1 /** @file
2 * @brief Internal APIs for Bluetooth connection handling.
3 */
4
5 /*
6 * Copyright (c) 2015 Intel Corporation
7 * Copyright (c) 2021 Nordic Semiconductor ASA
8 *
9 * SPDX-License-Identifier: Apache-2.0
10 */
11
12 #include <zephyr/bluetooth/iso.h>
13
14 typedef enum __packed {
15 BT_CONN_DISCONNECTED, /* Disconnected, conn is completely down */
16 BT_CONN_DISCONNECT_COMPLETE, /* Received disconn comp event, transition to DISCONNECTED */
17 BT_CONN_CONNECTING_SCAN, /* Central passive scanning */
18 BT_CONN_CONNECTING_AUTO, /* Central connection establishment w/ filter */
19 BT_CONN_CONNECTING_ADV, /* Peripheral connectable advertising */
20 BT_CONN_CONNECTING_DIR_ADV, /* Peripheral directed advertising */
21 BT_CONN_CONNECTING, /* Central connection establishment */
22 BT_CONN_CONNECTED, /* Peripheral or Central connected */
23 BT_CONN_DISCONNECTING, /* Peripheral or Central issued disconnection command */
24 } bt_conn_state_t;
25
26 /* bt_conn flags: the flags defined here represent connection parameters */
27 enum {
28 BT_CONN_AUTO_CONNECT,
29 BT_CONN_BR_LEGACY_SECURE, /* 16 digits legacy PIN tracker */
30 BT_CONN_USER, /* user I/O when pairing */
31 BT_CONN_BR_PAIRING, /* BR connection in pairing context */
32 BT_CONN_BR_NOBOND, /* SSP no bond pairing tracker */
33 BT_CONN_BR_PAIRING_INITIATOR, /* local host starts authentication */
34 BT_CONN_CLEANUP, /* Disconnected, pending cleanup */
35 BT_CONN_PERIPHERAL_PARAM_UPDATE, /* If periph param update timer fired */
36 BT_CONN_PERIPHERAL_PARAM_AUTO_UPDATE, /* If periph param auto update on timer fired */
37 BT_CONN_PERIPHERAL_PARAM_SET, /* If periph param were set from app */
38 BT_CONN_PERIPHERAL_PARAM_L2CAP, /* If should force L2CAP for CPUP */
39 BT_CONN_FORCE_PAIR, /* Pairing even with existing keys. */
40 #if defined(CONFIG_BT_GATT_CLIENT)
41 BT_CONN_ATT_MTU_EXCHANGED, /* If ATT MTU has been exchanged. */
42 #endif /* CONFIG_BT_GATT_CLIENT */
43
44 BT_CONN_AUTO_FEATURE_EXCH, /* Auto-initiated LE Feat done */
45 BT_CONN_AUTO_VERSION_INFO, /* Auto-initiated LE version done */
46
47 BT_CONN_CTE_RX_ENABLED, /* CTE receive and sampling is enabled */
48 BT_CONN_CTE_RX_PARAMS_SET, /* CTE parameters are set */
49 BT_CONN_CTE_TX_PARAMS_SET, /* CTE transmission parameters are set */
50 BT_CONN_CTE_REQ_ENABLED, /* CTE request procedure is enabled */
51 BT_CONN_CTE_RSP_ENABLED, /* CTE response procedure is enabled */
52
53 /* Total number of flags - must be at the end of the enum */
54 BT_CONN_NUM_FLAGS,
55 };
56
57 struct bt_conn_le {
58 bt_addr_le_t dst;
59
60 bt_addr_le_t init_addr;
61 bt_addr_le_t resp_addr;
62
63 uint16_t interval;
64 uint16_t interval_min;
65 uint16_t interval_max;
66
67 uint16_t latency;
68 uint16_t timeout;
69 uint16_t pending_latency;
70 uint16_t pending_timeout;
71
72 #if defined(CONFIG_BT_GAP_AUTO_UPDATE_CONN_PARAMS)
73 uint8_t conn_param_retry_countdown;
74 #endif
75
76 uint8_t features[8];
77
78 struct bt_keys *keys;
79
80 #if defined(CONFIG_BT_USER_PHY_UPDATE)
81 struct bt_conn_le_phy_info phy;
82 #endif
83
84 #if defined(CONFIG_BT_USER_DATA_LEN_UPDATE)
85 struct bt_conn_le_data_len_info data_len;
86 #endif
87 };
88
89 #if defined(CONFIG_BT_BREDR)
90 /* For now reserve space for 2 pages of LMP remote features */
91 #define LMP_MAX_PAGES 2
92
93 struct bt_conn_br {
94 bt_addr_t dst;
95 uint8_t remote_io_capa;
96 uint8_t remote_auth;
97 uint8_t pairing_method;
98 /* remote LMP features pages per 8 bytes each */
99 uint8_t features[LMP_MAX_PAGES][8];
100
101 struct bt_keys_link_key *link_key;
102 };
103
104 struct bt_conn_sco {
105 /* Reference to ACL Connection */
106 struct bt_conn *acl;
107 uint16_t pkt_type;
108 };
109 #endif
110
111 struct bt_conn_iso {
112 /* Reference to ACL Connection */
113 struct bt_conn *acl;
114
115 /* Reference to the struct bt_iso_chan */
116 struct bt_iso_chan *chan;
117
118 union {
119 /* CIG ID */
120 uint8_t cig_id;
121 /* BIG handle */
122 uint8_t big_handle;
123 };
124
125 union {
126 /* CIS ID within the CIG */
127 uint8_t cis_id;
128
129 /* BIS ID within the BIG*/
130 uint8_t bis_id;
131 };
132
133 /** Stored information about the ISO stream */
134 struct bt_iso_info info;
135 };
136
137 typedef void (*bt_conn_tx_cb_t)(struct bt_conn *conn, void *user_data, int err);
138
139 struct bt_conn_tx {
140 sys_snode_t node;
141
142 bt_conn_tx_cb_t cb;
143 void *user_data;
144
145 /* Number of pending packets without a callback after this one */
146 uint32_t pending_no_cb;
147 };
148
149 struct bt_conn {
150 uint16_t handle;
151 enum bt_conn_type type;
152 uint8_t role;
153
154 ATOMIC_DEFINE(flags, BT_CONN_NUM_FLAGS);
155
156 /* Which local identity address this connection uses */
157 uint8_t id;
158
159 #if defined(CONFIG_BT_SMP) || defined(CONFIG_BT_BREDR)
160 bt_security_t sec_level;
161 bt_security_t required_sec_level;
162 uint8_t encrypt;
163 #endif /* CONFIG_BT_SMP || CONFIG_BT_BREDR */
164
165 #if defined(CONFIG_BT_DF_CONNECTION_CTE_RX)
166 /**
167 * @brief Bitfield with allowed CTE types.
168 *
169 * Allowed values are defined by @ref bt_df_cte_type, except BT_DF_CTE_TYPE_NONE.
170 */
171 uint8_t cte_types;
172 #endif /* CONFIG_BT_DF_CONNECTION_CTE_RX */
173
174 /* Connection error or reason for disconnect */
175 uint8_t err;
176
177 bt_conn_state_t state;
178 uint16_t rx_len;
179 struct net_buf *rx;
180
181 /* Sent but not acknowledged TX packets with a callback */
182 sys_slist_t tx_pending;
183 /* Sent but not acknowledged TX packets without a callback before
184 * the next packet (if any) in tx_pending.
185 */
186 uint32_t pending_no_cb;
187
188 /* Completed TX for which we need to call the callback */
189 sys_slist_t tx_complete;
190 #if defined(CONFIG_BT_CONN_TX)
191 struct k_work tx_complete_work;
192 #endif /* CONFIG_BT_CONN_TX */
193
194 /* Queue for outgoing ACL data */
195 struct k_fifo tx_queue;
196
197 /* Active L2CAP channels */
198 sys_slist_t channels;
199
200 /* Delayed work deferred tasks:
201 * - Peripheral delayed connection update.
202 * - Initiator connect create cancel.
203 * - Connection cleanup.
204 */
205 struct k_work_delayable deferred_work;
206
207 union {
208 struct bt_conn_le le;
209 #if defined(CONFIG_BT_BREDR)
210 struct bt_conn_br br;
211 struct bt_conn_sco sco;
212 #endif
213 #if defined(CONFIG_BT_ISO)
214 struct bt_conn_iso iso;
215 #endif
216 };
217
218 #if defined(CONFIG_BT_REMOTE_VERSION)
219 struct bt_conn_rv {
220 uint8_t version;
221 uint16_t manufacturer;
222 uint16_t subversion;
223 } rv;
224 #endif
225 /* Must be at the end so that everything else in the structure can be
226 * memset to zero without affecting the ref.
227 */
228 atomic_t ref;
229 };
230
231 void bt_conn_reset_rx_state(struct bt_conn *conn);
232
233 /* Process incoming data for a connection */
234 void bt_conn_recv(struct bt_conn *conn, struct net_buf *buf, uint8_t flags);
235
236 /* Send data over a connection
237 *
238 * Buffer ownership is transferred to stack in case of success.
239 *
240 * Calling this from RX thread is assumed to never fail so the return can be
241 * ignored.
242 */
243 int bt_conn_send_cb(struct bt_conn *conn, struct net_buf *buf,
244 bt_conn_tx_cb_t cb, void *user_data);
245
246 /* Thin wrapper over `bt_conn_send_cb`
247 *
248 * Used to set the TS_Flag bit in `buf`'s metadata.
249 *
250 * Return values & buf ownership same as parent.
251 */
252 int bt_conn_send_iso_cb(struct bt_conn *conn, struct net_buf *buf,
253 bt_conn_tx_cb_t cb, bool has_ts);
254
bt_conn_send(struct bt_conn * conn,struct net_buf * buf)255 static inline int bt_conn_send(struct bt_conn *conn, struct net_buf *buf)
256 {
257 return bt_conn_send_cb(conn, buf, NULL, NULL);
258 }
259
260 /* Check if a connection object with the peer already exists */
261 bool bt_conn_exists_le(uint8_t id, const bt_addr_le_t *peer);
262
263 /* Add a new LE connection */
264 struct bt_conn *bt_conn_add_le(uint8_t id, const bt_addr_le_t *peer);
265
266 /** Connection parameters for ISO connections */
267 struct bt_iso_create_param {
268 uint8_t id;
269 uint8_t num_conns;
270 struct bt_conn **conns;
271 struct bt_iso_chan **chans;
272 };
273
274 int bt_conn_iso_init(void);
275
276 /* Cleanup ISO references */
277 void bt_iso_cleanup_acl(struct bt_conn *iso_conn);
278
279 /* Add a new BR/EDR connection */
280 struct bt_conn *bt_conn_add_br(const bt_addr_t *peer);
281
282 /* Add a new SCO connection */
283 struct bt_conn *bt_conn_add_sco(const bt_addr_t *peer, int link_type);
284
285 /* Cleanup SCO references */
286 void bt_sco_cleanup(struct bt_conn *sco_conn);
287
288 /* Look up an existing sco connection by BT address */
289 struct bt_conn *bt_conn_lookup_addr_sco(const bt_addr_t *peer);
290
291 /* Look up an existing connection by BT address */
292 struct bt_conn *bt_conn_lookup_addr_br(const bt_addr_t *peer);
293
294 void bt_conn_disconnect_all(uint8_t id);
295
296 /* Allocate new connection object */
297 struct bt_conn *bt_conn_new(struct bt_conn *conns, size_t size);
298
299 /* Look up an existing connection */
300 struct bt_conn *bt_conn_lookup_handle(uint16_t handle, enum bt_conn_type type);
301
bt_conn_is_handle_valid(struct bt_conn * conn)302 static inline bool bt_conn_is_handle_valid(struct bt_conn *conn)
303 {
304 switch (conn->state) {
305 case BT_CONN_CONNECTED:
306 case BT_CONN_DISCONNECTING:
307 case BT_CONN_DISCONNECT_COMPLETE:
308 return true;
309 case BT_CONN_CONNECTING:
310 /* ISO connection handle assigned at connect state */
311 if (IS_ENABLED(CONFIG_BT_ISO) &&
312 conn->type == BT_CONN_TYPE_ISO) {
313 return true;
314 }
315 __fallthrough;
316 default:
317 return false;
318 }
319 }
320
321 /* Check if the connection is with the given peer. */
322 bool bt_conn_is_peer_addr_le(const struct bt_conn *conn, uint8_t id,
323 const bt_addr_le_t *peer);
324
325 /* Helpers for identifying & looking up connections based on the the index to
326 * the connection list. This is useful for O(1) lookups, but can't be used
327 * e.g. as the handle since that's assigned to us by the controller.
328 */
329 #define BT_CONN_INDEX_INVALID 0xff
330 struct bt_conn *bt_conn_lookup_index(uint8_t index);
331
332 /* Look up a connection state. For BT_ADDR_LE_ANY, returns the first connection
333 * with the specific state
334 */
335 struct bt_conn *bt_conn_lookup_state_le(uint8_t id, const bt_addr_le_t *peer,
336 const bt_conn_state_t state);
337
338 /* Set connection object in certain state and perform action related to state */
339 void bt_conn_set_state(struct bt_conn *conn, bt_conn_state_t state);
340
341 void bt_conn_connected(struct bt_conn *conn);
342
343 int bt_conn_le_conn_update(struct bt_conn *conn,
344 const struct bt_le_conn_param *param);
345
346 void notify_remote_info(struct bt_conn *conn);
347
348 void notify_le_param_updated(struct bt_conn *conn);
349
350 void notify_le_data_len_updated(struct bt_conn *conn);
351
352 void notify_le_phy_updated(struct bt_conn *conn);
353
354 bool le_param_req(struct bt_conn *conn, struct bt_le_conn_param *param);
355
356 #if defined(CONFIG_BT_SMP)
357 /* If role specific LTK is present */
358 bool bt_conn_ltk_present(const struct bt_conn *conn);
359
360 /* rand and ediv should be in BT order */
361 int bt_conn_le_start_encryption(struct bt_conn *conn, uint8_t rand[8],
362 uint8_t ediv[2], const uint8_t *ltk, size_t len);
363
364 /* Notify higher layers that RPA was resolved */
365 void bt_conn_identity_resolved(struct bt_conn *conn);
366 #endif /* CONFIG_BT_SMP */
367
368 #if defined(CONFIG_BT_SMP) || defined(CONFIG_BT_BREDR)
369 /* Notify higher layers that connection security changed */
370 void bt_conn_security_changed(struct bt_conn *conn, uint8_t hci_err,
371 enum bt_security_err err);
372 #endif /* CONFIG_BT_SMP || CONFIG_BT_BREDR */
373
374 /* Prepare a PDU to be sent over a connection */
375 #if defined(CONFIG_NET_BUF_LOG)
376 struct net_buf *bt_conn_create_pdu_timeout_debug(struct net_buf_pool *pool,
377 size_t reserve,
378 k_timeout_t timeout,
379 const char *func, int line);
380 #define bt_conn_create_pdu_timeout(_pool, _reserve, _timeout) \
381 bt_conn_create_pdu_timeout_debug(_pool, _reserve, _timeout, \
382 __func__, __LINE__)
383
384 #define bt_conn_create_pdu(_pool, _reserve) \
385 bt_conn_create_pdu_timeout_debug(_pool, _reserve, K_FOREVER, \
386 __func__, __line__)
387 #else
388 struct net_buf *bt_conn_create_pdu_timeout(struct net_buf_pool *pool,
389 size_t reserve, k_timeout_t timeout);
390
391 #define bt_conn_create_pdu(_pool, _reserve) \
392 bt_conn_create_pdu_timeout(_pool, _reserve, K_FOREVER)
393 #endif
394
395 /* Prepare a PDU to be sent over a connection */
396 #if defined(CONFIG_NET_BUF_LOG)
397 struct net_buf *bt_conn_create_frag_timeout_debug(size_t reserve,
398 k_timeout_t timeout,
399 const char *func, int line);
400
401 #define bt_conn_create_frag_timeout(_reserve, _timeout) \
402 bt_conn_create_frag_timeout_debug(_reserve, _timeout, \
403 __func__, __LINE__)
404
405 #define bt_conn_create_frag(_reserve) \
406 bt_conn_create_frag_timeout_debug(_reserve, K_FOREVER, \
407 __func__, __LINE__)
408 #else
409 struct net_buf *bt_conn_create_frag_timeout(size_t reserve,
410 k_timeout_t timeout);
411
412 #define bt_conn_create_frag(_reserve) \
413 bt_conn_create_frag_timeout(_reserve, K_FOREVER)
414 #endif
415
416 /* Initialize connection management */
417 int bt_conn_init(void);
418
419 /* Reset states of connections and set state to BT_CONN_DISCONNECTED. */
420 void bt_conn_cleanup_all(void);
421
422 /* Selects based on connection type right semaphore for ACL packets */
423 struct k_sem *bt_conn_get_pkts(struct bt_conn *conn);
424
425 /* k_poll related helpers for the TX thread */
426 int bt_conn_prepare_events(struct k_poll_event events[]);
427 void bt_conn_process_tx(struct bt_conn *conn);
428
