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 #ifdef ENABLE_CLASSIC 214 l2cap_channels = NULL; 215 l2cap_services = NULL; 216 require_security_level2_for_outgoing_sdp = 0; 217 #endif 218 219 #ifdef ENABLE_LE_DATA_CHANNELS 220 l2cap_le_services = NULL; 221 l2cap_le_channels = NULL; 222 #endif 223 224 #ifdef ENABLE_BLE 225 l2cap_event_packet_handler = NULL; 226 #endif 227 memset(fixed_channels, 0, sizeof(fixed_channels)); 228 229 // 230 // register callback with HCI 231 // 232 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 233 hci_add_event_handler(&hci_event_callback_registration); 234 235 hci_register_acl_packet_handler(&l2cap_acl_handler); 236 237 #ifdef ENABLE_CLASSIC 238 gap_connectable_control(0); // no services yet 239 #endif 240 } 241 242 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 243 #ifdef ENABLE_BLE 244 l2cap_event_packet_handler = handler; 245 #else 246 UNUSED(handler); 247 #endif 248 } 249 250 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 251 UNUSED(con_handle); 252 253 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 254 if (index < 0) return; 255 fixed_channels[index].waiting_for_can_send_now = 1; 256 l2cap_notify_channel_can_send(); 257 } 258 259 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 260 UNUSED(channel_id); 261 262 return hci_can_send_acl_packet_now(con_handle); 263 } 264 265 uint8_t *l2cap_get_outgoing_buffer(void){ 266 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 267 } 268 269 int l2cap_reserve_packet_buffer(void){ 270 return hci_reserve_packet_buffer(); 271 } 272 273 void l2cap_release_packet_buffer(void){ 274 hci_release_packet_buffer(); 275 } 276 277 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){ 278 // 0 - Connection handle : PB=pb : BC=00 279 little_endian_store_16(acl_buffer, 0, con_handle | (packet_boundary << 12) | (0 << 14)); 280 // 2 - ACL length 281 little_endian_store_16(acl_buffer, 2, len + 4); 282 // 4 - L2CAP packet length 283 little_endian_store_16(acl_buffer, 4, len + 0); 284 // 6 - L2CAP channel DEST 285 little_endian_store_16(acl_buffer, 6, remote_cid); 286 } 287 288 // assumption - only on LE connections 289 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 290 291 if (!hci_is_packet_buffer_reserved()){ 292 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 293 return BTSTACK_ACL_BUFFERS_FULL; 294 } 295 296 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 297 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 298 return BTSTACK_ACL_BUFFERS_FULL; 299 } 300 301 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 302 303 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 304 l2cap_setup_header(acl_buffer, con_handle, 0, cid, len); 305 // send 306 return hci_send_acl_packet_buffer(len+8); 307 } 308 309 // assumption - only on LE connections 310 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 311 312 if (!hci_can_send_acl_packet_now(con_handle)){ 313 log_info("l2cap_send cid 0x%02x, cannot send", cid); 314 return BTSTACK_ACL_BUFFERS_FULL; 315 } 316 317 hci_reserve_packet_buffer(); 318 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 319 320 memcpy(&acl_buffer[8], data, len); 321 322 return l2cap_send_prepared_connectionless(con_handle, cid, len); 323 } 324 325 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 326 log_debug("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 327 uint8_t event[4]; 328 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 329 event[1] = sizeof(event) - 2; 330 little_endian_store_16(event, 2, channel); 331 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 332 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 333 } 334 335 #ifdef L2CAP_USES_CHANNELS 336 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 337 (* (channel->packet_handler))(type, channel->local_cid, data, size); 338 } 339 340 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 341 uint8_t event[4]; 342 event[0] = event_code; 343 event[1] = sizeof(event) - 2; 344 little_endian_store_16(event, 2, channel->local_cid); 345 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 346 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 347 } 348 #endif 349 350 #ifdef ENABLE_CLASSIC 351 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 352 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", 353 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 354 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 355 uint8_t event[24]; 356 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 357 event[1] = sizeof(event) - 2; 358 event[2] = status; 359 reverse_bd_addr(channel->address, &event[3]); 360 little_endian_store_16(event, 9, channel->con_handle); 361 little_endian_store_16(event, 11, channel->psm); 362 little_endian_store_16(event, 13, channel->local_cid); 363 little_endian_store_16(event, 15, channel->remote_cid); 364 little_endian_store_16(event, 17, channel->local_mtu); 365 little_endian_store_16(event, 19, channel->remote_mtu); 366 little_endian_store_16(event, 21, channel->flush_timeout); 367 event[23] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 368 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 369 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 370 } 371 372 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 373 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 374 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 375 } 376 377 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 378 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 379 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 380 uint8_t event[16]; 381 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 382 event[1] = sizeof(event) - 2; 383 reverse_bd_addr(channel->address, &event[2]); 384 little_endian_store_16(event, 8, channel->con_handle); 385 little_endian_store_16(event, 10, channel->psm); 386 little_endian_store_16(event, 12, channel->local_cid); 387 little_endian_store_16(event, 14, channel->remote_cid); 388 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 389 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 390 } 391 392 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 393 btstack_linked_list_iterator_t it; 394 btstack_linked_list_iterator_init(&it, &l2cap_channels); 395 while (btstack_linked_list_iterator_has_next(&it)){ 396 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 397 if ( channel->local_cid == local_cid) { 398 return channel; 399 } 400 } 401 return NULL; 402 } 403 404 /// 405 406 void l2cap_request_can_send_now_event(uint16_t local_cid){ 407 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 408 if (!channel) return; 409 channel->waiting_for_can_send_now = 1; 410 l2cap_notify_channel_can_send(); 411 } 412 413 int l2cap_can_send_packet_now(uint16_t local_cid){ 414 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 415 if (!channel) return 0; 416 return hci_can_send_acl_packet_now(channel->con_handle); 417 } 418 419 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 420 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 421 if (!channel) return 0; 422 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 423 } 424 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 425 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 426 if (channel) { 427 return channel->remote_mtu; 428 } 429 return 0; 430 } 431 432 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 433 btstack_linked_list_iterator_t it; 434 btstack_linked_list_iterator_init(&it, &l2cap_channels); 435 while (btstack_linked_list_iterator_has_next(&it)){ 436 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 437 if ( &channel->rtx == ts) { 438 return channel; 439 } 440 } 441 return NULL; 442 } 443 444 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 445 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 446 if (!channel) return; 447 448 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 449 450 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 451 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 452 // notify client 453 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 454 455 // discard channel 456 // no need to stop timer here, it is removed from list during timer callback 457 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 458 btstack_memory_l2cap_channel_free(channel); 459 } 460 461 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 462 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 463 btstack_run_loop_remove_timer(&channel->rtx); 464 } 465 466 static void l2cap_start_rtx(l2cap_channel_t * channel){ 467 l2cap_stop_rtx(channel); 468 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 469 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 470 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 471 btstack_run_loop_add_timer(&channel->rtx); 472 } 473 474 static void l2cap_start_ertx(l2cap_channel_t * channel){ 475 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 476 l2cap_stop_rtx(channel); 477 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 478 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 479 btstack_run_loop_add_timer(&channel->rtx); 480 } 481 482 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 483 require_security_level2_for_outgoing_sdp = 1; 484 } 485 486 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 487 return (psm == BLUETOOTH_PROTOCOL_SDP) && (!require_security_level2_for_outgoing_sdp); 488 } 489 490 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 491 if (!hci_can_send_acl_packet_now(handle)){ 492 log_info("l2cap_send_signaling_packet, cannot send"); 493 return BTSTACK_ACL_BUFFERS_FULL; 494 } 495 496 // log_info("l2cap_send_signaling_packet type %u", cmd); 497 hci_reserve_packet_buffer(); 498 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 499 va_list argptr; 500 va_start(argptr, identifier); 501 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 502 va_end(argptr); 503 // log_info("l2cap_send_signaling_packet con %u!", handle); 504 return hci_send_acl_packet_buffer(len); 505 } 506 507 // assumption - only on Classic connections 508 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 509 510 if (!hci_is_packet_buffer_reserved()){ 511 log_error("l2cap_send_prepared called without reserving packet first"); 512 return BTSTACK_ACL_BUFFERS_FULL; 513 } 514 515 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 516 if (!channel) { 517 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 518 return -1; // TODO: define error 519 } 520 521 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 522 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 523 return BTSTACK_ACL_BUFFERS_FULL; 524 } 525 526 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 527 528 int fcs_size = 0; 529 530 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 531 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 532 fcs_size = 2; 533 } 534 #endif 535 536 // set non-flushable packet boundary flag if supported on Controller 537 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 538 uint8_t packet_boundary_flag = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 539 l2cap_setup_header(acl_buffer, channel->con_handle, packet_boundary_flag, channel->remote_cid, len + fcs_size); 540 541 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 542 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 543 // calculate FCS over l2cap data 544 uint16_t fcs = crc16_calc(acl_buffer + 4, 4 + len); 545 log_info("I-Frame: fcs 0x%04x", fcs); 546 little_endian_store_16(acl_buffer, 8 + len, fcs); 547 } 548 #endif 549 550 // send 551 return hci_send_acl_packet_buffer(len+8+fcs_size); 552 } 553 554 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 555 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){ 556 return (((uint16_t) sar) << 14) | (req_seq << 8) | (final << 7) | (tx_seq << 1) | 0; 557 } 558 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){ 559 return (req_seq << 8) | (final << 7) | (poll << 4) | (((int) supervisory_function) << 2) | 1; 560 } 561 static int l2cap_next_ertm_seq_nr(int seq_nr){ 562 return (seq_nr + 1) & 0x3f; 563 } 564 static void l2cap_ertm_next_tx_write_index(l2cap_channel_t * channel){ 565 channel->tx_write_index++; 566 if (channel->tx_write_index < channel->num_tx_buffers) return; 567 channel->tx_write_index = 0; 568 } 569 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts){ 570 log_info("l2cap_ertm_monitor_timeout_callback"); 571 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 572 573 // TODO: we assume that it's the oldest packet 574 l2cap_ertm_tx_packet_state_t * tx_state; 575 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 576 577 // check retry count 578 if (tx_state->retry_count < l2cap_channel->remote_max_transmit){ 579 // increment retry count 580 tx_state->retry_count++; 581 582 // start monitor timer 583 btstack_run_loop_set_timer_handler(&tx_state->monitor_timer, &l2cap_ertm_monitor_timeout_callback); 584 btstack_run_loop_set_timer_context(&tx_state->monitor_timer, l2cap_channel); 585 btstack_run_loop_set_timer(&tx_state->monitor_timer, l2cap_channel->local_monitor_timeout_ms); 586 btstack_run_loop_add_timer(&tx_state->monitor_timer); 587 588 // send RR/P=1 589 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 590 } else { 591 log_info("Monitor timer expired & retry count >= max transmit -> disconnect"); 592 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 593 } 594 l2cap_run(); 595 } 596 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts){ 597 log_info("l2cap_ertm_retransmission_timeout_callback"); 598 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 599 600 // TODO: we assume that it's the oldest packet 601 l2cap_ertm_tx_packet_state_t * tx_state; 602 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 603 604 // set retry count = 1 605 tx_state->retry_count = 1; 606 607 // start monitor timer 608 btstack_run_loop_set_timer_handler(&tx_state->monitor_timer, &l2cap_ertm_monitor_timeout_callback); 609 btstack_run_loop_set_timer_context(&tx_state->monitor_timer, l2cap_channel); 610 btstack_run_loop_set_timer(&tx_state->monitor_timer, l2cap_channel->local_monitor_timeout_ms); 611 btstack_run_loop_add_timer(&tx_state->monitor_timer); 612 613 // send RR/P=1 614 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 615 l2cap_run(); 616 } 617 static int l2cap_ertm_send_information_frame(l2cap_channel_t * channel, int index, int final){ 618 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 619 hci_reserve_packet_buffer(); 620 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 621 uint16_t control = l2cap_encanced_control_field_for_information_frame(tx_state->tx_seq, final, channel->req_seq, L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU); 622 log_info("I-Frame: control 0x%04x", control); 623 little_endian_store_16(acl_buffer, 8, control); 624 memcpy(&acl_buffer[8+2], &channel->tx_packets_data[index * channel->local_mtu], tx_state->len); 625 // send 626 return l2cap_send_prepared(channel->local_cid, 2 + tx_state->len); 627 } 628 static int l2cap_ertm_send(l2cap_channel_t * channel, uint8_t * data, uint16_t len){ 629 if (len > channel->remote_mtu){ 630 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", channel->local_cid); 631 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 632 } 633 // TODO: check tx_transmit 634 // store int tx packet bufferx 635 int index = channel->tx_write_index; 636 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 637 tx_state->tx_seq = channel->next_tx_seq; 638 tx_state->len = len; 639 tx_state->retry_count = 0; 640 memcpy(&channel->tx_packets_data[index * channel->local_mtu], data, len); 641 // update 642 channel->next_tx_seq = l2cap_next_ertm_seq_nr(channel->next_tx_seq); 643 l2cap_ertm_next_tx_write_index(channel); 644 // set retransmission timer 645 btstack_run_loop_set_timer_handler(&tx_state->retransmission_timer, &l2cap_ertm_retransmission_timeout_callback); 646 btstack_run_loop_set_timer_context(&tx_state->retransmission_timer, channel); 647 btstack_run_loop_set_timer(&tx_state->retransmission_timer, channel->local_retransmission_timeout_ms); 648 btstack_run_loop_add_timer(&tx_state->retransmission_timer); 649 // try to send 650 l2cap_run(); 651 return 0; 652 } 653 #endif 654 655 // assumption - only on Classic connections 656 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 657 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 658 if (!channel) { 659 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 660 return -1; // TODO: define error 661 } 662 663 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 664 // send in ERTM 665 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 666 return l2cap_ertm_send(channel, data, len); 667 } 668 #endif 669 670 if (len > channel->remote_mtu){ 671 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 672 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 673 } 674 675 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 676 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 677 return BTSTACK_ACL_BUFFERS_FULL; 678 } 679 680 hci_reserve_packet_buffer(); 681 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 682 memcpy(&acl_buffer[8], data, len); 683 return l2cap_send_prepared(local_cid, len); 684 } 685 686 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 687 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 688 } 689 690 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 691 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 692 } 693 694 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 695 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 696 } 697 #endif 698 699 700 #ifdef ENABLE_BLE 701 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 702 703 if (!hci_can_send_acl_packet_now(handle)){ 704 log_info("l2cap_send_le_signaling_packet, cannot send"); 705 return BTSTACK_ACL_BUFFERS_FULL; 706 } 707 708 // log_info("l2cap_send_le_signaling_packet type %u", cmd); 709 hci_reserve_packet_buffer(); 710 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 711 va_list argptr; 712 va_start(argptr, identifier); 713 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 714 va_end(argptr); 715 // log_info("l2cap_send_le_signaling_packet con %u!", handle); 716 return hci_send_acl_packet_buffer(len); 717 } 718 #endif 719 720 uint16_t l2cap_max_mtu(void){ 721 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 722 } 723 724 uint16_t l2cap_max_le_mtu(void){ 725 return l2cap_max_mtu(); 726 } 727 728 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 729 static uint16_t l2cap_setup_options_ertm(l2cap_channel_t * channel, uint8_t * config_options){ 730 config_options[0] = 0x04; // RETRANSMISSION AND FLOW CONTROL OPTION 731 config_options[1] = 9; // length 732 config_options[2] = (uint8_t) channel->mode; 733 config_options[3] = channel->num_rx_buffers; // == TxWindows size 734 config_options[4] = channel->local_max_transmit; 735 little_endian_store_16( config_options, 5, channel->local_retransmission_timeout_ms); 736 little_endian_store_16( config_options, 7, channel->local_monitor_timeout_ms); 737 little_endian_store_16( config_options, 9, channel->local_mtu); 738 return 11; 739 } 740 static int l2cap_ertm_send_supervisor_frame(l2cap_channel_t * channel, uint16_t control){ 741 hci_reserve_packet_buffer(); 742 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 743 log_info("S-Frame: control 0x%04x", control); 744 little_endian_store_16(acl_buffer, 8, control); 745 return l2cap_send_prepared(channel->local_cid, 2); 746 } 747 static int l2cap_ertm_num_unacknowledged_tx_packets(l2cap_channel_t * channel){ 748 int unacknowledged_packets = channel->tx_send_index - channel->tx_read_index; 749 if (unacknowledged_packets < 0){ 750 unacknowledged_packets += channel->num_tx_buffers; 751 } 752 return unacknowledged_packets; 753 } 754 #endif 755 756 #ifdef ENABLE_CLASSIC 757 758 static uint16_t l2cap_setup_options_mtu(l2cap_channel_t * channel, uint8_t * config_options){ 759 config_options[0] = 1; // MTU 760 config_options[1] = 2; // len param 761 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 762 return 4; 763 } 764 765 static uint16_t l2cap_setup_options(l2cap_channel_t * channel, uint8_t * config_options){ 766 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 767 // use ERTM options if supported 768 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 769 if ((connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_DONE) && (connection->l2cap_state.extended_feature_mask & 0x08)){ 770 return l2cap_setup_options_ertm(channel, config_options); 771 772 } 773 #endif 774 return l2cap_setup_options_mtu(channel, config_options); 775 } 776 777 static uint32_t l2cap_extended_features_mask(void){ 778 // extended features request supported, features: fixed channels, unicast connectionless data reception 779 uint32_t features = 0x280; 780 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 781 features |= 0x0008; 782 #endif 783 return features; 784 } 785 #endif 786 787 // MARK: L2CAP_RUN 788 // process outstanding signaling tasks 789 static void l2cap_run(void){ 790 791 // log_info("l2cap_run: entered"); 792 793 // check pending signaling responses 794 while (signaling_responses_pending){ 795 796 hci_con_handle_t handle = signaling_responses[0].handle; 797 798 if (!hci_can_send_acl_packet_now(handle)) break; 799 800 uint8_t sig_id = signaling_responses[0].sig_id; 801 uint8_t response_code = signaling_responses[0].code; 802 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 803 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 804 #ifdef ENABLE_CLASSIC 805 uint16_t source_cid = signaling_responses[0].cid; // CONNECTION_REQUEST 806 #endif 807 UNUSED(infoType); 808 809 // remove first item before sending (to avoid sending response mutliple times) 810 signaling_responses_pending--; 811 int i; 812 for (i=0; i < signaling_responses_pending; i++){ 813 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 814 } 815 816 switch (response_code){ 817 #ifdef ENABLE_CLASSIC 818 case CONNECTION_REQUEST: 819 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, source_cid, 0, result, 0); 820 // also disconnect if result is 0x0003 - security blocked 821 if (result == 0x0003){ 822 hci_disconnect_security_block(handle); 823 } 824 break; 825 case ECHO_REQUEST: 826 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 827 break; 828 case INFORMATION_REQUEST: 829 switch (infoType){ 830 case 1: { // Connectionless MTU 831 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 832 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 833 } 834 break; 835 case 2: { // Extended Features Supported 836 uint32_t features = l2cap_extended_features_mask(); 837 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 838 } 839 break; 840 case 3: { // Fixed Channels Supported 841 uint8_t map[8]; 842 memset(map, 0, 8); 843 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 844 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 845 } 846 break; 847 default: 848 // all other types are not supported 849 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 850 break; 851 } 852 break; 853 case COMMAND_REJECT: 854 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 855 break; 856 #endif 857 #ifdef ENABLE_BLE 858 case LE_CREDIT_BASED_CONNECTION_REQUEST: 859 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 860 break; 861 case COMMAND_REJECT_LE: 862 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 863 break; 864 #endif 865 default: 866 // should not happen 867 break; 868 } 869 } 870 871 btstack_linked_list_iterator_t it; 872 UNUSED(it); 873 874 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 875 // send l2cap information request if neccessary 876 hci_connections_get_iterator(&it); 877 while(btstack_linked_list_iterator_has_next(&it)){ 878 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 879 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST){ 880 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W4_EXTENDED_FEATURE_RESPONSE; 881 // send information request for extended features 882 uint8_t sig_id = l2cap_next_sig_id(); 883 uint8_t info_type = 2; 884 l2cap_send_signaling_packet(connection->con_handle, INFORMATION_REQUEST, sig_id, info_type); 885 return; 886 } 887 } 888 #endif 889 890 #ifdef ENABLE_CLASSIC 891 uint8_t config_options[10]; 892 btstack_linked_list_iterator_init(&it, &l2cap_channels); 893 while (btstack_linked_list_iterator_has_next(&it)){ 894 895 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 896 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 897 switch (channel->state){ 898 899 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 900 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 901 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 902 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 903 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 904 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 905 } 906 break; 907 908 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 909 if (!hci_can_send_command_packet_now()) break; 910 // send connection request - set state first 911 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 912 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 913 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 914 break; 915 916 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 917 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 918 channel->state = L2CAP_STATE_INVALID; 919 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 920 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 921 l2cap_stop_rtx(channel); 922 btstack_linked_list_iterator_remove(&it); 923 btstack_memory_l2cap_channel_free(channel); 924 break; 925 926 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 927 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 928 channel->state = L2CAP_STATE_CONFIG; 929 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 930 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 931 break; 932 933 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 934 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 935 // success, start l2cap handshake 936 channel->local_sig_id = l2cap_next_sig_id(); 937 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 938 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 939 l2cap_start_rtx(channel); 940 break; 941 942 case L2CAP_STATE_CONFIG: 943 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 944 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 945 uint16_t flags = 0; 946 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 947 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 948 flags = 1; 949 } else { 950 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 951 } 952 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 953 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 954 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 955 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 956 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED){ 957 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 958 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 959 uint16_t options_size = l2cap_setup_options(channel, config_options); 960 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); 961 #endif 962 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 963 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 964 uint16_t options_size = l2cap_setup_options(channel, config_options); 965 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); 966 } else { 967 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, 0, NULL); 968 } 969 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 970 } 971 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 972 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 973 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 974 channel->local_sig_id = l2cap_next_sig_id(); 975 uint16_t options_size = l2cap_setup_options(channel, config_options); 976 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, options_size, &config_options); 977 l2cap_start_rtx(channel); 978 } 979 if (l2cap_channel_ready_for_open(channel)){ 980 channel->state = L2CAP_STATE_OPEN; 981 l2cap_emit_channel_opened(channel, 0); // success 982 } 983 break; 984 985 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 986 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 987 channel->state = L2CAP_STATE_INVALID; 988 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 989 // 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 :) 990 l2cap_finialize_channel_close(channel); // -- remove from list 991 break; 992 993 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 994 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 995 channel->local_sig_id = l2cap_next_sig_id(); 996 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 997 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 998 break; 999 default: 1000 break; 1001 } 1002 1003 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1004 // send s-frame to acknowledge received packets 1005 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1006 1007 if (channel->tx_send_index != channel->tx_write_index){ 1008 int unacknowledged_packets = l2cap_ertm_num_unacknowledged_tx_packets(channel); 1009 // check remote tx window 1010 log_info("unacknowledged_packets %u, remote tx window size %u", unacknowledged_packets, channel->remote_tx_window_size); 1011 if (unacknowledged_packets < channel->remote_tx_window_size){ 1012 int index = channel->tx_send_index; 1013 channel->tx_send_index++; 1014 if (channel->tx_send_index >= channel->num_tx_buffers){ 1015 channel->tx_send_index = 0; 1016 } 1017 l2cap_ertm_send_information_frame(channel, index, 0); // final = 0 1018 continue; 1019 } 1020 } 1021 1022 if (channel->send_supervisor_frame_receiver_ready){ 1023 channel->send_supervisor_frame_receiver_ready = 0; 1024 log_info("Send S-Frame: RR %u, final %u", channel->req_seq, channel->set_final_bit_after_packet_with_poll_bit_set); 1025 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY, 0, channel->set_final_bit_after_packet_with_poll_bit_set, channel->req_seq); 1026 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1027 l2cap_ertm_send_supervisor_frame(channel, control); 1028 continue; 1029 } 1030 if (channel->send_supervisor_frame_receiver_ready_poll){ 1031 channel->send_supervisor_frame_receiver_ready_poll = 0; 1032 log_info("Send S-Frame: RR %u with poll=1 ", channel->req_seq); 1033 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY, 1, 0, channel->req_seq); 1034 l2cap_ertm_send_supervisor_frame(channel, control); 1035 continue; 1036 } 1037 if (channel->send_supervisor_frame_receiver_not_ready){ 1038 channel->send_supervisor_frame_receiver_not_ready = 0; 1039 log_info("Send S-Frame: RNR %u", channel->req_seq); 1040 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY, 0, 0, channel->req_seq); 1041 l2cap_ertm_send_supervisor_frame(channel, control); 1042 continue; 1043 } 1044 if (channel->send_supervisor_frame_reject){ 1045 channel->send_supervisor_frame_reject = 0; 1046 log_info("Send S-Frame: REJ %u", channel->req_seq); 1047 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT, 0, 0, channel->req_seq); 1048 l2cap_ertm_send_supervisor_frame(channel, control); 1049 continue; 1050 } 1051 if (channel->send_supervisor_frame_selective_reject){ 1052 channel->send_supervisor_frame_selective_reject = 0; 1053 log_info("Send S-Frame: SREJ %u", channel->expected_tx_seq); 1054 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT, 0, 0, channel->expected_tx_seq); 1055 l2cap_ertm_send_supervisor_frame(channel, control); 1056 continue; 1057 } 1058 1059 if (channel->srej_active){ 1060 int i; 1061 for (i=0;i<channel->num_tx_buffers;i++){ 1062 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[i]; 1063 if (tx_state->retransmission_requested) { 1064 tx_state->retransmission_requested = 0; 1065 uint8_t final = channel->set_final_bit_after_packet_with_poll_bit_set; 1066 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1067 l2cap_ertm_send_information_frame(channel, i, final); 1068 break; 1069 } 1070 } 1071 if (i == channel->num_tx_buffers){ 1072 // no retransmission request found 1073 channel->srej_active = 0; 1074 } else { 1075 // packet was sent 1076 continue; 1077 } 1078 } 1079 #endif 1080 1081 } 1082 #endif 1083 1084 #ifdef ENABLE_LE_DATA_CHANNELS 1085 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1086 while (btstack_linked_list_iterator_has_next(&it)){ 1087 uint8_t * acl_buffer; 1088 uint8_t * l2cap_payload; 1089 uint16_t pos; 1090 uint16_t payload_size; 1091 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1092 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1093 switch (channel->state){ 1094 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 1095 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1096 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 1097 // le psm, source cid, mtu, mps, initial credits 1098 channel->local_sig_id = l2cap_next_sig_id(); 1099 channel->credits_incoming = channel->new_credits_incoming; 1100 channel->new_credits_incoming = 0; 1101 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); 1102 break; 1103 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1104 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1105 // TODO: support larger MPS 1106 channel->state = L2CAP_STATE_OPEN; 1107 channel->credits_incoming = channel->new_credits_incoming; 1108 channel->new_credits_incoming = 0; 1109 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); 1110 // notify client 1111 l2cap_emit_le_channel_opened(channel, 0); 1112 break; 1113 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1114 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1115 channel->state = L2CAP_STATE_INVALID; 1116 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 1117 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1118 l2cap_stop_rtx(channel); 1119 btstack_linked_list_iterator_remove(&it); 1120 btstack_memory_l2cap_channel_free(channel); 1121 break; 1122 case L2CAP_STATE_OPEN: 1123 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1124 1125 // send credits 1126 if (channel->new_credits_incoming){ 1127 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 1128 channel->local_sig_id = l2cap_next_sig_id(); 1129 uint16_t new_credits = channel->new_credits_incoming; 1130 channel->new_credits_incoming = 0; 1131 channel->credits_incoming += new_credits; 1132 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 1133 break; 1134 } 1135 1136 // send data 1137 if (!channel->send_sdu_buffer) break; 1138 if (!channel->credits_outgoing) break; 1139 1140 // send part of SDU 1141 hci_reserve_packet_buffer(); 1142 acl_buffer = hci_get_outgoing_packet_buffer(); 1143 l2cap_payload = acl_buffer + 8; 1144 pos = 0; 1145 if (!channel->send_sdu_pos){ 1146 // store SDU len 1147 channel->send_sdu_pos += 2; 1148 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 1149 pos += 2; 1150 } 1151 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 1152 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 1153 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 1154 pos += payload_size; 1155 channel->send_sdu_pos += payload_size; 1156 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 1157 // done 1158 1159 channel->credits_outgoing--; 1160 1161 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 1162 channel->send_sdu_buffer = NULL; 1163 // send done event 1164 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 1165 // inform about can send now 1166 l2cap_le_notify_channel_can_send(channel); 1167 } 1168 hci_send_acl_packet_buffer(8 + pos); 1169 break; 1170 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1171 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1172 channel->local_sig_id = l2cap_next_sig_id(); 1173 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1174 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1175 break; 1176 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1177 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1178 channel->state = L2CAP_STATE_INVALID; 1179 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1180 l2cap_le_finialize_channel_close(channel); // -- remove from list 1181 break; 1182 default: 1183 break; 1184 } 1185 } 1186 #endif 1187 1188 #ifdef ENABLE_BLE 1189 // send l2cap con paramter update if necessary 1190 hci_connections_get_iterator(&it); 1191 while(btstack_linked_list_iterator_has_next(&it)){ 1192 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1193 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 1194 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 1195 switch (connection->le_con_parameter_update_state){ 1196 case CON_PARAMETER_UPDATE_SEND_REQUEST: 1197 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1198 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 1199 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 1200 break; 1201 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 1202 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 1203 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 1204 break; 1205 case CON_PARAMETER_UPDATE_DENY: 1206 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1207 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 1208 break; 1209 default: 1210 break; 1211 } 1212 } 1213 #endif 1214 1215 // log_info("l2cap_run: exit"); 1216 } 1217 1218 #ifdef ENABLE_CLASSIC 1219 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 1220 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 1221 log_info("l2cap_handle_connection_complete expected state"); 1222 // success, start l2cap handshake 1223 channel->con_handle = con_handle; 1224 // check remote SSP feature first 1225 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 1226 } 1227 } 1228 1229 static void l2cap_ready_to_connect(l2cap_channel_t * channel){ 1230 1231 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1232 // assumption: outgoing connection 1233 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1234 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_IDLE){ 1235 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1236 channel->state = L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES; 1237 return; 1238 } 1239 #endif 1240 1241 // fine, go ahead 1242 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1243 } 1244 1245 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 1246 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 1247 1248 // we have been waiting for remote supported features, if both support SSP, 1249 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)); 1250 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 1251 // request security level 2 1252 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 1253 gap_request_security_level(channel->con_handle, LEVEL_2); 1254 return; 1255 } 1256 1257 l2cap_ready_to_connect(channel); 1258 } 1259 #endif 1260 1261 #ifdef L2CAP_USES_CHANNELS 1262 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 1263 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 1264 1265 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1266 if (!channel) { 1267 return NULL; 1268 } 1269 1270 // Init memory (make valgrind happy) 1271 memset(channel, 0, sizeof(l2cap_channel_t)); 1272 1273 // fill in 1274 channel->packet_handler = packet_handler; 1275 bd_addr_copy(channel->address, address); 1276 channel->address_type = address_type; 1277 channel->psm = psm; 1278 channel->local_mtu = local_mtu; 1279 channel->remote_mtu = L2CAP_MINIMAL_MTU; 1280 channel->required_security_level = security_level; 1281 1282 // 1283 channel->local_cid = l2cap_next_local_cid(); 1284 channel->con_handle = 0; 1285 1286 // set initial state 1287 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 1288 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 1289 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 1290 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 1291 1292 return channel; 1293 } 1294 #endif 1295 1296 #ifdef ENABLE_CLASSIC 1297 1298 /** 1299 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 1300 * @param packet_handler 1301 * @param address 1302 * @param psm 1303 * @param mtu 1304 * @param local_cid 1305 */ 1306 1307 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){ 1308 // limit MTU to the size of our outtgoing HCI buffer 1309 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1310 1311 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1312 1313 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1314 if (!channel) { 1315 return BTSTACK_MEMORY_ALLOC_FAILED; 1316 } 1317 1318 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1319 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1320 #endif 1321 1322 // add to connections list 1323 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1324 1325 // store local_cid 1326 if (out_local_cid){ 1327 *out_local_cid = channel->local_cid; 1328 } 1329 1330 // check if hci connection is already usable 1331 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1332 if (conn){ 1333 log_info("l2cap_create_channel, hci connection already exists"); 1334 l2cap_handle_connection_complete(conn->con_handle, channel); 1335 // check if remote supported fearures are already received 1336 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1337 l2cap_handle_remote_supported_features_received(channel); 1338 } 1339 } 1340 1341 l2cap_run(); 1342 1343 return 0; 1344 } 1345 1346 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1347 1348 static uint8_t l2cap_ertm_validate_local_config(uint8_t max_transmit, uint16_t retransmission_timeout_ms, 1349 uint16_t monitor_timeout_ms, uint8_t num_tx_buffers, uint8_t num_rx_buffers, uint8_t * buffer, uint32_t size){ 1350 UNUSED(buffer); 1351 UNUSED(size); 1352 1353 uint8_t result = ERROR_CODE_SUCCESS; 1354 if (max_transmit < 1){ 1355 log_error("max_transmit must be >= 1"); 1356 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 1357 } 1358 if (retransmission_timeout_ms < 2000){ 1359 log_error("retransmission_timeout_ms must be >= 2000 ms"); 1360 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 1361 } 1362 if (monitor_timeout_ms < 12000){ 1363 log_error("monitor_timeout_ms must be >= 12000 ms"); 1364 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 1365 } 1366 if (num_rx_buffers < 1){ 1367 log_error("num_rx_buffers must be >= 1"); 1368 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 1369 } 1370 if (num_tx_buffers < 1){ 1371 log_error("num_rx_buffers must be >= 1"); 1372 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 1373 } 1374 return result; 1375 } 1376 1377 static void l2cap_ertm_configure_channel(l2cap_channel_t * channel, int ertm_mandatory, uint8_t max_transmit, 1378 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){ 1379 1380 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 1381 channel->ertm_mandatory = ertm_mandatory; 1382 channel->local_max_transmit = max_transmit; 1383 channel->local_retransmission_timeout_ms = retransmission_timeout_ms; 1384 channel->local_monitor_timeout_ms = monitor_timeout_ms; 1385 channel->num_rx_buffers = num_rx_buffers; 1386 channel->num_tx_buffers = num_tx_buffers; 1387 1388 // TODO: align buffer pointer 1389 uint32_t pos = 0; 1390 channel->rx_packets_state = (l2cap_ertm_rx_packet_state_t *) &buffer[pos]; 1391 pos += num_rx_buffers * sizeof(l2cap_ertm_rx_packet_state_t); 1392 channel->tx_packets_state = (l2cap_ertm_tx_packet_state_t *) &buffer[pos]; 1393 pos += num_tx_buffers * sizeof(l2cap_ertm_tx_packet_state_t); 1394 // calculate MTU 1395 channel->local_mtu = (size - pos) / (num_rx_buffers + num_tx_buffers); 1396 log_info("Local ERTM MTU: %u", channel->local_mtu); 1397 channel->rx_packets_data = &buffer[pos]; 1398 pos += num_rx_buffers * channel->local_mtu; 1399 channel->tx_packets_data = &buffer[pos]; 1400 log_info("RX packets %p, TX packets %p", channel->rx_packets_data, channel->tx_packets_data); 1401 } 1402 1403 uint8_t l2cap_create_ertm_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, 1404 int ertm_mandatory, uint8_t max_transmit, uint16_t retransmission_timeout_ms, uint16_t monitor_timeout_ms, 1405 uint8_t num_tx_buffers, uint8_t num_rx_buffers, uint8_t * buffer, uint32_t size, uint16_t * out_local_cid){ 1406 1407 // limit MTU to the size of our outtgoing HCI buffer 1408 uint16_t local_mtu = l2cap_max_mtu(); 1409 1410 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x -> local mtu %u", bd_addr_to_str(address), psm, local_mtu); 1411 1412 // validate local config 1413 uint8_t result = l2cap_ertm_validate_local_config(max_transmit, retransmission_timeout_ms, monitor_timeout_ms, num_tx_buffers, num_rx_buffers, buffer, size); 1414 if (result) return result; 1415 1416 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1417 if (!channel) { 1418 return BTSTACK_MEMORY_ALLOC_FAILED; 1419 } 1420 1421 // configure ERTM 1422 l2cap_ertm_configure_channel(channel, ertm_mandatory, max_transmit, retransmission_timeout_ms, 1423 monitor_timeout_ms, num_tx_buffers, num_rx_buffers, buffer, size); 1424 1425 // add to connections list 1426 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1427 1428 // store local_cid 1429 if (out_local_cid){ 1430 *out_local_cid = channel->local_cid; 1431 } 1432 1433 // check if hci connection is already usable 1434 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1435 if (conn){ 1436 log_info("l2cap_create_channel, hci connection already exists"); 1437 l2cap_handle_connection_complete(conn->con_handle, channel); 1438 // check if remote supported fearures are already received 1439 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1440 l2cap_handle_remote_supported_features_received(channel); 1441 } 1442 } 1443 1444 l2cap_run(); 1445 1446 return 0; 1447 } 1448 #endif 1449 1450 void 1451 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1452 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1453 // find channel for local_cid 1454 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1455 if (channel) { 1456 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1457 } 1458 // process 1459 l2cap_run(); 1460 } 1461 1462 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1463 btstack_linked_list_iterator_t it; 1464 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1465 while (btstack_linked_list_iterator_has_next(&it)){ 1466 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1467 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1468 // channel for this address found 1469 switch (channel->state){ 1470 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1471 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1472 // failure, forward error code 1473 l2cap_emit_channel_opened(channel, status); 1474 // discard channel 1475 l2cap_stop_rtx(channel); 1476 btstack_linked_list_iterator_remove(&it); 1477 btstack_memory_l2cap_channel_free(channel); 1478 break; 1479 default: 1480 break; 1481 } 1482 } 1483 } 1484 1485 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1486 btstack_linked_list_iterator_t it; 1487 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1488 while (btstack_linked_list_iterator_has_next(&it)){ 1489 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1490 if ( ! bd_addr_cmp( channel->address, address) ){ 1491 l2cap_handle_connection_complete(handle, channel); 1492 } 1493 } 1494 // process 1495 l2cap_run(); 1496 } 1497 #endif 1498 1499 static void l2cap_notify_channel_can_send(void){ 1500 1501 #ifdef ENABLE_CLASSIC 1502 btstack_linked_list_iterator_t it; 1503 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1504 while (btstack_linked_list_iterator_has_next(&it)){ 1505 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1506 if (!channel->waiting_for_can_send_now) continue; 1507 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1508 channel->waiting_for_can_send_now = 0; 1509 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1510 } 1511 #endif 1512 1513 int i; 1514 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1515 if (!fixed_channels[i].callback) continue; 1516 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1517 int can_send = 0; 1518 if (l2cap_fixed_channel_table_index_is_le(i)){ 1519 #ifdef ENABLE_BLE 1520 can_send = hci_can_send_acl_le_packet_now(); 1521 #endif 1522 } else { 1523 #ifdef ENABLE_CLASSIC 1524 can_send = hci_can_send_acl_classic_packet_now(); 1525 #endif 1526 } 1527 if (!can_send) continue; 1528 fixed_channels[i].waiting_for_can_send_now = 0; 1529 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1530 } 1531 } 1532 1533 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1534 1535 UNUSED(packet_type); 1536 UNUSED(cid); 1537 UNUSED(size); 1538 1539 bd_addr_t address; 1540 hci_con_handle_t handle; 1541 int hci_con_used; 1542 btstack_linked_list_iterator_t it; 1543 1544 // avoid unused warnings 1545 UNUSED(address); 1546 UNUSED(hci_con_used); 1547 UNUSED(it); 1548 UNUSED(handle); 1549 1550 switch(hci_event_packet_get_type(packet)){ 1551 1552 // Notify channel packet handler if they can send now 1553 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1554 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1555 l2cap_run(); // try sending signaling packets first 1556 l2cap_notify_channel_can_send(); 1557 break; 1558 1559 case HCI_EVENT_COMMAND_STATUS: 1560 l2cap_run(); // try sending signaling packets first 1561 break; 1562 1563 #ifdef ENABLE_CLASSIC 1564 // handle connection complete events 1565 case HCI_EVENT_CONNECTION_COMPLETE: 1566 reverse_bd_addr(&packet[5], address); 1567 if (packet[2] == 0){ 1568 handle = little_endian_read_16(packet, 3); 1569 l2cap_handle_connection_success_for_addr(address, handle); 1570 } else { 1571 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1572 } 1573 break; 1574 1575 // handle successful create connection cancel command 1576 case HCI_EVENT_COMMAND_COMPLETE: 1577 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1578 if (packet[5] == 0){ 1579 reverse_bd_addr(&packet[6], address); 1580 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1581 l2cap_handle_connection_failed_for_addr(address, 0x16); 1582 } 1583 } 1584 l2cap_run(); // try sending signaling packets first 1585 break; 1586 #endif 1587 1588 // handle disconnection complete events 1589 case HCI_EVENT_DISCONNECTION_COMPLETE: 1590 // send l2cap disconnect events for all channels on this handle and free them 1591 #ifdef ENABLE_CLASSIC 1592 handle = little_endian_read_16(packet, 3); 1593 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1594 while (btstack_linked_list_iterator_has_next(&it)){ 1595 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1596 if (channel->con_handle != handle) continue; 1597 l2cap_emit_channel_closed(channel); 1598 l2cap_stop_rtx(channel); 1599 btstack_linked_list_iterator_remove(&it); 1600 btstack_memory_l2cap_channel_free(channel); 1601 } 1602 #endif 1603 #ifdef ENABLE_LE_DATA_CHANNELS 1604 handle = little_endian_read_16(packet, 3); 1605 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1606 while (btstack_linked_list_iterator_has_next(&it)){ 1607 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1608 if (channel->con_handle != handle) continue; 1609 l2cap_emit_channel_closed(channel); 1610 btstack_linked_list_iterator_remove(&it); 1611 btstack_memory_l2cap_channel_free(channel); 1612 } 1613 #endif 1614 break; 1615 1616 // HCI Connection Timeouts 1617 #ifdef ENABLE_CLASSIC 1618 case L2CAP_EVENT_TIMEOUT_CHECK: 1619 handle = little_endian_read_16(packet, 2); 1620 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1621 if (hci_authentication_active_for_handle(handle)) break; 1622 hci_con_used = 0; 1623 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1624 while (btstack_linked_list_iterator_has_next(&it)){ 1625 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1626 if (channel->con_handle != handle) continue; 1627 hci_con_used = 1; 1628 break; 1629 } 1630 if (hci_con_used) break; 1631 if (!hci_can_send_command_packet_now()) break; 1632 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1633 break; 1634 1635 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1636 handle = little_endian_read_16(packet, 3); 1637 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1638 while (btstack_linked_list_iterator_has_next(&it)){ 1639 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1640 if (channel->con_handle != handle) continue; 1641 l2cap_handle_remote_supported_features_received(channel); 1642 break; 1643 } 1644 break; 1645 1646 case GAP_EVENT_SECURITY_LEVEL: 1647 handle = little_endian_read_16(packet, 2); 1648 log_info("l2cap - security level update"); 1649 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1650 while (btstack_linked_list_iterator_has_next(&it)){ 1651 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1652 if (channel->con_handle != handle) continue; 1653 1654 log_info("l2cap - state %u", channel->state); 1655 1656 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1657 gap_security_level_t required_level = channel->required_security_level; 1658 1659 switch (channel->state){ 1660 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1661 if (actual_level >= required_level){ 1662 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1663 // we need to know if ERTM is supported before sending a config response 1664 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1665 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1666 channel->state = L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES; 1667 #else 1668 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1669 l2cap_emit_incoming_connection(channel); 1670 #endif 1671 } else { 1672 channel->reason = 0x0003; // security block 1673 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1674 } 1675 break; 1676 1677 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1678 if (actual_level >= required_level){ 1679 l2cap_ready_to_connect(channel); 1680 } else { 1681 // disconnnect, authentication not good enough 1682 hci_disconnect_security_block(handle); 1683 } 1684 break; 1685 1686 default: 1687 break; 1688 } 1689 } 1690 break; 1691 #endif 1692 1693 default: 1694 break; 1695 } 1696 1697 l2cap_run(); 1698 } 1699 1700 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 1701 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1702 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1703 signaling_responses[signaling_responses_pending].handle = handle; 1704 signaling_responses[signaling_responses_pending].code = code; 1705 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1706 signaling_responses[signaling_responses_pending].cid = cid; 1707 signaling_responses[signaling_responses_pending].data = data; 1708 signaling_responses_pending++; 1709 l2cap_run(); 1710 } 1711 } 1712 1713 #ifdef ENABLE_CLASSIC 1714 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1715 channel->remote_sig_id = identifier; 1716 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1717 l2cap_run(); 1718 } 1719 1720 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1721 1722 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1723 l2cap_service_t *service = l2cap_get_service(psm); 1724 if (!service) { 1725 // 0x0002 PSM not supported 1726 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1727 return; 1728 } 1729 1730 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1731 if (!hci_connection) { 1732 // 1733 log_error("no hci_connection for handle %u", handle); 1734 return; 1735 } 1736 1737 // alloc structure 1738 // log_info("l2cap_handle_connection_request register channel"); 1739 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1740 psm, service->mtu, service->required_security_level); 1741 if (!channel){ 1742 // 0x0004 No resources available 1743 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 1744 return; 1745 } 1746 1747 channel->con_handle = handle; 1748 channel->remote_cid = source_cid; 1749 channel->remote_sig_id = sig_id; 1750 1751 // limit local mtu to max acl packet length - l2cap header 1752 if (channel->local_mtu > l2cap_max_mtu()) { 1753 channel->local_mtu = l2cap_max_mtu(); 1754 } 1755 1756 // set initial state 1757 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1758 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 1759 1760 // add to connections list 1761 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1762 1763 // assert security requirements 1764 gap_request_security_level(handle, channel->required_security_level); 1765 } 1766 1767 void l2cap_accept_connection(uint16_t local_cid){ 1768 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1769 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1770 if (!channel) { 1771 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1772 return; 1773 } 1774 1775 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1776 // configure L2CAP Basic mode 1777 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1778 #endif 1779 1780 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1781 1782 // process 1783 l2cap_run(); 1784 } 1785 1786 1787 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1788 uint8_t l2cap_accept_ertm_connection(uint16_t local_cid, int ertm_mandatory, uint8_t max_transmit, 1789 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){ 1790 1791 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 1792 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1793 if (!channel) { 1794 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1795 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1796 } 1797 1798 // validate local config 1799 uint8_t result = l2cap_ertm_validate_local_config(max_transmit, retransmission_timeout_ms, monitor_timeout_ms, num_tx_buffers, num_rx_buffers, buffer, size); 1800 if (result) return result; 1801 1802 // configure L2CAP ERTM 1803 l2cap_ertm_configure_channel(channel, ertm_mandatory, max_transmit, retransmission_timeout_ms, monitor_timeout_ms, num_tx_buffers, num_rx_buffers, buffer, size); 1804 1805 // continue 1806 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1807 1808 // process 1809 l2cap_run(); 1810 1811 return ERROR_CODE_SUCCESS; 1812 } 1813 1814 uint8_t l2cap_ertm_set_busy(uint16_t local_cid){ 1815 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1816 if (!channel) { 1817 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1818 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1819 } 1820 if (!channel->local_busy){ 1821 channel->local_busy = 1; 1822 channel->send_supervisor_frame_receiver_not_ready = 1; 1823 l2cap_run(); 1824 } 1825 return ERROR_CODE_SUCCESS; 1826 } 1827 1828 uint8_t l2cap_ertm_set_ready(uint16_t local_cid){ 1829 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1830 if (!channel) { 1831 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1832 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1833 } 1834 if (channel->local_busy){ 1835 channel->local_busy = 0; 1836 channel->send_supervisor_frame_receiver_ready_poll = 1; 1837 l2cap_run(); 1838 } 1839 return ERROR_CODE_SUCCESS; 1840 } 1841 1842 static void l2cap_ertm_handle_req_seq(l2cap_channel_t * l2cap_channel, uint8_t req_seq){ 1843 l2cap_ertm_tx_packet_state_t * tx_state; 1844 while (1){ 1845 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 1846 // calc delta 1847 int delta = (req_seq - tx_state->tx_seq) & 0x03f; 1848 if (delta == 0) break; // all packets acknowledged 1849 if (delta > l2cap_channel->remote_tx_window_size) break; 1850 1851 log_info("RR seq %u => packet with tx_seq %u done", req_seq, tx_state->tx_seq); 1852 1853 // stop retransmission timer 1854 btstack_run_loop_remove_timer(&tx_state->retransmission_timer); 1855 l2cap_channel->tx_read_index++; 1856 if (l2cap_channel->tx_read_index >= l2cap_channel->num_rx_buffers){ 1857 l2cap_channel->tx_read_index = 0; 1858 } 1859 1860 // no unack packages 1861 if (l2cap_channel->tx_read_index == l2cap_channel->tx_write_index) break; 1862 } 1863 } 1864 1865 static l2cap_ertm_tx_packet_state_t * l2cap_ertm_get_tx_state(l2cap_channel_t * l2cap_channel, uint8_t tx_seq){ 1866 int i; 1867 for (i=0;i<l2cap_channel->num_tx_buffers;i++){ 1868 l2cap_ertm_tx_packet_state_t * tx_state = &l2cap_channel->tx_packets_state[i]; 1869 if (tx_state->tx_seq == tx_seq) return tx_state; 1870 } 1871 return NULL; 1872 } 1873 #endif 1874 1875 1876 void l2cap_decline_connection(uint16_t local_cid){ 1877 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1878 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1879 if (!channel) { 1880 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1881 return; 1882 } 1883 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1884 channel->reason = 0x04; // no resources available 1885 l2cap_run(); 1886 } 1887 1888 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1889 1890 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1891 1892 uint16_t flags = little_endian_read_16(command, 6); 1893 if (flags & 1) { 1894 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1895 } 1896 1897 // accept the other's configuration options 1898 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1899 uint16_t pos = 8; 1900 while (pos < end_pos){ 1901 uint8_t option_hint = command[pos] >> 7; 1902 uint8_t option_type = command[pos] & 0x7f; 1903 // log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1904 pos++; 1905 uint8_t length = command[pos++]; 1906 // MTU { type(8): 1, len(8):2, MTU(16) } 1907 if (option_type == 1 && length == 2){ 1908 channel->remote_mtu = little_endian_read_16(command, pos); 1909 log_info("Remote MTU %u", channel->remote_mtu); 1910 if (channel->remote_mtu > l2cap_max_mtu()){ 1911 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 1912 channel->remote_mtu = l2cap_max_mtu(); 1913 } 1914 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1915 } 1916 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1917 if (option_type == 2 && length == 2){ 1918 channel->flush_timeout = little_endian_read_16(command, pos); 1919 log_info("Flush timeout: %u ms", channel->flush_timeout); 1920 } 1921 1922 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1923 // Retransmission and Flow Control Option 1924 if (option_type == 4 && length == 9){ 1925 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 1926 switch(channel->mode){ 1927 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1928 // Store remote config 1929 channel->remote_tx_window_size = command[pos+1]; 1930 channel->remote_max_transmit = command[pos+2]; 1931 channel->remote_retransmission_timeout_ms = little_endian_read_16(command, pos + 3); 1932 channel->remote_monitor_timeout_ms = little_endian_read_16(command, pos + 5); 1933 channel->remote_mps = little_endian_read_16(command, pos + 7); 1934 log_info("FC&C config: tx window: %u, max transmit %u, retrans timeout %u, monitor timeout %u, mps %u", 1935 channel->remote_tx_window_size, 1936 channel->remote_max_transmit, 1937 channel->remote_retransmission_timeout_ms, 1938 channel->remote_monitor_timeout_ms, 1939 channel->remote_mps); 1940 // If ERTM mandatory, but remote doens't offer ERTM -> disconnect 1941 if (channel->ertm_mandatory && mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1942 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1943 } else { 1944 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1945 } 1946 break; 1947 case L2CAP_CHANNEL_MODE_BASIC: 1948 switch (mode){ 1949 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1950 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 1951 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 1952 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1953 } 1954 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 1955 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 1956 break; 1957 default: // case L2CAP_CHANNEL_MODE_BASIC: 1958 // TODO store and evaluate configuration 1959 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1960 break; 1961 } 1962 break; 1963 default: 1964 break; 1965 } 1966 } 1967 #endif 1968 // check for unknown options 1969 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1970 log_info("l2cap cid %u, unknown options", channel->local_cid); 1971 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1972 } 1973 pos += length; 1974 } 1975 } 1976 1977 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 1978 log_info("l2cap_signaling_handle_configure_response"); 1979 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1980 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1981 uint16_t pos = 10; 1982 while (pos < end_pos){ 1983 uint8_t option_hint = command[pos] >> 7; 1984 uint8_t option_type = command[pos] & 0x7f; 1985 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1986 pos++; 1987 uint8_t length = command[pos++]; 1988 1989 // Retransmission and Flow Control Option 1990 if (option_type == 4 && length == 9){ 1991 switch (channel->mode){ 1992 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1993 if (channel->ertm_mandatory){ 1994 // ?? 1995 } else { 1996 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 1997 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 1998 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1999 } 2000 } 2001 break; 2002 case L2CAP_CHANNEL_MODE_BASIC: 2003 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2004 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 2005 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2006 } 2007 break; 2008 default: 2009 break; 2010 } 2011 } 2012 2013 // check for unknown options 2014 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 2015 log_info("l2cap cid %u, unknown options", channel->local_cid); 2016 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2017 } 2018 2019 pos += length; 2020 } 2021 #endif 2022 } 2023 2024 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 2025 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 2026 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 2027 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 2028 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 2029 if (channel->state == L2CAP_STATE_OPEN) return 0; 2030 return 1; 2031 } 2032 2033 2034 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 2035 2036 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2037 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2038 uint16_t result = 0; 2039 2040 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 2041 2042 // handle DISCONNECT REQUESTS seperately 2043 if (code == DISCONNECTION_REQUEST){ 2044 switch (channel->state){ 2045 case L2CAP_STATE_CONFIG: 2046 case L2CAP_STATE_OPEN: 2047 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2048 case L2CAP_STATE_WAIT_DISCONNECT: 2049 l2cap_handle_disconnect_request(channel, identifier); 2050 break; 2051 2052 default: 2053 // ignore in other states 2054 break; 2055 } 2056 return; 2057 } 2058 2059 // @STATEMACHINE(l2cap) 2060 switch (channel->state) { 2061 2062 case L2CAP_STATE_WAIT_CONNECT_RSP: 2063 switch (code){ 2064 case CONNECTION_RESPONSE: 2065 l2cap_stop_rtx(channel); 2066 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2067 switch (result) { 2068 case 0: 2069 // successful connection 2070 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2071 channel->state = L2CAP_STATE_CONFIG; 2072 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2073 break; 2074 case 1: 2075 // connection pending. get some coffee, but start the ERTX 2076 l2cap_start_ertx(channel); 2077 break; 2078 default: 2079 // channel closed 2080 channel->state = L2CAP_STATE_CLOSED; 2081 // map l2cap connection response result to BTstack status enumeration 2082 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 2083 2084 // drop link key if security block 2085 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 2086 gap_drop_link_key_for_bd_addr(channel->address); 2087 } 2088 2089 // discard channel 2090 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2091 btstack_memory_l2cap_channel_free(channel); 2092 break; 2093 } 2094 break; 2095 2096 default: 2097 //@TODO: implement other signaling packets 2098 break; 2099 } 2100 break; 2101 2102 case L2CAP_STATE_CONFIG: 2103 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2104 switch (code) { 2105 case CONFIGURE_REQUEST: 2106 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 2107 l2cap_signaling_handle_configure_request(channel, command); 2108 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 2109 // only done if continuation not set 2110 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 2111 } 2112 break; 2113 case CONFIGURE_RESPONSE: 2114 l2cap_stop_rtx(channel); 2115 l2cap_signaling_handle_configure_response(channel, result, command); 2116 switch (result){ 2117 case 0: // success 2118 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 2119 break; 2120 case 4: // pending 2121 l2cap_start_ertx(channel); 2122 break; 2123 default: 2124 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2125 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 2126 // remote does not offer ertm but it's required 2127 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2128 break; 2129 } 2130 #endif 2131 // retry on negative result 2132 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2133 break; 2134 } 2135 break; 2136 default: 2137 break; 2138 } 2139 if (l2cap_channel_ready_for_open(channel)){ 2140 // for open: 2141 channel->state = L2CAP_STATE_OPEN; 2142 l2cap_emit_channel_opened(channel, 0); 2143 } 2144 break; 2145 2146 case L2CAP_STATE_WAIT_DISCONNECT: 2147 switch (code) { 2148 case DISCONNECTION_RESPONSE: 2149 l2cap_finialize_channel_close(channel); 2150 break; 2151 default: 2152 //@TODO: implement other signaling packets 2153 break; 2154 } 2155 break; 2156 2157 case L2CAP_STATE_CLOSED: 2158 // @TODO handle incoming requests 2159 break; 2160 2161 case L2CAP_STATE_OPEN: 2162 //@TODO: implement other signaling packets, e.g. re-configure 2163 break; 2164 default: 2165 break; 2166 } 2167 // log_info("new state %u", channel->state); 2168 } 2169 2170 2171 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 2172 2173 btstack_linked_list_iterator_t it; 2174 2175 // get code, signalind identifier and command len 2176 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2177 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2178 2179 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 2180 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 2181 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2182 return; 2183 } 2184 2185 // general commands without an assigned channel 2186 switch(code) { 2187 2188 case CONNECTION_REQUEST: { 2189 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2190 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2191 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 2192 return; 2193 } 2194 2195 case ECHO_REQUEST: 2196 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 2197 return; 2198 2199 case INFORMATION_REQUEST: { 2200 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2201 l2cap_register_signaling_response(handle, code, sig_id, 0, infoType); 2202 return; 2203 } 2204 2205 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2206 case INFORMATION_RESPONSE: { 2207 hci_connection_t * connection = hci_connection_for_handle(handle); 2208 if (!connection) return; 2209 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2210 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2211 if (result != 0) return; 2212 if (info_type != 0x02) return; 2213 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 2214 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2215 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 2216 // trigger connection request 2217 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2218 while (btstack_linked_list_iterator_has_next(&it)){ 2219 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2220 if (channel->con_handle != handle) continue; 2221 // bail if ERTM was requested but is not supported 2222 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 2223 if (channel->ertm_mandatory){ 2224 // channel closed 2225 channel->state = L2CAP_STATE_CLOSED; 2226 // map l2cap connection response result to BTstack status enumeration 2227 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTD); 2228 // discard channel 2229 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2230 btstack_memory_l2cap_channel_free(channel); 2231 continue; 2232 } else { 2233 // fallback to Basic mode 2234 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2235 } 2236 } 2237 // start connecting 2238 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 2239 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 2240 } 2241 // respond to connection request 2242 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 2243 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2244 l2cap_emit_incoming_connection(channel); 2245 } 2246 } 2247 return; 2248 } 2249 #endif 2250 2251 default: 2252 break; 2253 } 2254 2255 2256 // Get potential destination CID 2257 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2258 2259 // Find channel for this sig_id and connection handle 2260 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2261 while (btstack_linked_list_iterator_has_next(&it)){ 2262 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2263 if (channel->con_handle != handle) continue; 2264 if (code & 1) { 2265 // match odd commands (responses) by previous signaling identifier 2266 if (channel->local_sig_id == sig_id) { 2267 l2cap_signaling_handler_channel(channel, command); 2268 break; 2269 } 2270 } else { 2271 // match even commands (requests) by local channel id 2272 if (channel->local_cid == dest_cid) { 2273 l2cap_signaling_handler_channel(channel, command); 2274 break; 2275 } 2276 } 2277 } 2278 } 2279 #endif 2280 2281 #ifdef ENABLE_BLE 2282 2283 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 2284 uint8_t event[6]; 2285 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 2286 event[1] = 4; 2287 little_endian_store_16(event, 2, con_handle); 2288 little_endian_store_16(event, 4, result); 2289 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2290 if (!l2cap_event_packet_handler) return; 2291 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 2292 } 2293 2294 // @returns valid 2295 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 2296 hci_connection_t * connection; 2297 uint16_t result; 2298 uint8_t event[10]; 2299 2300 #ifdef ENABLE_LE_DATA_CHANNELS 2301 btstack_linked_list_iterator_t it; 2302 l2cap_channel_t * channel; 2303 uint16_t local_cid; 2304 uint16_t le_psm; 2305 uint16_t new_credits; 2306 uint16_t credits_before; 2307 l2cap_service_t * service; 2308 uint16_t source_cid; 2309 #endif 2310 2311 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2312 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 2313 2314 switch (code){ 2315 2316 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2317 result = little_endian_read_16(command, 4); 2318 l2cap_emit_connection_parameter_update_response(handle, result); 2319 break; 2320 2321 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2322 connection = hci_connection_for_handle(handle); 2323 if (connection){ 2324 if (connection->role != HCI_ROLE_MASTER){ 2325 // reject command without notifying upper layer when not in master role 2326 return 0; 2327 } 2328 int update_parameter = 1; 2329 le_connection_parameter_range_t existing_range; 2330 gap_get_connection_parameter_range(&existing_range); 2331 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 2332 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 2333 uint16_t le_conn_latency = little_endian_read_16(command,12); 2334 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 2335 2336 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 2337 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 2338 2339 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 2340 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 2341 2342 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 2343 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 2344 2345 if (update_parameter){ 2346 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2347 connection->le_conn_interval_min = le_conn_interval_min; 2348 connection->le_conn_interval_max = le_conn_interval_max; 2349 connection->le_conn_latency = le_conn_latency; 2350 connection->le_supervision_timeout = le_supervision_timeout; 2351 } else { 2352 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2353 } 2354 connection->le_con_param_update_identifier = sig_id; 2355 } 2356 2357 if (!l2cap_event_packet_handler) break; 2358 2359 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2360 event[1] = 8; 2361 memcpy(&event[2], &command[4], 8); 2362 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2363 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2364 break; 2365 2366 #ifdef ENABLE_LE_DATA_CHANNELS 2367 2368 case COMMAND_REJECT: 2369 // Find channel for this sig_id and connection handle 2370 channel = NULL; 2371 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2372 while (btstack_linked_list_iterator_has_next(&it)){ 2373 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2374 if (a_channel->con_handle != handle) continue; 2375 if (a_channel->local_sig_id != sig_id) continue; 2376 channel = a_channel; 2377 break; 2378 } 2379 if (!channel) break; 2380 2381 // if received while waiting for le connection response, assume legacy device 2382 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2383 channel->state = L2CAP_STATE_CLOSED; 2384 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2385 l2cap_emit_le_channel_opened(channel, 0x0002); 2386 2387 // discard channel 2388 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2389 btstack_memory_l2cap_channel_free(channel); 2390 break; 2391 } 2392 break; 2393 2394 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2395 2396 // get hci connection, bail if not found (must not happen) 2397 connection = hci_connection_for_handle(handle); 2398 if (!connection) return 0; 2399 2400 // check if service registered 2401 le_psm = little_endian_read_16(command, 4); 2402 service = l2cap_le_get_service(le_psm); 2403 source_cid = little_endian_read_16(command, 6); 2404 2405 if (service){ 2406 if (source_cid < 0x40){ 2407 // 0x0009 Connection refused - Invalid Source CID 2408 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2409 return 1; 2410 } 2411 2412 // go through list of channels for this ACL connection and check if we get a match 2413 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2414 while (btstack_linked_list_iterator_has_next(&it)){ 2415 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2416 if (a_channel->con_handle != handle) continue; 2417 if (a_channel->remote_cid != source_cid) continue; 2418 // 0x000a Connection refused - Source CID already allocated 2419 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2420 return 1; 2421 } 2422 2423 // security: check encryption 2424 if (service->required_security_level >= LEVEL_2){ 2425 if (sm_encryption_key_size(handle) == 0){ 2426 // 0x0008 Connection refused - insufficient encryption 2427 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2428 return 1; 2429 } 2430 // anything less than 16 byte key size is insufficient 2431 if (sm_encryption_key_size(handle) < 16){ 2432 // 0x0007 Connection refused – insufficient encryption key size 2433 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2434 return 1; 2435 } 2436 } 2437 2438 // security: check authencation 2439 if (service->required_security_level >= LEVEL_3){ 2440 if (!sm_authenticated(handle)){ 2441 // 0x0005 Connection refused – insufficient authentication 2442 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2443 return 1; 2444 } 2445 } 2446 2447 // security: check authorization 2448 if (service->required_security_level >= LEVEL_4){ 2449 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2450 // 0x0006 Connection refused – insufficient authorization 2451 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2452 return 1; 2453 } 2454 } 2455 2456 // allocate channel 2457 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 2458 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2459 if (!channel){ 2460 // 0x0004 Connection refused – no resources available 2461 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2462 return 1; 2463 } 2464 2465 channel->con_handle = handle; 2466 channel->remote_cid = source_cid; 2467 channel->remote_sig_id = sig_id; 2468 channel->remote_mtu = little_endian_read_16(command, 8); 2469 channel->remote_mps = little_endian_read_16(command, 10); 2470 channel->credits_outgoing = little_endian_read_16(command, 12); 2471 2472 // set initial state 2473 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2474 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2475 2476 // add to connections list 2477 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2478 2479 // post connection request event 2480 l2cap_emit_le_incoming_connection(channel); 2481 2482 } else { 2483 // Connection refused – LE_PSM not supported 2484 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2485 } 2486 break; 2487 2488 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2489 // Find channel for this sig_id and connection handle 2490 channel = NULL; 2491 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2492 while (btstack_linked_list_iterator_has_next(&it)){ 2493 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2494 if (a_channel->con_handle != handle) continue; 2495 if (a_channel->local_sig_id != sig_id) continue; 2496 channel = a_channel; 2497 break; 2498 } 2499 if (!channel) break; 2500 2501 // cid + 0 2502 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2503 if (result){ 2504 channel->state = L2CAP_STATE_CLOSED; 2505 // map l2cap connection response result to BTstack status enumeration 2506 l2cap_emit_le_channel_opened(channel, result); 2507 2508 // discard channel 2509 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2510 btstack_memory_l2cap_channel_free(channel); 2511 break; 2512 } 2513 2514 // success 2515 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2516 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2517 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2518 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2519 channel->state = L2CAP_STATE_OPEN; 2520 l2cap_emit_le_channel_opened(channel, result); 2521 break; 2522 2523 case LE_FLOW_CONTROL_CREDIT: 2524 // find channel 2525 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2526 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2527 if (!channel) { 2528 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2529 break; 2530 } 2531 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2532 credits_before = channel->credits_outgoing; 2533 channel->credits_outgoing += new_credits; 2534 // check for credit overrun 2535 if (credits_before > channel->credits_outgoing){ 2536 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2537 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2538 break; 2539 } 2540 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2541 break; 2542 2543 case DISCONNECTION_REQUEST: 2544 // find channel 2545 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2546 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2547 if (!channel) { 2548 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2549 break; 2550 } 2551 channel->remote_sig_id = sig_id; 2552 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2553 break; 2554 2555 #endif 2556 2557 case DISCONNECTION_RESPONSE: 2558 break; 2559 2560 default: 2561 // command unknown -> reject command 2562 return 0; 2563 } 2564 return 1; 2565 } 2566 #endif 2567 2568 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 2569 UNUSED(packet_type); 2570 UNUSED(channel); 2571 2572 l2cap_channel_t * l2cap_channel; 2573 UNUSED(l2cap_channel); 2574 2575 // Get Channel ID 2576 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 2577 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 2578 2579 switch (channel_id) { 2580 2581 #ifdef ENABLE_CLASSIC 2582 case L2CAP_CID_SIGNALING: { 2583 uint16_t command_offset = 8; 2584 while (command_offset < size) { 2585 // handle signaling commands 2586 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 2587 2588 // increment command_offset 2589 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2590 } 2591 break; 2592 } 2593 #endif 2594 2595 #ifdef ENABLE_BLE 2596 case L2CAP_CID_SIGNALING_LE: { 2597 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 2598 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 2599 if (!valid){ 2600 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2601 } 2602 break; 2603 } 2604 #endif 2605 2606 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 2607 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 2608 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2609 } 2610 break; 2611 2612 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 2613 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 2614 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2615 } 2616 break; 2617 2618 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 2619 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 2620 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2621 } 2622 break; 2623 2624 default: 2625 #ifdef ENABLE_CLASSIC 2626 // Find channel for this channel_id and connection handle 2627 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 2628 if (l2cap_channel) { 2629 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2630 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2631 2632 // verify FCS 2633 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 2634 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 2635 log_info("Packet FCS 0x%04x, calculated FCS 0x%04x", fcs_packet, fcs_calculated); 2636 if (fcs_calculated != fcs_packet){ 2637 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 2638 // TODO: trigger retransmission or something like that 2639 break; 2640 } 2641 2642 // switch on packet type 2643 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2644 uint8_t req_seq = (control >> 8) & 0x3f; 2645 int final = (control >> 7) & 0x01; 2646 if (control & 1){ 2647 // S-Frame 2648 int poll = (control >> 4) & 0x01; 2649 l2cap_supervisory_function_t s = (l2cap_supervisory_function_t) ((control >> 2) & 0x03); 2650 log_info("Control: 0x%04x => Supervisory function %u, ReqSeq %02u", control, (int) s, req_seq); 2651 l2cap_ertm_tx_packet_state_t * tx_state; 2652 switch (s){ 2653 case L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY: 2654 log_info("L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY"); 2655 l2cap_ertm_handle_req_seq(l2cap_channel, req_seq); 2656 if (poll && final){ 2657 // S-frames shall not be transmitted with both the F-bit and the P-bit set to 1 at the same time. 2658 log_error("P=F=1 in S-Frame"); 2659 break; 2660 } 2661 if (poll){ 2662 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = 1; 2663 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2664 } 2665 if (final){ 2666 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 2667 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2668 } 2669 break; 2670 case L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT: 2671 log_info("L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT"); 2672 l2cap_ertm_handle_req_seq(l2cap_channel, req_seq); 2673 // rsetart transmittion from last unacknowledted packet (earlier packets already freed in l2cap_ertm_handle_req_seq) 2674 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2675 break; 2676 case L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY: 2677 log_error("L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY"); 2678 break; 2679 case L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT: 2680 log_info("L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT"); 2681 if (poll){ 2682 l2cap_ertm_handle_req_seq(l2cap_channel, req_seq); 2683 } 2684 // find requested i-frame 2685 tx_state = l2cap_ertm_get_tx_state(l2cap_channel, req_seq); 2686 if (tx_state){ 2687 log_info("Retransmission for tx_seq %u requested", req_seq); 2688 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = poll; 2689 tx_state->retransmission_requested = 1; 2690 l2cap_channel->srej_active = 1; 2691 } 2692 break; 2693 default: 2694 break; 2695 } 2696 break; 2697 } else { 2698 // I-Frame 2699 // get control 2700 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 2701 uint8_t tx_seq = (control >> 1) & 0x3f; 2702 log_info("Control: 0x%04x => SAR %u, ReqSeq %02u, R?, TxSeq %02u", control, (int) sar, req_seq, tx_seq); 2703 log_info("SAR: pos %u", l2cap_channel->rx_packets_state->pos); 2704 log_info("State: expected_tx_seq %02u, req_seq %02u", l2cap_channel->expected_tx_seq, l2cap_channel->req_seq); 2705 l2cap_ertm_handle_req_seq(l2cap_channel, req_seq); 2706 if (final){ 2707 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 2708 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2709 } 2710 // check ordering 2711 if (l2cap_channel->expected_tx_seq == tx_seq){ 2712 log_info("Received expected frame with TxSeq == ExpectedTxSeq == %02u", tx_seq); 2713 l2cap_channel->req_seq = (tx_seq+1) & 0x3f; 2714 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2715 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 2716 uint16_t sdu_length; 2717 uint16_t segment_length; 2718 uint16_t payload_offset; 2719 switch (sar){ 2720 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 2721 payload_offset = COMPLETE_L2CAP_HEADER+2; 2722 segment_length = payload_offset-2; 2723 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER+2], segment_length); 2724 break; 2725 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 2726 // TODO: use current packet 2727 // TODO: check if reassembly started 2728 // TODO: check len against local mtu 2729 sdu_length = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER+2); 2730 payload_offset = COMPLETE_L2CAP_HEADER+4; 2731 segment_length = size - payload_offset-2; 2732 memcpy(&l2cap_channel->rx_packets_data[0], &packet[payload_offset], segment_length); 2733 l2cap_channel->rx_packets_state->sdu_length = sdu_length; 2734 l2cap_channel->rx_packets_state->pos = segment_length; 2735 break; 2736 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 2737 payload_offset = COMPLETE_L2CAP_HEADER+2; 2738 segment_length = size - payload_offset-2; 2739 memcpy(&l2cap_channel->rx_packets_data[l2cap_channel->rx_packets_state->pos], &packet[payload_offset], segment_length); 2740 l2cap_channel->rx_packets_state->pos += segment_length; 2741 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->rx_packets_data, l2cap_channel->rx_packets_state[0].pos); 2742 break; 2743 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 2744 payload_offset = COMPLETE_L2CAP_HEADER+2; 2745 segment_length = size - payload_offset-2; 2746 memcpy(&l2cap_channel->rx_packets_data[l2cap_channel->rx_packets_state->pos], &packet[payload_offset], segment_length); 2747 l2cap_channel->rx_packets_state->pos += segment_length; 2748 break; 2749 } 2750 } else { 2751 int delta = (tx_seq - l2cap_channel->expected_tx_seq) & 0x3f; 2752 if (delta < 2){ 2753 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-SREJ", tx_seq, l2cap_channel->expected_tx_seq); 2754 l2cap_channel->send_supervisor_frame_selective_reject = 1; 2755 } else { 2756 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-REJ", tx_seq, l2cap_channel->expected_tx_seq); 2757 l2cap_channel->send_supervisor_frame_reject = 1; 2758 } 2759 } 2760 } 2761 break; 2762 } 2763 #endif 2764 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2765 } 2766 #endif 2767 #ifdef ENABLE_LE_DATA_CHANNELS 2768 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 2769 if (l2cap_channel) { 2770 // credit counting 2771 if (l2cap_channel->credits_incoming == 0){ 2772 log_error("LE Data Channel packet received but no incoming credits"); 2773 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2774 break; 2775 } 2776 l2cap_channel->credits_incoming--; 2777 2778 // automatic credits 2779 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 2780 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 2781 } 2782 2783 // first fragment 2784 uint16_t pos = 0; 2785 if (!l2cap_channel->receive_sdu_len){ 2786 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2787 l2cap_channel->receive_sdu_pos = 0; 2788 pos += 2; 2789 size -= 2; 2790 } 2791 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 2792 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 2793 // done? 2794 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 2795 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 2796 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 2797 l2cap_channel->receive_sdu_len = 0; 2798 } 2799 } else { 2800 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 2801 } 2802 #endif 2803 break; 2804 } 2805 2806 l2cap_run(); 2807 } 2808 2809 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 2810 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 2811 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 2812 if (index < 0) return; 2813 fixed_channels[index].callback = the_packet_handler; 2814 } 2815 2816 #ifdef ENABLE_CLASSIC 2817 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2818 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 2819 channel->state = L2CAP_STATE_CLOSED; 2820 l2cap_emit_channel_closed(channel); 2821 // discard channel 2822 l2cap_stop_rtx(channel); 2823 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2824 btstack_memory_l2cap_channel_free(channel); 2825 } 2826 2827 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 2828 btstack_linked_list_iterator_t it; 2829 btstack_linked_list_iterator_init(&it, services); 2830 while (btstack_linked_list_iterator_has_next(&it)){ 2831 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 2832 if ( service->psm == psm){ 2833 return service; 2834 }; 2835 } 2836 return NULL; 2837 } 2838 2839 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 2840 return l2cap_get_service_internal(&l2cap_services, psm); 2841 } 2842 2843 2844 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 2845 2846 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 2847 2848 // check for alread registered psm 2849 l2cap_service_t *service = l2cap_get_service(psm); 2850 if (service) { 2851 log_error("l2cap_register_service: PSM %u already registered", psm); 2852 return L2CAP_SERVICE_ALREADY_REGISTERED; 2853 } 2854 2855 // alloc structure 2856 service = btstack_memory_l2cap_service_get(); 2857 if (!service) { 2858 log_error("l2cap_register_service: no memory for l2cap_service_t"); 2859 return BTSTACK_MEMORY_ALLOC_FAILED; 2860 } 2861 2862 // fill in 2863 service->psm = psm; 2864 service->mtu = mtu; 2865 service->packet_handler = service_packet_handler; 2866 service->required_security_level = security_level; 2867 2868 // add to services list 2869 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 2870 2871 // enable page scan 2872 gap_connectable_control(1); 2873 2874 return 0; 2875 } 2876 2877 uint8_t l2cap_unregister_service(uint16_t psm){ 2878 2879 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2880 2881 l2cap_service_t *service = l2cap_get_service(psm); 2882 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2883 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2884 btstack_memory_l2cap_service_free(service); 2885 2886 // disable page scan when no services registered 2887 if (btstack_linked_list_empty(&l2cap_services)) { 2888 gap_connectable_control(0); 2889 } 2890 return 0; 2891 } 2892 #endif 2893 2894 2895 #ifdef ENABLE_LE_DATA_CHANNELS 2896 2897 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2898 if (!channel->waiting_for_can_send_now) return; 2899 if (channel->send_sdu_buffer) return; 2900 channel->waiting_for_can_send_now = 0; 2901 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2902 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2903 } 2904 2905 // 1BH2222 2906 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2907 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", 2908 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2909 uint8_t event[19]; 2910 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2911 event[1] = sizeof(event) - 2; 2912 event[2] = channel->address_type; 2913 reverse_bd_addr(channel->address, &event[3]); 2914 little_endian_store_16(event, 9, channel->con_handle); 2915 little_endian_store_16(event, 11, channel->psm); 2916 little_endian_store_16(event, 13, channel->local_cid); 2917 little_endian_store_16(event, 15, channel->remote_cid); 2918 little_endian_store_16(event, 17, channel->remote_mtu); 2919 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2920 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2921 } 2922 // 11BH22222 2923 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2924 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", 2925 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2926 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2927 uint8_t event[23]; 2928 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2929 event[1] = sizeof(event) - 2; 2930 event[2] = status; 2931 event[3] = channel->address_type; 2932 reverse_bd_addr(channel->address, &event[4]); 2933 little_endian_store_16(event, 10, channel->con_handle); 2934 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2935 little_endian_store_16(event, 13, channel->psm); 2936 little_endian_store_16(event, 15, channel->local_cid); 2937 little_endian_store_16(event, 17, channel->remote_cid); 2938 little_endian_store_16(event, 19, channel->local_mtu); 2939 little_endian_store_16(event, 21, channel->remote_mtu); 2940 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2941 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2942 } 2943 2944 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2945 btstack_linked_list_iterator_t it; 2946 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2947 while (btstack_linked_list_iterator_has_next(&it)){ 2948 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2949 if ( channel->local_cid == local_cid) { 2950 return channel; 2951 } 2952 } 2953 return NULL; 2954 } 2955 2956 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2957 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2958 channel->state = L2CAP_STATE_CLOSED; 2959 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2960 // discard channel 2961 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2962 btstack_memory_l2cap_channel_free(channel); 2963 } 2964 2965 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2966 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2967 } 2968 2969 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2970 2971 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2972 2973 // check for alread registered psm 2974 l2cap_service_t *service = l2cap_le_get_service(psm); 2975 if (service) { 2976 return L2CAP_SERVICE_ALREADY_REGISTERED; 2977 } 2978 2979 // alloc structure 2980 service = btstack_memory_l2cap_service_get(); 2981 if (!service) { 2982 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2983 return BTSTACK_MEMORY_ALLOC_FAILED; 2984 } 2985 2986 // fill in 2987 service->psm = psm; 2988 service->mtu = 0; 2989 service->packet_handler = packet_handler; 2990 service->required_security_level = security_level; 2991 2992 // add to services list 2993 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2994 2995 // done 2996 return 0; 2997 } 2998 2999 uint8_t l2cap_le_unregister_service(uint16_t psm) { 3000 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 3001 l2cap_service_t *service = l2cap_le_get_service(psm); 3002 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3003 3004 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 3005 btstack_memory_l2cap_service_free(service); 3006 return 0; 3007 } 3008 3009 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 3010 // get channel 3011 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3012 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3013 3014 // validate state 3015 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3016 return ERROR_CODE_COMMAND_DISALLOWED; 3017 } 3018 3019 // set state accept connection 3020 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 3021 channel->receive_sdu_buffer = receive_sdu_buffer; 3022 channel->local_mtu = mtu; 3023 channel->new_credits_incoming = initial_credits; 3024 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3025 3026 // test 3027 // channel->new_credits_incoming = 1; 3028 3029 // go 3030 l2cap_run(); 3031 return 0; 3032 } 3033 3034 /** 3035 * @brief Deny incoming LE Data Channel connection due to resource constraints 3036 * @param local_cid L2CAP LE Data Channel Identifier 3037 */ 3038 3039 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 3040 // get channel 3041 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3042 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3043 3044 // validate state 3045 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3046 return ERROR_CODE_COMMAND_DISALLOWED; 3047 } 3048 3049 // set state decline connection 3050 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 3051 channel->reason = 0x04; // no resources available 3052 l2cap_run(); 3053 return 0; 3054 } 3055 3056 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 3057 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 3058 uint16_t * out_local_cid) { 3059 3060 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 3061 3062 3063 hci_connection_t * connection = hci_connection_for_handle(con_handle); 3064 if (!connection) { 3065 log_error("no hci_connection for handle 0x%04x", con_handle); 3066 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 3067 } 3068 3069 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 3070 if (!channel) { 3071 return BTSTACK_MEMORY_ALLOC_FAILED; 3072 } 3073 log_info("l2cap_le_create_channel %p", channel); 3074 3075 // store local_cid 3076 if (out_local_cid){ 3077 *out_local_cid = channel->local_cid; 3078 } 3079 3080 // provide buffer 3081 channel->con_handle = con_handle; 3082 channel->receive_sdu_buffer = receive_sdu_buffer; 3083 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 3084 channel->new_credits_incoming = initial_credits; 3085 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3086 3087 // add to connections list 3088 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 3089 3090 // go 3091 l2cap_run(); 3092 return 0; 3093 } 3094 3095 /** 3096 * @brief Provide credtis for LE Data Channel 3097 * @param local_cid L2CAP LE Data Channel Identifier 3098 * @param credits Number additional credits for peer 3099 */ 3100 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 3101 3102 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3103 if (!channel) { 3104 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3105 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3106 } 3107 3108 // check state 3109 if (channel->state != L2CAP_STATE_OPEN){ 3110 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 3111 } 3112 3113 // assert incoming credits + credits <= 0xffff 3114 uint32_t total_credits = channel->credits_incoming; 3115 total_credits += channel->new_credits_incoming; 3116 total_credits += credits; 3117 if (total_credits > 0xffff){ 3118 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 3119 channel->new_credits_incoming, credits); 3120 } 3121 3122 // set credits_granted 3123 channel->new_credits_incoming += credits; 3124 3125 // go 3126 l2cap_run(); 3127 return 0; 3128 } 3129 3130 /** 3131 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 3132 * @param local_cid L2CAP LE Data Channel Identifier 3133 */ 3134 int l2cap_le_can_send_now(uint16_t local_cid){ 3135 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3136 if (!channel) { 3137 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3138 return 0; 3139 } 3140 3141 // check state 3142 if (channel->state != L2CAP_STATE_OPEN) return 0; 3143 3144 // check queue 3145 if (channel->send_sdu_buffer) return 0; 3146 3147 // fine, go ahead 3148 return 1; 3149 } 3150 3151 /** 3152 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 3153 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 3154 * so packet handler should be ready to handle it 3155 * @param local_cid L2CAP LE Data Channel Identifier 3156 */ 3157 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 3158 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3159 if (!channel) { 3160 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 3161 return 0; 3162 } 3163 channel->waiting_for_can_send_now = 1; 3164 l2cap_le_notify_channel_can_send(channel); 3165 return 0; 3166 } 3167 3168 /** 3169 * @brief Send data via LE Data Channel 3170 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 3171 * @param local_cid L2CAP LE Data Channel Identifier 3172 * @param data data to send 3173 * @param size data size 3174 */ 3175 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 3176 3177 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3178 if (!channel) { 3179 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3180 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3181 } 3182 3183 if (len > channel->remote_mtu){ 3184 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 3185 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 3186 } 3187 3188 if (channel->send_sdu_buffer){ 3189 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 3190 return BTSTACK_ACL_BUFFERS_FULL; 3191 } 3192 3193 channel->send_sdu_buffer = data; 3194 channel->send_sdu_len = len; 3195 channel->send_sdu_pos = 0; 3196 3197 l2cap_run(); 3198 return 0; 3199 } 3200 3201 /** 3202 * @brief Disconnect from LE Data Channel 3203 * @param local_cid L2CAP LE Data Channel Identifier 3204 */ 3205 uint8_t l2cap_le_disconnect(uint16_t local_cid) 3206 { 3207 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3208 if (!channel) { 3209 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3210 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3211 } 3212 3213 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3214 l2cap_run(); 3215 return 0; 3216 } 3217 3218 #endif 3219