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 bufferx 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 1710 static void l2cap_ertm_handle_req_seq(l2cap_channel_t * l2cap_channel, uint8_t req_seq){ 1711 l2cap_ertm_tx_packet_state_t * tx_state; 1712 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 1713 if ( ((req_seq - 1) & 0x3f) == tx_state->tx_seq){ 1714 log_info("RR seq %u == seq of oldest tx packet -> packet done", req_seq); 1715 l2cap_channel->tx_read_index++; 1716 if (l2cap_channel->tx_read_index >= l2cap_channel->num_rx_buffers){ 1717 l2cap_channel->tx_read_index = 0; 1718 } 1719 } else { 1720 log_info("RR seq %u != seq of oldest tx packet %u ???", req_seq, tx_state->tx_seq); 1721 } 1722 } 1723 #endif 1724 1725 1726 void l2cap_decline_connection(uint16_t local_cid){ 1727 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1728 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1729 if (!channel) { 1730 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1731 return; 1732 } 1733 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1734 channel->reason = 0x04; // no resources available 1735 l2cap_run(); 1736 } 1737 1738 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1739 1740 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1741 1742 uint16_t flags = little_endian_read_16(command, 6); 1743 if (flags & 1) { 1744 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1745 } 1746 1747 // accept the other's configuration options 1748 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1749 uint16_t pos = 8; 1750 while (pos < end_pos){ 1751 uint8_t option_hint = command[pos] >> 7; 1752 uint8_t option_type = command[pos] & 0x7f; 1753 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1754 pos++; 1755 uint8_t length = command[pos++]; 1756 // MTU { type(8): 1, len(8):2, MTU(16) } 1757 if (option_type == 1 && length == 2){ 1758 channel->remote_mtu = little_endian_read_16(command, pos); 1759 if (channel->remote_mtu > l2cap_max_mtu()){ 1760 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 1761 channel->remote_mtu = l2cap_max_mtu(); 1762 } 1763 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1764 } 1765 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1766 if (option_type == 2 && length == 2){ 1767 channel->flush_timeout = little_endian_read_16(command, pos); 1768 } 1769 1770 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1771 // Retransmission and Flow Control Option 1772 if (option_type == 4 && length == 9){ 1773 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 1774 switch(channel->mode){ 1775 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1776 // Store remote config 1777 channel->remote_tx_window_size = command[pos+1]; 1778 channel->remote_max_transmit = command[pos+2]; 1779 channel->remote_retransmission_timeout_ms = little_endian_read_16(command, pos + 3); 1780 channel->remote_monitor_timeout_ms = little_endian_read_16(command, pos + 5); 1781 log_info("FC&C config: tx window: %u, max transmit %u, retrans timeout %u, monitor timeout %u", 1782 channel->remote_tx_window_size, 1783 channel->remote_max_transmit, 1784 channel->remote_retransmission_timeout_ms, 1785 channel->remote_monitor_timeout_ms); 1786 // we store remote MPS in remote_mtu, might need to get re-evaluated 1787 channel->remote_mtu = little_endian_read_16(command, pos + 7); 1788 // If ERTM mandatory, but remote doens't offer ERTM -> disconnect 1789 if (channel->ertm_mandatory && mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1790 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1791 } else { 1792 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1793 } 1794 break; 1795 case L2CAP_CHANNEL_MODE_BASIC: 1796 switch (mode){ 1797 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1798 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 1799 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 1800 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1801 } 1802 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 1803 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 1804 break; 1805 default: // case L2CAP_CHANNEL_MODE_BASIC: 1806 // TODO store and evaluate configuration 1807 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1808 break; 1809 } 1810 break; 1811 default: 1812 break; 1813 } 1814 } 1815 #endif 1816 // check for unknown options 1817 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1818 log_info("l2cap cid %u, unknown options", channel->local_cid); 1819 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1820 } 1821 pos += length; 1822 } 1823 } 1824 1825 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 1826 log_info("l2cap_signaling_handle_configure_response"); 1827 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1828 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1829 uint16_t pos = 10; 1830 while (pos < end_pos){ 1831 uint8_t option_hint = command[pos] >> 7; 1832 uint8_t option_type = command[pos] & 0x7f; 1833 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1834 pos++; 1835 uint8_t length = command[pos++]; 1836 1837 // Retransmission and Flow Control Option 1838 if (option_type == 4 && length == 9){ 1839 switch (channel->mode){ 1840 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1841 if (channel->ertm_mandatory){ 1842 // ?? 1843 } else { 1844 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 1845 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 1846 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1847 } 1848 } 1849 break; 1850 case L2CAP_CHANNEL_MODE_BASIC: 1851 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 1852 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 1853 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1854 } 1855 break; 1856 default: 1857 break; 1858 } 1859 } 1860 1861 // check for unknown options 1862 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1863 log_info("l2cap cid %u, unknown options", channel->local_cid); 1864 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1865 } 1866 1867 pos += length; 1868 } 1869 #endif 1870 } 1871 1872 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1873 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1874 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1875 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1876 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1877 if (channel->state == L2CAP_STATE_OPEN) return 0; 1878 return 1; 1879 } 1880 1881 1882 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1883 1884 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1885 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1886 uint16_t result = 0; 1887 1888 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1889 1890 // handle DISCONNECT REQUESTS seperately 1891 if (code == DISCONNECTION_REQUEST){ 1892 switch (channel->state){ 1893 case L2CAP_STATE_CONFIG: 1894 case L2CAP_STATE_OPEN: 1895 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1896 case L2CAP_STATE_WAIT_DISCONNECT: 1897 l2cap_handle_disconnect_request(channel, identifier); 1898 break; 1899 1900 default: 1901 // ignore in other states 1902 break; 1903 } 1904 return; 1905 } 1906 1907 // @STATEMACHINE(l2cap) 1908 switch (channel->state) { 1909 1910 case L2CAP_STATE_WAIT_CONNECT_RSP: 1911 switch (code){ 1912 case CONNECTION_RESPONSE: 1913 l2cap_stop_rtx(channel); 1914 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1915 switch (result) { 1916 case 0: 1917 // successful connection 1918 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1919 channel->state = L2CAP_STATE_CONFIG; 1920 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1921 break; 1922 case 1: 1923 // connection pending. get some coffee, but start the ERTX 1924 l2cap_start_ertx(channel); 1925 break; 1926 default: 1927 // channel closed 1928 channel->state = L2CAP_STATE_CLOSED; 1929 // map l2cap connection response result to BTstack status enumeration 1930 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1931 1932 // drop link key if security block 1933 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1934 gap_drop_link_key_for_bd_addr(channel->address); 1935 } 1936 1937 // discard channel 1938 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1939 btstack_memory_l2cap_channel_free(channel); 1940 break; 1941 } 1942 break; 1943 1944 default: 1945 //@TODO: implement other signaling packets 1946 break; 1947 } 1948 break; 1949 1950 case L2CAP_STATE_CONFIG: 1951 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1952 switch (code) { 1953 case CONFIGURE_REQUEST: 1954 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1955 l2cap_signaling_handle_configure_request(channel, command); 1956 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1957 // only done if continuation not set 1958 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1959 } 1960 break; 1961 case CONFIGURE_RESPONSE: 1962 l2cap_stop_rtx(channel); 1963 l2cap_signaling_handle_configure_response(channel, result, command); 1964 switch (result){ 1965 case 0: // success 1966 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1967 break; 1968 case 4: // pending 1969 l2cap_start_ertx(channel); 1970 break; 1971 default: 1972 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1973 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 1974 // remote does not offer ertm but it's required 1975 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1976 break; 1977 } 1978 #endif 1979 // retry on negative result 1980 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1981 break; 1982 } 1983 break; 1984 default: 1985 break; 1986 } 1987 if (l2cap_channel_ready_for_open(channel)){ 1988 // for open: 1989 channel->state = L2CAP_STATE_OPEN; 1990 l2cap_emit_channel_opened(channel, 0); 1991 } 1992 break; 1993 1994 case L2CAP_STATE_WAIT_DISCONNECT: 1995 switch (code) { 1996 case DISCONNECTION_RESPONSE: 1997 l2cap_finialize_channel_close(channel); 1998 break; 1999 default: 2000 //@TODO: implement other signaling packets 2001 break; 2002 } 2003 break; 2004 2005 case L2CAP_STATE_CLOSED: 2006 // @TODO handle incoming requests 2007 break; 2008 2009 case L2CAP_STATE_OPEN: 2010 //@TODO: implement other signaling packets, e.g. re-configure 2011 break; 2012 default: 2013 break; 2014 } 2015 // log_info("new state %u", channel->state); 2016 } 2017 2018 2019 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 2020 2021 btstack_linked_list_iterator_t it; 2022 2023 // get code, signalind identifier and command len 2024 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2025 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2026 2027 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 2028 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 2029 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2030 return; 2031 } 2032 2033 // general commands without an assigned channel 2034 switch(code) { 2035 2036 case CONNECTION_REQUEST: { 2037 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2038 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2039 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 2040 return; 2041 } 2042 2043 case ECHO_REQUEST: 2044 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 2045 return; 2046 2047 case INFORMATION_REQUEST: { 2048 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2049 l2cap_register_signaling_response(handle, code, sig_id, 0, infoType); 2050 return; 2051 } 2052 2053 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2054 case INFORMATION_RESPONSE: { 2055 hci_connection_t * connection = hci_connection_for_handle(handle); 2056 if (!connection) return; 2057 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2058 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2059 if (result != 0) return; 2060 if (info_type != 0x02) return; 2061 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 2062 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2063 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 2064 // trigger connection request 2065 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2066 while (btstack_linked_list_iterator_has_next(&it)){ 2067 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2068 if (channel->con_handle != handle) continue; 2069 // bail if ERTM was requested but is not supported 2070 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 2071 if (channel->ertm_mandatory){ 2072 // channel closed 2073 channel->state = L2CAP_STATE_CLOSED; 2074 // map l2cap connection response result to BTstack status enumeration 2075 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTD); 2076 // discard channel 2077 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2078 btstack_memory_l2cap_channel_free(channel); 2079 continue; 2080 } else { 2081 // fallback to Basic mode 2082 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2083 } 2084 } 2085 // start connecting 2086 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 2087 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 2088 } 2089 // respond to connection request 2090 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 2091 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2092 l2cap_emit_incoming_connection(channel); 2093 } 2094 } 2095 return; 2096 } 2097 #endif 2098 2099 default: 2100 break; 2101 } 2102 2103 2104 // Get potential destination CID 2105 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2106 2107 // Find channel for this sig_id and connection handle 2108 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2109 while (btstack_linked_list_iterator_has_next(&it)){ 2110 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2111 if (channel->con_handle != handle) continue; 2112 if (code & 1) { 2113 // match odd commands (responses) by previous signaling identifier 2114 if (channel->local_sig_id == sig_id) { 2115 l2cap_signaling_handler_channel(channel, command); 2116 break; 2117 } 2118 } else { 2119 // match even commands (requests) by local channel id 2120 if (channel->local_cid == dest_cid) { 2121 l2cap_signaling_handler_channel(channel, command); 2122 break; 2123 } 2124 } 2125 } 2126 } 2127 #endif 2128 2129 #ifdef ENABLE_BLE 2130 2131 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 2132 uint8_t event[6]; 2133 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 2134 event[1] = 4; 2135 little_endian_store_16(event, 2, con_handle); 2136 little_endian_store_16(event, 4, result); 2137 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2138 if (!l2cap_event_packet_handler) return; 2139 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 2140 } 2141 2142 // @returns valid 2143 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 2144 hci_connection_t * connection; 2145 uint16_t result; 2146 uint8_t event[10]; 2147 2148 #ifdef ENABLE_LE_DATA_CHANNELS 2149 btstack_linked_list_iterator_t it; 2150 l2cap_channel_t * channel; 2151 uint16_t local_cid; 2152 uint16_t le_psm; 2153 uint16_t new_credits; 2154 uint16_t credits_before; 2155 l2cap_service_t * service; 2156 uint16_t source_cid; 2157 #endif 2158 2159 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2160 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 2161 2162 switch (code){ 2163 2164 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2165 result = little_endian_read_16(command, 4); 2166 l2cap_emit_connection_parameter_update_response(handle, result); 2167 break; 2168 2169 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2170 connection = hci_connection_for_handle(handle); 2171 if (connection){ 2172 if (connection->role != HCI_ROLE_MASTER){ 2173 // reject command without notifying upper layer when not in master role 2174 return 0; 2175 } 2176 int update_parameter = 1; 2177 le_connection_parameter_range_t existing_range; 2178 gap_get_connection_parameter_range(&existing_range); 2179 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 2180 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 2181 uint16_t le_conn_latency = little_endian_read_16(command,12); 2182 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 2183 2184 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 2185 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 2186 2187 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 2188 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 2189 2190 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 2191 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 2192 2193 if (update_parameter){ 2194 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2195 connection->le_conn_interval_min = le_conn_interval_min; 2196 connection->le_conn_interval_max = le_conn_interval_max; 2197 connection->le_conn_latency = le_conn_latency; 2198 connection->le_supervision_timeout = le_supervision_timeout; 2199 } else { 2200 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2201 } 2202 connection->le_con_param_update_identifier = sig_id; 2203 } 2204 2205 if (!l2cap_event_packet_handler) break; 2206 2207 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2208 event[1] = 8; 2209 memcpy(&event[2], &command[4], 8); 2210 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2211 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2212 break; 2213 2214 #ifdef ENABLE_LE_DATA_CHANNELS 2215 2216 case COMMAND_REJECT: 2217 // Find channel for this sig_id and connection handle 2218 channel = NULL; 2219 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2220 while (btstack_linked_list_iterator_has_next(&it)){ 2221 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2222 if (a_channel->con_handle != handle) continue; 2223 if (a_channel->local_sig_id != sig_id) continue; 2224 channel = a_channel; 2225 break; 2226 } 2227 if (!channel) break; 2228 2229 // if received while waiting for le connection response, assume legacy device 2230 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2231 channel->state = L2CAP_STATE_CLOSED; 2232 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2233 l2cap_emit_le_channel_opened(channel, 0x0002); 2234 2235 // discard channel 2236 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2237 btstack_memory_l2cap_channel_free(channel); 2238 break; 2239 } 2240 break; 2241 2242 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2243 2244 // get hci connection, bail if not found (must not happen) 2245 connection = hci_connection_for_handle(handle); 2246 if (!connection) return 0; 2247 2248 // check if service registered 2249 le_psm = little_endian_read_16(command, 4); 2250 service = l2cap_le_get_service(le_psm); 2251 source_cid = little_endian_read_16(command, 6); 2252 2253 if (service){ 2254 if (source_cid < 0x40){ 2255 // 0x0009 Connection refused - Invalid Source CID 2256 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2257 return 1; 2258 } 2259 2260 // go through list of channels for this ACL connection and check if we get a match 2261 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2262 while (btstack_linked_list_iterator_has_next(&it)){ 2263 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2264 if (a_channel->con_handle != handle) continue; 2265 if (a_channel->remote_cid != source_cid) continue; 2266 // 0x000a Connection refused - Source CID already allocated 2267 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2268 return 1; 2269 } 2270 2271 // security: check encryption 2272 if (service->required_security_level >= LEVEL_2){ 2273 if (sm_encryption_key_size(handle) == 0){ 2274 // 0x0008 Connection refused - insufficient encryption 2275 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2276 return 1; 2277 } 2278 // anything less than 16 byte key size is insufficient 2279 if (sm_encryption_key_size(handle) < 16){ 2280 // 0x0007 Connection refused – insufficient encryption key size 2281 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2282 return 1; 2283 } 2284 } 2285 2286 // security: check authencation 2287 if (service->required_security_level >= LEVEL_3){ 2288 if (!sm_authenticated(handle)){ 2289 // 0x0005 Connection refused – insufficient authentication 2290 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2291 return 1; 2292 } 2293 } 2294 2295 // security: check authorization 2296 if (service->required_security_level >= LEVEL_4){ 2297 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2298 // 0x0006 Connection refused – insufficient authorization 2299 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2300 return 1; 2301 } 2302 } 2303 2304 // allocate channel 2305 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 2306 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2307 if (!channel){ 2308 // 0x0004 Connection refused – no resources available 2309 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2310 return 1; 2311 } 2312 2313 channel->con_handle = handle; 2314 channel->remote_cid = source_cid; 2315 channel->remote_sig_id = sig_id; 2316 channel->remote_mtu = little_endian_read_16(command, 8); 2317 channel->remote_mps = little_endian_read_16(command, 10); 2318 channel->credits_outgoing = little_endian_read_16(command, 12); 2319 2320 // set initial state 2321 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2322 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2323 2324 // add to connections list 2325 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2326 2327 // post connection request event 2328 l2cap_emit_le_incoming_connection(channel); 2329 2330 } else { 2331 // Connection refused – LE_PSM not supported 2332 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2333 } 2334 break; 2335 2336 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2337 // Find channel for this sig_id and connection handle 2338 channel = NULL; 2339 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2340 while (btstack_linked_list_iterator_has_next(&it)){ 2341 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2342 if (a_channel->con_handle != handle) continue; 2343 if (a_channel->local_sig_id != sig_id) continue; 2344 channel = a_channel; 2345 break; 2346 } 2347 if (!channel) break; 2348 2349 // cid + 0 2350 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2351 if (result){ 2352 channel->state = L2CAP_STATE_CLOSED; 2353 // map l2cap connection response result to BTstack status enumeration 2354 l2cap_emit_le_channel_opened(channel, result); 2355 2356 // discard channel 2357 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2358 btstack_memory_l2cap_channel_free(channel); 2359 break; 2360 } 2361 2362 // success 2363 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2364 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2365 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2366 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2367 channel->state = L2CAP_STATE_OPEN; 2368 l2cap_emit_le_channel_opened(channel, result); 2369 break; 2370 2371 case LE_FLOW_CONTROL_CREDIT: 2372 // find channel 2373 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2374 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2375 if (!channel) { 2376 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2377 break; 2378 } 2379 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2380 credits_before = channel->credits_outgoing; 2381 channel->credits_outgoing += new_credits; 2382 // check for credit overrun 2383 if (credits_before > channel->credits_outgoing){ 2384 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2385 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2386 break; 2387 } 2388 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2389 break; 2390 2391 case DISCONNECTION_REQUEST: 2392 // find channel 2393 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2394 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2395 if (!channel) { 2396 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2397 break; 2398 } 2399 channel->remote_sig_id = sig_id; 2400 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2401 break; 2402 2403 #endif 2404 2405 case DISCONNECTION_RESPONSE: 2406 break; 2407 2408 default: 2409 // command unknown -> reject command 2410 return 0; 2411 } 2412 return 1; 2413 } 2414 #endif 2415 2416 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 2417 UNUSED(packet_type); 2418 UNUSED(channel); 2419 2420 l2cap_channel_t * l2cap_channel; 2421 UNUSED(l2cap_channel); 2422 2423 // Get Channel ID 2424 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 2425 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 2426 2427 switch (channel_id) { 2428 2429 #ifdef ENABLE_CLASSIC 2430 case L2CAP_CID_SIGNALING: { 2431 uint16_t command_offset = 8; 2432 while (command_offset < size) { 2433 // handle signaling commands 2434 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 2435 2436 // increment command_offset 2437 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2438 } 2439 break; 2440 } 2441 #endif 2442 2443 #ifdef ENABLE_BLE 2444 case L2CAP_CID_SIGNALING_LE: { 2445 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 2446 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 2447 if (!valid){ 2448 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2449 } 2450 break; 2451 } 2452 #endif 2453 2454 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 2455 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 2456 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2457 } 2458 break; 2459 2460 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 2461 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 2462 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2463 } 2464 break; 2465 2466 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 2467 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 2468 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2469 } 2470 break; 2471 2472 default: 2473 #ifdef ENABLE_CLASSIC 2474 // Find channel for this channel_id and connection handle 2475 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 2476 if (l2cap_channel) { 2477 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2478 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2479 2480 // verify FCS 2481 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 2482 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 2483 log_info("Packet FCS 0x%04x, calculated FCS 0x%04x", fcs_packet, fcs_calculated); 2484 if (fcs_calculated != fcs_packet){ 2485 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 2486 // TODO: trigger retransmission or something like that 2487 break; 2488 } 2489 2490 // switch on packet type 2491 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2492 uint8_t req_seq = (control >> 8) & 0x3f; 2493 if (control & 1){ 2494 // S-Frame 2495 // int poll = (control >> 7) & 0x01; 2496 l2cap_supervisory_function_t s = (l2cap_supervisory_function_t) ((control >> 2) & 0x03); 2497 switch (s){ 2498 case L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY: 2499 l2cap_ertm_handle_req_seq(l2cap_channel, req_seq); 2500 break; 2501 default: 2502 break; 2503 } 2504 break; 2505 } else { 2506 // I-Frame 2507 // get control 2508 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 2509 uint8_t tx_seq = (control >> 1) & 0x3f; 2510 log_info("Control: 0x%04x => SAR %u, ReqSeq %02u, R?, TxSeq %02u", control, (int) sar, req_seq, tx_seq); 2511 log_info("SAR: pos %u", l2cap_channel->rx_packets_state->pos); 2512 log_info("State: expected_tx_seq %02u, req_seq %02u", l2cap_channel->expected_tx_seq, l2cap_channel->req_seq); 2513 l2cap_ertm_handle_req_seq(l2cap_channel, req_seq); 2514 // check ordering 2515 if (l2cap_channel->expected_tx_seq == tx_seq){ 2516 log_info("Received expected frame with TxSeq == ExpectedTxSeq == %02u", tx_seq); 2517 l2cap_channel->req_seq = tx_seq; 2518 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2519 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 2520 uint16_t sdu_length; 2521 uint16_t segment_length; 2522 uint16_t payload_offset; 2523 switch (sar){ 2524 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 2525 payload_offset = COMPLETE_L2CAP_HEADER+2; 2526 segment_length = payload_offset-2; 2527 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER+2], segment_length); 2528 break; 2529 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 2530 // TODO: use current packet 2531 // TODO: check if reassembly started 2532 // TODO: check len against local mtu 2533 sdu_length = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER+2); 2534 payload_offset = COMPLETE_L2CAP_HEADER+4; 2535 segment_length = size - payload_offset-2; 2536 memcpy(&l2cap_channel->rx_packets_data[0], &packet[payload_offset], segment_length); 2537 l2cap_channel->rx_packets_state->sdu_length = sdu_length; 2538 l2cap_channel->rx_packets_state->pos = segment_length; 2539 break; 2540 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 2541 payload_offset = COMPLETE_L2CAP_HEADER+2; 2542 segment_length = size - payload_offset-2; 2543 memcpy(&l2cap_channel->rx_packets_data[l2cap_channel->rx_packets_state->pos], &packet[payload_offset], segment_length); 2544 l2cap_channel->rx_packets_state->pos += segment_length; 2545 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->rx_packets_data, l2cap_channel->rx_packets_state[0].pos); 2546 break; 2547 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 2548 payload_offset = COMPLETE_L2CAP_HEADER+2; 2549 segment_length = size - payload_offset-2; 2550 memcpy(&l2cap_channel->rx_packets_data[l2cap_channel->rx_packets_state->pos], &packet[payload_offset], segment_length); 2551 l2cap_channel->rx_packets_state->pos += segment_length; 2552 break; 2553 } 2554 } 2555 } 2556 break; 2557 } 2558 #endif 2559 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2560 } 2561 #endif 2562 #ifdef ENABLE_LE_DATA_CHANNELS 2563 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 2564 if (l2cap_channel) { 2565 // credit counting 2566 if (l2cap_channel->credits_incoming == 0){ 2567 log_error("LE Data Channel packet received but no incoming credits"); 2568 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2569 break; 2570 } 2571 l2cap_channel->credits_incoming--; 2572 2573 // automatic credits 2574 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 2575 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 2576 } 2577 2578 // first fragment 2579 uint16_t pos = 0; 2580 if (!l2cap_channel->receive_sdu_len){ 2581 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2582 l2cap_channel->receive_sdu_pos = 0; 2583 pos += 2; 2584 size -= 2; 2585 } 2586 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 2587 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 2588 // done? 2589 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 2590 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 2591 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 2592 l2cap_channel->receive_sdu_len = 0; 2593 } 2594 } else { 2595 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 2596 } 2597 #endif 2598 break; 2599 } 2600 2601 l2cap_run(); 2602 } 2603 2604 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 2605 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 2606 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 2607 if (index < 0) return; 2608 fixed_channels[index].callback = the_packet_handler; 2609 } 2610 2611 #ifdef ENABLE_CLASSIC 2612 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2613 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 2614 channel->state = L2CAP_STATE_CLOSED; 2615 l2cap_emit_channel_closed(channel); 2616 // discard channel 2617 l2cap_stop_rtx(channel); 2618 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2619 btstack_memory_l2cap_channel_free(channel); 2620 } 2621 2622 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 2623 btstack_linked_list_iterator_t it; 2624 btstack_linked_list_iterator_init(&it, services); 2625 while (btstack_linked_list_iterator_has_next(&it)){ 2626 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 2627 if ( service->psm == psm){ 2628 return service; 2629 }; 2630 } 2631 return NULL; 2632 } 2633 2634 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 2635 return l2cap_get_service_internal(&l2cap_services, psm); 2636 } 2637 2638 2639 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 2640 2641 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 2642 2643 // check for alread registered psm 2644 l2cap_service_t *service = l2cap_get_service(psm); 2645 if (service) { 2646 log_error("l2cap_register_service: PSM %u already registered", psm); 2647 return L2CAP_SERVICE_ALREADY_REGISTERED; 2648 } 2649 2650 // alloc structure 2651 service = btstack_memory_l2cap_service_get(); 2652 if (!service) { 2653 log_error("l2cap_register_service: no memory for l2cap_service_t"); 2654 return BTSTACK_MEMORY_ALLOC_FAILED; 2655 } 2656 2657 // fill in 2658 service->psm = psm; 2659 service->mtu = mtu; 2660 service->packet_handler = service_packet_handler; 2661 service->required_security_level = security_level; 2662 2663 // add to services list 2664 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 2665 2666 // enable page scan 2667 gap_connectable_control(1); 2668 2669 return 0; 2670 } 2671 2672 uint8_t l2cap_unregister_service(uint16_t psm){ 2673 2674 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2675 2676 l2cap_service_t *service = l2cap_get_service(psm); 2677 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2678 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2679 btstack_memory_l2cap_service_free(service); 2680 2681 // disable page scan when no services registered 2682 if (btstack_linked_list_empty(&l2cap_services)) { 2683 gap_connectable_control(0); 2684 } 2685 return 0; 2686 } 2687 #endif 2688 2689 2690 #ifdef ENABLE_LE_DATA_CHANNELS 2691 2692 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2693 if (!channel->waiting_for_can_send_now) return; 2694 if (channel->send_sdu_buffer) return; 2695 channel->waiting_for_can_send_now = 0; 2696 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2697 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2698 } 2699 2700 // 1BH2222 2701 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2702 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", 2703 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2704 uint8_t event[19]; 2705 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2706 event[1] = sizeof(event) - 2; 2707 event[2] = channel->address_type; 2708 reverse_bd_addr(channel->address, &event[3]); 2709 little_endian_store_16(event, 9, channel->con_handle); 2710 little_endian_store_16(event, 11, channel->psm); 2711 little_endian_store_16(event, 13, channel->local_cid); 2712 little_endian_store_16(event, 15, channel->remote_cid); 2713 little_endian_store_16(event, 17, channel->remote_mtu); 2714 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2715 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2716 } 2717 // 11BH22222 2718 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2719 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", 2720 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2721 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2722 uint8_t event[23]; 2723 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2724 event[1] = sizeof(event) - 2; 2725 event[2] = status; 2726 event[3] = channel->address_type; 2727 reverse_bd_addr(channel->address, &event[4]); 2728 little_endian_store_16(event, 10, channel->con_handle); 2729 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2730 little_endian_store_16(event, 13, channel->psm); 2731 little_endian_store_16(event, 15, channel->local_cid); 2732 little_endian_store_16(event, 17, channel->remote_cid); 2733 little_endian_store_16(event, 19, channel->local_mtu); 2734 little_endian_store_16(event, 21, channel->remote_mtu); 2735 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2736 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2737 } 2738 2739 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2740 btstack_linked_list_iterator_t it; 2741 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2742 while (btstack_linked_list_iterator_has_next(&it)){ 2743 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2744 if ( channel->local_cid == local_cid) { 2745 return channel; 2746 } 2747 } 2748 return NULL; 2749 } 2750 2751 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2752 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2753 channel->state = L2CAP_STATE_CLOSED; 2754 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2755 // discard channel 2756 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2757 btstack_memory_l2cap_channel_free(channel); 2758 } 2759 2760 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2761 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2762 } 2763 2764 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2765 2766 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2767 2768 // check for alread registered psm 2769 l2cap_service_t *service = l2cap_le_get_service(psm); 2770 if (service) { 2771 return L2CAP_SERVICE_ALREADY_REGISTERED; 2772 } 2773 2774 // alloc structure 2775 service = btstack_memory_l2cap_service_get(); 2776 if (!service) { 2777 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2778 return BTSTACK_MEMORY_ALLOC_FAILED; 2779 } 2780 2781 // fill in 2782 service->psm = psm; 2783 service->mtu = 0; 2784 service->packet_handler = packet_handler; 2785 service->required_security_level = security_level; 2786 2787 // add to services list 2788 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2789 2790 // done 2791 return 0; 2792 } 2793 2794 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2795 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2796 l2cap_service_t *service = l2cap_le_get_service(psm); 2797 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2798 2799 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2800 btstack_memory_l2cap_service_free(service); 2801 return 0; 2802 } 2803 2804 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2805 // get channel 2806 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2807 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2808 2809 // validate state 2810 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2811 return ERROR_CODE_COMMAND_DISALLOWED; 2812 } 2813 2814 // set state accept connection 2815 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2816 channel->receive_sdu_buffer = receive_sdu_buffer; 2817 channel->local_mtu = mtu; 2818 channel->new_credits_incoming = initial_credits; 2819 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2820 2821 // test 2822 // channel->new_credits_incoming = 1; 2823 2824 // go 2825 l2cap_run(); 2826 return 0; 2827 } 2828 2829 /** 2830 * @brief Deny incoming LE Data Channel connection due to resource constraints 2831 * @param local_cid L2CAP LE Data Channel Identifier 2832 */ 2833 2834 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2835 // get channel 2836 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2837 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2838 2839 // validate state 2840 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2841 return ERROR_CODE_COMMAND_DISALLOWED; 2842 } 2843 2844 // set state decline connection 2845 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2846 channel->reason = 0x04; // no resources available 2847 l2cap_run(); 2848 return 0; 2849 } 2850 2851 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2852 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2853 uint16_t * out_local_cid) { 2854 2855 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2856 2857 2858 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2859 if (!connection) { 2860 log_error("no hci_connection for handle 0x%04x", con_handle); 2861 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2862 } 2863 2864 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2865 if (!channel) { 2866 return BTSTACK_MEMORY_ALLOC_FAILED; 2867 } 2868 log_info("l2cap_le_create_channel %p", channel); 2869 2870 // store local_cid 2871 if (out_local_cid){ 2872 *out_local_cid = channel->local_cid; 2873 } 2874 2875 // provide buffer 2876 channel->con_handle = con_handle; 2877 channel->receive_sdu_buffer = receive_sdu_buffer; 2878 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2879 channel->new_credits_incoming = initial_credits; 2880 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2881 2882 // add to connections list 2883 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2884 2885 // go 2886 l2cap_run(); 2887 return 0; 2888 } 2889 2890 /** 2891 * @brief Provide credtis for LE Data Channel 2892 * @param local_cid L2CAP LE Data Channel Identifier 2893 * @param credits Number additional credits for peer 2894 */ 2895 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2896 2897 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2898 if (!channel) { 2899 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2900 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2901 } 2902 2903 // check state 2904 if (channel->state != L2CAP_STATE_OPEN){ 2905 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2906 } 2907 2908 // assert incoming credits + credits <= 0xffff 2909 uint32_t total_credits = channel->credits_incoming; 2910 total_credits += channel->new_credits_incoming; 2911 total_credits += credits; 2912 if (total_credits > 0xffff){ 2913 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2914 channel->new_credits_incoming, credits); 2915 } 2916 2917 // set credits_granted 2918 channel->new_credits_incoming += credits; 2919 2920 // go 2921 l2cap_run(); 2922 return 0; 2923 } 2924 2925 /** 2926 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2927 * @param local_cid L2CAP LE Data Channel Identifier 2928 */ 2929 int l2cap_le_can_send_now(uint16_t local_cid){ 2930 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2931 if (!channel) { 2932 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2933 return 0; 2934 } 2935 2936 // check state 2937 if (channel->state != L2CAP_STATE_OPEN) return 0; 2938 2939 // check queue 2940 if (channel->send_sdu_buffer) return 0; 2941 2942 // fine, go ahead 2943 return 1; 2944 } 2945 2946 /** 2947 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2948 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2949 * so packet handler should be ready to handle it 2950 * @param local_cid L2CAP LE Data Channel Identifier 2951 */ 2952 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2953 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2954 if (!channel) { 2955 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2956 return 0; 2957 } 2958 channel->waiting_for_can_send_now = 1; 2959 l2cap_le_notify_channel_can_send(channel); 2960 return 0; 2961 } 2962 2963 /** 2964 * @brief Send data via LE Data Channel 2965 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2966 * @param local_cid L2CAP LE Data Channel Identifier 2967 * @param data data to send 2968 * @param size data size 2969 */ 2970 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2971 2972 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2973 if (!channel) { 2974 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2975 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2976 } 2977 2978 if (len > channel->remote_mtu){ 2979 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2980 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2981 } 2982 2983 if (channel->send_sdu_buffer){ 2984 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2985 return BTSTACK_ACL_BUFFERS_FULL; 2986 } 2987 2988 channel->send_sdu_buffer = data; 2989 channel->send_sdu_len = len; 2990 channel->send_sdu_pos = 0; 2991 2992 l2cap_run(); 2993 return 0; 2994 } 2995 2996 /** 2997 * @brief Disconnect from LE Data Channel 2998 * @param local_cid L2CAP LE Data Channel Identifier 2999 */ 3000 uint8_t l2cap_le_disconnect(uint16_t local_cid) 3001 { 3002 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3003 if (!channel) { 3004 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3005 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3006 } 3007 3008 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3009 l2cap_run(); 3010 return 0; 3011 } 3012 3013 #endif 3014