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 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1056 // assumption: outgoing connection 1057 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1058 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_IDLE){ 1059 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1060 channel->state = L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES; 1061 return; 1062 } 1063 #endif 1064 1065 // fine, go ahead 1066 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1067 } 1068 1069 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 1070 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 1071 1072 // we have been waiting for remote supported features, if both support SSP, 1073 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)); 1074 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 1075 // request security level 2 1076 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 1077 gap_request_security_level(channel->con_handle, LEVEL_2); 1078 return; 1079 } 1080 1081 l2cap_ready_to_connect(channel); 1082 } 1083 #endif 1084 1085 #ifdef L2CAP_USES_CHANNELS 1086 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 1087 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 1088 1089 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1090 if (!channel) { 1091 return NULL; 1092 } 1093 1094 // Init memory (make valgrind happy) 1095 memset(channel, 0, sizeof(l2cap_channel_t)); 1096 1097 // fill in 1098 channel->packet_handler = packet_handler; 1099 bd_addr_copy(channel->address, address); 1100 channel->address_type = address_type; 1101 channel->psm = psm; 1102 channel->local_mtu = local_mtu; 1103 channel->remote_mtu = L2CAP_MINIMAL_MTU; 1104 channel->required_security_level = security_level; 1105 1106 // 1107 channel->local_cid = l2cap_next_local_cid(); 1108 channel->con_handle = 0; 1109 1110 // set initial state 1111 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 1112 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 1113 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 1114 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 1115 return channel; 1116 } 1117 #endif 1118 1119 #ifdef ENABLE_CLASSIC 1120 1121 /** 1122 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 1123 * @param packet_handler 1124 * @param address 1125 * @param psm 1126 * @param mtu 1127 * @param local_cid 1128 */ 1129 1130 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){ 1131 // limit MTU to the size of our outtgoing HCI buffer 1132 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1133 1134 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1135 1136 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1137 if (!channel) { 1138 return BTSTACK_MEMORY_ALLOC_FAILED; 1139 } 1140 1141 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1142 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1143 #endif 1144 1145 // add to connections list 1146 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1147 1148 // store local_cid 1149 if (out_local_cid){ 1150 *out_local_cid = channel->local_cid; 1151 } 1152 1153 // check if hci connection is already usable 1154 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1155 if (conn){ 1156 log_info("l2cap_create_channel, hci connection already exists"); 1157 l2cap_handle_connection_complete(conn->con_handle, channel); 1158 // check if remote supported fearures are already received 1159 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1160 l2cap_handle_remote_supported_features_received(channel); 1161 } 1162 } 1163 1164 l2cap_run(); 1165 1166 return 0; 1167 } 1168 1169 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1170 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){ 1171 // limit MTU to the size of our outtgoing HCI buffer 1172 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1173 1174 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1175 1176 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1177 if (!channel) { 1178 return BTSTACK_MEMORY_ALLOC_FAILED; 1179 } 1180 1181 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 1182 channel->ertm_mandatory = ertm_mandatory; 1183 1184 // add to connections list 1185 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1186 1187 // store local_cid 1188 if (out_local_cid){ 1189 *out_local_cid = channel->local_cid; 1190 } 1191 1192 // check if hci connection is already usable 1193 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1194 if (conn){ 1195 log_info("l2cap_create_channel, hci connection already exists"); 1196 l2cap_handle_connection_complete(conn->con_handle, channel); 1197 // check if remote supported fearures are already received 1198 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1199 l2cap_handle_remote_supported_features_received(channel); 1200 } 1201 } 1202 1203 l2cap_run(); 1204 1205 return 0; 1206 } 1207 #endif 1208 1209 void 1210 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1211 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1212 // find channel for local_cid 1213 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1214 if (channel) { 1215 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1216 } 1217 // process 1218 l2cap_run(); 1219 } 1220 1221 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1222 btstack_linked_list_iterator_t it; 1223 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1224 while (btstack_linked_list_iterator_has_next(&it)){ 1225 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1226 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1227 // channel for this address found 1228 switch (channel->state){ 1229 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1230 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1231 // failure, forward error code 1232 l2cap_emit_channel_opened(channel, status); 1233 // discard channel 1234 l2cap_stop_rtx(channel); 1235 btstack_linked_list_iterator_remove(&it); 1236 btstack_memory_l2cap_channel_free(channel); 1237 break; 1238 default: 1239 break; 1240 } 1241 } 1242 } 1243 1244 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1245 btstack_linked_list_iterator_t it; 1246 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1247 while (btstack_linked_list_iterator_has_next(&it)){ 1248 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1249 if ( ! bd_addr_cmp( channel->address, address) ){ 1250 l2cap_handle_connection_complete(handle, channel); 1251 } 1252 } 1253 // process 1254 l2cap_run(); 1255 } 1256 #endif 1257 1258 static void l2cap_notify_channel_can_send(void){ 1259 1260 #ifdef ENABLE_CLASSIC 1261 btstack_linked_list_iterator_t it; 1262 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1263 while (btstack_linked_list_iterator_has_next(&it)){ 1264 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1265 if (!channel->waiting_for_can_send_now) continue; 1266 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1267 channel->waiting_for_can_send_now = 0; 1268 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1269 } 1270 #endif 1271 1272 int i; 1273 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1274 if (!fixed_channels[i].callback) continue; 1275 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1276 int can_send = 0; 1277 if (l2cap_fixed_channel_table_index_is_le(i)){ 1278 #ifdef ENABLE_BLE 1279 can_send = hci_can_send_acl_le_packet_now(); 1280 #endif 1281 } else { 1282 #ifdef ENABLE_CLASSIC 1283 can_send = hci_can_send_acl_classic_packet_now(); 1284 #endif 1285 } 1286 if (!can_send) continue; 1287 fixed_channels[i].waiting_for_can_send_now = 0; 1288 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1289 } 1290 } 1291 1292 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1293 1294 UNUSED(packet_type); 1295 UNUSED(cid); 1296 UNUSED(size); 1297 1298 bd_addr_t address; 1299 hci_con_handle_t handle; 1300 int hci_con_used; 1301 btstack_linked_list_iterator_t it; 1302 1303 // avoid unused warnings 1304 UNUSED(address); 1305 UNUSED(hci_con_used); 1306 UNUSED(it); 1307 UNUSED(handle); 1308 1309 switch(hci_event_packet_get_type(packet)){ 1310 1311 // Notify channel packet handler if they can send now 1312 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1313 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1314 l2cap_run(); // try sending signaling packets first 1315 l2cap_notify_channel_can_send(); 1316 break; 1317 1318 case HCI_EVENT_COMMAND_STATUS: 1319 l2cap_run(); // try sending signaling packets first 1320 break; 1321 1322 #ifdef ENABLE_CLASSIC 1323 // handle connection complete events 1324 case HCI_EVENT_CONNECTION_COMPLETE: 1325 reverse_bd_addr(&packet[5], address); 1326 if (packet[2] == 0){ 1327 handle = little_endian_read_16(packet, 3); 1328 l2cap_handle_connection_success_for_addr(address, handle); 1329 } else { 1330 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1331 } 1332 break; 1333 1334 // handle successful create connection cancel command 1335 case HCI_EVENT_COMMAND_COMPLETE: 1336 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1337 if (packet[5] == 0){ 1338 reverse_bd_addr(&packet[6], address); 1339 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1340 l2cap_handle_connection_failed_for_addr(address, 0x16); 1341 } 1342 } 1343 l2cap_run(); // try sending signaling packets first 1344 break; 1345 #endif 1346 1347 // handle disconnection complete events 1348 case HCI_EVENT_DISCONNECTION_COMPLETE: 1349 // send l2cap disconnect events for all channels on this handle and free them 1350 #ifdef ENABLE_CLASSIC 1351 handle = little_endian_read_16(packet, 3); 1352 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1353 while (btstack_linked_list_iterator_has_next(&it)){ 1354 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1355 if (channel->con_handle != handle) continue; 1356 l2cap_emit_channel_closed(channel); 1357 l2cap_stop_rtx(channel); 1358 btstack_linked_list_iterator_remove(&it); 1359 btstack_memory_l2cap_channel_free(channel); 1360 } 1361 #endif 1362 #ifdef ENABLE_LE_DATA_CHANNELS 1363 handle = little_endian_read_16(packet, 3); 1364 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1365 while (btstack_linked_list_iterator_has_next(&it)){ 1366 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1367 if (channel->con_handle != handle) continue; 1368 l2cap_emit_channel_closed(channel); 1369 btstack_linked_list_iterator_remove(&it); 1370 btstack_memory_l2cap_channel_free(channel); 1371 } 1372 #endif 1373 break; 1374 1375 // HCI Connection Timeouts 1376 #ifdef ENABLE_CLASSIC 1377 case L2CAP_EVENT_TIMEOUT_CHECK: 1378 handle = little_endian_read_16(packet, 2); 1379 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1380 if (hci_authentication_active_for_handle(handle)) break; 1381 hci_con_used = 0; 1382 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1383 while (btstack_linked_list_iterator_has_next(&it)){ 1384 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1385 if (channel->con_handle != handle) continue; 1386 hci_con_used = 1; 1387 break; 1388 } 1389 if (hci_con_used) break; 1390 if (!hci_can_send_command_packet_now()) break; 1391 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1392 break; 1393 1394 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1395 handle = little_endian_read_16(packet, 3); 1396 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1397 while (btstack_linked_list_iterator_has_next(&it)){ 1398 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1399 if (channel->con_handle != handle) continue; 1400 l2cap_handle_remote_supported_features_received(channel); 1401 break; 1402 } 1403 break; 1404 1405 case GAP_EVENT_SECURITY_LEVEL: 1406 handle = little_endian_read_16(packet, 2); 1407 log_info("l2cap - security level update"); 1408 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1409 while (btstack_linked_list_iterator_has_next(&it)){ 1410 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1411 if (channel->con_handle != handle) continue; 1412 1413 log_info("l2cap - state %u", channel->state); 1414 1415 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1416 gap_security_level_t required_level = channel->required_security_level; 1417 1418 switch (channel->state){ 1419 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1420 if (actual_level >= required_level){ 1421 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1422 // we need to know if ERTM is supported before sending a config response 1423 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1424 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1425 channel->state = L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES; 1426 #else 1427 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1428 l2cap_emit_incoming_connection(channel); 1429 #endif 1430 } else { 1431 channel->reason = 0x0003; // security block 1432 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1433 } 1434 break; 1435 1436 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1437 if (actual_level >= required_level){ 1438 l2cap_ready_to_connect(channel); 1439 } else { 1440 // disconnnect, authentication not good enough 1441 hci_disconnect_security_block(handle); 1442 } 1443 break; 1444 1445 default: 1446 break; 1447 } 1448 } 1449 break; 1450 #endif 1451 1452 default: 1453 break; 1454 } 1455 1456 l2cap_run(); 1457 } 1458 1459 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 1460 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1461 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1462 signaling_responses[signaling_responses_pending].handle = handle; 1463 signaling_responses[signaling_responses_pending].code = code; 1464 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1465 signaling_responses[signaling_responses_pending].cid = cid; 1466 signaling_responses[signaling_responses_pending].data = data; 1467 signaling_responses_pending++; 1468 l2cap_run(); 1469 } 1470 } 1471 1472 #ifdef ENABLE_CLASSIC 1473 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1474 channel->remote_sig_id = identifier; 1475 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1476 l2cap_run(); 1477 } 1478 1479 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1480 1481 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1482 l2cap_service_t *service = l2cap_get_service(psm); 1483 if (!service) { 1484 // 0x0002 PSM not supported 1485 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1486 return; 1487 } 1488 1489 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1490 if (!hci_connection) { 1491 // 1492 log_error("no hci_connection for handle %u", handle); 1493 return; 1494 } 1495 1496 // alloc structure 1497 // log_info("l2cap_handle_connection_request register channel"); 1498 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1499 psm, service->mtu, service->required_security_level); 1500 if (!channel){ 1501 // 0x0004 No resources available 1502 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 1503 return; 1504 } 1505 1506 channel->con_handle = handle; 1507 channel->remote_cid = source_cid; 1508 channel->remote_sig_id = sig_id; 1509 1510 // limit local mtu to max acl packet length - l2cap header 1511 if (channel->local_mtu > l2cap_max_mtu()) { 1512 channel->local_mtu = l2cap_max_mtu(); 1513 } 1514 1515 // set initial state 1516 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1517 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 1518 1519 // add to connections list 1520 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1521 1522 // assert security requirements 1523 gap_request_security_level(handle, channel->required_security_level); 1524 } 1525 1526 void l2cap_accept_connection(uint16_t local_cid){ 1527 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1528 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1529 if (!channel) { 1530 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1531 return; 1532 } 1533 1534 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1535 // configure L2CAP Basic mode 1536 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1537 #endif 1538 1539 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1540 1541 // process 1542 l2cap_run(); 1543 } 1544 1545 1546 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1547 void l2cap_accept_ertm_connection(uint16_t local_cid, int ertm_mandatory){ 1548 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 1549 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1550 if (!channel) { 1551 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1552 return; 1553 } 1554 1555 // configure L2CAP ERTM 1556 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 1557 channel->ertm_mandatory = ertm_mandatory; 1558 1559 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1560 1561 // process 1562 l2cap_run(); 1563 } 1564 #endif 1565 1566 1567 void l2cap_decline_connection(uint16_t local_cid){ 1568 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1569 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1570 if (!channel) { 1571 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1572 return; 1573 } 1574 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1575 channel->reason = 0x04; // no resources available 1576 l2cap_run(); 1577 } 1578 1579 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1580 1581 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1582 1583 uint16_t flags = little_endian_read_16(command, 6); 1584 if (flags & 1) { 1585 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1586 } 1587 1588 // accept the other's configuration options 1589 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1590 uint16_t pos = 8; 1591 while (pos < end_pos){ 1592 uint8_t option_hint = command[pos] >> 7; 1593 uint8_t option_type = command[pos] & 0x7f; 1594 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1595 pos++; 1596 uint8_t length = command[pos++]; 1597 // MTU { type(8): 1, len(8):2, MTU(16) } 1598 if (option_type == 1 && length == 2){ 1599 channel->remote_mtu = little_endian_read_16(command, pos); 1600 if (channel->remote_mtu > l2cap_max_mtu()){ 1601 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 1602 channel->remote_mtu = l2cap_max_mtu(); 1603 } 1604 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1605 } 1606 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1607 if (option_type == 2 && length == 2){ 1608 channel->flush_timeout = little_endian_read_16(command, pos); 1609 } 1610 1611 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1612 // Retransmission and Flow Control Option 1613 if (option_type == 4 && length == 9){ 1614 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 1615 switch(channel->mode){ 1616 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1617 if (channel->ertm_mandatory){ 1618 // ERTM mandatory, but remote doens't offer ERTM -> disconnect 1619 if (mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1620 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1621 } else { 1622 // Both sides selected ERTM 1623 // TODO store and evaluate configuration 1624 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1625 } 1626 } else { 1627 // ERTM is optional 1628 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1629 } 1630 break; 1631 case L2CAP_CHANNEL_MODE_BASIC: 1632 switch (mode){ 1633 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1634 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 1635 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 1636 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1637 } 1638 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 1639 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 1640 break; 1641 default: // case L2CAP_CHANNEL_MODE_BASIC: 1642 // TODO store and evaluate configuration 1643 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1644 break; 1645 } 1646 break; 1647 default: 1648 break; 1649 } 1650 } 1651 #endif 1652 // check for unknown options 1653 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1654 log_info("l2cap cid %u, unknown options", channel->local_cid); 1655 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1656 } 1657 pos += length; 1658 } 1659 } 1660 1661 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 1662 log_info("l2cap_signaling_handle_configure_response"); 1663 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1664 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1665 uint16_t pos = 10; 1666 while (pos < end_pos){ 1667 uint8_t option_hint = command[pos] >> 7; 1668 uint8_t option_type = command[pos] & 0x7f; 1669 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1670 pos++; 1671 uint8_t length = command[pos++]; 1672 1673 // Retransmission and Flow Control Option 1674 if (option_type == 4 && length == 9){ 1675 switch (channel->mode){ 1676 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1677 if (channel->ertm_mandatory){ 1678 // ?? 1679 } else { 1680 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 1681 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 1682 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1683 } 1684 } 1685 break; 1686 case L2CAP_CHANNEL_MODE_BASIC: 1687 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 1688 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 1689 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1690 } 1691 break; 1692 default: 1693 break; 1694 } 1695 } 1696 1697 // check for unknown options 1698 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1699 log_info("l2cap cid %u, unknown options", channel->local_cid); 1700 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1701 } 1702 1703 pos += length; 1704 } 1705 #endif 1706 } 1707 1708 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1709 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1710 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1711 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1712 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1713 if (channel->state == L2CAP_STATE_OPEN) return 0; 1714 return 1; 1715 } 1716 1717 1718 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1719 1720 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1721 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1722 uint16_t result = 0; 1723 1724 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1725 1726 // handle DISCONNECT REQUESTS seperately 1727 if (code == DISCONNECTION_REQUEST){ 1728 switch (channel->state){ 1729 case L2CAP_STATE_CONFIG: 1730 case L2CAP_STATE_OPEN: 1731 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1732 case L2CAP_STATE_WAIT_DISCONNECT: 1733 l2cap_handle_disconnect_request(channel, identifier); 1734 break; 1735 1736 default: 1737 // ignore in other states 1738 break; 1739 } 1740 return; 1741 } 1742 1743 // @STATEMACHINE(l2cap) 1744 switch (channel->state) { 1745 1746 case L2CAP_STATE_WAIT_CONNECT_RSP: 1747 switch (code){ 1748 case CONNECTION_RESPONSE: 1749 l2cap_stop_rtx(channel); 1750 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1751 switch (result) { 1752 case 0: 1753 // successful connection 1754 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1755 channel->state = L2CAP_STATE_CONFIG; 1756 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1757 break; 1758 case 1: 1759 // connection pending. get some coffee, but start the ERTX 1760 l2cap_start_ertx(channel); 1761 break; 1762 default: 1763 // channel closed 1764 channel->state = L2CAP_STATE_CLOSED; 1765 // map l2cap connection response result to BTstack status enumeration 1766 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1767 1768 // drop link key if security block 1769 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1770 gap_drop_link_key_for_bd_addr(channel->address); 1771 } 1772 1773 // discard channel 1774 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1775 btstack_memory_l2cap_channel_free(channel); 1776 break; 1777 } 1778 break; 1779 1780 default: 1781 //@TODO: implement other signaling packets 1782 break; 1783 } 1784 break; 1785 1786 case L2CAP_STATE_CONFIG: 1787 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1788 switch (code) { 1789 case CONFIGURE_REQUEST: 1790 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1791 l2cap_signaling_handle_configure_request(channel, command); 1792 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1793 // only done if continuation not set 1794 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1795 } 1796 break; 1797 case CONFIGURE_RESPONSE: 1798 l2cap_stop_rtx(channel); 1799 l2cap_signaling_handle_configure_response(channel, result, command); 1800 switch (result){ 1801 case 0: // success 1802 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1803 break; 1804 case 4: // pending 1805 l2cap_start_ertx(channel); 1806 break; 1807 default: 1808 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1809 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 1810 // remote does not offer ertm but it's required 1811 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1812 break; 1813 } 1814 #endif 1815 // retry on negative result 1816 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1817 break; 1818 } 1819 break; 1820 default: 1821 break; 1822 } 1823 if (l2cap_channel_ready_for_open(channel)){ 1824 // for open: 1825 channel->state = L2CAP_STATE_OPEN; 1826 l2cap_emit_channel_opened(channel, 0); 1827 } 1828 break; 1829 1830 case L2CAP_STATE_WAIT_DISCONNECT: 1831 switch (code) { 1832 case DISCONNECTION_RESPONSE: 1833 l2cap_finialize_channel_close(channel); 1834 break; 1835 default: 1836 //@TODO: implement other signaling packets 1837 break; 1838 } 1839 break; 1840 1841 case L2CAP_STATE_CLOSED: 1842 // @TODO handle incoming requests 1843 break; 1844 1845 case L2CAP_STATE_OPEN: 1846 //@TODO: implement other signaling packets, e.g. re-configure 1847 break; 1848 default: 1849 break; 1850 } 1851 // log_info("new state %u", channel->state); 1852 } 1853 1854 1855 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1856 1857 btstack_linked_list_iterator_t it; 1858 1859 // get code, signalind identifier and command len 1860 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1861 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1862 1863 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 1864 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 1865 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 1866 return; 1867 } 1868 1869 // general commands without an assigned channel 1870 switch(code) { 1871 1872 case CONNECTION_REQUEST: { 1873 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1874 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1875 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1876 return; 1877 } 1878 1879 case ECHO_REQUEST: 1880 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 1881 return; 1882 1883 case INFORMATION_REQUEST: { 1884 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1885 l2cap_register_signaling_response(handle, code, sig_id, 0, infoType); 1886 return; 1887 } 1888 1889 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1890 case INFORMATION_RESPONSE: { 1891 hci_connection_t * connection = hci_connection_for_handle(handle); 1892 if (!connection) return; 1893 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1894 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1895 if (result != 0) return; 1896 if (info_type != 0x02) return; 1897 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 1898 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1899 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 1900 // trigger connection request 1901 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1902 while (btstack_linked_list_iterator_has_next(&it)){ 1903 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1904 if (channel->con_handle != handle) continue; 1905 // bail if ERTM was requested but is not supported 1906 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 1907 if (channel->ertm_mandatory){ 1908 // channel closed 1909 channel->state = L2CAP_STATE_CLOSED; 1910 // map l2cap connection response result to BTstack status enumeration 1911 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTD); 1912 // discard channel 1913 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1914 btstack_memory_l2cap_channel_free(channel); 1915 continue; 1916 } else { 1917 // fallback to Basic mode 1918 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1919 } 1920 } 1921 // start connecting 1922 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 1923 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1924 } 1925 // respond to connection request 1926 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 1927 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1928 l2cap_emit_incoming_connection(channel); 1929 } 1930 } 1931 return; 1932 } 1933 #endif 1934 1935 default: 1936 break; 1937 } 1938 1939 1940 // Get potential destination CID 1941 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1942 1943 // Find channel for this sig_id and connection handle 1944 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1945 while (btstack_linked_list_iterator_has_next(&it)){ 1946 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1947 if (channel->con_handle != handle) continue; 1948 if (code & 1) { 1949 // match odd commands (responses) by previous signaling identifier 1950 if (channel->local_sig_id == sig_id) { 1951 l2cap_signaling_handler_channel(channel, command); 1952 break; 1953 } 1954 } else { 1955 // match even commands (requests) by local channel id 1956 if (channel->local_cid == dest_cid) { 1957 l2cap_signaling_handler_channel(channel, command); 1958 break; 1959 } 1960 } 1961 } 1962 } 1963 #endif 1964 1965 #ifdef ENABLE_BLE 1966 1967 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 1968 uint8_t event[6]; 1969 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 1970 event[1] = 4; 1971 little_endian_store_16(event, 2, con_handle); 1972 little_endian_store_16(event, 4, result); 1973 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1974 if (!l2cap_event_packet_handler) return; 1975 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1976 } 1977 1978 // @returns valid 1979 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1980 hci_connection_t * connection; 1981 uint16_t result; 1982 uint8_t event[10]; 1983 1984 #ifdef ENABLE_LE_DATA_CHANNELS 1985 btstack_linked_list_iterator_t it; 1986 l2cap_channel_t * channel; 1987 uint16_t local_cid; 1988 uint16_t le_psm; 1989 uint16_t new_credits; 1990 uint16_t credits_before; 1991 l2cap_service_t * service; 1992 uint16_t source_cid; 1993 #endif 1994 1995 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1996 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1997 1998 switch (code){ 1999 2000 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2001 result = little_endian_read_16(command, 4); 2002 l2cap_emit_connection_parameter_update_response(handle, result); 2003 break; 2004 2005 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2006 connection = hci_connection_for_handle(handle); 2007 if (connection){ 2008 if (connection->role != HCI_ROLE_MASTER){ 2009 // reject command without notifying upper layer when not in master role 2010 return 0; 2011 } 2012 int update_parameter = 1; 2013 le_connection_parameter_range_t existing_range; 2014 gap_get_connection_parameter_range(&existing_range); 2015 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 2016 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 2017 uint16_t le_conn_latency = little_endian_read_16(command,12); 2018 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 2019 2020 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 2021 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 2022 2023 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 2024 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 2025 2026 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 2027 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 2028 2029 if (update_parameter){ 2030 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2031 connection->le_conn_interval_min = le_conn_interval_min; 2032 connection->le_conn_interval_max = le_conn_interval_max; 2033 connection->le_conn_latency = le_conn_latency; 2034 connection->le_supervision_timeout = le_supervision_timeout; 2035 } else { 2036 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2037 } 2038 connection->le_con_param_update_identifier = sig_id; 2039 } 2040 2041 if (!l2cap_event_packet_handler) break; 2042 2043 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2044 event[1] = 8; 2045 memcpy(&event[2], &command[4], 8); 2046 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2047 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2048 break; 2049 2050 #ifdef ENABLE_LE_DATA_CHANNELS 2051 2052 case COMMAND_REJECT: 2053 // Find channel for this sig_id and connection handle 2054 channel = NULL; 2055 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2056 while (btstack_linked_list_iterator_has_next(&it)){ 2057 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2058 if (a_channel->con_handle != handle) continue; 2059 if (a_channel->local_sig_id != sig_id) continue; 2060 channel = a_channel; 2061 break; 2062 } 2063 if (!channel) break; 2064 2065 // if received while waiting for le connection response, assume legacy device 2066 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2067 channel->state = L2CAP_STATE_CLOSED; 2068 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2069 l2cap_emit_le_channel_opened(channel, 0x0002); 2070 2071 // discard channel 2072 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2073 btstack_memory_l2cap_channel_free(channel); 2074 break; 2075 } 2076 break; 2077 2078 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2079 2080 // get hci connection, bail if not found (must not happen) 2081 connection = hci_connection_for_handle(handle); 2082 if (!connection) return 0; 2083 2084 // check if service registered 2085 le_psm = little_endian_read_16(command, 4); 2086 service = l2cap_le_get_service(le_psm); 2087 source_cid = little_endian_read_16(command, 6); 2088 2089 if (service){ 2090 if (source_cid < 0x40){ 2091 // 0x0009 Connection refused - Invalid Source CID 2092 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2093 return 1; 2094 } 2095 2096 // go through list of channels for this ACL connection and check if we get a match 2097 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2098 while (btstack_linked_list_iterator_has_next(&it)){ 2099 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2100 if (a_channel->con_handle != handle) continue; 2101 if (a_channel->remote_cid != source_cid) continue; 2102 // 0x000a Connection refused - Source CID already allocated 2103 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2104 return 1; 2105 } 2106 2107 // security: check encryption 2108 if (service->required_security_level >= LEVEL_2){ 2109 if (sm_encryption_key_size(handle) == 0){ 2110 // 0x0008 Connection refused - insufficient encryption 2111 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2112 return 1; 2113 } 2114 // anything less than 16 byte key size is insufficient 2115 if (sm_encryption_key_size(handle) < 16){ 2116 // 0x0007 Connection refused – insufficient encryption key size 2117 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2118 return 1; 2119 } 2120 } 2121 2122 // security: check authencation 2123 if (service->required_security_level >= LEVEL_3){ 2124 if (!sm_authenticated(handle)){ 2125 // 0x0005 Connection refused – insufficient authentication 2126 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2127 return 1; 2128 } 2129 } 2130 2131 // security: check authorization 2132 if (service->required_security_level >= LEVEL_4){ 2133 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2134 // 0x0006 Connection refused – insufficient authorization 2135 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2136 return 1; 2137 } 2138 } 2139 2140 // allocate channel 2141 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 2142 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2143 if (!channel){ 2144 // 0x0004 Connection refused – no resources available 2145 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2146 return 1; 2147 } 2148 2149 channel->con_handle = handle; 2150 channel->remote_cid = source_cid; 2151 channel->remote_sig_id = sig_id; 2152 channel->remote_mtu = little_endian_read_16(command, 8); 2153 channel->remote_mps = little_endian_read_16(command, 10); 2154 channel->credits_outgoing = little_endian_read_16(command, 12); 2155 2156 // set initial state 2157 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2158 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2159 2160 // add to connections list 2161 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2162 2163 // post connection request event 2164 l2cap_emit_le_incoming_connection(channel); 2165 2166 } else { 2167 // Connection refused – LE_PSM not supported 2168 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2169 } 2170 break; 2171 2172 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2173 // Find channel for this sig_id and connection handle 2174 channel = NULL; 2175 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2176 while (btstack_linked_list_iterator_has_next(&it)){ 2177 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2178 if (a_channel->con_handle != handle) continue; 2179 if (a_channel->local_sig_id != sig_id) continue; 2180 channel = a_channel; 2181 break; 2182 } 2183 if (!channel) break; 2184 2185 // cid + 0 2186 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2187 if (result){ 2188 channel->state = L2CAP_STATE_CLOSED; 2189 // map l2cap connection response result to BTstack status enumeration 2190 l2cap_emit_le_channel_opened(channel, result); 2191 2192 // discard channel 2193 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2194 btstack_memory_l2cap_channel_free(channel); 2195 break; 2196 } 2197 2198 // success 2199 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2200 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2201 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2202 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2203 channel->state = L2CAP_STATE_OPEN; 2204 l2cap_emit_le_channel_opened(channel, result); 2205 break; 2206 2207 case LE_FLOW_CONTROL_CREDIT: 2208 // find channel 2209 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2210 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2211 if (!channel) { 2212 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2213 break; 2214 } 2215 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2216 credits_before = channel->credits_outgoing; 2217 channel->credits_outgoing += new_credits; 2218 // check for credit overrun 2219 if (credits_before > channel->credits_outgoing){ 2220 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2221 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2222 break; 2223 } 2224 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2225 break; 2226 2227 case DISCONNECTION_REQUEST: 2228 // find channel 2229 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2230 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2231 if (!channel) { 2232 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2233 break; 2234 } 2235 channel->remote_sig_id = sig_id; 2236 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2237 break; 2238 2239 #endif 2240 2241 case DISCONNECTION_RESPONSE: 2242 break; 2243 2244 default: 2245 // command unknown -> reject command 2246 return 0; 2247 } 2248 return 1; 2249 } 2250 #endif 2251 2252 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 2253 UNUSED(packet_type); 2254 UNUSED(channel); 2255 2256 l2cap_channel_t * l2cap_channel; 2257 UNUSED(l2cap_channel); 2258 2259 // Get Channel ID 2260 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 2261 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 2262 2263 switch (channel_id) { 2264 2265 #ifdef ENABLE_CLASSIC 2266 case L2CAP_CID_SIGNALING: { 2267 uint16_t command_offset = 8; 2268 while (command_offset < size) { 2269 // handle signaling commands 2270 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 2271 2272 // increment command_offset 2273 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2274 } 2275 break; 2276 } 2277 #endif 2278 2279 #ifdef ENABLE_BLE 2280 case L2CAP_CID_SIGNALING_LE: { 2281 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 2282 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 2283 if (!valid){ 2284 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2285 } 2286 break; 2287 } 2288 #endif 2289 2290 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 2291 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 2292 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2293 } 2294 break; 2295 2296 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 2297 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 2298 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2299 } 2300 break; 2301 2302 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 2303 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 2304 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2305 } 2306 break; 2307 2308 default: 2309 #ifdef ENABLE_CLASSIC 2310 // Find channel for this channel_id and connection handle 2311 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 2312 if (l2cap_channel) { 2313 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2314 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2315 2316 // verify FCS 2317 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 2318 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 2319 log_info("Packet FCS 0x%04x, calculated FCS 0x%04x", fcs_packet, fcs_calculated); 2320 if (fcs_calculated != fcs_packet){ 2321 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 2322 // TODO: trigger retransmission or something like that 2323 break; 2324 } 2325 2326 // switch on packet type 2327 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2328 if (control & 1){ 2329 log_info("S-Frame not not implemented yet"); 2330 // S-Frame 2331 break; 2332 } else { 2333 // I-Frame 2334 // get control 2335 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 2336 log_info("Control: 0x%04x, SAR type %u", control, (int) sar); 2337 switch (sar){ 2338 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 2339 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2+2)); 2340 break; 2341 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 2342 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 2343 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 2344 log_info("SAR type %u not implemented yet", (int) sar); 2345 break; 2346 } 2347 } 2348 break; 2349 } 2350 #endif 2351 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2352 } 2353 #endif 2354 #ifdef ENABLE_LE_DATA_CHANNELS 2355 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 2356 if (l2cap_channel) { 2357 // credit counting 2358 if (l2cap_channel->credits_incoming == 0){ 2359 log_error("LE Data Channel packet received but no incoming credits"); 2360 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2361 break; 2362 } 2363 l2cap_channel->credits_incoming--; 2364 2365 // automatic credits 2366 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 2367 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 2368 } 2369 2370 // first fragment 2371 uint16_t pos = 0; 2372 if (!l2cap_channel->receive_sdu_len){ 2373 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2374 l2cap_channel->receive_sdu_pos = 0; 2375 pos += 2; 2376 size -= 2; 2377 } 2378 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 2379 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 2380 // done? 2381 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 2382 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 2383 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 2384 l2cap_channel->receive_sdu_len = 0; 2385 } 2386 } else { 2387 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 2388 } 2389 #endif 2390 break; 2391 } 2392 2393 l2cap_run(); 2394 } 2395 2396 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 2397 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 2398 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 2399 if (index < 0) return; 2400 fixed_channels[index].callback = the_packet_handler; 2401 } 2402 2403 #ifdef ENABLE_CLASSIC 2404 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2405 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 2406 channel->state = L2CAP_STATE_CLOSED; 2407 l2cap_emit_channel_closed(channel); 2408 // discard channel 2409 l2cap_stop_rtx(channel); 2410 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2411 btstack_memory_l2cap_channel_free(channel); 2412 } 2413 2414 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 2415 btstack_linked_list_iterator_t it; 2416 btstack_linked_list_iterator_init(&it, services); 2417 while (btstack_linked_list_iterator_has_next(&it)){ 2418 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 2419 if ( service->psm == psm){ 2420 return service; 2421 }; 2422 } 2423 return NULL; 2424 } 2425 2426 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 2427 return l2cap_get_service_internal(&l2cap_services, psm); 2428 } 2429 2430 2431 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 2432 2433 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 2434 2435 // check for alread registered psm 2436 l2cap_service_t *service = l2cap_get_service(psm); 2437 if (service) { 2438 log_error("l2cap_register_service: PSM %u already registered", psm); 2439 return L2CAP_SERVICE_ALREADY_REGISTERED; 2440 } 2441 2442 // alloc structure 2443 service = btstack_memory_l2cap_service_get(); 2444 if (!service) { 2445 log_error("l2cap_register_service: no memory for l2cap_service_t"); 2446 return BTSTACK_MEMORY_ALLOC_FAILED; 2447 } 2448 2449 // fill in 2450 service->psm = psm; 2451 service->mtu = mtu; 2452 service->packet_handler = service_packet_handler; 2453 service->required_security_level = security_level; 2454 2455 // add to services list 2456 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 2457 2458 // enable page scan 2459 gap_connectable_control(1); 2460 2461 return 0; 2462 } 2463 2464 uint8_t l2cap_unregister_service(uint16_t psm){ 2465 2466 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2467 2468 l2cap_service_t *service = l2cap_get_service(psm); 2469 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2470 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2471 btstack_memory_l2cap_service_free(service); 2472 2473 // disable page scan when no services registered 2474 if (btstack_linked_list_empty(&l2cap_services)) { 2475 gap_connectable_control(0); 2476 } 2477 return 0; 2478 } 2479 #endif 2480 2481 2482 #ifdef ENABLE_LE_DATA_CHANNELS 2483 2484 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2485 if (!channel->waiting_for_can_send_now) return; 2486 if (channel->send_sdu_buffer) return; 2487 channel->waiting_for_can_send_now = 0; 2488 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2489 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2490 } 2491 2492 // 1BH2222 2493 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2494 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", 2495 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2496 uint8_t event[19]; 2497 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2498 event[1] = sizeof(event) - 2; 2499 event[2] = channel->address_type; 2500 reverse_bd_addr(channel->address, &event[3]); 2501 little_endian_store_16(event, 9, channel->con_handle); 2502 little_endian_store_16(event, 11, channel->psm); 2503 little_endian_store_16(event, 13, channel->local_cid); 2504 little_endian_store_16(event, 15, channel->remote_cid); 2505 little_endian_store_16(event, 17, channel->remote_mtu); 2506 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2507 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2508 } 2509 // 11BH22222 2510 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2511 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", 2512 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2513 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2514 uint8_t event[23]; 2515 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2516 event[1] = sizeof(event) - 2; 2517 event[2] = status; 2518 event[3] = channel->address_type; 2519 reverse_bd_addr(channel->address, &event[4]); 2520 little_endian_store_16(event, 10, channel->con_handle); 2521 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2522 little_endian_store_16(event, 13, channel->psm); 2523 little_endian_store_16(event, 15, channel->local_cid); 2524 little_endian_store_16(event, 17, channel->remote_cid); 2525 little_endian_store_16(event, 19, channel->local_mtu); 2526 little_endian_store_16(event, 21, channel->remote_mtu); 2527 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2528 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2529 } 2530 2531 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2532 btstack_linked_list_iterator_t it; 2533 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2534 while (btstack_linked_list_iterator_has_next(&it)){ 2535 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2536 if ( channel->local_cid == local_cid) { 2537 return channel; 2538 } 2539 } 2540 return NULL; 2541 } 2542 2543 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2544 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2545 channel->state = L2CAP_STATE_CLOSED; 2546 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2547 // discard channel 2548 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2549 btstack_memory_l2cap_channel_free(channel); 2550 } 2551 2552 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2553 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2554 } 2555 2556 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2557 2558 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2559 2560 // check for alread registered psm 2561 l2cap_service_t *service = l2cap_le_get_service(psm); 2562 if (service) { 2563 return L2CAP_SERVICE_ALREADY_REGISTERED; 2564 } 2565 2566 // alloc structure 2567 service = btstack_memory_l2cap_service_get(); 2568 if (!service) { 2569 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2570 return BTSTACK_MEMORY_ALLOC_FAILED; 2571 } 2572 2573 // fill in 2574 service->psm = psm; 2575 service->mtu = 0; 2576 service->packet_handler = packet_handler; 2577 service->required_security_level = security_level; 2578 2579 // add to services list 2580 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2581 2582 // done 2583 return 0; 2584 } 2585 2586 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2587 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2588 l2cap_service_t *service = l2cap_le_get_service(psm); 2589 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2590 2591 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2592 btstack_memory_l2cap_service_free(service); 2593 return 0; 2594 } 2595 2596 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2597 // get channel 2598 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2599 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2600 2601 // validate state 2602 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2603 return ERROR_CODE_COMMAND_DISALLOWED; 2604 } 2605 2606 // set state accept connection 2607 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2608 channel->receive_sdu_buffer = receive_sdu_buffer; 2609 channel->local_mtu = mtu; 2610 channel->new_credits_incoming = initial_credits; 2611 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2612 2613 // test 2614 // channel->new_credits_incoming = 1; 2615 2616 // go 2617 l2cap_run(); 2618 return 0; 2619 } 2620 2621 /** 2622 * @brief Deny incoming LE Data Channel connection due to resource constraints 2623 * @param local_cid L2CAP LE Data Channel Identifier 2624 */ 2625 2626 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2627 // get channel 2628 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2629 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2630 2631 // validate state 2632 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2633 return ERROR_CODE_COMMAND_DISALLOWED; 2634 } 2635 2636 // set state decline connection 2637 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2638 channel->reason = 0x04; // no resources available 2639 l2cap_run(); 2640 return 0; 2641 } 2642 2643 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2644 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2645 uint16_t * out_local_cid) { 2646 2647 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2648 2649 2650 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2651 if (!connection) { 2652 log_error("no hci_connection for handle 0x%04x", con_handle); 2653 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2654 } 2655 2656 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2657 if (!channel) { 2658 return BTSTACK_MEMORY_ALLOC_FAILED; 2659 } 2660 log_info("l2cap_le_create_channel %p", channel); 2661 2662 // store local_cid 2663 if (out_local_cid){ 2664 *out_local_cid = channel->local_cid; 2665 } 2666 2667 // provide buffer 2668 channel->con_handle = con_handle; 2669 channel->receive_sdu_buffer = receive_sdu_buffer; 2670 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2671 channel->new_credits_incoming = initial_credits; 2672 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2673 2674 // add to connections list 2675 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2676 2677 // go 2678 l2cap_run(); 2679 return 0; 2680 } 2681 2682 /** 2683 * @brief Provide credtis for LE Data Channel 2684 * @param local_cid L2CAP LE Data Channel Identifier 2685 * @param credits Number additional credits for peer 2686 */ 2687 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2688 2689 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2690 if (!channel) { 2691 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2692 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2693 } 2694 2695 // check state 2696 if (channel->state != L2CAP_STATE_OPEN){ 2697 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2698 } 2699 2700 // assert incoming credits + credits <= 0xffff 2701 uint32_t total_credits = channel->credits_incoming; 2702 total_credits += channel->new_credits_incoming; 2703 total_credits += credits; 2704 if (total_credits > 0xffff){ 2705 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2706 channel->new_credits_incoming, credits); 2707 } 2708 2709 // set credits_granted 2710 channel->new_credits_incoming += credits; 2711 2712 // go 2713 l2cap_run(); 2714 return 0; 2715 } 2716 2717 /** 2718 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2719 * @param local_cid L2CAP LE Data Channel Identifier 2720 */ 2721 int l2cap_le_can_send_now(uint16_t local_cid){ 2722 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2723 if (!channel) { 2724 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2725 return 0; 2726 } 2727 2728 // check state 2729 if (channel->state != L2CAP_STATE_OPEN) return 0; 2730 2731 // check queue 2732 if (channel->send_sdu_buffer) return 0; 2733 2734 // fine, go ahead 2735 return 1; 2736 } 2737 2738 /** 2739 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2740 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2741 * so packet handler should be ready to handle it 2742 * @param local_cid L2CAP LE Data Channel Identifier 2743 */ 2744 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2745 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2746 if (!channel) { 2747 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2748 return 0; 2749 } 2750 channel->waiting_for_can_send_now = 1; 2751 l2cap_le_notify_channel_can_send(channel); 2752 return 0; 2753 } 2754 2755 /** 2756 * @brief Send data via LE Data Channel 2757 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2758 * @param local_cid L2CAP LE Data Channel Identifier 2759 * @param data data to send 2760 * @param size data size 2761 */ 2762 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2763 2764 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2765 if (!channel) { 2766 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2767 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2768 } 2769 2770 if (len > channel->remote_mtu){ 2771 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2772 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2773 } 2774 2775 if (channel->send_sdu_buffer){ 2776 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2777 return BTSTACK_ACL_BUFFERS_FULL; 2778 } 2779 2780 channel->send_sdu_buffer = data; 2781 channel->send_sdu_len = len; 2782 channel->send_sdu_pos = 0; 2783 2784 l2cap_run(); 2785 return 0; 2786 } 2787 2788 /** 2789 * @brief Disconnect from LE Data Channel 2790 * @param local_cid L2CAP LE Data Channel Identifier 2791 */ 2792 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2793 { 2794 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2795 if (!channel) { 2796 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2797 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2798 } 2799 2800 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2801 l2cap_run(); 2802 return 0; 2803 } 2804 2805 #endif 2806