_store_16(event, 14, channel->remote_cid); 391 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 392 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 393 } 394 395 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 396 btstack_linked_list_iterator_t it; 397 btstack_linked_list_iterator_init(&it, &l2cap_channels); 398 while (btstack_linked_list_iterator_has_next(&it)){ 399 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 400 if ( channel->local_cid == local_cid) { 401 return channel; 402 } 403 } 404 return NULL; 405 } 406 407 /// 408 409 void l2cap_request_can_send_now_event(uint16_t local_cid){ 410 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 411 if (!channel) return; 412 channel->waiting_for_can_send_now = 1; 413 l2cap_notify_channel_can_send(); 414 } 415 416 int l2cap_can_send_packet_now(uint16_t local_cid){ 417 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 418 if (!channel) return 0; 419 return hci_can_send_acl_packet_now(channel->con_handle); 420 } 421 422 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 423 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 424 if (!channel) return 0; 425 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 426 } 427 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 428 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 429 if (channel) { 430 return channel->remote_mtu; 431 } 432 return 0; 433 } 434 435 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 436 btstack_linked_list_iterator_t it; 437 btstack_linked_list_iterator_init(&it, &l2cap_channels); 438 while (btstack_linked_list_iterator_has_next(&it)){ 439 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 440 if ( &channel->rtx == ts) { 441 return channel; 442 } 443 } 444 return NULL; 445 } 446 447 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 448 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 449 if (!channel) return; 450 451 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 452 453 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 454 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 455 // notify client 456 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 457 458 // discard channel 459 // no need to stop timer here, it is removed from list during timer callback 460 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 461 btstack_memory_l2cap_channel_free(channel); 462 } 463 464 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 465 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 466 btstack_run_loop_remove_timer(&channel->rtx); 467 } 468 469 static void l2cap_start_rtx(l2cap_channel_t * channel){ 470 l2cap_stop_rtx(channel); 471 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 472 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 473 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 474 btstack_run_loop_add_timer(&channel->rtx); 475 } 476 477 static void l2cap_start_ertx(l2cap_channel_t * channel){ 478 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 479 l2cap_stop_rtx(channel); 480 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 481 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 482 btstack_run_loop_add_timer(&channel->rtx); 483 } 484 485 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 486 require_security_level2_for_outgoing_sdp = 1; 487 } 488 489 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 490 return (psm == BLUETOOTH_PROTOCOL_SDP) && (!require_security_level2_for_outgoing_sdp); 491 } 492 493 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 494 if (!hci_can_send_acl_packet_now(handle)){ 495 log_info("l2cap_send_signaling_packet, cannot send"); 496 return BTSTACK_ACL_BUFFERS_FULL; 497 } 498 499 // log_info("l2cap_send_signaling_packet type %u", cmd); 500 hci_reserve_packet_buffer(); 501 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 502 va_list argptr; 503 va_start(argptr, identifier); 504 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 505 va_end(argptr); 506 // log_info("l2cap_send_signaling_packet con %u!", handle); 507 return hci_send_acl_packet_buffer(len); 508 } 509 510 // assumption - only on Classic connections 511 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 512 513 if (!hci_is_packet_buffer_reserved()){ 514 log_error("l2cap_send_prepared called without reserving packet first"); 515 return BTSTACK_ACL_BUFFERS_FULL; 516 } 517 518 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 519 if (!channel) { 520 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 521 return -1; // TODO: define error 522 } 523 524 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 525 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 526 return BTSTACK_ACL_BUFFERS_FULL; 527 } 528 529 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 530 531 int fcs_size = 0; 532 533 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 534 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 535 fcs_size = 2; 536 } 537 #endif 538 539 // set non-flushable packet boundary flag if supported on Controller 540 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 541 uint8_t packet_boundary_flag = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 542 l2cap_setup_header(acl_buffer, channel->con_handle, packet_boundary_flag, channel->remote_cid, len + fcs_size); 543 544 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 545 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 546 // calculate FCS over l2cap data 547 uint16_t fcs = crc16_calc(acl_buffer + 4, 4 + len); 548 log_info("I-Frame: fcs 0x%04x", fcs); 549 little_endian_store_16(acl_buffer, 8 + len, fcs); 550 } 551 #endif 552 553 // send 554 return hci_send_acl_packet_buffer(len+8+fcs_size); 555 } 556 557 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 558 static inline uint16_t l2cap_encanced_control_field_for_information_frame(uint8_t tx_seq, int final, uint8_t req_seq, l2cap_segmentation_and_reassembly_t sar){ 559 return (((uint16_t) sar) << 14) | (req_seq << 8) | (final << 7) | (tx_seq << 1) | 0; 560 } 561 static inline uint16_t l2cap_encanced_control_field_for_supevisor_frame(l2cap_supervisory_function_t supervisory_function, int poll, int final, uint8_t req_seq){ 562 return (req_seq << 8) | (final << 7) | (poll << 4) | (((int) supervisory_function) << 2) | 1; 563 } 564 static int l2cap_next_ertm_seq_nr(int seq_nr){ 565 return (seq_nr + 1) & 0x3f; 566 } 567 static void l2cap_ertm_next_tx_write_index(l2cap_channel_t * channel){ 568 channel->tx_write_index++; 569 if (channel->tx_write_index < channel->num_tx_buffers) return; 570 channel->tx_write_index = 0; 571 } 572 static int l2cap_ertm_send_information_frame(l2cap_channel_t * channel, int index){ 573 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 574 hci_reserve_packet_buffer(); 575 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 576 uint16_t control = l2cap_encanced_control_field_for_information_frame(tx_state->tx_seq, 0, 0, L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU); 577 log_info("I-Frame: control 0x%04x", control); 578 little_endian_store_16(acl_buffer, 8, control); 579 memcpy(&acl_buffer[8+2], &channel->tx_packets_data[index * channel->local_mtu], tx_state->len); 580 // send 581 return l2cap_send_prepared(channel->local_cid, 2 + tx_state->len); 582 } 583 static int l2cap_ertm_send(l2cap_channel_t * channel, uint8_t * data, uint16_t len){ 584 if (len > channel->remote_mtu){ 585 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", channel->local_cid); 586 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 587 } 588 // TODO: check tx_transmit 589 // store int tx packet buffer 590 int index = channel->tx_write_index; 591 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 592 tx_state->tx_seq = channel->next_tx_seq; 593 tx_state->len = len; 594 memcpy(&channel->tx_packets_data[index * channel->local_mtu], data, len); 595 // update 596 channel->next_tx_seq = l2cap_next_ertm_seq_nr(channel->next_tx_seq); 597 l2cap_ertm_next_tx_write_index(channel); 598 // try to send 599 l2cap_run(); 600 return 0; 601 } 602 #endif 603 604 // assumption - only on Classic connections 605 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 606 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 607 if (!channel) { 608 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 609 return -1; // TODO: define error 610 } 611 612 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 613 // send in ERTM 614 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 615 return l2cap_ertm_send(channel, data, len); 616 } 617 #endif 618 619 if (len > channel->remote_mtu){ 620 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 621 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 622 } 623 624 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 625 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 626 return BTSTACK_ACL_BUFFERS_FULL; 627 } 628 629 hci_reserve_packet_buffer(); 630 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 631 memcpy(&acl_buffer[8], data, len); 632 return l2cap_send_prepared(local_cid, len); 633 } 634 635 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 636 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 637 } 638 639 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 640 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 641 } 642 643 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 644 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 645 } 646 #endif 647 648 649 #ifdef ENABLE_BLE 650 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 651 652 if (!hci_can_send_acl_packet_now(handle)){ 653 log_info("l2cap_send_le_signaling_packet, cannot send"); 654 return BTSTACK_ACL_BUFFERS_FULL; 655 } 656 657 // log_info("l2cap_send_le_signaling_packet type %u", cmd); 658 hci_reserve_packet_buffer(); 659 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 660 va_list argptr; 661 va_start(argptr, identifier); 662 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 663 va_end(argptr); 664 // log_info("l2cap_send_le_signaling_packet con %u!", handle); 665 return hci_send_acl_packet_buffer(len); 666 } 667 #endif 668 669 uint16_t l2cap_max_mtu(void){ 670 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 671 } 672 673 uint16_t l2cap_max_le_mtu(void){ 674 return l2cap_max_mtu(); 675 } 676 677 static uint16_t l2cap_setup_options_mtu(l2cap_channel_t * channel, uint8_t * config_options){ 678 config_options[0] = 1; // MTU 679 config_options[1] = 2; // len param 680 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 681 return 4; 682 } 683 684 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 685 static uint16_t l2cap_setup_options_ertm(l2cap_channel_t * channel, uint8_t * config_options){ 686 config_options[0] = 0x04; // RETRANSMISSION AND FLOW CONTROL OPTION 687 config_options[1] = 9; // length 688 config_options[2] = (uint8_t) channel->mode; 689 config_options[3] = channel->num_rx_buffers; // == TxWindows size 690 config_options[4] = channel->local_max_transmit; 691 little_endian_store_16( config_options, 5, channel->local_retransmission_timeout_ms); 692 little_endian_store_16( config_options, 7, channel->local_monitor_timeout_ms); 693 little_endian_store_16( config_options, 9, channel->local_mtu); 694 return 11; 695 } 696 static int l2cap_ertm_send_supervisor_frame(l2cap_channel_t * channel, uint16_t control){ 697 hci_reserve_packet_buffer(); 698 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 699 log_info("S-Frame: control 0x%04x", control); 700 little_endian_store_16(acl_buffer, 8, control); 701 return l2cap_send_prepared(channel->local_cid, 2); 702 } 703 static int l2cap_ertm_num_unacknowledged_tx_packets(l2cap_channel_t * channel){ 704 int unacknowledged_packets = channel->tx_send_index - channel->tx_read_index; 705 if (unacknowledged_packets < 0){ 706 unacknowledged_packets += channel->num_tx_buffers; 707 } 708 return unacknowledged_packets; 709 } 710 #endif 711 712 static uint16_t l2cap_setup_options(l2cap_channel_t * channel, uint8_t * config_options){ 713 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 714 // use ERTM options if supported 715 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 716 if ((connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_DONE) && (connection->l2cap_state.extended_feature_mask & 0x08)){ 717 return l2cap_setup_options_ertm(channel, config_options); 718 719 } 720 #endif 721 return l2cap_setup_options_mtu(channel, config_options); 722 } 723 724 static uint32_t l2cap_extended_features_mask(void){ 725 // extended features request supported, features: fixed channels, unicast connectionless data reception 726 uint32_t features = 0x280; 727 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 728 features |= 0x0008; 729 #endif 730 return features; 731 } 732 733 // MARK: L2CAP_RUN 734 // process outstanding signaling tasks 735 static void l2cap_run(void){ 736 737 // log_info("l2cap_run: entered"); 738 739 // check pending signaling responses 740 while (signaling_responses_pending){ 741 742 hci_con_handle_t handle = signaling_responses[0].handle; 743 744 if (!hci_can_send_acl_packet_now(handle)) break; 745 746 uint8_t sig_id = signaling_responses[0].sig_id; 747 uint8_t response_code = signaling_responses[0].code; 748 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 749 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 750 #ifdef ENABLE_CLASSIC 751 uint16_t source_cid = signaling_responses[0].cid; // CONNECTION_REQUEST 752 #endif 753 UNUSED(infoType); 754 755 // remove first item before sending (to avoid sending response mutliple times) 756 signaling_responses_pending--; 757 int i; 758 for (i=0; i < signaling_responses_pending; i++){ 759 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 760 } 761 762 switch (response_code){ 763 #ifdef ENABLE_CLASSIC 764 case CONNECTION_REQUEST: 765 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, source_cid, 0, result, 0); 766 // also disconnect if result is 0x0003 - security blocked 767 if (result == 0x0003){ 768 hci_disconnect_security_block(handle); 769 } 770 break; 771 case ECHO_REQUEST: 772 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 773 break; 774 case INFORMATION_REQUEST: 775 switch (infoType){ 776 case 1: { // Connectionless MTU 777 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 778 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 779 } 780 break; 781 case 2: { // Extended Features Supported 782 uint32_t features = l2cap_extended_features_mask(); 783 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 784 } 785 break; 786 case 3: { // Fixed Channels Supported 787 uint8_t map[8]; 788 memset(map, 0, 8); 789 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 790 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 791 } 792 break; 793 default: 794 // all other types are not supported 795 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 796 break; 797 } 798 break; 799 case COMMAND_REJECT: 800 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 801 break; 802 #endif 803 #ifdef ENABLE_BLE 804 case LE_CREDIT_BASED_CONNECTION_REQUEST: 805 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 806 break; 807 case COMMAND_REJECT_LE: 808 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 809 break; 810 #endif 811 default: 812 // should not happen 813 break; 814 } 815 } 816 817 btstack_linked_list_iterator_t it; 818 UNUSED(it); 819 820 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 821 // send l2cap information request if neccessary 822 hci_connections_get_iterator(&it); 823 while(btstack_linked_list_iterator_has_next(&it)){ 824 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 825 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST){ 826 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W4_EXTENDED_FEATURE_RESPONSE; 827 // send information request for extended features 828 uint8_t sig_id = l2cap_next_sig_id(); 829 uint8_t info_type = 2; 830 l2cap_send_signaling_packet(connection->con_handle, INFORMATION_REQUEST, sig_id, info_type); 831 return; 832 } 833 } 834 #endif 835 836 #ifdef ENABLE_CLASSIC 837 uint8_t config_options[10]; 838 btstack_linked_list_iterator_init(&it, &l2cap_channels); 839 while (btstack_linked_list_iterator_has_next(&it)){ 840 841 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 842 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 843 switch (channel->state){ 844 845 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 846 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 847 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 848 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 849 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 850 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 851 } 852 break; 853 854 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 855 if (!hci_can_send_command_packet_now()) break; 856 // send connection request - set state first 857 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 858 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 859 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 860 break; 861 862 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 863 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 864 channel->state = L2CAP_STATE_INVALID; 865 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 866 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 867 l2cap_stop_rtx(channel); 868 btstack_linked_list_iterator_remove(&it); 869 btstack_memory_l2cap_channel_free(channel); 870 break; 871 872 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 873 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 874 channel->state = L2CAP_STATE_CONFIG; 875 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 876 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 877 break; 878 879 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 880 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 881 // success, start l2cap handshake 882 channel->local_sig_id = l2cap_next_sig_id(); 883 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 884 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 885 l2cap_start_rtx(channel); 886 break; 887 888 case L2CAP_STATE_CONFIG: 889 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 890 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 891 uint16_t flags = 0; 892 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 893 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 894 flags = 1; 895 } else { 896 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 897 } 898 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 899 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 900 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 901 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 902 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED){ 903 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 904 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 905 uint16_t options_size = l2cap_setup_options(channel, config_options); 906 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS, options_size, &config_options); 907 #endif 908 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 909 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 910 uint16_t options_size = l2cap_setup_options(channel, config_options); 911 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, options_size, &config_options); 912 } else { 913 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, 0, NULL); 914 } 915 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 916 } 917 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 918 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 919 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 920 channel->local_sig_id = l2cap_next_sig_id(); 921 uint16_t options_size = l2cap_setup_options(channel, config_options); 922 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, options_size, &config_options); 923 l2cap_start_rtx(channel); 924 } 925 if (l2cap_channel_ready_for_open(channel)){ 926 channel->state = L2CAP_STATE_OPEN; 927 l2cap_emit_channel_opened(channel, 0); // success 928 } 929 break; 930 931 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 932 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 933 channel->state = L2CAP_STATE_INVALID; 934 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 935 // we don't start an RTX timer for a disconnect - there's no point in closing the channel if the other side doesn't respond :) 936 l2cap_finialize_channel_close(channel); // -- remove from list 937 break; 938 939 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 940 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 941 channel->local_sig_id = l2cap_next_sig_id(); 942 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 943 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 944 break; 945 default: 946 break; 947 } 948 949 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 950 // send s-frame to acknowledge received packets 951 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 952 953 if (channel->tx_send_index != channel->tx_write_index){ 954 int unacknowledged_packets = l2cap_ertm_num_unacknowledged_tx_packets(channel); 955 // check remote tx window 956 log_info("unacknowledged_packets %u, remote tx window size %u", unacknowledged_packets, channel->remote_tx_window_size); 957 if (unacknowledged_packets < channel->remote_tx_window_size){ 958 int index = channel->tx_send_index; 959 channel->tx_send_index++; 960 if (channel->tx_send_index >= channel->num_tx_buffers){ 961 channel->tx_send_index = 0; 962 } 963 l2cap_ertm_send_information_frame(channel, index); 964 continue; 965 } 966 } 967 968 if (channel->send_supervisor_frame_receiver_ready){ 969 channel->send_supervisor_frame_receiver_ready = 0;; 970 log_info("Send S-Frame: RR %u", channel->req_seq); 971 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY, 0, 0, channel->req_seq); 972 l2cap_ertm_send_supervisor_frame(channel, control); 973 continue; 974 } 975 #endif 976 977 } 978 #endif 979 980 #ifdef ENABLE_LE_DATA_CHANNELS 981 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 982 while (btstack_linked_list_iterator_has_next(&it)){ 983 uint8_t * acl_buffer; 984 uint8_t * l2cap_payload; 985 uint16_t pos; 986 uint16_t payload_size; 987 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 988 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 989 switch (channel->state){ 990 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 991 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 992 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 993 // le psm, source cid, mtu, mps, initial credits 994 channel->local_sig_id = l2cap_next_sig_id(); 995 channel->credits_incoming = channel->new_credits_incoming; 996 channel->new_credits_incoming = 0; 997 l2cap_send_le_signaling_packet( channel->con_handle, LE_CREDIT_BASED_CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid, channel->local_mtu, 23, channel->credits_incoming); 998 break; 999 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1000 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1001 // TODO: support larger MPS 1002 channel->state = L2CAP_STATE_OPEN; 1003 channel->credits_incoming = channel->new_credits_incoming; 1004 channel->new_credits_incoming = 0; 1005 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->local_mtu, 23, channel->credits_incoming, 0); 1006 // notify client 1007 l2cap_emit_le_channel_opened(channel, 0); 1008 break; 1009 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1010 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1011 channel->state = L2CAP_STATE_INVALID; 1012 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 1013 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1014 l2cap_stop_rtx(channel); 1015 btstack_linked_list_iterator_remove(&it); 1016 btstack_memory_l2cap_channel_free(channel); 1017 break; 1018 case L2CAP_STATE_OPEN: 1019 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1020 1021 // send credits 1022 if (channel->new_credits_incoming){ 1023 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 1024 channel->local_sig_id = l2cap_next_sig_id(); 1025 uint16_t new_credits = channel->new_credits_incoming; 1026 channel->new_credits_incoming = 0; 1027 channel->credits_incoming += new_credits; 1028 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 1029 break; 1030 } 1031 1032 // send data 1033 if (!channel->send_sdu_buffer) break; 1034 if (!channel->credits_outgoing) break; 1035 1036 // send part of SDU 1037 hci_reserve_packet_buffer(); 1038 acl_buffer = hci_get_outgoing_packet_buffer(); 1039 l2cap_payload = acl_buffer + 8; 1040 pos = 0; 1041 if (!channel->send_sdu_pos){ 1042 // store SDU len 1043 channel->send_sdu_pos += 2; 1044 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 1045 pos += 2; 1046 } 1047 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 1048 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 1049 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 1050 pos += payload_size; 1051 channel->send_sdu_pos += payload_size; 1052 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 1053 // done 1054 1055 channel->credits_outgoing--; 1056 1057 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 1058 channel->send_sdu_buffer = NULL; 1059 // send done event 1060 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 1061 // inform about can send now 1062 l2cap_le_notify_channel_can_send(channel); 1063 } 1064 hci_send_acl_packet_buffer(8 + pos); 1065 break; 1066 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1067 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1068 channel->local_sig_id = l2cap_next_sig_id(); 1069 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1070 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1071 break; 1072 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1073 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1074 channel->state = L2CAP_STATE_INVALID; 1075 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1076 l2cap_le_finialize_channel_close(channel); // -- remove from list 1077 break; 1078 default: 1079 break; 1080 } 1081 } 1082 #endif 1083 1084 #ifdef ENABLE_BLE 1085 // send l2cap con paramter update if necessary 1086 hci_connections_get_iterator(&it); 1087 while(btstack_linked_list_iterator_has_next(&it)){ 1088 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1089 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 1090 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 1091 switch (connection->le_con_parameter_update_state){ 1092 case CON_PARAMETER_UPDATE_SEND_REQUEST: 1093 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1094 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 1095 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 1096 break; 1097 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 1098 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 1099 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 1100 break; 1101 case CON_PARAMETER_UPDATE_DENY: 1102 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1103 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 1104 break; 1105 default: 1106 break; 1107 } 1108 } 1109 #endif 1110 1111 // log_info("l2cap_run: exit"); 1112 } 1113 1114 #ifdef ENABLE_CLASSIC 1115 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 1116 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 1117 log_info("l2cap_handle_connection_complete expected state"); 1118 // success, start l2cap handshake 1119 channel->con_handle = con_handle; 1120 // check remote SSP feature first 1121 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 1122 } 1123 } 1124 1125 static void l2cap_ready_to_connect(l2cap_channel_t * channel){ 1126 1127 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1128 // assumption: outgoing connection 1129 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1130 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_IDLE){ 1131 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1132 channel->state = L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES; 1133 return; 1134 } 1135 #endif 1136 1137 // fine, go ahead 1138 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1139 } 1140 1141 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 1142 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 1143 1144 // we have been waiting for remote supported features, if both support SSP, 1145 log_info("l2cap received remote supported features, sec_level_0_allowed for psm %u = %u", channel->psm, l2cap_security_level_0_allowed_for_PSM(channel->psm)); 1146 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 1147 // request security level 2 1148 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 1149 gap_request_security_level(channel->con_handle, LEVEL_2); 1150 return; 1151 } 1152 1153 l2cap_ready_to_connect(channel); 1154 } 1155 #endif 1156 1157 #ifdef L2CAP_USES_CHANNELS 1158 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 1159 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 1160 1161 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1162 if (!channel) { 1163 return NULL; 1164 } 1165 1166 // Init memory (make valgrind happy) 1167 memset(channel, 0, sizeof(l2cap_channel_t)); 1168 1169 // fill in 1170 channel->packet_handler = packet_handler; 1171 bd_addr_copy(channel->address, address); 1172 channel->address_type = address_type; 1173 channel->psm = psm; 1174 channel->local_mtu = local_mtu; 1175 channel->remote_mtu = L2CAP_MINIMAL_MTU; 1176 channel->required_security_level = security_level; 1177 1178 // 1179 channel->local_cid = l2cap_next_local_cid(); 1180 channel->con_handle = 0; 1181 1182 // set initial state 1183 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 1184 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 1185 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 1186 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 1187 1188 return channel; 1189 } 1190 #endif 1191 1192 #ifdef ENABLE_CLASSIC 1193 1194 /** 1195 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 1196 * @param packet_handler 1197 * @param address 1198 * @param psm 1199 * @param mtu 1200 * @param local_cid 1201 */ 1202 1203 uint8_t l2cap_create_channel(btstack_packet_handler_t channel_packet_handler, bd_addr_t address, uint16_t psm, uint16_t mtu, uint16_t * out_local_cid){ 1204 // limit MTU to the size of our outtgoing HCI buffer 1205 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1206 1207 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1208 1209 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1210 if (!channel) { 1211 return BTSTACK_MEMORY_ALLOC_FAILED; 1212 } 1213 1214 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1215 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1216 #endif 1217 1218 // add to connections list 1219 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1220 1221 // store local_cid 1222 if (out_local_cid){ 1223 *out_local_cid = channel->local_cid; 1224 } 1225 1226 // check if hci connection is already usable 1227 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1228 if (conn){ 1229 log_info("l2cap_create_channel, hci connection already exists"); 1230 l2cap_handle_connection_complete(conn->con_handle, channel); 1231 // check if remote supported fearures are already received 1232 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1233 l2cap_handle_remote_supported_features_received(channel); 1234 } 1235 } 1236 1237 l2cap_run(); 1238 1239 return 0; 1240 } 1241 1242 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1243 1244 static uint8_t l2cap_ertm_validate_local_config(uint8_t max_transmit, uint16_t retransmission_timeout_ms, 1245 uint16_t monitor_timeout_ms, uint8_t num_tx_buffers, uint8_t num_rx_buffers, uint8_t * buffer, uint32_t size){ 1246 UNUSED(buffer); 1247 UNUSED(size); 1248 1249 uint8_t result = ERROR_CODE_SUCCESS; 1250 if (max_transmit < 1){ 1251 log_error("max_transmit must be >= 1"); 1252 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 1253 } 1254 if (retransmission_timeout_ms < 2000){ 1255 log_error("retransmission_timeout_ms must be >= 2000 ms"); 1256 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 1257 } 1258 if (monitor_timeout_ms < 12000){ 1259 log_error("monitor_timeout_ms must be >= 12000 ms"); 1260 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 1261 } 1262 if (num_rx_buffers < 1){ 1263 log_error("num_rx_buffers must be >= 1"); 1264 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 1265 } 1266 if (num_tx_buffers < 1){ 1267 log_error("num_rx_buffers must be >= 1"); 1268 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 1269 } 1270 return result; 1271 } 1272 1273 static void l2cap_ertm_configure_channel(l2cap_channel_t * channel, int ertm_mandatory, uint8_t max_transmit, 1274 uint16_t retransmission_timeout_ms, uint16_t monitor_timeout_ms, uint8_t num_tx_buffers, uint8_t num_rx_buffers, uint8_t * buffer, uint32_t size){ 1275 1276 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 1277 channel->ertm_mandatory = ertm_mandatory; 1278 channel->local_max_transmit = max_transmit; 1279 channel->local_retransmission_timeout_ms = retransmission_timeout_ms; 1280 channel->local_monitor_timeout_ms = monitor_timeout_ms; 1281 channel->num_rx_buffers = num_rx_buffers; 1282 channel->num_tx_buffers = num_tx_buffers; 1283 1284 // TODO: align buffer pointer 1285 uint32_t pos = 0; 1286 channel->rx_packets_state = (l2cap_ertm_rx_packet_state_t *) &buffer[pos]; 1287 pos += num_rx_buffers * sizeof(l2cap_ertm_rx_packet_state_t); 1288 channel->tx_packets_state = (l2cap_ertm_tx_packet_state_t *) &buffer[pos]; 1289 pos += num_tx_buffers * sizeof(l2cap_ertm_tx_packet_state_t); 1290 // calculate MTU 1291 channel->local_mtu = (size - pos) / (num_rx_buffers + num_tx_buffers); 1292 log_info("Local ERTM MTU: %u", channel->local_mtu); 1293 channel->rx_packets_data = &buffer[pos]; 1294 pos += num_rx_buffers * channel->local_mtu; 1295 channel->tx_packets_data = &buffer[pos]; 1296 log_info("RX packets %p, TX packets %p", channel->rx_packets_data, channel->tx_packets_data); 1297 } 1298 1299 uint8_t l2cap_create_ertm_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, 1300 int ertm_mandatory, uint8_t max_transmit, uint16_t retransmission_timeout_ms, uint16_t monitor_timeout_ms, 1301 uint8_t num_tx_buffers, uint8_t num_rx_buffers, uint8_t * buffer, uint32_t size, uint16_t * out_local_cid){ 1302 1303 // limit MTU to the size of our outtgoing HCI buffer 1304 uint16_t local_mtu = l2cap_max_mtu(); 1305 1306 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x -> local mtu %u", bd_addr_to_str(address), psm, local_mtu); 1307 1308 // validate local config 1309 uint8_t result = l2cap_ertm_validate_local_config(max_transmit, retransmission_timeout_ms, monitor_timeout_ms, num_tx_buffers, num_rx_buffers, buffer, size); 1310 if (result) return result; 1311 1312 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1313 if (!channel) { 1314 return BTSTACK_MEMORY_ALLOC_FAILED; 1315 } 1316 1317 // configure ERTM 1318 l2cap_ertm_configure_channel(channel, ertm_mandatory, max_transmit, retransmission_timeout_ms, 1319 monitor_timeout_ms, num_tx_buffers, num_rx_buffers, buffer, size); 1320 1321 // add to connections list 1322 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1323 1324 // store local_cid 1325 if (out_local_cid){ 1326 *out_local_cid = channel->local_cid; 1327 } 1328 1329 // check if hci connection is already usable 1330 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1331 if (conn){ 1332 log_info("l2cap_create_channel, hci connection already exists"); 1333 l2cap_handle_connection_complete(conn->con_handle, channel); 1334 // check if remote supported fearures are already received 1335 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1336 l2cap_handle_remote_supported_features_received(channel); 1337 } 1338 } 1339 1340 l2cap_run(); 1341 1342 return 0; 1343 } 1344 #endif 1345 1346 void 1347 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1348 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1349 // find channel for local_cid 1350 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1351 if (channel) { 1352 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1353 } 1354 // process 1355 l2cap_run(); 1356 } 1357 1358 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1359 btstack_linked_list_iterator_t it; 1360 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1361 while (btstack_linked_list_iterator_has_next(&it)){ 1362 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1363 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1364 // channel for this address found 1365 switch (channel->state){ 1366 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1367 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1368 // failure, forward error code 1369 l2cap_emit_channel_opened(channel, status); 1370 // discard channel 1371 l2cap_stop_rtx(channel); 1372 btstack_linked_list_iterator_remove(&it); 1373 btstack_memory_l2cap_channel_free(channel); 1374 break; 1375 default: 1376 break; 1377 } 1378 } 1379 } 1380 1381 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1382 btstack_linked_list_iterator_t it; 1383 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1384 while (btstack_linked_list_iterator_has_next(&it)){ 1385 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1386 if ( ! bd_addr_cmp( channel->address, address) ){ 1387 l2cap_handle_connection_complete(handle, channel); 1388 } 1389 } 1390 // process 1391 l2cap_run(); 1392 } 1393 #endif 1394 1395 static void l2cap_notify_channel_can_send(void){ 1396 1397 #ifdef ENABLE_CLASSIC 1398 btstack_linked_list_iterator_t it; 1399 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1400 while (btstack_linked_list_iterator_has_next(&it)){ 1401 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1402 if (!channel->waiting_for_can_send_now) continue; 1403 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1404 channel->waiting_for_can_send_now = 0; 1405 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1406 } 1407 #endif 1408 1409 int i; 1410 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1411 if (!fixed_channels[i].callback) continue; 1412 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1413 int can_send = 0; 1414 if (l2cap_fixed_channel_table_index_is_le(i)){ 1415 #ifdef ENABLE_BLE 1416 can_send = hci_can_send_acl_le_packet_now(); 1417 #endif 1418 } else { 1419 #ifdef ENABLE_CLASSIC 1420 can_send = hci_can_send_acl_classic_packet_now(); 1421 #endif 1422 } 1423 if (!can_send) continue; 1424 fixed_channels[i].waiting_for_can_send_now = 0; 1425 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1426 } 1427 } 1428 1429 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1430 1431 UNUSED(packet_type); 1432 UNUSED(cid); 1433 UNUSED(size); 1434 1435 bd_addr_t address; 1436 hci_con_handle_t handle; 1437 int hci_con_used; 1438 btstack_linked_list_iterator_t it; 1439 1440 // avoid unused warnings 1441 UNUSED(address); 1442 UNUSED(hci_con_used); 1443 UNUSED(it); 1444 UNUSED(handle); 1445 1446 switch(hci_event_packet_get_type(packet)){ 1447 1448 // Notify channel packet handler if they can send now 1449 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1450 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1451 l2cap_run(); // try sending signaling packets first 1452 l2cap_notify_channel_can_send(); 1453 break; 1454 1455 case HCI_EVENT_COMMAND_STATUS: 1456 l2cap_run(); // try sending signaling packets first 1457 break; 1458 1459 #ifdef ENABLE_CLASSIC 1460 // handle connection complete events 1461 case HCI_EVENT_CONNECTION_COMPLETE: 1462 reverse_bd_addr(&packet[5], address); 1463 if (packet[2] == 0){ 1464 handle = little_endian_read_16(packet, 3); 1465 l2cap_handle_connection_success_for_addr(address, handle); 1466 } else { 1467 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1468 } 1469 break; 1470 1471 // handle successful create connection cancel command 1472 case HCI_EVENT_COMMAND_COMPLETE: 1473 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1474 if (packet[5] == 0){ 1475 reverse_bd_addr(&packet[6], address); 1476 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1477 l2cap_handle_connection_failed_for_addr(address, 0x16); 1478 } 1479 } 1480 l2cap_run(); // try sending signaling packets first 1481 break; 1482 #endif 1483 1484 // handle disconnection complete events 1485 case HCI_EVENT_DISCONNECTION_COMPLETE: 1486 // send l2cap disconnect events for all channels on this handle and free them 1487 #ifdef ENABLE_CLASSIC 1488 handle = little_endian_read_16(packet, 3); 1489 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1490 while (btstack_linked_list_iterator_has_next(&it)){ 1491 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1492 if (channel->con_handle != handle) continue; 1493 l2cap_emit_channel_closed(channel); 1494 l2cap_stop_rtx(channel); 1495 btstack_linked_list_iterator_remove(&it); 1496 btstack_memory_l2cap_channel_free(channel); 1497 } 1498 #endif 1499 #ifdef ENABLE_LE_DATA_CHANNELS 1500 handle = little_endian_read_16(packet, 3); 1501 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1502 while (btstack_linked_list_iterator_has_next(&it)){ 1503 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1504 if (channel->con_handle != handle) continue; 1505 l2cap_emit_channel_closed(channel); 1506 btstack_linked_list_iterator_remove(&it); 1507 btstack_memory_l2cap_channel_free(channel); 1508 } 1509 #endif 1510 break; 1511 1512 // HCI Connection Timeouts 1513 #ifdef ENABLE_CLASSIC 1514 case L2CAP_EVENT_TIMEOUT_CHECK: 1515 handle = little_endian_read_16(packet, 2); 1516 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1517 if (hci_authentication_active_for_handle(handle)) break; 1518 hci_con_used = 0; 1519 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1520 while (btstack_linked_list_iterator_has_next(&it)){ 1521 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1522 if (channel->con_handle != handle) continue; 1523 hci_con_used = 1; 1524 break; 1525 } 1526 if (hci_con_used) break; 1527 if (!hci_can_send_command_packet_now()) break; 1528 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1529 break; 1530 1531 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1532 handle = little_endian_read_16(packet, 3); 1533 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1534 while (btstack_linked_list_iterator_has_next(&it)){ 1535 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1536 if (channel->con_handle != handle) continue; 1537 l2cap_handle_remote_supported_features_received(channel); 1538 break; 1539 } 1540 break; 1541 1542 case GAP_EVENT_SECURITY_LEVEL: 1543 handle = little_endian_read_16(packet, 2); 1544 log_info("l2cap - security level update"); 1545 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1546 while (btstack_linked_list_iterator_has_next(&it)){ 1547 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1548 if (channel->con_handle != handle) continue; 1549 1550 log_info("l2cap - state %u", channel->state); 1551 1552 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1553 gap_security_level_t required_level = channel->required_security_level; 1554 1555 switch (channel->state){ 1556 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1557 if (actual_level >= required_level){ 1558 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1559 // we need to know if ERTM is supported before sending a config response 1560 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1561 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1562 channel->state = L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES; 1563 #else 1564 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1565 l2cap_emit_incoming_connection(channel); 1566 #endif 1567 } else { 1568 channel->reason = 0x0003; // security block 1569 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1570 } 1571 break; 1572 1573 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1574 if (actual_level >= required_level){ 1575 l2cap_ready_to_connect(channel); 1576 } else { 1577 // disconnnect, authentication not good enough 1578 hci_disconnect_security_block(handle); 1579 } 1580 break; 1581 1582 default: 1583 break; 1584 } 1585 } 1586 break; 1587 #endif 1588 1589 default: 1590 break; 1591 } 1592 1593 l2cap_run(); 1594 } 1595 1596 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 1597 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1598 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1599 signaling_responses[signaling_responses_pending].handle = handle; 1600 signaling_responses[signaling_responses_pending].code = code; 1601 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1602 signaling_responses[signaling_responses_pending].cid = cid; 1603 signaling_responses[signaling_responses_pending].data = data; 1604 signaling_responses_pending++; 1605 l2cap_run(); 1606 } 1607 } 1608 1609 #ifdef ENABLE_CLASSIC 1610 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1611 channel->remote_sig_id = identifier; 1612 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1613 l2cap_run(); 1614 } 1615 1616 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1617 1618 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1619 l2cap_service_t *service = l2cap_get_service(psm); 1620 if (!service) { 1621 // 0x0002 PSM not supported 1622 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1623 return; 1624 } 1625 1626 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1627 if (!hci_connection) { 1628 // 1629 log_error("no hci_connection for handle %u", handle); 1630 return; 1631 } 1632 1633 // alloc structure 1634 // log_info("l2cap_handle_connection_request register channel"); 1635 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1636 psm, service->mtu, service->required_security_level); 1637 if (!channel){ 1638 // 0x0004 No resources available 1639 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 1640 return; 1641 } 1642 1643 channel->con_handle = handle; 1644 channel->remote_cid = source_cid; 1645 channel->remote_sig_id = sig_id; 1646 1647 // limit local mtu to max acl packet length - l2cap header 1648 if (channel->local_mtu > l2cap_max_mtu()) { 1649 channel->local_mtu = l2cap_max_mtu(); 1650 } 1651 1652 // set initial state 1653 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1654 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 1655 1656 // add to connections list 1657 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1658 1659 // assert security requirements 1660 gap_request_security_level(handle, channel->required_security_level); 1661 } 1662 1663 void l2cap_accept_connection(uint16_t local_cid){ 1664 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1665 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1666 if (!channel) { 1667 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1668 return; 1669 } 1670 1671 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1672 // configure L2CAP Basic mode 1673 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1674 #endif 1675 1676 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1677 1678 // process 1679 l2cap_run(); 1680 } 1681 1682 1683 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1684 uint8_t l2cap_accept_ertm_connection(uint16_t local_cid, int ertm_mandatory, uint8_t max_transmit, 1685 uint16_t retransmission_timeout_ms, uint16_t monitor_timeout_ms, uint8_t num_tx_buffers, uint8_t num_rx_buffers, uint8_t * buffer, uint32_t size){ 1686 1687 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 1688 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1689 if (!channel) { 1690 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1691 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1692 } 1693 1694 // validate local config 1695 uint8_t result = l2cap_ertm_validate_local_config(max_transmit, retransmission_timeout_ms, monitor_timeout_ms, num_tx_buffers, num_rx_buffers, buffer, size); 1696 if (result) return result; 1697 1698 // configure L2CAP ERTM 1699 l2cap_ertm_configure_channel(channel, ertm_mandatory, max_transmit, retransmission_timeout_ms, monitor_timeout_ms, num_tx_buffers, num_rx_buffers, buffer, size); 1700 1701 // continue 1702 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1703 1704 // process 1705 l2cap_run(); 1706 1707 return ERROR_CODE_SUCCESS; 1708 } 1709 #endif 1710 1711 1712 void l2cap_decline_connection(uint16_t local_cid){ 1713 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1714 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1715 if (!channel) { 1716 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1717 return; 1718 } 1719 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1720 channel->reason = 0x04; // no resources available 1721 l2cap_run(); 1722 } 1723 1724 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1725 1726 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1727 1728 uint16_t flags = little_endian_read_16(command, 6); 1729 if (flags & 1) { 1730 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1731 } 1732 1733 // accept the other's configuration options 1734 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1735 uint16_t pos = 8; 1736 while (pos < end_pos){ 1737 uint8_t option_hint = command[pos] >> 7; 1738 uint8_t option_type = command[pos] & 0x7f; 1739 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1740 pos++; 1741 uint8_t length = command[pos++]; 1742 // MTU { type(8): 1, len(8):2, MTU(16) } 1743 if (option_type == 1 && length == 2){ 1744 channel->remote_mtu = little_endian_read_16(command, pos); 1745 if (channel->remote_mtu > l2cap_max_mtu()){ 1746 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 1747 channel->remote_mtu = l2cap_max_mtu(); 1748 } 1749 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1750 } 1751 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1752 if (option_type == 2 && length == 2){ 1753 channel->flush_timeout = little_endian_read_16(command, pos); 1754 } 1755 1756 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1757 // Retransmission and Flow Control Option 1758 if (option_type == 4 && length == 9){ 1759 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 1760 switch(channel->mode){ 1761 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1762 // Store remote config 1763 channel->remote_tx_window_size = command[pos+1]; 1764 channel->remote_max_transmit = command[pos+2]; 1765 channel->remote_retransmission_timeout_ms = little_endian_read_16(command, pos + 3); 1766 channel->remote_monitor_timeout_ms = little_endian_read_16(command, pos + 5); 1767 log_info("FC&C config: tx window: %u, max transmit %u, retrans timeout %u, monitor timeout %u", 1768 channel->remote_tx_window_size, 1769 channel->remote_max_transmit, 1770 channel->remote_retransmission_timeout_ms, 1771 channel->remote_monitor_timeout_ms); 1772 // we store remote MPS in remote_mtu, might need to get re-evaluated 1773 channel->remote_mtu = little_endian_read_16(command, pos + 7); 1774 // If ERTM mandatory, but remote doens't offer ERTM -> disconnect 1775 if (channel->ertm_mandatory && mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1776 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1777 } else { 1778 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1779 } 1780 break; 1781 case L2CAP_CHANNEL_MODE_BASIC: 1782 switch (mode){ 1783 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1784 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 1785 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 1786 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1787 } 1788 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 1789 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 1790 break; 1791 default: // case L2CAP_CHANNEL_MODE_BASIC: 1792 // TODO store and evaluate configuration 1793 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1794 break; 1795 } 1796 break; 1797 default: 1798 break; 1799 } 1800 } 1801 #endif 1802 // check for unknown options 1803 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1804 log_info("l2cap cid %u, unknown options", channel->local_cid); 1805 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1806 } 1807 pos += length; 1808 } 1809 } 1810 1811 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 1812 log_info("l2cap_signaling_handle_configure_response"); 1813 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1814 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1815 uint16_t pos = 10; 1816 while (pos < end_pos){ 1817 uint8_t option_hint = command[pos] >> 7; 1818 uint8_t option_type = command[pos] & 0x7f; 1819 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1820 pos++; 1821 uint8_t length = command[pos++]; 1822 1823 // Retransmission and Flow Control Option 1824 if (option_type == 4 && length == 9){ 1825 switch (channel->mode){ 1826 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1827 if (channel->ertm_mandatory){ 1828 // ?? 1829 } else { 1830 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 1831 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 1832 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1833 } 1834 } 1835 break; 1836 case L2CAP_CHANNEL_MODE_BASIC: 1837 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 1838 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 1839 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1840 } 1841 break; 1842 default: 1843 break; 1844 } 1845 } 1846 1847 // check for unknown options 1848 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1849 log_info("l2cap cid %u, unknown options", channel->local_cid); 1850 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1851 } 1852 1853 pos += length; 1854 } 1855 #endif 1856 } 1857 1858 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1859 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1860 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1861 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1862 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1863 if (channel->state == L2CAP_STATE_OPEN) return 0; 1864 return 1; 1865 } 1866 1867 1868 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1869 1870 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1871 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1872 uint16_t result = 0; 1873 1874 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1875 1876 // handle DISCONNECT REQUESTS seperately 1877 if (code == DISCONNECTION_REQUEST){ 1878 switch (channel->state){ 1879 case L2CAP_STATE_CONFIG: 1880 case L2CAP_STATE_OPEN: 1881 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1882 case L2CAP_STATE_WAIT_DISCONNECT: 1883 l2cap_handle_disconnect_request(channel, identifier); 1884 break; 1885 1886 default: 1887 // ignore in other states 1888 break; 1889 } 1890 return; 1891 } 1892 1893 // @STATEMACHINE(l2cap) 1894 switch (channel->state) { 1895 1896 case L2CAP_STATE_WAIT_CONNECT_RSP: 1897 switch (code){ 1898 case CONNECTION_RESPONSE: 1899 l2cap_stop_rtx(channel); 1900 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1901 switch (result) { 1902 case 0: 1903 // successful connection 1904 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1905 channel->state = L2CAP_STATE_CONFIG; 1906 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1907 break; 1908 case 1: 1909 // connection pending. get some coffee, but start the ERTX 1910 l2cap_start_ertx(channel); 1911 break; 1912 default: 1913 // channel closed 1914 channel->state = L2CAP_STATE_CLOSED; 1915 // map l2cap connection response result to BTstack status enumeration 1916 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1917 1918 // drop link key if security block 1919 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1920 gap_drop_link_key_for_bd_addr(channel->address); 1921 } 1922 1923 // discard channel 1924 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1925 btstack_memory_l2cap_channel_free(channel); 1926 break; 1927 } 1928 break; 1929 1930 default: 1931 //@TODO: implement other signaling packets 1932 break; 1933 } 1934 break; 1935 1936 case L2CAP_STATE_CONFIG: 1937 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1938 switch (code) { 1939 case CONFIGURE_REQUEST: 1940 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1941 l2cap_signaling_handle_configure_request(channel, command); 1942 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1943 // only done if continuation not set 1944 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1945 } 1946 break; 1947 case CONFIGURE_RESPONSE: 1948 l2cap_stop_rtx(channel); 1949 l2cap_signaling_handle_configure_response(channel, result, command); 1950 switch (result){ 1951 case 0: // success 1952 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1953 break; 1954 case 4: // pending 1955 l2cap_start_ertx(channel); 1956 break; 1957 default: 1958 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1959 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 1960 // remote does not offer ertm but it's required 1961 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1962 break; 1963 } 1964 #endif 1965 // retry on negative result 1966 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1967 break; 1968 } 1969 break; 1970 default: 1971 break; 1972 } 1973 if (l2cap_channel_ready_for_open(channel)){ 1974 // for open: 1975 channel->state = L2CAP_STATE_OPEN; 1976 l2cap_emit_channel_opened(channel, 0); 1977 } 1978 break; 1979 1980 case L2CAP_STATE_WAIT_DISCONNECT: 1981 switch (code) { 1982 case DISCONNECTION_RESPONSE: 1983 l2cap_finialize_channel_close(channel); 1984 break; 1985 default: 1986 //@TODO: implement other signaling packets 1987 break; 1988 } 1989 break; 1990 1991 case L2CAP_STATE_CLOSED: 1992 // @TODO handle incoming requests 1993 break; 1994 1995 case L2CAP_STATE_OPEN: 1996 //@TODO: implement other signaling packets, e.g. re-configure 1997 break; 1998 default: 1999 break; 2000 } 2001 // log_info("new state %u", channel->state); 2002 } 2003 2004 2005 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 2006 2007 btstack_linked_list_iterator_t it; 2008 2009 // get code, signalind identifier and command len 2010 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2011 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2012 2013 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 2014 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 2015 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2016 return; 2017 } 2018 2019 // general commands without an assigned channel 2020 switch(code) { 2021 2022 case CONNECTION_REQUEST: { 2023 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2024 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2025 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 2026 return; 2027 } 2028 2029 case ECHO_REQUEST: 2030 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 2031 return; 2032 2033 case INFORMATION_REQUEST: { 2034 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2035 l2cap_register_signaling_response(handle, code, sig_id, 0, infoType); 2036 return; 2037 } 2038 2039 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2040 case INFORMATION_RESPONSE: { 2041 hci_connection_t * connection = hci_connection_for_handle(handle); 2042 if (!connection) return; 2043 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2044 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2045 if (result != 0) return; 2046 if (info_type != 0x02) return; 2047 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 2048 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2049 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 2050 // trigger connection request 2051 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2052 while (btstack_linked_list_iterator_has_next(&it)){ 2053 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2054 if (channel->con_handle != handle) continue; 2055 // bail if ERTM was requested but is not supported 2056 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 2057 if (channel->ertm_mandatory){ 2058 // channel closed 2059 channel->state = L2CAP_STATE_CLOSED; 2060 // map l2cap connection response result to BTstack status enumeration 2061 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTD); 2062 // discard channel 2063 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2064 btstack_memory_l2cap_channel_free(channel); 2065 continue; 2066 } else { 2067 // fallback to Basic mode 2068 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2069 } 2070 } 2071 // start connecting 2072 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 2073 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 2074 } 2075 // respond to connection request 2076 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 2077 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2078 l2cap_emit_incoming_connection(channel); 2079 } 2080 } 2081 return; 2082 } 2083 #endif 2084 2085 default: 2086 break; 2087 } 2088 2089 2090 // Get potential destination CID 2091 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2092 2093 // Find channel for this sig_id and connection handle 2094 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2095 while (btstack_linked_list_iterator_has_next(&it)){ 2096 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2097 if (channel->con_handle != handle) continue; 2098 if (code & 1) { 2099 // match odd commands (responses) by previous signaling identifier 2100 if (channel->local_sig_id == sig_id) { 2101 l2cap_signaling_handler_channel(channel, command); 2102 break; 2103 } 2104 } else { 2105 // match even commands (requests) by local channel id 2106 if (channel->local_cid == dest_cid) { 2107 l2cap_signaling_handler_channel(channel, command); 2108 break; 2109 } 2110 } 2111 } 2112 } 2113 #endif 2114 2115 #ifdef ENABLE_BLE 2116 2117 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 2118 uint8_t event[6]; 2119 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 2120 event[1] = 4; 2121 little_endian_store_16(event, 2, con_handle); 2122 little_endian_store_16(event, 4, result); 2123 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2124 if (!l2cap_event_packet_handler) return; 2125 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 2126 } 2127 2128 // @returns valid 2129 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 2130 hci_connection_t * connection; 2131 uint16_t result; 2132 uint8_t event[10]; 2133 2134 #ifdef ENABLE_LE_DATA_CHANNELS 2135 btstack_linked_list_iterator_t it; 2136 l2cap_channel_t * channel; 2137 uint16_t local_cid; 2138 uint16_t le_psm; 2139 uint16_t new_credits; 2140 uint16_t credits_before; 2141 l2cap_service_t * service; 2142 uint16_t source_cid; 2143 #endif 2144 2145 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2146 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 2147 2148 switch (code){ 2149 2150 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2151 result = little_endian_read_16(command, 4); 2152 l2cap_emit_connection_parameter_update_response(handle, result); 2153 break; 2154 2155 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2156 connection = hci_connection_for_handle(handle); 2157 if (connection){ 2158 if (connection->role != HCI_ROLE_MASTER){ 2159 // reject command without notifying upper layer when not in master role 2160 return 0; 2161 } 2162 int update_parameter = 1; 2163 le_connection_parameter_range_t existing_range; 2164 gap_get_connection_parameter_range(&existing_range); 2165 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 2166 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 2167 uint16_t le_conn_latency = little_endian_read_16(command,12); 2168 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 2169 2170 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 2171 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 2172 2173 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 2174 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 2175 2176 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 2177 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 2178 2179 if (update_parameter){ 2180 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2181 connection->le_conn_interval_min = le_conn_interval_min; 2182 connection->le_conn_interval_max = le_conn_interval_max; 2183 connection->le_conn_latency = le_conn_latency; 2184 connection->le_supervision_timeout = le_supervision_timeout; 2185 } else { 2186 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2187 } 2188 connection->le_con_param_update_identifier = sig_id; 2189 } 2190 2191 if (!l2cap_event_packet_handler) break; 2192 2193 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2194 event[1] = 8; 2195 memcpy(&event[2], &command[4], 8); 2196 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2197 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2198 break; 2199 2200 #ifdef ENABLE_LE_DATA_CHANNELS 2201 2202 case COMMAND_REJECT: 2203 // Find channel for this sig_id and connection handle 2204 channel = NULL; 2205 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2206 while (btstack_linked_list_iterator_has_next(&it)){ 2207 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2208 if (a_channel->con_handle != handle) continue; 2209 if (a_channel->local_sig_id != sig_id) continue; 2210 channel = a_channel; 2211 break; 2212 } 2213 if (!channel) break; 2214 2215 // if received while waiting for le connection response, assume legacy device 2216 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2217 channel->state = L2CAP_STATE_CLOSED; 2218 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2219 l2cap_emit_le_channel_opened(channel, 0x0002); 2220 2221 // discard channel 2222 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2223 btstack_memory_l2cap_channel_free(channel); 2224 break; 2225 } 2226 break; 2227 2228 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2229 2230 // get hci connection, bail if not found (must not happen) 2231 connection = hci_connection_for_handle(handle); 2232 if (!connection) return 0; 2233 2234 // check if service registered 2235 le_psm = little_endian_read_16(command, 4); 2236 service = l2cap_le_get_service(le_psm); 2237 source_cid = little_endian_read_16(command, 6); 2238 2239 if (service){ 2240 if (source_cid < 0x40){ 2241 // 0x0009 Connection refused - Invalid Source CID 2242 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2243 return 1; 2244 } 2245 2246 // go through list of channels for this ACL connection and check if we get a match 2247 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2248 while (btstack_linked_list_iterator_has_next(&it)){ 2249 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2250 if (a_channel->con_handle != handle) continue; 2251 if (a_channel->remote_cid != source_cid) continue; 2252 // 0x000a Connection refused - Source CID already allocated 2253 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2254 return 1; 2255 } 2256 2257 // security: check encryption 2258 if (service->required_security_level >= LEVEL_2){ 2259 if (sm_encryption_key_size(handle) == 0){ 2260 // 0x0008 Connection refused - insufficient encryption 2261 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2262 return 1; 2263 } 2264 // anything less than 16 byte key size is insufficient 2265 if (sm_encryption_key_size(handle) < 16){ 2266 // 0x0007 Connection refused – insufficient encryption key size 2267 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2268 return 1; 2269 } 2270 } 2271 2272 // security: check authencation 2273 if (service->required_security_level >= LEVEL_3){ 2274 if (!sm_authenticated(handle)){ 2275 // 0x0005 Connection refused – insufficient authentication 2276 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2277 return 1; 2278 } 2279 } 2280 2281 // security: check authorization 2282 if (service->required_security_level >= LEVEL_4){ 2283 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2284 // 0x0006 Connection refused – insufficient authorization 2285 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2286 return 1; 2287 } 2288 } 2289 2290 // allocate channel 2291 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 2292 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2293 if (!channel){ 2294 // 0x0004 Connection refused – no resources available 2295 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2296 return 1; 2297 } 2298 2299 channel->con_handle = handle; 2300 channel->remote_cid = source_cid; 2301 channel->remote_sig_id = sig_id; 2302 channel->remote_mtu = little_endian_read_16(command, 8); 2303 channel->remote_mps = little_endian_read_16(command, 10); 2304 channel->credits_outgoing = little_endian_read_16(command, 12); 2305 2306 // set initial state 2307 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2308 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2309 2310 // add to connections list 2311 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2312 2313 // post connection request event 2314 l2cap_emit_le_incoming_connection(channel); 2315 2316 } else { 2317 // Connection refused – LE_PSM not supported 2318 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2319 } 2320 break; 2321 2322 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2323 // Find channel for this sig_id and connection handle 2324 channel = NULL; 2325 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2326 while (btstack_linked_list_iterator_has_next(&it)){ 2327 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2328 if (a_channel->con_handle != handle) continue; 2329 if (a_channel->local_sig_id != sig_id) continue; 2330 channel = a_channel; 2331 break; 2332 } 2333 if (!channel) break; 2334 2335 // cid + 0 2336 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2337 if (result){ 2338 channel->state = L2CAP_STATE_CLOSED; 2339 // map l2cap connection response result to BTstack status enumeration 2340 l2cap_emit_le_channel_opened(channel, result); 2341 2342 // discard channel 2343 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2344 btstack_memory_l2cap_channel_free(channel); 2345 break; 2346 } 2347 2348 // success 2349 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2350 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2351 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2352 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2353 channel->state = L2CAP_STATE_OPEN; 2354 l2cap_emit_le_channel_opened(channel, result); 2355 break; 2356 2357 case LE_FLOW_CONTROL_CREDIT: 2358 // find channel 2359 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2360 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2361 if (!channel) { 2362 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2363 break; 2364 } 2365 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2366 credits_before = channel->credits_outgoing; 2367 channel->credits_outgoing += new_credits; 2368 // check for credit overrun 2369 if (credits_before > channel->credits_outgoing){ 2370 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2371 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2372 break; 2373 } 2374 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2375 break; 2376 2377 case DISCONNECTION_REQUEST: 2378 // find channel 2379 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2380 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2381 if (!channel) { 2382 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2383 break; 2384 } 2385 channel->remote_sig_id = sig_id; 2386 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2387 break; 2388 2389 #endif 2390 2391 case DISCONNECTION_RESPONSE: 2392 break; 2393 2394 default: 2395 // command unknown -> reject command 2396 return 0; 2397 } 2398 return 1; 2399 } 2400 #endif 2401 2402 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 2403 UNUSED(packet_type); 2404 UNUSED(channel); 2405 2406 l2cap_channel_t * l2cap_channel; 2407 UNUSED(l2cap_channel); 2408 2409 // Get Channel ID 2410 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 2411 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 2412 2413 switch (channel_id) { 2414 2415 #ifdef ENABLE_CLASSIC 2416 case L2CAP_CID_SIGNALING: { 2417 uint16_t command_offset = 8; 2418 while (command_offset < size) { 2419 // handle signaling commands 2420 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 2421 2422 // increment command_offset 2423 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2424 } 2425 break; 2426 } 2427 #endif 2428 2429 #ifdef ENABLE_BLE 2430 case L2CAP_CID_SIGNALING_LE: { 2431 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 2432 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 2433 if (!valid){ 2434 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2435 } 2436 break; 2437 } 2438 #endif 2439 2440 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 2441 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 2442 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2443 } 2444 break; 2445 2446 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 2447 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 2448 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2449 } 2450 break; 2451 2452 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 2453 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 2454 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2455 } 2456 break; 2457 2458 default: 2459 #ifdef ENABLE_CLASSIC 2460 // Find channel for this channel_id and connection handle 2461 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 2462 if (l2cap_channel) { 2463 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2464 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2465 2466 // verify FCS 2467 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 2468 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 2469 log_info("Packet FCS 0x%04x, calculated FCS 0x%04x", fcs_packet, fcs_calculated); 2470 if (fcs_calculated != fcs_packet){ 2471 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 2472 // TODO: trigger retransmission or something like that 2473 break; 2474 } 2475 2476 // switch on packet type 2477 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2478 uint8_t req_seq = (control >> 8) & 0x3f; 2479 if (control & 1){ 2480 // S-Frame 2481 // int poll = (control >> 7) & 0x01; 2482 l2cap_supervisory_function_t s = (l2cap_supervisory_function_t) ((control >> 2) & 0x03); 2483 l2cap_ertm_tx_packet_state_t * tx_state; 2484 switch (s){ 2485 case L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY: 2486 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 2487 if ( ((req_seq - 1) & 0x3f) == tx_state->tx_seq){ 2488 log_info("RR seq %u == seq of oldest tx packet -> packet done", req_seq); 2489 l2cap_channel->tx_read_index++; 2490 if (l2cap_channel->tx_read_index >= l2cap_channel->num_rx_buffers){ 2491 l2cap_channel->tx_read_index = 0; 2492 } 2493 } else { 2494 log_info("RR seq %u != seq of oldest tx packet %u ???", req_seq, tx_state->tx_seq); 2495 } 2496 break; 2497 default: 2498 break; 2499 } 2500 break; 2501 } else { 2502 // I-Frame 2503 // get control 2504 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 2505 uint8_t tx_seq = (control >> 1) & 0x3f; 2506 log_info("Control: 0x%04x => SAR %u, ReqSeq %02u, R?, TxSeq %02u", control, (int) sar, req_seq, tx_seq); 2507 log_info("SAR: pos %u", l2cap_channel->rx_packets_state->pos); 2508 log_info("State: expected_tx_seq %02u, req_seq %02u", l2cap_channel->expected_tx_seq, l2cap_channel->req_seq); 2509 // check ordering 2510 if (l2cap_channel->expected_tx_seq == tx_seq){ 2511 log_info("Received expected frame with TxSeq == ExpectedTxSeq == %02u", tx_seq); 2512 l2cap_channel->req_seq = tx_seq; 2513 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2514 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 2515 uint16_t sdu_length; 2516 uint16_t segment_length; 2517 uint16_t payload_offset; 2518 switch (sar){ 2519 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 2520 payload_offset = COMPLETE_L2CAP_HEADER+2; 2521 segment_length = payload_offset-2; 2522 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER+2], segment_length); 2523 break; 2524 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 2525 // TODO: use current packet 2526 // TODO: check if reassembly started 2527 // TODO: check len against local mtu 2528 sdu_length = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER+2); 2529 payload_offset = COMPLETE_L2CAP_HEADER+4; 2530 segment_length = size - payload_offset-2; 2531 memcpy(&l2cap_channel->rx_packets_data[0], &packet[payload_offset], segment_length); 2532 l2cap_channel->rx_packets_state->sdu_length = sdu_length; 2533 l2cap_channel->rx_packets_state->pos = segment_length; 2534 break; 2535 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 2536 payload_offset = COMPLETE_L2CAP_HEADER+2; 2537 segment_length = size - payload_offset-2; 2538 memcpy(&l2cap_channel->rx_packets_data[l2cap_channel->rx_packets_state->pos], &packet[payload_offset], segment_length); 2539 l2cap_channel->rx_packets_state->pos += segment_length; 2540 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->rx_packets_data, l2cap_channel->rx_packets_state[0].pos); 2541 break; 2542 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 2543 payload_offset = COMPLETE_L2CAP_HEADER+2; 2544 segment_length = size - payload_offset-2; 2545 memcpy(&l2cap_channel->rx_packets_data[l2cap_channel->rx_packets_state->pos], &packet[payload_offset], segment_length); 2546 l2cap_channel->rx_packets_state->pos += segment_length; 2547 break; 2548 } 2549 } 2550 } 2551 break; 2552 } 2553 #endif 2554 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2555 } 2556 #endif 2557 #ifdef ENABLE_LE_DATA_CHANNELS 2558 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 2559 if (l2cap_channel) { 2560 // credit counting 2561 if (l2cap_channel->credits_incoming == 0){ 2562 log_error("LE Data Channel packet received but no incoming credits"); 2563 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2564 break; 2565 } 2566 l2cap_channel->credits_incoming--; 2567 2568 // automatic credits 2569 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 2570 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 2571 } 2572 2573 // first fragment 2574 uint16_t pos = 0; 2575 if (!l2cap_channel->receive_sdu_len){ 2576 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2577 l2cap_channel->receive_sdu_pos = 0; 2578 pos += 2; 2579 size -= 2; 2580 } 2581 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 2582 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 2583 // done? 2584 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 2585 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 2586 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 2587 l2cap_channel->receive_sdu_len = 0; 2588 } 2589 } else { 2590 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 2591 } 2592 #endif 2593 break; 2594 } 2595 2596 l2cap_run(); 2597 } 2598 2599 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 2600 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 2601 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 2602 if (index < 0) return; 2603 fixed_channels[index].callback = the_packet_handler; 2604 } 2605 2606 #ifdef ENABLE_CLASSIC 2607 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2608 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 2609 channel->state = L2CAP_STATE_CLOSED; 2610 l2cap_emit_channel_closed(channel); 2611 // discard channel 2612 l2cap_stop_rtx(channel); 2613 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2614 btstack_memory_l2cap_channel_free(channel); 2615 } 2616 2617 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 2618 btstack_linked_list_iterator_t it; 2619 btstack_linked_list_iterator_init(&it, services); 2620 while (btstack_linked_list_iterator_has_next(&it)){ 2621 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 2622 if ( service->psm == psm){ 2623 return service; 2624 }; 2625 } 2626 return NULL; 2627 } 2628 2629 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 2630 return l2cap_get_service_internal(&l2cap_services, psm); 2631 } 2632 2633 2634 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 2635 2636 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 2637 2638 // check for alread registered psm 2639 l2cap_service_t *service = l2cap_get_service(psm); 2640 if (service) { 2641 log_error("l2cap_register_service: PSM %u already registered", psm); 2642 return L2CAP_SERVICE_ALREADY_REGISTERED; 2643 } 2644 2645 // alloc structure 2646 service = btstack_memory_l2cap_service_get(); 2647 if (!service) { 2648 log_error("l2cap_register_service: no memory for l2cap_service_t"); 2649 return BTSTACK_MEMORY_ALLOC_FAILED; 2650 } 2651 2652 // fill in 2653 service->psm = psm; 2654 service->mtu = mtu; 2655 service->packet_handler = service_packet_handler; 2656 service->required_security_level = security_level; 2657 2658 // add to services list 2659 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 2660 2661 // enable page scan 2662 gap_connectable_control(1); 2663 2664 return 0; 2665 } 2666 2667 uint8_t l2cap_unregister_service(uint16_t psm){ 2668 2669 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2670 2671 l2cap_service_t *service = l2cap_get_service(psm); 2672 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2673 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2674 btstack_memory_l2cap_service_free(service); 2675 2676 // disable page scan when no services registered 2677 if (btstack_linked_list_empty(&l2cap_services)) { 2678 gap_connectable_control(0); 2679 } 2680 return 0; 2681 } 2682 #endif 2683 2684 2685 #ifdef ENABLE_LE_DATA_CHANNELS 2686 2687 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2688 if (!channel->waiting_for_can_send_now) return; 2689 if (channel->send_sdu_buffer) return; 2690 channel->waiting_for_can_send_now = 0; 2691 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2692 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2693 } 2694 2695 // 1BH2222 2696 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2697 log_info("L2CAP_EVENT_LE_INCOMING_CONNECTION addr_type %u, addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x, remote_mtu %u", 2698 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2699 uint8_t event[19]; 2700 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2701 event[1] = sizeof(event) - 2; 2702 event[2] = channel->address_type; 2703 reverse_bd_addr(channel->address, &event[3]); 2704 little_endian_store_16(event, 9, channel->con_handle); 2705 little_endian_store_16(event, 11, channel->psm); 2706 little_endian_store_16(event, 13, channel->local_cid); 2707 little_endian_store_16(event, 15, channel->remote_cid); 2708 little_endian_store_16(event, 17, channel->remote_mtu); 2709 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2710 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2711 } 2712 // 11BH22222 2713 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2714 log_info("L2CAP_EVENT_LE_CHANNEL_OPENED status 0x%x addr_type %u addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u", 2715 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2716 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2717 uint8_t event[23]; 2718 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2719 event[1] = sizeof(event) - 2; 2720 event[2] = status; 2721 event[3] = channel->address_type; 2722 reverse_bd_addr(channel->address, &event[4]); 2723 little_endian_store_16(event, 10, channel->con_handle); 2724 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2725 little_endian_store_16(event, 13, channel->psm); 2726 little_endian_store_16(event, 15, channel->local_cid); 2727 little_endian_store_16(event, 17, channel->remote_cid); 2728 little_endian_store_16(event, 19, channel->local_mtu); 2729 little_endian_store_16(event, 21, channel->remote_mtu); 2730 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2731 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2732 } 2733 2734 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2735 btstack_linked_list_iterator_t it; 2736 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2737 while (btstack_linked_list_iterator_has_next(&it)){ 2738 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2739 if ( channel->local_cid == local_cid) { 2740 return channel; 2741 } 2742 } 2743 return NULL; 2744 } 2745 2746 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2747 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2748 channel->state = L2CAP_STATE_CLOSED; 2749 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2750 // discard channel 2751 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2752 btstack_memory_l2cap_channel_free(channel); 2753 } 2754 2755 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2756 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2757 } 2758 2759 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2760 2761 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2762 2763 // check for alread registered psm 2764 l2cap_service_t *service = l2cap_le_get_service(psm); 2765 if (service) { 2766 return L2CAP_SERVICE_ALREADY_REGISTERED; 2767 } 2768 2769 // alloc structure 2770 service = btstack_memory_l2cap_service_get(); 2771 if (!service) { 2772 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2773 return BTSTACK_MEMORY_ALLOC_FAILED; 2774 } 2775 2776 // fill in 2777 service->psm = psm; 2778 service->mtu = 0; 2779 service->packet_handler = packet_handler; 2780 service->required_security_level = security_level; 2781 2782 // add to services list 2783 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2784 2785 // done 2786 return 0; 2787 } 2788 2789 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2790 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2791 l2cap_service_t *service = l2cap_le_get_service(psm); 2792 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2793 2794 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2795 btstack_memory_l2cap_service_free(service); 2796 return 0; 2797 } 2798 2799 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2800 // get channel 2801 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2802 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2803 2804 // validate state 2805 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2806 return ERROR_CODE_COMMAND_DISALLOWED; 2807 } 2808 2809 // set state accept connection 2810 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2811 channel->receive_sdu_buffer = receive_sdu_buffer; 2812 channel->local_mtu = mtu; 2813 channel->new_credits_incoming = initial_credits; 2814 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2815 2816 // test 2817 // channel->new_credits_incoming = 1; 2818 2819 // go 2820 l2cap_run(); 2821 return 0; 2822 } 2823 2824 /** 2825 * @brief Deny incoming LE Data Channel connection due to resource constraints 2826 * @param local_cid L2CAP LE Data Channel Identifier 2827 */ 2828 2829 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2830 // get channel 2831 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2832 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2833 2834 // validate state 2835 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2836 return ERROR_CODE_COMMAND_DISALLOWED; 2837 } 2838 2839 // set state decline connection 2840 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2841 channel->reason = 0x04; // no resources available 2842 l2cap_run(); 2843 return 0; 2844 } 2845 2846 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2847 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2848 uint16_t * out_local_cid) { 2849 2850 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2851 2852 2853 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2854 if (!connection) { 2855 log_error("no hci_connection for handle 0x%04x", con_handle); 2856 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2857 } 2858 2859 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2860 if (!channel) { 2861 return BTSTACK_MEMORY_ALLOC_FAILED; 2862 } 2863 log_info("l2cap_le_create_channel %p", channel); 2864 2865 // store local_cid 2866 if (out_local_cid){ 2867 *out_local_cid = channel->local_cid; 2868 } 2869 2870 // provide buffer 2871 channel->con_handle = con_handle; 2872 channel->receive_sdu_buffer = receive_sdu_buffer; 2873 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2874 channel->new_credits_incoming = initial_credits; 2875 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2876 2877 // add to connections list 2878 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2879 2880 // go 2881 l2cap_run(); 2882 return 0; 2883 } 2884 2885 /** 2886 * @brief Provide credtis for LE Data Channel 2887 * @param local_cid L2CAP LE Data Channel Identifier 2888 * @param credits Number additional credits for peer 2889 */ 2890 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2891 2892 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2893 if (!channel) { 2894 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2895 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2896 } 2897 2898 // check state 2899 if (channel->state != L2CAP_STATE_OPEN){ 2900 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2901 } 2902 2903 // assert incoming credits + credits <= 0xffff 2904 uint32_t total_credits = channel->credits_incoming; 2905 total_credits += channel->new_credits_incoming; 2906 total_credits += credits; 2907 if (total_credits > 0xffff){ 2908 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2909 channel->new_credits_incoming, credits); 2910 } 2911 2912 // set credits_granted 2913 channel->new_credits_incoming += credits; 2914 2915 // go 2916 l2cap_run(); 2917 return 0; 2918 } 2919 2920 /** 2921 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2922 * @param local_cid L2CAP LE Data Channel Identifier 2923 */ 2924 int l2cap_le_can_send_now(uint16_t local_cid){ 2925 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2926 if (!channel) { 2927 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2928 return 0; 2929 } 2930 2931 // check state 2932 if (channel->state != L2CAP_STATE_OPEN) return 0; 2933 2934 // check queue 2935 if (channel->send_sdu_buffer) return 0; 2936 2937 // fine, go ahead 2938 return 1; 2939 } 2940 2941 /** 2942 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2943 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2944 * so packet handler should be ready to handle it 2945 * @param local_cid L2CAP LE Data Channel Identifier 2946 */ 2947 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2948 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2949 if (!channel) { 2950 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2951 return 0; 2952 } 2953 channel->waiting_for_can_send_now = 1; 2954 l2cap_le_notify_channel_can_send(channel); 2955 return 0; 2956 } 2957 2958 /** 2959 * @brief Send data via LE Data Channel 2960 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2961 * @param local_cid L2CAP LE Data Channel Identifier 2962 * @param data data to send 2963 * @param size data size 2964 */ 2965 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2966 2967 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2968 if (!channel) { 2969 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2970 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2971 } 2972 2973 if (len > channel->remote_mtu){ 2974 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2975 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2976 } 2977 2978 if (channel->send_sdu_buffer){ 2979 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2980 return BTSTACK_ACL_BUFFERS_FULL; 2981 } 2982 2983 channel->send_sdu_buffer = data; 2984 channel->send_sdu_len = len; 2985 channel->send_sdu_pos = 0; 2986 2987 l2cap_run(); 2988 return 0; 2989 } 2990 2991 /** 2992 * @brief Disconnect from LE Data Channel 2993 * @param local_cid L2CAP LE Data Channel Identifier 2994 */ 2995 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2996 { 2997 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2998 if (!channel) { 2999 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3000 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3001 } 3002 3003 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3004 l2cap_run(); 3005 return 0; 3006 } 3007 3008 #endif 3009