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 packet_handler, bd_addr_t address, uint16_t psm, 1171 int ertm_mandatory, uint8_t max_transmit, uint16_t retransmission_timeout_ms, uint16_t monitor_timeout_ms, 1172 uint8_t num_tx_buffers, uint8_t num_rx_buffers, uint8_t * buffer, uint32_t size, uint16_t * out_local_cid){ 1173 1174 UNUSED(max_transmit); 1175 UNUSED(retransmission_timeout_ms); 1176 UNUSED(monitor_timeout_ms); 1177 UNUSED(num_rx_buffers); 1178 UNUSED(num_tx_buffers); 1179 UNUSED(buffer); 1180 UNUSED(size); 1181 1182 // limit MTU to the size of our outtgoing HCI buffer 1183 uint16_t local_mtu = l2cap_max_mtu(); 1184 1185 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x -> local mtu %u", bd_addr_to_str(address), psm, local_mtu); 1186 1187 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1188 if (!channel) { 1189 return BTSTACK_MEMORY_ALLOC_FAILED; 1190 } 1191 1192 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 1193 channel->ertm_mandatory = ertm_mandatory; 1194 1195 // add to connections list 1196 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1197 1198 // store local_cid 1199 if (out_local_cid){ 1200 *out_local_cid = channel->local_cid; 1201 } 1202 1203 // check if hci connection is already usable 1204 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1205 if (conn){ 1206 log_info("l2cap_create_channel, hci connection already exists"); 1207 l2cap_handle_connection_complete(conn->con_handle, channel); 1208 // check if remote supported fearures are already received 1209 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1210 l2cap_handle_remote_supported_features_received(channel); 1211 } 1212 } 1213 1214 l2cap_run(); 1215 1216 return 0; 1217 } 1218 #endif 1219 1220 void 1221 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1222 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1223 // find channel for local_cid 1224 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1225 if (channel) { 1226 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1227 } 1228 // process 1229 l2cap_run(); 1230 } 1231 1232 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1233 btstack_linked_list_iterator_t it; 1234 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1235 while (btstack_linked_list_iterator_has_next(&it)){ 1236 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1237 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1238 // channel for this address found 1239 switch (channel->state){ 1240 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1241 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1242 // failure, forward error code 1243 l2cap_emit_channel_opened(channel, status); 1244 // discard channel 1245 l2cap_stop_rtx(channel); 1246 btstack_linked_list_iterator_remove(&it); 1247 btstack_memory_l2cap_channel_free(channel); 1248 break; 1249 default: 1250 break; 1251 } 1252 } 1253 } 1254 1255 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1256 btstack_linked_list_iterator_t it; 1257 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1258 while (btstack_linked_list_iterator_has_next(&it)){ 1259 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1260 if ( ! bd_addr_cmp( channel->address, address) ){ 1261 l2cap_handle_connection_complete(handle, channel); 1262 } 1263 } 1264 // process 1265 l2cap_run(); 1266 } 1267 #endif 1268 1269 static void l2cap_notify_channel_can_send(void){ 1270 1271 #ifdef ENABLE_CLASSIC 1272 btstack_linked_list_iterator_t it; 1273 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1274 while (btstack_linked_list_iterator_has_next(&it)){ 1275 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1276 if (!channel->waiting_for_can_send_now) continue; 1277 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1278 channel->waiting_for_can_send_now = 0; 1279 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1280 } 1281 #endif 1282 1283 int i; 1284 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1285 if (!fixed_channels[i].callback) continue; 1286 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1287 int can_send = 0; 1288 if (l2cap_fixed_channel_table_index_is_le(i)){ 1289 #ifdef ENABLE_BLE 1290 can_send = hci_can_send_acl_le_packet_now(); 1291 #endif 1292 } else { 1293 #ifdef ENABLE_CLASSIC 1294 can_send = hci_can_send_acl_classic_packet_now(); 1295 #endif 1296 } 1297 if (!can_send) continue; 1298 fixed_channels[i].waiting_for_can_send_now = 0; 1299 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1300 } 1301 } 1302 1303 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1304 1305 UNUSED(packet_type); 1306 UNUSED(cid); 1307 UNUSED(size); 1308 1309 bd_addr_t address; 1310 hci_con_handle_t handle; 1311 int hci_con_used; 1312 btstack_linked_list_iterator_t it; 1313 1314 // avoid unused warnings 1315 UNUSED(address); 1316 UNUSED(hci_con_used); 1317 UNUSED(it); 1318 UNUSED(handle); 1319 1320 switch(hci_event_packet_get_type(packet)){ 1321 1322 // Notify channel packet handler if they can send now 1323 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1324 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1325 l2cap_run(); // try sending signaling packets first 1326 l2cap_notify_channel_can_send(); 1327 break; 1328 1329 case HCI_EVENT_COMMAND_STATUS: 1330 l2cap_run(); // try sending signaling packets first 1331 break; 1332 1333 #ifdef ENABLE_CLASSIC 1334 // handle connection complete events 1335 case HCI_EVENT_CONNECTION_COMPLETE: 1336 reverse_bd_addr(&packet[5], address); 1337 if (packet[2] == 0){ 1338 handle = little_endian_read_16(packet, 3); 1339 l2cap_handle_connection_success_for_addr(address, handle); 1340 } else { 1341 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1342 } 1343 break; 1344 1345 // handle successful create connection cancel command 1346 case HCI_EVENT_COMMAND_COMPLETE: 1347 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1348 if (packet[5] == 0){ 1349 reverse_bd_addr(&packet[6], address); 1350 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1351 l2cap_handle_connection_failed_for_addr(address, 0x16); 1352 } 1353 } 1354 l2cap_run(); // try sending signaling packets first 1355 break; 1356 #endif 1357 1358 // handle disconnection complete events 1359 case HCI_EVENT_DISCONNECTION_COMPLETE: 1360 // send l2cap disconnect events for all channels on this handle and free them 1361 #ifdef ENABLE_CLASSIC 1362 handle = little_endian_read_16(packet, 3); 1363 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1364 while (btstack_linked_list_iterator_has_next(&it)){ 1365 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1366 if (channel->con_handle != handle) continue; 1367 l2cap_emit_channel_closed(channel); 1368 l2cap_stop_rtx(channel); 1369 btstack_linked_list_iterator_remove(&it); 1370 btstack_memory_l2cap_channel_free(channel); 1371 } 1372 #endif 1373 #ifdef ENABLE_LE_DATA_CHANNELS 1374 handle = little_endian_read_16(packet, 3); 1375 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1376 while (btstack_linked_list_iterator_has_next(&it)){ 1377 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1378 if (channel->con_handle != handle) continue; 1379 l2cap_emit_channel_closed(channel); 1380 btstack_linked_list_iterator_remove(&it); 1381 btstack_memory_l2cap_channel_free(channel); 1382 } 1383 #endif 1384 break; 1385 1386 // HCI Connection Timeouts 1387 #ifdef ENABLE_CLASSIC 1388 case L2CAP_EVENT_TIMEOUT_CHECK: 1389 handle = little_endian_read_16(packet, 2); 1390 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1391 if (hci_authentication_active_for_handle(handle)) break; 1392 hci_con_used = 0; 1393 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1394 while (btstack_linked_list_iterator_has_next(&it)){ 1395 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1396 if (channel->con_handle != handle) continue; 1397 hci_con_used = 1; 1398 break; 1399 } 1400 if (hci_con_used) break; 1401 if (!hci_can_send_command_packet_now()) break; 1402 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1403 break; 1404 1405 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1406 handle = little_endian_read_16(packet, 3); 1407 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1408 while (btstack_linked_list_iterator_has_next(&it)){ 1409 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1410 if (channel->con_handle != handle) continue; 1411 l2cap_handle_remote_supported_features_received(channel); 1412 break; 1413 } 1414 break; 1415 1416 case GAP_EVENT_SECURITY_LEVEL: 1417 handle = little_endian_read_16(packet, 2); 1418 log_info("l2cap - security level update"); 1419 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1420 while (btstack_linked_list_iterator_has_next(&it)){ 1421 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1422 if (channel->con_handle != handle) continue; 1423 1424 log_info("l2cap - state %u", channel->state); 1425 1426 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1427 gap_security_level_t required_level = channel->required_security_level; 1428 1429 switch (channel->state){ 1430 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1431 if (actual_level >= required_level){ 1432 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1433 // we need to know if ERTM is supported before sending a config response 1434 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1435 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1436 channel->state = L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES; 1437 #else 1438 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1439 l2cap_emit_incoming_connection(channel); 1440 #endif 1441 } else { 1442 channel->reason = 0x0003; // security block 1443 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1444 } 1445 break; 1446 1447 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1448 if (actual_level >= required_level){ 1449 l2cap_ready_to_connect(channel); 1450 } else { 1451 // disconnnect, authentication not good enough 1452 hci_disconnect_security_block(handle); 1453 } 1454 break; 1455 1456 default: 1457 break; 1458 } 1459 } 1460 break; 1461 #endif 1462 1463 default: 1464 break; 1465 } 1466 1467 l2cap_run(); 1468 } 1469 1470 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 1471 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1472 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1473 signaling_responses[signaling_responses_pending].handle = handle; 1474 signaling_responses[signaling_responses_pending].code = code; 1475 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1476 signaling_responses[signaling_responses_pending].cid = cid; 1477 signaling_responses[signaling_responses_pending].data = data; 1478 signaling_responses_pending++; 1479 l2cap_run(); 1480 } 1481 } 1482 1483 #ifdef ENABLE_CLASSIC 1484 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1485 channel->remote_sig_id = identifier; 1486 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1487 l2cap_run(); 1488 } 1489 1490 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1491 1492 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1493 l2cap_service_t *service = l2cap_get_service(psm); 1494 if (!service) { 1495 // 0x0002 PSM not supported 1496 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1497 return; 1498 } 1499 1500 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1501 if (!hci_connection) { 1502 // 1503 log_error("no hci_connection for handle %u", handle); 1504 return; 1505 } 1506 1507 // alloc structure 1508 // log_info("l2cap_handle_connection_request register channel"); 1509 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1510 psm, service->mtu, service->required_security_level); 1511 if (!channel){ 1512 // 0x0004 No resources available 1513 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 1514 return; 1515 } 1516 1517 channel->con_handle = handle; 1518 channel->remote_cid = source_cid; 1519 channel->remote_sig_id = sig_id; 1520 1521 // limit local mtu to max acl packet length - l2cap header 1522 if (channel->local_mtu > l2cap_max_mtu()) { 1523 channel->local_mtu = l2cap_max_mtu(); 1524 } 1525 1526 // set initial state 1527 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1528 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 1529 1530 // add to connections list 1531 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1532 1533 // assert security requirements 1534 gap_request_security_level(handle, channel->required_security_level); 1535 } 1536 1537 void l2cap_accept_connection(uint16_t local_cid){ 1538 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1539 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1540 if (!channel) { 1541 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1542 return; 1543 } 1544 1545 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1546 // configure L2CAP Basic mode 1547 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1548 #endif 1549 1550 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1551 1552 // process 1553 l2cap_run(); 1554 } 1555 1556 1557 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1558 void l2cap_accept_ertm_connection(uint16_t local_cid, int ertm_mandatory, uint8_t max_transmit, 1559 uint16_t retransmission_timeout_ms, uint16_t monitor_timeout_ms, uint8_t num_tx_buffers, uint8_t num_rx_buffers, uint8_t * buffer, uint32_t size){ 1560 1561 UNUSED(max_transmit); 1562 UNUSED(retransmission_timeout_ms); 1563 UNUSED(monitor_timeout_ms); 1564 UNUSED(num_rx_buffers); 1565 UNUSED(num_tx_buffers); 1566 UNUSED(buffer); 1567 UNUSED(size); 1568 1569 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 1570 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1571 if (!channel) { 1572 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1573 return; 1574 } 1575 1576 // configure L2CAP ERTM 1577 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 1578 channel->ertm_mandatory = ertm_mandatory; 1579 1580 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1581 1582 // process 1583 l2cap_run(); 1584 } 1585 #endif 1586 1587 1588 void l2cap_decline_connection(uint16_t local_cid){ 1589 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1590 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1591 if (!channel) { 1592 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1593 return; 1594 } 1595 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1596 channel->reason = 0x04; // no resources available 1597 l2cap_run(); 1598 } 1599 1600 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1601 1602 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1603 1604 uint16_t flags = little_endian_read_16(command, 6); 1605 if (flags & 1) { 1606 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1607 } 1608 1609 // accept the other's configuration options 1610 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1611 uint16_t pos = 8; 1612 while (pos < end_pos){ 1613 uint8_t option_hint = command[pos] >> 7; 1614 uint8_t option_type = command[pos] & 0x7f; 1615 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1616 pos++; 1617 uint8_t length = command[pos++]; 1618 // MTU { type(8): 1, len(8):2, MTU(16) } 1619 if (option_type == 1 && length == 2){ 1620 channel->remote_mtu = little_endian_read_16(command, pos); 1621 if (channel->remote_mtu > l2cap_max_mtu()){ 1622 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 1623 channel->remote_mtu = l2cap_max_mtu(); 1624 } 1625 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1626 } 1627 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1628 if (option_type == 2 && length == 2){ 1629 channel->flush_timeout = little_endian_read_16(command, pos); 1630 } 1631 1632 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1633 // Retransmission and Flow Control Option 1634 if (option_type == 4 && length == 9){ 1635 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 1636 switch(channel->mode){ 1637 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1638 if (channel->ertm_mandatory){ 1639 // ERTM mandatory, but remote doens't offer ERTM -> disconnect 1640 if (mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1641 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1642 } else { 1643 // Both sides selected ERTM 1644 // TODO store and evaluate configuration 1645 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1646 } 1647 } else { 1648 // ERTM is optional 1649 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1650 } 1651 break; 1652 case L2CAP_CHANNEL_MODE_BASIC: 1653 switch (mode){ 1654 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1655 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 1656 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 1657 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1658 } 1659 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 1660 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 1661 break; 1662 default: // case L2CAP_CHANNEL_MODE_BASIC: 1663 // TODO store and evaluate configuration 1664 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1665 break; 1666 } 1667 break; 1668 default: 1669 break; 1670 } 1671 } 1672 #endif 1673 // check for unknown options 1674 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1675 log_info("l2cap cid %u, unknown options", channel->local_cid); 1676 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1677 } 1678 pos += length; 1679 } 1680 } 1681 1682 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 1683 log_info("l2cap_signaling_handle_configure_response"); 1684 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1685 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1686 uint16_t pos = 10; 1687 while (pos < end_pos){ 1688 uint8_t option_hint = command[pos] >> 7; 1689 uint8_t option_type = command[pos] & 0x7f; 1690 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1691 pos++; 1692 uint8_t length = command[pos++]; 1693 1694 // Retransmission and Flow Control Option 1695 if (option_type == 4 && length == 9){ 1696 switch (channel->mode){ 1697 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 1698 if (channel->ertm_mandatory){ 1699 // ?? 1700 } else { 1701 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 1702 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 1703 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1704 } 1705 } 1706 break; 1707 case L2CAP_CHANNEL_MODE_BASIC: 1708 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 1709 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 1710 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1711 } 1712 break; 1713 default: 1714 break; 1715 } 1716 } 1717 1718 // check for unknown options 1719 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1720 log_info("l2cap cid %u, unknown options", channel->local_cid); 1721 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1722 } 1723 1724 pos += length; 1725 } 1726 #endif 1727 } 1728 1729 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1730 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1731 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1732 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1733 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1734 if (channel->state == L2CAP_STATE_OPEN) return 0; 1735 return 1; 1736 } 1737 1738 1739 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1740 1741 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1742 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1743 uint16_t result = 0; 1744 1745 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1746 1747 // handle DISCONNECT REQUESTS seperately 1748 if (code == DISCONNECTION_REQUEST){ 1749 switch (channel->state){ 1750 case L2CAP_STATE_CONFIG: 1751 case L2CAP_STATE_OPEN: 1752 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1753 case L2CAP_STATE_WAIT_DISCONNECT: 1754 l2cap_handle_disconnect_request(channel, identifier); 1755 break; 1756 1757 default: 1758 // ignore in other states 1759 break; 1760 } 1761 return; 1762 } 1763 1764 // @STATEMACHINE(l2cap) 1765 switch (channel->state) { 1766 1767 case L2CAP_STATE_WAIT_CONNECT_RSP: 1768 switch (code){ 1769 case CONNECTION_RESPONSE: 1770 l2cap_stop_rtx(channel); 1771 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1772 switch (result) { 1773 case 0: 1774 // successful connection 1775 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1776 channel->state = L2CAP_STATE_CONFIG; 1777 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1778 break; 1779 case 1: 1780 // connection pending. get some coffee, but start the ERTX 1781 l2cap_start_ertx(channel); 1782 break; 1783 default: 1784 // channel closed 1785 channel->state = L2CAP_STATE_CLOSED; 1786 // map l2cap connection response result to BTstack status enumeration 1787 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1788 1789 // drop link key if security block 1790 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1791 gap_drop_link_key_for_bd_addr(channel->address); 1792 } 1793 1794 // discard channel 1795 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1796 btstack_memory_l2cap_channel_free(channel); 1797 break; 1798 } 1799 break; 1800 1801 default: 1802 //@TODO: implement other signaling packets 1803 break; 1804 } 1805 break; 1806 1807 case L2CAP_STATE_CONFIG: 1808 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1809 switch (code) { 1810 case CONFIGURE_REQUEST: 1811 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1812 l2cap_signaling_handle_configure_request(channel, command); 1813 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1814 // only done if continuation not set 1815 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1816 } 1817 break; 1818 case CONFIGURE_RESPONSE: 1819 l2cap_stop_rtx(channel); 1820 l2cap_signaling_handle_configure_response(channel, result, command); 1821 switch (result){ 1822 case 0: // success 1823 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1824 break; 1825 case 4: // pending 1826 l2cap_start_ertx(channel); 1827 break; 1828 default: 1829 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1830 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 1831 // remote does not offer ertm but it's required 1832 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1833 break; 1834 } 1835 #endif 1836 // retry on negative result 1837 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1838 break; 1839 } 1840 break; 1841 default: 1842 break; 1843 } 1844 if (l2cap_channel_ready_for_open(channel)){ 1845 // for open: 1846 channel->state = L2CAP_STATE_OPEN; 1847 l2cap_emit_channel_opened(channel, 0); 1848 } 1849 break; 1850 1851 case L2CAP_STATE_WAIT_DISCONNECT: 1852 switch (code) { 1853 case DISCONNECTION_RESPONSE: 1854 l2cap_finialize_channel_close(channel); 1855 break; 1856 default: 1857 //@TODO: implement other signaling packets 1858 break; 1859 } 1860 break; 1861 1862 case L2CAP_STATE_CLOSED: 1863 // @TODO handle incoming requests 1864 break; 1865 1866 case L2CAP_STATE_OPEN: 1867 //@TODO: implement other signaling packets, e.g. re-configure 1868 break; 1869 default: 1870 break; 1871 } 1872 // log_info("new state %u", channel->state); 1873 } 1874 1875 1876 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1877 1878 btstack_linked_list_iterator_t it; 1879 1880 // get code, signalind identifier and command len 1881 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1882 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1883 1884 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 1885 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 1886 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 1887 return; 1888 } 1889 1890 // general commands without an assigned channel 1891 switch(code) { 1892 1893 case CONNECTION_REQUEST: { 1894 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1895 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1896 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1897 return; 1898 } 1899 1900 case ECHO_REQUEST: 1901 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 1902 return; 1903 1904 case INFORMATION_REQUEST: { 1905 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1906 l2cap_register_signaling_response(handle, code, sig_id, 0, infoType); 1907 return; 1908 } 1909 1910 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1911 case INFORMATION_RESPONSE: { 1912 hci_connection_t * connection = hci_connection_for_handle(handle); 1913 if (!connection) return; 1914 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1915 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1916 if (result != 0) return; 1917 if (info_type != 0x02) return; 1918 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 1919 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1920 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 1921 // trigger connection request 1922 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1923 while (btstack_linked_list_iterator_has_next(&it)){ 1924 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1925 if (channel->con_handle != handle) continue; 1926 // bail if ERTM was requested but is not supported 1927 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 1928 if (channel->ertm_mandatory){ 1929 // channel closed 1930 channel->state = L2CAP_STATE_CLOSED; 1931 // map l2cap connection response result to BTstack status enumeration 1932 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTD); 1933 // discard channel 1934 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1935 btstack_memory_l2cap_channel_free(channel); 1936 continue; 1937 } else { 1938 // fallback to Basic mode 1939 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1940 } 1941 } 1942 // start connecting 1943 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 1944 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1945 } 1946 // respond to connection request 1947 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 1948 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1949 l2cap_emit_incoming_connection(channel); 1950 } 1951 } 1952 return; 1953 } 1954 #endif 1955 1956 default: 1957 break; 1958 } 1959 1960 1961 // Get potential destination CID 1962 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1963 1964 // Find channel for this sig_id and connection handle 1965 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1966 while (btstack_linked_list_iterator_has_next(&it)){ 1967 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1968 if (channel->con_handle != handle) continue; 1969 if (code & 1) { 1970 // match odd commands (responses) by previous signaling identifier 1971 if (channel->local_sig_id == sig_id) { 1972 l2cap_signaling_handler_channel(channel, command); 1973 break; 1974 } 1975 } else { 1976 // match even commands (requests) by local channel id 1977 if (channel->local_cid == dest_cid) { 1978 l2cap_signaling_handler_channel(channel, command); 1979 break; 1980 } 1981 } 1982 } 1983 } 1984 #endif 1985 1986 #ifdef ENABLE_BLE 1987 1988 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 1989 uint8_t event[6]; 1990 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 1991 event[1] = 4; 1992 little_endian_store_16(event, 2, con_handle); 1993 little_endian_store_16(event, 4, result); 1994 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1995 if (!l2cap_event_packet_handler) return; 1996 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1997 } 1998 1999 // @returns valid 2000 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 2001 hci_connection_t * connection; 2002 uint16_t result; 2003 uint8_t event[10]; 2004 2005 #ifdef ENABLE_LE_DATA_CHANNELS 2006 btstack_linked_list_iterator_t it; 2007 l2cap_channel_t * channel; 2008 uint16_t local_cid; 2009 uint16_t le_psm; 2010 uint16_t new_credits; 2011 uint16_t credits_before; 2012 l2cap_service_t * service; 2013 uint16_t source_cid; 2014 #endif 2015 2016 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2017 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 2018 2019 switch (code){ 2020 2021 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2022 result = little_endian_read_16(command, 4); 2023 l2cap_emit_connection_parameter_update_response(handle, result); 2024 break; 2025 2026 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2027 connection = hci_connection_for_handle(handle); 2028 if (connection){ 2029 if (connection->role != HCI_ROLE_MASTER){ 2030 // reject command without notifying upper layer when not in master role 2031 return 0; 2032 } 2033 int update_parameter = 1; 2034 le_connection_parameter_range_t existing_range; 2035 gap_get_connection_parameter_range(&existing_range); 2036 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 2037 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 2038 uint16_t le_conn_latency = little_endian_read_16(command,12); 2039 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 2040 2041 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 2042 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 2043 2044 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 2045 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 2046 2047 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 2048 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 2049 2050 if (update_parameter){ 2051 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2052 connection->le_conn_interval_min = le_conn_interval_min; 2053 connection->le_conn_interval_max = le_conn_interval_max; 2054 connection->le_conn_latency = le_conn_latency; 2055 connection->le_supervision_timeout = le_supervision_timeout; 2056 } else { 2057 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2058 } 2059 connection->le_con_param_update_identifier = sig_id; 2060 } 2061 2062 if (!l2cap_event_packet_handler) break; 2063 2064 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2065 event[1] = 8; 2066 memcpy(&event[2], &command[4], 8); 2067 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2068 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2069 break; 2070 2071 #ifdef ENABLE_LE_DATA_CHANNELS 2072 2073 case COMMAND_REJECT: 2074 // Find channel for this sig_id and connection handle 2075 channel = NULL; 2076 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2077 while (btstack_linked_list_iterator_has_next(&it)){ 2078 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2079 if (a_channel->con_handle != handle) continue; 2080 if (a_channel->local_sig_id != sig_id) continue; 2081 channel = a_channel; 2082 break; 2083 } 2084 if (!channel) break; 2085 2086 // if received while waiting for le connection response, assume legacy device 2087 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2088 channel->state = L2CAP_STATE_CLOSED; 2089 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2090 l2cap_emit_le_channel_opened(channel, 0x0002); 2091 2092 // discard channel 2093 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2094 btstack_memory_l2cap_channel_free(channel); 2095 break; 2096 } 2097 break; 2098 2099 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2100 2101 // get hci connection, bail if not found (must not happen) 2102 connection = hci_connection_for_handle(handle); 2103 if (!connection) return 0; 2104 2105 // check if service registered 2106 le_psm = little_endian_read_16(command, 4); 2107 service = l2cap_le_get_service(le_psm); 2108 source_cid = little_endian_read_16(command, 6); 2109 2110 if (service){ 2111 if (source_cid < 0x40){ 2112 // 0x0009 Connection refused - Invalid Source CID 2113 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2114 return 1; 2115 } 2116 2117 // go through list of channels for this ACL connection and check if we get a match 2118 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2119 while (btstack_linked_list_iterator_has_next(&it)){ 2120 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2121 if (a_channel->con_handle != handle) continue; 2122 if (a_channel->remote_cid != source_cid) continue; 2123 // 0x000a Connection refused - Source CID already allocated 2124 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2125 return 1; 2126 } 2127 2128 // security: check encryption 2129 if (service->required_security_level >= LEVEL_2){ 2130 if (sm_encryption_key_size(handle) == 0){ 2131 // 0x0008 Connection refused - insufficient encryption 2132 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2133 return 1; 2134 } 2135 // anything less than 16 byte key size is insufficient 2136 if (sm_encryption_key_size(handle) < 16){ 2137 // 0x0007 Connection refused – insufficient encryption key size 2138 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2139 return 1; 2140 } 2141 } 2142 2143 // security: check authencation 2144 if (service->required_security_level >= LEVEL_3){ 2145 if (!sm_authenticated(handle)){ 2146 // 0x0005 Connection refused – insufficient authentication 2147 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2148 return 1; 2149 } 2150 } 2151 2152 // security: check authorization 2153 if (service->required_security_level >= LEVEL_4){ 2154 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2155 // 0x0006 Connection refused – insufficient authorization 2156 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2157 return 1; 2158 } 2159 } 2160 2161 // allocate channel 2162 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 2163 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2164 if (!channel){ 2165 // 0x0004 Connection refused – no resources available 2166 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2167 return 1; 2168 } 2169 2170 channel->con_handle = handle; 2171 channel->remote_cid = source_cid; 2172 channel->remote_sig_id = sig_id; 2173 channel->remote_mtu = little_endian_read_16(command, 8); 2174 channel->remote_mps = little_endian_read_16(command, 10); 2175 channel->credits_outgoing = little_endian_read_16(command, 12); 2176 2177 // set initial state 2178 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2179 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2180 2181 // add to connections list 2182 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2183 2184 // post connection request event 2185 l2cap_emit_le_incoming_connection(channel); 2186 2187 } else { 2188 // Connection refused – LE_PSM not supported 2189 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2190 } 2191 break; 2192 2193 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2194 // Find channel for this sig_id and connection handle 2195 channel = NULL; 2196 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2197 while (btstack_linked_list_iterator_has_next(&it)){ 2198 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2199 if (a_channel->con_handle != handle) continue; 2200 if (a_channel->local_sig_id != sig_id) continue; 2201 channel = a_channel; 2202 break; 2203 } 2204 if (!channel) break; 2205 2206 // cid + 0 2207 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2208 if (result){ 2209 channel->state = L2CAP_STATE_CLOSED; 2210 // map l2cap connection response result to BTstack status enumeration 2211 l2cap_emit_le_channel_opened(channel, result); 2212 2213 // discard channel 2214 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2215 btstack_memory_l2cap_channel_free(channel); 2216 break; 2217 } 2218 2219 // success 2220 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2221 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2222 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2223 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2224 channel->state = L2CAP_STATE_OPEN; 2225 l2cap_emit_le_channel_opened(channel, result); 2226 break; 2227 2228 case LE_FLOW_CONTROL_CREDIT: 2229 // find channel 2230 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2231 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2232 if (!channel) { 2233 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2234 break; 2235 } 2236 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2237 credits_before = channel->credits_outgoing; 2238 channel->credits_outgoing += new_credits; 2239 // check for credit overrun 2240 if (credits_before > channel->credits_outgoing){ 2241 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2242 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2243 break; 2244 } 2245 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2246 break; 2247 2248 case DISCONNECTION_REQUEST: 2249 // find channel 2250 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2251 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2252 if (!channel) { 2253 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2254 break; 2255 } 2256 channel->remote_sig_id = sig_id; 2257 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2258 break; 2259 2260 #endif 2261 2262 case DISCONNECTION_RESPONSE: 2263 break; 2264 2265 default: 2266 // command unknown -> reject command 2267 return 0; 2268 } 2269 return 1; 2270 } 2271 #endif 2272 2273 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 2274 UNUSED(packet_type); 2275 UNUSED(channel); 2276 2277 l2cap_channel_t * l2cap_channel; 2278 UNUSED(l2cap_channel); 2279 2280 // Get Channel ID 2281 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 2282 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 2283 2284 switch (channel_id) { 2285 2286 #ifdef ENABLE_CLASSIC 2287 case L2CAP_CID_SIGNALING: { 2288 uint16_t command_offset = 8; 2289 while (command_offset < size) { 2290 // handle signaling commands 2291 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 2292 2293 // increment command_offset 2294 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2295 } 2296 break; 2297 } 2298 #endif 2299 2300 #ifdef ENABLE_BLE 2301 case L2CAP_CID_SIGNALING_LE: { 2302 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 2303 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 2304 if (!valid){ 2305 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2306 } 2307 break; 2308 } 2309 #endif 2310 2311 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 2312 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 2313 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2314 } 2315 break; 2316 2317 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 2318 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 2319 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2320 } 2321 break; 2322 2323 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 2324 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 2325 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2326 } 2327 break; 2328 2329 default: 2330 #ifdef ENABLE_CLASSIC 2331 // Find channel for this channel_id and connection handle 2332 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 2333 if (l2cap_channel) { 2334 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2335 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2336 2337 // verify FCS 2338 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 2339 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 2340 log_info("Packet FCS 0x%04x, calculated FCS 0x%04x", fcs_packet, fcs_calculated); 2341 if (fcs_calculated != fcs_packet){ 2342 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 2343 // TODO: trigger retransmission or something like that 2344 break; 2345 } 2346 2347 // switch on packet type 2348 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2349 if (control & 1){ 2350 log_info("S-Frame not not implemented yet"); 2351 // S-Frame 2352 break; 2353 } else { 2354 // I-Frame 2355 // get control 2356 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 2357 log_info("Control: 0x%04x, SAR type %u", control, (int) sar); 2358 switch (sar){ 2359 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 2360 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2+2)); 2361 break; 2362 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 2363 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 2364 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 2365 log_info("SAR type %u not implemented yet", (int) sar); 2366 break; 2367 } 2368 } 2369 break; 2370 } 2371 #endif 2372 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2373 } 2374 #endif 2375 #ifdef ENABLE_LE_DATA_CHANNELS 2376 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 2377 if (l2cap_channel) { 2378 // credit counting 2379 if (l2cap_channel->credits_incoming == 0){ 2380 log_error("LE Data Channel packet received but no incoming credits"); 2381 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2382 break; 2383 } 2384 l2cap_channel->credits_incoming--; 2385 2386 // automatic credits 2387 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 2388 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 2389 } 2390 2391 // first fragment 2392 uint16_t pos = 0; 2393 if (!l2cap_channel->receive_sdu_len){ 2394 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2395 l2cap_channel->receive_sdu_pos = 0; 2396 pos += 2; 2397 size -= 2; 2398 } 2399 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 2400 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 2401 // done? 2402 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 2403 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 2404 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 2405 l2cap_channel->receive_sdu_len = 0; 2406 } 2407 } else { 2408 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 2409 } 2410 #endif 2411 break; 2412 } 2413 2414 l2cap_run(); 2415 } 2416 2417 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 2418 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 2419 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 2420 if (index < 0) return; 2421 fixed_channels[index].callback = the_packet_handler; 2422 } 2423 2424 #ifdef ENABLE_CLASSIC 2425 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2426 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 2427 channel->state = L2CAP_STATE_CLOSED; 2428 l2cap_emit_channel_closed(channel); 2429 // discard channel 2430 l2cap_stop_rtx(channel); 2431 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2432 btstack_memory_l2cap_channel_free(channel); 2433 } 2434 2435 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 2436 btstack_linked_list_iterator_t it; 2437 btstack_linked_list_iterator_init(&it, services); 2438 while (btstack_linked_list_iterator_has_next(&it)){ 2439 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 2440 if ( service->psm == psm){ 2441 return service; 2442 }; 2443 } 2444 return NULL; 2445 } 2446 2447 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 2448 return l2cap_get_service_internal(&l2cap_services, psm); 2449 } 2450 2451 2452 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 2453 2454 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 2455 2456 // check for alread registered psm 2457 l2cap_service_t *service = l2cap_get_service(psm); 2458 if (service) { 2459 log_error("l2cap_register_service: PSM %u already registered", psm); 2460 return L2CAP_SERVICE_ALREADY_REGISTERED; 2461 } 2462 2463 // alloc structure 2464 service = btstack_memory_l2cap_service_get(); 2465 if (!service) { 2466 log_error("l2cap_register_service: no memory for l2cap_service_t"); 2467 return BTSTACK_MEMORY_ALLOC_FAILED; 2468 } 2469 2470 // fill in 2471 service->psm = psm; 2472 service->mtu = mtu; 2473 service->packet_handler = service_packet_handler; 2474 service->required_security_level = security_level; 2475 2476 // add to services list 2477 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 2478 2479 // enable page scan 2480 gap_connectable_control(1); 2481 2482 return 0; 2483 } 2484 2485 uint8_t l2cap_unregister_service(uint16_t psm){ 2486 2487 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2488 2489 l2cap_service_t *service = l2cap_get_service(psm); 2490 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2491 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2492 btstack_memory_l2cap_service_free(service); 2493 2494 // disable page scan when no services registered 2495 if (btstack_linked_list_empty(&l2cap_services)) { 2496 gap_connectable_control(0); 2497 } 2498 return 0; 2499 } 2500 #endif 2501 2502 2503 #ifdef ENABLE_LE_DATA_CHANNELS 2504 2505 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2506 if (!channel->waiting_for_can_send_now) return; 2507 if (channel->send_sdu_buffer) return; 2508 channel->waiting_for_can_send_now = 0; 2509 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2510 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2511 } 2512 2513 // 1BH2222 2514 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2515 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", 2516 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2517 uint8_t event[19]; 2518 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2519 event[1] = sizeof(event) - 2; 2520 event[2] = channel->address_type; 2521 reverse_bd_addr(channel->address, &event[3]); 2522 little_endian_store_16(event, 9, channel->con_handle); 2523 little_endian_store_16(event, 11, channel->psm); 2524 little_endian_store_16(event, 13, channel->local_cid); 2525 little_endian_store_16(event, 15, channel->remote_cid); 2526 little_endian_store_16(event, 17, 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 // 11BH22222 2531 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2532 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", 2533 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2534 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2535 uint8_t event[23]; 2536 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2537 event[1] = sizeof(event) - 2; 2538 event[2] = status; 2539 event[3] = channel->address_type; 2540 reverse_bd_addr(channel->address, &event[4]); 2541 little_endian_store_16(event, 10, channel->con_handle); 2542 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2543 little_endian_store_16(event, 13, channel->psm); 2544 little_endian_store_16(event, 15, channel->local_cid); 2545 little_endian_store_16(event, 17, channel->remote_cid); 2546 little_endian_store_16(event, 19, channel->local_mtu); 2547 little_endian_store_16(event, 21, channel->remote_mtu); 2548 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2549 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2550 } 2551 2552 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2553 btstack_linked_list_iterator_t it; 2554 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2555 while (btstack_linked_list_iterator_has_next(&it)){ 2556 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2557 if ( channel->local_cid == local_cid) { 2558 return channel; 2559 } 2560 } 2561 return NULL; 2562 } 2563 2564 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2565 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2566 channel->state = L2CAP_STATE_CLOSED; 2567 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2568 // discard channel 2569 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2570 btstack_memory_l2cap_channel_free(channel); 2571 } 2572 2573 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2574 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2575 } 2576 2577 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2578 2579 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2580 2581 // check for alread registered psm 2582 l2cap_service_t *service = l2cap_le_get_service(psm); 2583 if (service) { 2584 return L2CAP_SERVICE_ALREADY_REGISTERED; 2585 } 2586 2587 // alloc structure 2588 service = btstack_memory_l2cap_service_get(); 2589 if (!service) { 2590 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2591 return BTSTACK_MEMORY_ALLOC_FAILED; 2592 } 2593 2594 // fill in 2595 service->psm = psm; 2596 service->mtu = 0; 2597 service->packet_handler = packet_handler; 2598 service->required_security_level = security_level; 2599 2600 // add to services list 2601 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2602 2603 // done 2604 return 0; 2605 } 2606 2607 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2608 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2609 l2cap_service_t *service = l2cap_le_get_service(psm); 2610 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2611 2612 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2613 btstack_memory_l2cap_service_free(service); 2614 return 0; 2615 } 2616 2617 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2618 // get channel 2619 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2620 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2621 2622 // validate state 2623 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2624 return ERROR_CODE_COMMAND_DISALLOWED; 2625 } 2626 2627 // set state accept connection 2628 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2629 channel->receive_sdu_buffer = receive_sdu_buffer; 2630 channel->local_mtu = mtu; 2631 channel->new_credits_incoming = initial_credits; 2632 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2633 2634 // test 2635 // channel->new_credits_incoming = 1; 2636 2637 // go 2638 l2cap_run(); 2639 return 0; 2640 } 2641 2642 /** 2643 * @brief Deny incoming LE Data Channel connection due to resource constraints 2644 * @param local_cid L2CAP LE Data Channel Identifier 2645 */ 2646 2647 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2648 // get channel 2649 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2650 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2651 2652 // validate state 2653 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2654 return ERROR_CODE_COMMAND_DISALLOWED; 2655 } 2656 2657 // set state decline connection 2658 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2659 channel->reason = 0x04; // no resources available 2660 l2cap_run(); 2661 return 0; 2662 } 2663 2664 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2665 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2666 uint16_t * out_local_cid) { 2667 2668 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2669 2670 2671 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2672 if (!connection) { 2673 log_error("no hci_connection for handle 0x%04x", con_handle); 2674 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2675 } 2676 2677 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2678 if (!channel) { 2679 return BTSTACK_MEMORY_ALLOC_FAILED; 2680 } 2681 log_info("l2cap_le_create_channel %p", channel); 2682 2683 // store local_cid 2684 if (out_local_cid){ 2685 *out_local_cid = channel->local_cid; 2686 } 2687 2688 // provide buffer 2689 channel->con_handle = con_handle; 2690 channel->receive_sdu_buffer = receive_sdu_buffer; 2691 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2692 channel->new_credits_incoming = initial_credits; 2693 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2694 2695 // add to connections list 2696 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2697 2698 // go 2699 l2cap_run(); 2700 return 0; 2701 } 2702 2703 /** 2704 * @brief Provide credtis for LE Data Channel 2705 * @param local_cid L2CAP LE Data Channel Identifier 2706 * @param credits Number additional credits for peer 2707 */ 2708 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2709 2710 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2711 if (!channel) { 2712 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2713 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2714 } 2715 2716 // check state 2717 if (channel->state != L2CAP_STATE_OPEN){ 2718 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2719 } 2720 2721 // assert incoming credits + credits <= 0xffff 2722 uint32_t total_credits = channel->credits_incoming; 2723 total_credits += channel->new_credits_incoming; 2724 total_credits += credits; 2725 if (total_credits > 0xffff){ 2726 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2727 channel->new_credits_incoming, credits); 2728 } 2729 2730 // set credits_granted 2731 channel->new_credits_incoming += credits; 2732 2733 // go 2734 l2cap_run(); 2735 return 0; 2736 } 2737 2738 /** 2739 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2740 * @param local_cid L2CAP LE Data Channel Identifier 2741 */ 2742 int l2cap_le_can_send_now(uint16_t local_cid){ 2743 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2744 if (!channel) { 2745 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2746 return 0; 2747 } 2748 2749 // check state 2750 if (channel->state != L2CAP_STATE_OPEN) return 0; 2751 2752 // check queue 2753 if (channel->send_sdu_buffer) return 0; 2754 2755 // fine, go ahead 2756 return 1; 2757 } 2758 2759 /** 2760 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2761 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2762 * so packet handler should be ready to handle it 2763 * @param local_cid L2CAP LE Data Channel Identifier 2764 */ 2765 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2766 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2767 if (!channel) { 2768 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2769 return 0; 2770 } 2771 channel->waiting_for_can_send_now = 1; 2772 l2cap_le_notify_channel_can_send(channel); 2773 return 0; 2774 } 2775 2776 /** 2777 * @brief Send data via LE Data Channel 2778 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2779 * @param local_cid L2CAP LE Data Channel Identifier 2780 * @param data data to send 2781 * @param size data size 2782 */ 2783 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2784 2785 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2786 if (!channel) { 2787 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2788 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2789 } 2790 2791 if (len > channel->remote_mtu){ 2792 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2793 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2794 } 2795 2796 if (channel->send_sdu_buffer){ 2797 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2798 return BTSTACK_ACL_BUFFERS_FULL; 2799 } 2800 2801 channel->send_sdu_buffer = data; 2802 channel->send_sdu_len = len; 2803 channel->send_sdu_pos = 0; 2804 2805 l2cap_run(); 2806 return 0; 2807 } 2808 2809 /** 2810 * @brief Disconnect from LE Data Channel 2811 * @param local_cid L2CAP LE Data Channel Identifier 2812 */ 2813 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2814 { 2815 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2816 if (!channel) { 2817 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2818 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2819 } 2820 2821 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2822 l2cap_run(); 2823 return 0; 2824 } 2825 2826 #endif 2827