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