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1 /******************************************************************************
2  *
3  *  Copyright (C) 2009-2012 Broadcom Corporation
4  *
5  *  Licensed under the Apache License, Version 2.0 (the "License");
6  *  you may not use this file except in compliance with the License.
7  *  You may obtain a copy of the License at:
8  *
9  *  http://www.apache.org/licenses/LICENSE-2.0
10  *
11  *  Unless required by applicable law or agreed to in writing, software
12  *  distributed under the License is distributed on an "AS IS" BASIS,
13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  *  See the License for the specific language governing permissions and
15  *  limitations under the License.
16  *
17  ******************************************************************************/
18 
19 /******************************************************************************
20  *
21  *  this file contains GATT database building and query functions
22  *
23  ******************************************************************************/
24 
25 #include "bt_target.h"
26 
27 #include "bt_trace.h"
28 #include "bt_utils.h"
29 
30 #include <stdio.h>
31 #include <string.h>
32 #include "btm_int.h"
33 #include "gatt_int.h"
34 #include "l2c_api.h"
35 #include "osi/include/osi.h"
36 
37 /*******************************************************************************
38  *             L O C A L    F U N C T I O N     P R O T O T Y P E S            *
39  ******************************************************************************/
40 static tGATT_ATTR& allocate_attr_in_db(tGATT_SVC_DB& db, const tBT_UUID& uuid,
41                                        tGATT_PERM perm);
42 static tGATT_STATUS gatts_send_app_read_request(
43     tGATT_TCB* p_tcb, uint8_t op_code, uint16_t handle, uint16_t offset,
44     uint32_t trans_id, bt_gatt_db_attribute_type_t gatt_type);
45 
46 /**
47  * Initialize a memory space to be a service database.
48  */
gatts_init_service_db(tGATT_SVC_DB & db,tBT_UUID * p_service,bool is_pri,uint16_t s_hdl,uint16_t num_handle)49 void gatts_init_service_db(tGATT_SVC_DB& db, tBT_UUID* p_service, bool is_pri,
50                            uint16_t s_hdl, uint16_t num_handle) {
51   db.attr_list.reserve(num_handle);
52 
53   GATT_TRACE_DEBUG("%s: s_hdl= %d num_handle= %d", __func__, s_hdl, num_handle);
54 
55   /* update service database information */
56   db.next_handle = s_hdl;
57   db.end_handle = s_hdl + num_handle;
58 
59   /* add service declration record */
60   tBT_UUID uuid = {LEN_UUID_16, {0}};
61   uuid.uu.uuid16 = is_pri ? GATT_UUID_PRI_SERVICE : GATT_UUID_SEC_SERVICE;
62   tGATT_ATTR& attr = allocate_attr_in_db(db, uuid, GATT_PERM_READ);
63   attr.p_value.reset((tGATT_ATTR_VALUE*)(new tBT_UUID));
64   memcpy(&attr.p_value->uuid, p_service, sizeof(tBT_UUID));
65 }
66 
gatts_get_service_uuid(tGATT_SVC_DB * p_db)67 tBT_UUID* gatts_get_service_uuid(tGATT_SVC_DB* p_db) {
68   if (!p_db || p_db->attr_list.empty()) {
69     GATT_TRACE_ERROR("service DB empty");
70     return NULL;
71   } else {
72     return &p_db->attr_list[0].p_value->uuid;
73   }
74 }
75 
76 /** Check attribute readability. Returns status of operation. */
gatts_check_attr_readability(const tGATT_ATTR & attr,UNUSED_ATTR uint16_t offset,bool read_long,tGATT_SEC_FLAG sec_flag,uint8_t key_size)77 static tGATT_STATUS gatts_check_attr_readability(const tGATT_ATTR& attr,
78                                                  UNUSED_ATTR uint16_t offset,
79                                                  bool read_long,
80                                                  tGATT_SEC_FLAG sec_flag,
81                                                  uint8_t key_size) {
82   uint16_t min_key_size;
83   tGATT_PERM perm = attr.permission;
84 
85   min_key_size = (((perm & GATT_ENCRYPT_KEY_SIZE_MASK) >> 12));
86   if (min_key_size != 0) {
87     min_key_size += 6;
88   }
89 
90   if (!(perm & GATT_READ_ALLOWED)) {
91     GATT_TRACE_ERROR("%s: GATT_READ_NOT_PERMIT", __func__);
92     return GATT_READ_NOT_PERMIT;
93   }
94 
95   if ((perm & GATT_READ_AUTH_REQUIRED) &&
96       !(sec_flag & GATT_SEC_FLAG_LKEY_UNAUTHED) &&
97       !(sec_flag & BTM_SEC_FLAG_ENCRYPTED)) {
98     GATT_TRACE_ERROR("%s: GATT_INSUF_AUTHENTICATION", __func__);
99     return GATT_INSUF_AUTHENTICATION;
100   }
101 
102   if ((perm & GATT_READ_MITM_REQUIRED) &&
103       !(sec_flag & GATT_SEC_FLAG_LKEY_AUTHED)) {
104     GATT_TRACE_ERROR("%s: GATT_INSUF_AUTHENTICATION: MITM Required", __func__);
105     return GATT_INSUF_AUTHENTICATION;
106   }
107 
108   if ((perm & GATT_READ_ENCRYPTED_REQUIRED) &&
109       !(sec_flag & GATT_SEC_FLAG_ENCRYPTED)) {
110     GATT_TRACE_ERROR("%s: GATT_INSUF_ENCRYPTION", __func__);
111     return GATT_INSUF_ENCRYPTION;
112   }
113 
114   if ((perm & GATT_READ_ENCRYPTED_REQUIRED) &&
115       (sec_flag & GATT_SEC_FLAG_ENCRYPTED) && (key_size < min_key_size)) {
116     GATT_TRACE_ERROR("%s: GATT_INSUF_KEY_SIZE", __func__);
117     return GATT_INSUF_KEY_SIZE;
118   }
119 
120   if (read_long && attr.uuid.len == LEN_UUID_16) {
121     switch (attr.uuid.uu.uuid16) {
122       case GATT_UUID_PRI_SERVICE:
123       case GATT_UUID_SEC_SERVICE:
124       case GATT_UUID_CHAR_DECLARE:
125       case GATT_UUID_INCLUDE_SERVICE:
126       case GATT_UUID_CHAR_EXT_PROP:
127       case GATT_UUID_CHAR_CLIENT_CONFIG:
128       case GATT_UUID_CHAR_SRVR_CONFIG:
129       case GATT_UUID_CHAR_PRESENT_FORMAT:
130         GATT_TRACE_ERROR("%s: GATT_NOT_LONG", __func__);
131         return GATT_NOT_LONG;
132 
133       default:
134         break;
135     }
136   }
137 
138   return GATT_SUCCESS;
139 }
140 
141 /*******************************************************************************
142  *
143  * Function         read_attr_value
144  *
145  * Description      Utility function to read an attribute value.
146  *
147  * Parameter        p_attr: pointer to the attribute to read.
148  *                  offset: read offset.
149  *                  p_value: output parameter to carry out the attribute value.
150  *                  p_len: output parameter to carry out the attribute length.
151  *                  read_long: this is a read blob request.
152  *                  mtu: MTU
153  *                  sec_flag: current link security status.
154  *                  key_size: encryption key size.
155  *
156  * Returns          status of operation.
157  *
158  ******************************************************************************/
read_attr_value(tGATT_ATTR & attr16,uint16_t offset,uint8_t ** p_data,bool read_long,uint16_t mtu,uint16_t * p_len,tGATT_SEC_FLAG sec_flag,uint8_t key_size)159 static tGATT_STATUS read_attr_value(tGATT_ATTR& attr16, uint16_t offset,
160                                     uint8_t** p_data, bool read_long,
161                                     uint16_t mtu, uint16_t* p_len,
162                                     tGATT_SEC_FLAG sec_flag, uint8_t key_size) {
163   uint16_t len = 0, uuid16 = 0;
164   uint8_t* p = *p_data;
165 
166   GATT_TRACE_DEBUG(
167       "%s: uuid=0x%04x perm=0x%02x sec_flag=0x%x offset=%d read_long=%d",
168       __func__, attr16.uuid, attr16.permission, sec_flag, offset, read_long);
169 
170   tGATT_STATUS status = gatts_check_attr_readability(attr16, offset, read_long,
171                                                      sec_flag, key_size);
172 
173   if (status != GATT_SUCCESS) return status;
174 
175   if (attr16.uuid.len == LEN_UUID_16) uuid16 = attr16.uuid.uu.uuid16;
176 
177   status = GATT_NO_RESOURCES;
178 
179   if (uuid16 == GATT_UUID_PRI_SERVICE || uuid16 == GATT_UUID_SEC_SERVICE) {
180     len = attr16.p_value->uuid.len;
181     if (mtu >= attr16.p_value->uuid.len) {
182       gatt_build_uuid_to_stream(&p, attr16.p_value->uuid);
183       status = GATT_SUCCESS;
184     }
185   } else if (uuid16 == GATT_UUID_CHAR_DECLARE) {
186     tGATT_ATTR* val_attr = &attr16 + 1;
187     len = (val_attr->uuid.len == LEN_UUID_16) ? 5 : 19;
188 
189     if (mtu >= len) {
190       UINT8_TO_STREAM(p, attr16.p_value->char_decl.property);
191       UINT16_TO_STREAM(p, attr16.p_value->char_decl.char_val_handle);
192 
193       if (val_attr->uuid.len == LEN_UUID_16) {
194         UINT16_TO_STREAM(p, val_attr->uuid.uu.uuid16);
195       }
196       /* convert a 32bits UUID to 128 bits */
197       else if (val_attr->uuid.len == LEN_UUID_32) {
198         gatt_convert_uuid32_to_uuid128(p, val_attr->uuid.uu.uuid32);
199         p += LEN_UUID_128;
200       } else {
201         ARRAY_TO_STREAM(p, val_attr->uuid.uu.uuid128, LEN_UUID_128);
202       }
203       status = GATT_SUCCESS;
204     }
205 
206   } else if (uuid16 == GATT_UUID_INCLUDE_SERVICE) {
207     if (attr16.p_value->incl_handle.service_type.len == LEN_UUID_16)
208       len = 6;
209     else
210       len = 4;
211 
212     if (mtu >= len) {
213       UINT16_TO_STREAM(p, attr16.p_value->incl_handle.s_handle);
214       UINT16_TO_STREAM(p, attr16.p_value->incl_handle.e_handle);
215 
216       if (attr16.p_value->incl_handle.service_type.len == LEN_UUID_16) {
217         UINT16_TO_STREAM(p, attr16.p_value->incl_handle.service_type.uu.uuid16);
218       }
219       status = GATT_SUCCESS;
220     }
221   } else /* characteristic description or characteristic value */
222   {
223     status = GATT_PENDING;
224   }
225 
226   *p_len = len;
227   *p_data = p;
228   return status;
229 }
230 
231 /*******************************************************************************
232  *
233  * Function         gatts_db_read_attr_value_by_type
234  *
235  * Description      Query attribute value by attribute type.
236  *
237  * Parameter        p_db: pointer to the attribute database.
238  *                  p_rsp: Read By type response data.
239  *                  s_handle: starting handle of the range we are looking for.
240  *                  e_handle: ending handle of the range we are looking for.
241  *                  type: Attribute type.
242  *                  mtu: MTU.
243  *                  sec_flag: current link security status.
244  *                  key_size: encryption key size.
245  *
246  * Returns          Status of the operation.
247  *
248  ******************************************************************************/
gatts_db_read_attr_value_by_type(tGATT_TCB * p_tcb,tGATT_SVC_DB * p_db,uint8_t op_code,BT_HDR * p_rsp,uint16_t s_handle,uint16_t e_handle,tBT_UUID type,uint16_t * p_len,tGATT_SEC_FLAG sec_flag,uint8_t key_size,uint32_t trans_id,uint16_t * p_cur_handle)249 tGATT_STATUS gatts_db_read_attr_value_by_type(
250     tGATT_TCB* p_tcb, tGATT_SVC_DB* p_db, uint8_t op_code, BT_HDR* p_rsp,
251     uint16_t s_handle, uint16_t e_handle, tBT_UUID type, uint16_t* p_len,
252     tGATT_SEC_FLAG sec_flag, uint8_t key_size, uint32_t trans_id,
253     uint16_t* p_cur_handle) {
254   tGATT_STATUS status = GATT_NOT_FOUND;
255   uint16_t len = 0;
256   uint8_t* p = (uint8_t*)(p_rsp + 1) + p_rsp->len + L2CAP_MIN_OFFSET;
257 
258   if (p_db) {
259     for (tGATT_ATTR& attr : p_db->attr_list) {
260       tBT_UUID attr_uuid = attr.uuid;
261 
262       if (attr.handle >= s_handle && gatt_uuid_compare(type, attr_uuid)) {
263         if (*p_len <= 2) {
264           status = GATT_NO_RESOURCES;
265           break;
266         }
267 
268         UINT16_TO_STREAM(p, attr.handle);
269 
270         status = read_attr_value(attr, 0, &p, false, (uint16_t)(*p_len - 2),
271                                  &len, sec_flag, key_size);
272 
273         if (status == GATT_PENDING) {
274           status = gatts_send_app_read_request(p_tcb, op_code, attr.handle, 0,
275                                                trans_id, attr.gatt_type);
276 
277           /* one callback at a time */
278           break;
279         } else if (status == GATT_SUCCESS) {
280           if (p_rsp->offset == 0) p_rsp->offset = len + 2;
281 
282           if (p_rsp->offset == len + 2) {
283             p_rsp->len += (len + 2);
284             *p_len -= (len + 2);
285           } else {
286             GATT_TRACE_ERROR("format mismatch");
287             status = GATT_NO_RESOURCES;
288             break;
289           }
290         } else {
291           *p_cur_handle = attr.handle;
292           break;
293         }
294       }
295     }
296   }
297 
298 #if (BLE_DELAY_REQUEST_ENC == TRUE)
299   uint8_t flag = 0;
300   if (BTM_GetSecurityFlags(p_tcb->peer_bda, &flag)) {
301     if ((p_tcb->att_lcid == L2CAP_ATT_CID) && (status == GATT_PENDING) &&
302         (type.uu.uuid16 == GATT_UUID_GAP_DEVICE_NAME)) {
303       if ((flag & (BTM_SEC_LINK_KEY_KNOWN | BTM_SEC_FLAG_ENCRYPTED)) ==
304           BTM_SEC_LINK_KEY_KNOWN) {
305         tACL_CONN* p = btm_bda_to_acl(p_tcb->peer_bda, BT_TRANSPORT_LE);
306         if ((p != NULL) && (p->link_role == BTM_ROLE_MASTER))
307           btm_ble_set_encryption(p_tcb->peer_bda, BTM_BLE_SEC_ENCRYPT,
308                                  p->link_role);
309       }
310     }
311   }
312 #endif
313   return status;
314 }
315 
316 /**
317  * This function adds an included service into a database.
318  *
319  * Parameter        db: database pointer.
320  *                  inc_srvc_type: included service type.
321  *
322  * Returns          Status of the operation.
323  *
324  */
gatts_add_included_service(tGATT_SVC_DB & db,uint16_t s_handle,uint16_t e_handle,tBT_UUID service)325 uint16_t gatts_add_included_service(tGATT_SVC_DB& db, uint16_t s_handle,
326                                     uint16_t e_handle, tBT_UUID service) {
327   tBT_UUID uuid = {LEN_UUID_16, {GATT_UUID_INCLUDE_SERVICE}};
328 
329   GATT_TRACE_DEBUG("%s: s_hdl = 0x%04x e_hdl = 0x%04x uuid = 0x%04x", __func__,
330                    s_handle, e_handle, service.uu.uuid16);
331 
332   if (service.len == 0 || s_handle == 0 || e_handle == 0) {
333     GATT_TRACE_ERROR("%s: Illegal Params.", __func__);
334     return 0;
335   }
336 
337   tGATT_ATTR& attr = allocate_attr_in_db(db, uuid, GATT_PERM_READ);
338 
339   attr.p_value.reset((tGATT_ATTR_VALUE*)(new tGATT_INCL_SRVC));
340   attr.p_value->incl_handle.s_handle = s_handle;
341   attr.p_value->incl_handle.e_handle = e_handle;
342   memcpy(&attr.p_value->incl_handle.service_type, &service, sizeof(tBT_UUID));
343 
344   return attr.handle;
345 }
346 
347 /*******************************************************************************
348  *
349  * Function         gatts_add_characteristic
350  *
351  * Description      This function add a characteristics and its descriptor into
352  *                  a servce identified by the service database pointer.
353  *
354  * Parameter        db: database.
355  *                  perm: permission (authentication and key size requirements)
356  *                  property: property of the characteristic.
357  *                  p_char: characteristic value information.
358  *
359  * Returns          Status of te operation.
360  *
361  ******************************************************************************/
gatts_add_characteristic(tGATT_SVC_DB & db,tGATT_PERM perm,tGATT_CHAR_PROP property,tBT_UUID & char_uuid)362 uint16_t gatts_add_characteristic(tGATT_SVC_DB& db, tGATT_PERM perm,
363                                   tGATT_CHAR_PROP property,
364                                   tBT_UUID& char_uuid) {
365   tBT_UUID uuid = {LEN_UUID_16, {GATT_UUID_CHAR_DECLARE}};
366 
367   GATT_TRACE_DEBUG("%s: perm=0x%0x property=0x%0x", __func__, perm, property);
368 
369   tGATT_ATTR& char_decl = allocate_attr_in_db(db, uuid, GATT_PERM_READ);
370   tGATT_ATTR& char_val = allocate_attr_in_db(db, char_uuid, perm);
371 
372   char_decl.p_value.reset((tGATT_ATTR_VALUE*)(new tGATT_CHAR_DECL));
373   char_decl.p_value->char_decl.property = property;
374   char_decl.p_value->char_decl.char_val_handle = char_val.handle;
375   char_val.gatt_type = BTGATT_DB_CHARACTERISTIC;
376   return char_val.handle;
377 }
378 
379 /*******************************************************************************
380  *
381  * Function         gatt_convertchar_descr_type
382  *
383  * Description      Convert a char descript UUID into descriptor type.
384  *
385  * Returns          descriptor type.
386  *
387  ******************************************************************************/
gatt_convertchar_descr_type(tBT_UUID * p_descr_uuid)388 uint8_t gatt_convertchar_descr_type(tBT_UUID* p_descr_uuid) {
389   tBT_UUID std_descr = {LEN_UUID_16, {GATT_UUID_CHAR_EXT_PROP}};
390 
391   if (gatt_uuid_compare(std_descr, *p_descr_uuid))
392     return GATT_DESCR_EXT_DSCPTOR;
393 
394   std_descr.uu.uuid16++;
395   if (gatt_uuid_compare(std_descr, *p_descr_uuid))
396     return GATT_DESCR_USER_DSCPTOR;
397 
398   std_descr.uu.uuid16++;
399   if (gatt_uuid_compare(std_descr, *p_descr_uuid)) return GATT_DESCR_CLT_CONFIG;
400 
401   std_descr.uu.uuid16++;
402   if (gatt_uuid_compare(std_descr, *p_descr_uuid)) return GATT_DESCR_SVR_CONFIG;
403 
404   std_descr.uu.uuid16++;
405   if (gatt_uuid_compare(std_descr, *p_descr_uuid))
406     return GATT_DESCR_PRES_FORMAT;
407 
408   std_descr.uu.uuid16++;
409   if (gatt_uuid_compare(std_descr, *p_descr_uuid))
410     return GATT_DESCR_AGGR_FORMAT;
411 
412   std_descr.uu.uuid16++;
413   if (gatt_uuid_compare(std_descr, *p_descr_uuid))
414     return GATT_DESCR_VALID_RANGE;
415 
416   return GATT_DESCR_UNKNOWN;
417 }
418 
419 /*******************************************************************************
420  *
421  * Function         gatts_add_char_descr
422  *
423  * Description      This function add a characteristics descriptor.
424  *
425  * Parameter        p_db: database pointer.
426  *                  perm: characteristic descriptor permission type.
427  *                  char_dscp_tpye: the characteristic descriptor masks.
428  *                  p_dscp_params: characteristic descriptors values.
429  *
430  * Returns          Status of the operation.
431  *
432  ******************************************************************************/
gatts_add_char_descr(tGATT_SVC_DB & db,tGATT_PERM perm,tBT_UUID & descr_uuid)433 uint16_t gatts_add_char_descr(tGATT_SVC_DB& db, tGATT_PERM perm,
434                               tBT_UUID& descr_uuid) {
435   GATT_TRACE_DEBUG("gatts_add_char_descr uuid=0x%04x", descr_uuid.uu.uuid16);
436 
437   /* Add characteristic descriptors */
438   tGATT_ATTR& char_dscptr = allocate_attr_in_db(db, descr_uuid, perm);
439   char_dscptr.gatt_type = BTGATT_DB_DESCRIPTOR;
440   return char_dscptr.handle;
441 }
442 
443 /******************************************************************************/
444 /* Service Attribute Database Query Utility Functions */
445 /******************************************************************************/
find_attr_by_handle(tGATT_SVC_DB * p_db,uint16_t handle)446 tGATT_ATTR* find_attr_by_handle(tGATT_SVC_DB* p_db, uint16_t handle) {
447   if (!p_db) return nullptr;
448 
449   for (auto& attr : p_db->attr_list) {
450     if (attr.handle == handle) return &attr;
451     if (attr.handle > handle) return nullptr;
452   }
453 
454   return nullptr;
455 }
456 
457 /*******************************************************************************
458  *
459  * Function         gatts_read_attr_value_by_handle
460  *
461  * Description      Query attribute value by attribute handle.
462  *
463  * Parameter        p_db: pointer to the attribute database.
464  *                  handle: Attribute handle to read.
465  *                  offset: Read offset.
466  *                  p_value: output parameter to carry out the attribute value.
467  *                  p_len: output parameter as attribute length read.
468  *                  read_long: this is a read blob request.
469  *                  mtu: MTU.
470  *                  sec_flag: current link security status.
471  *                  key_size: encryption key size
472  *
473  * Returns          Status of operation.
474  *
475  ******************************************************************************/
gatts_read_attr_value_by_handle(tGATT_TCB * p_tcb,tGATT_SVC_DB * p_db,uint8_t op_code,uint16_t handle,uint16_t offset,uint8_t * p_value,uint16_t * p_len,uint16_t mtu,tGATT_SEC_FLAG sec_flag,uint8_t key_size,uint32_t trans_id)476 tGATT_STATUS gatts_read_attr_value_by_handle(
477     tGATT_TCB* p_tcb, tGATT_SVC_DB* p_db, uint8_t op_code, uint16_t handle,
478     uint16_t offset, uint8_t* p_value, uint16_t* p_len, uint16_t mtu,
479     tGATT_SEC_FLAG sec_flag, uint8_t key_size, uint32_t trans_id) {
480   tGATT_ATTR* p_attr = find_attr_by_handle(p_db, handle);
481   if (!p_attr) return GATT_NOT_FOUND;
482 
483   uint8_t* pp = p_value;
484   tGATT_STATUS status = read_attr_value(*p_attr, offset, &pp,
485                                         (bool)(op_code == GATT_REQ_READ_BLOB),
486                                         mtu, p_len, sec_flag, key_size);
487 
488   if (status == GATT_PENDING) {
489     status = gatts_send_app_read_request(p_tcb, op_code, p_attr->handle, offset,
490                                          trans_id, p_attr->gatt_type);
491   }
492   return status;
493 }
494 
495 /*******************************************************************************
496  *
497  * Function         gatts_read_attr_perm_check
498  *
499  * Description      Check attribute readability.
500  *
501  * Parameter        p_db: pointer to the attribute database.
502  *                  handle: Attribute handle to read.
503  *                  offset: Read offset.
504  *                  p_value: output parameter to carry out the attribute value.
505  *                  p_len: output parameter as attribute length read.
506  *                  read_long: this is a read blob request.
507  *                  mtu: MTU.
508  *                  sec_flag: current link security status.
509  *                  key_size: encryption key size
510  *
511  * Returns          Status of operation.
512  *
513  ******************************************************************************/
gatts_read_attr_perm_check(tGATT_SVC_DB * p_db,bool is_long,uint16_t handle,tGATT_SEC_FLAG sec_flag,uint8_t key_size)514 tGATT_STATUS gatts_read_attr_perm_check(tGATT_SVC_DB* p_db, bool is_long,
515                                         uint16_t handle,
516                                         tGATT_SEC_FLAG sec_flag,
517                                         uint8_t key_size) {
518   tGATT_ATTR* p_attr = find_attr_by_handle(p_db, handle);
519   if (!p_attr) return GATT_NOT_FOUND;
520 
521   return gatts_check_attr_readability(*p_attr, 0, is_long, sec_flag, key_size);
522 }
523 
524 /*******************************************************************************
525  *
526  * Function         gatts_write_attr_perm_check
527  *
528  * Description      Write attribute value into database.
529  *
530  * Parameter        p_db: pointer to the attribute database.
531  *                  op_code:op code of this write.
532  *                  handle: handle of the attribute to write.
533  *                  offset: Write offset if write op code is write blob.
534  *                  p_data: Attribute value to write.
535  *                  len: attribute data length.
536  *                  sec_flag: current link security status.
537  *                  key_size: encryption key size
538  *
539  * Returns          Status of the operation.
540  *
541  ******************************************************************************/
gatts_write_attr_perm_check(tGATT_SVC_DB * p_db,uint8_t op_code,uint16_t handle,uint16_t offset,uint8_t * p_data,uint16_t len,tGATT_SEC_FLAG sec_flag,uint8_t key_size)542 tGATT_STATUS gatts_write_attr_perm_check(tGATT_SVC_DB* p_db, uint8_t op_code,
543                                          uint16_t handle, uint16_t offset,
544                                          uint8_t* p_data, uint16_t len,
545                                          tGATT_SEC_FLAG sec_flag,
546                                          uint8_t key_size) {
547   GATT_TRACE_DEBUG(
548       "%s: op_code=0x%0x handle=0x%04x offset=%d len=%d sec_flag=0x%0x "
549       "key_size=%d",
550       __func__, op_code, handle, offset, len, sec_flag, key_size);
551 
552   tGATT_ATTR* p_attr = find_attr_by_handle(p_db, handle);
553   if (!p_attr) return GATT_NOT_FOUND;
554 
555   tGATT_PERM perm = p_attr->permission;
556   uint16_t min_key_size = (((perm & GATT_ENCRYPT_KEY_SIZE_MASK) >> 12));
557   if (min_key_size != 0) {
558     min_key_size += 6;
559   }
560   GATT_TRACE_DEBUG("%s: p_attr->permission =0x%04x min_key_size==0x%04x",
561                    __func__, p_attr->permission, min_key_size);
562 
563   if ((op_code == GATT_CMD_WRITE || op_code == GATT_REQ_WRITE) &&
564       (perm & GATT_WRITE_SIGNED_PERM)) {
565     /* use the rules for the mixed security see section 10.2.3*/
566     /* use security mode 1 level 2 when the following condition follows */
567     /* LE security mode 2 level 1 and LE security mode 1 level 2 */
568     if ((perm & GATT_PERM_WRITE_SIGNED) && (perm & GATT_PERM_WRITE_ENCRYPTED)) {
569       perm = GATT_PERM_WRITE_ENCRYPTED;
570     }
571     /* use security mode 1 level 3 when the following condition follows */
572     /* LE security mode 2 level 2 and security mode 1 and LE */
573     else if (((perm & GATT_PERM_WRITE_SIGNED_MITM) &&
574               (perm & GATT_PERM_WRITE_ENCRYPTED)) ||
575              /* LE security mode 2 and security mode 1 level 3 */
576              ((perm & GATT_WRITE_SIGNED_PERM) &&
577               (perm & GATT_PERM_WRITE_ENC_MITM))) {
578       perm = GATT_PERM_WRITE_ENC_MITM;
579     }
580   }
581 
582   tGATT_STATUS status = GATT_NOT_FOUND;
583   if ((op_code == GATT_SIGN_CMD_WRITE) && !(perm & GATT_WRITE_SIGNED_PERM)) {
584     status = GATT_WRITE_NOT_PERMIT;
585     GATT_TRACE_DEBUG("%s: sign cmd write not allowed", __func__);
586   }
587   if ((op_code == GATT_SIGN_CMD_WRITE) &&
588       (sec_flag & GATT_SEC_FLAG_ENCRYPTED)) {
589     status = GATT_INVALID_PDU;
590     GATT_TRACE_ERROR("%s: Error!! sign cmd write sent on a encypted link",
591                      __func__);
592   } else if (!(perm & GATT_WRITE_ALLOWED)) {
593     status = GATT_WRITE_NOT_PERMIT;
594     GATT_TRACE_ERROR("%s: GATT_WRITE_NOT_PERMIT", __func__);
595   }
596   /* require authentication, but not been authenticated */
597   else if ((perm & GATT_WRITE_AUTH_REQUIRED) &&
598            !(sec_flag & GATT_SEC_FLAG_LKEY_UNAUTHED)) {
599     status = GATT_INSUF_AUTHENTICATION;
600     GATT_TRACE_ERROR("%s: GATT_INSUF_AUTHENTICATION", __func__);
601   } else if ((perm & GATT_WRITE_MITM_REQUIRED) &&
602              !(sec_flag & GATT_SEC_FLAG_LKEY_AUTHED)) {
603     status = GATT_INSUF_AUTHENTICATION;
604     GATT_TRACE_ERROR("%s: GATT_INSUF_AUTHENTICATION: MITM required", __func__);
605   } else if ((perm & GATT_WRITE_ENCRYPTED_PERM) &&
606              !(sec_flag & GATT_SEC_FLAG_ENCRYPTED)) {
607     status = GATT_INSUF_ENCRYPTION;
608     GATT_TRACE_ERROR("%s: GATT_INSUF_ENCRYPTION", __func__);
609   } else if ((perm & GATT_WRITE_ENCRYPTED_PERM) &&
610              (sec_flag & GATT_SEC_FLAG_ENCRYPTED) &&
611              (key_size < min_key_size)) {
612     status = GATT_INSUF_KEY_SIZE;
613     GATT_TRACE_ERROR("%s: GATT_INSUF_KEY_SIZE", __func__);
614   }
615   /* LE security mode 2 attribute  */
616   else if (perm & GATT_WRITE_SIGNED_PERM && op_code != GATT_SIGN_CMD_WRITE &&
617            !(sec_flag & GATT_SEC_FLAG_ENCRYPTED) &&
618            (perm & GATT_WRITE_ALLOWED) == 0) {
619     status = GATT_INSUF_AUTHENTICATION;
620     GATT_TRACE_ERROR(
621         "%s: GATT_INSUF_AUTHENTICATION: LE security mode 2 required", __func__);
622   } else /* writable: must be char value declaration or char descritpors
623             */
624   {
625     uint16_t max_size = 0;
626 
627     if (p_attr->uuid.len == LEN_UUID_16) {
628       switch (p_attr->uuid.uu.uuid16) {
629         case GATT_UUID_CHAR_PRESENT_FORMAT: /* should be readable only */
630         case GATT_UUID_CHAR_EXT_PROP:       /* should be readable only */
631         case GATT_UUID_CHAR_AGG_FORMAT:     /* should be readable only */
632         case GATT_UUID_CHAR_VALID_RANGE:
633           status = GATT_WRITE_NOT_PERMIT;
634           break;
635 
636         case GATT_UUID_CHAR_CLIENT_CONFIG:
637         /* fall through */
638         case GATT_UUID_CHAR_SRVR_CONFIG:
639           max_size = 2;
640         /* fall through */
641         case GATT_UUID_CHAR_DESCRIPTION:
642         default: /* any other must be character value declaration */
643           status = GATT_SUCCESS;
644           break;
645       }
646     } else if (p_attr->uuid.len == LEN_UUID_128 ||
647                p_attr->uuid.len == LEN_UUID_32) {
648       status = GATT_SUCCESS;
649     } else {
650       status = GATT_INVALID_PDU;
651     }
652 
653     if (p_data == NULL && len > 0) {
654       status = GATT_INVALID_PDU;
655     }
656     /* these attribute does not allow write blob */
657     else if ((p_attr->uuid.len == LEN_UUID_16) &&
658              (p_attr->uuid.uu.uuid16 == GATT_UUID_CHAR_CLIENT_CONFIG ||
659               p_attr->uuid.uu.uuid16 == GATT_UUID_CHAR_SRVR_CONFIG)) {
660       if (op_code == GATT_REQ_PREPARE_WRITE &&
661           offset != 0) /* does not allow write blob */
662       {
663         status = GATT_NOT_LONG;
664         GATT_TRACE_ERROR("%s: GATT_NOT_LONG", __func__);
665       } else if (len != max_size) /* data does not match the required format */
666       {
667         status = GATT_INVALID_ATTR_LEN;
668         GATT_TRACE_ERROR("%s: GATT_INVALID_PDU", __func__);
669       } else {
670         status = GATT_SUCCESS;
671       }
672     }
673   }
674 
675   return status;
676 }
677 
uuid_to_str(const tBT_UUID bt_uuid,char * str_buf,size_t buf_len)678 static void uuid_to_str(const tBT_UUID bt_uuid, char* str_buf, size_t buf_len) {
679   if (bt_uuid.len == LEN_UUID_16) {
680     snprintf(str_buf, buf_len, "0x%04x", bt_uuid.uu.uuid16);
681   } else if (bt_uuid.len == LEN_UUID_32) {
682     snprintf(str_buf, buf_len, "0x%08x", bt_uuid.uu.uuid32);
683   } else if (bt_uuid.len == LEN_UUID_128) {
684     int x = snprintf(str_buf, buf_len, "%02x%02x%02x%02x-%02x%02x-%02x%02x-",
685                      bt_uuid.uu.uuid128[15], bt_uuid.uu.uuid128[14],
686                      bt_uuid.uu.uuid128[13], bt_uuid.uu.uuid128[12],
687                      bt_uuid.uu.uuid128[11], bt_uuid.uu.uuid128[10],
688                      bt_uuid.uu.uuid128[9], bt_uuid.uu.uuid128[8]);
689     snprintf(&str_buf[x], buf_len - x, "%02x%02x-%02x%02x%02x%02x%02x%02x",
690              bt_uuid.uu.uuid128[7], bt_uuid.uu.uuid128[6],
691              bt_uuid.uu.uuid128[5], bt_uuid.uu.uuid128[4],
692              bt_uuid.uu.uuid128[3], bt_uuid.uu.uuid128[2],
693              bt_uuid.uu.uuid128[1], bt_uuid.uu.uuid128[0]);
694   } else
695     snprintf(str_buf, buf_len, "Unknown (len=%d)", bt_uuid.len);
696 }
697 
698 /**
699  * Description      Allocate a memory space for a new attribute, and link this
700  *                  attribute into the database attribute list.
701  *
702  *
703  * Parameter        p_db    : database pointer.
704  *                  uuid:     attribute UUID
705  *
706  * Returns          pointer to the newly allocated attribute.
707  *
708  */
allocate_attr_in_db(tGATT_SVC_DB & db,const tBT_UUID & uuid,tGATT_PERM perm)709 static tGATT_ATTR& allocate_attr_in_db(tGATT_SVC_DB& db, const tBT_UUID& uuid,
710                                        tGATT_PERM perm) {
711   if (db.next_handle >= db.end_handle) {
712     LOG(FATAL) << __func__
713                << " wrong number of handles! handle_max = " << +db.end_handle
714                << ", next_handle = " << +db.next_handle;
715   }
716 
717   db.attr_list.emplace_back();
718   tGATT_ATTR& attr = db.attr_list.back();
719   attr.handle = db.next_handle++;
720   attr.uuid = uuid;
721   attr.permission = perm;
722 
723   char uuid_str[37];
724   uuid_to_str(attr.uuid, uuid_str, sizeof(uuid_str));
725 
726   return attr;
727 }
728 
729 /*******************************************************************************
730  *
731  * Function         gatts_send_app_read_request
732  *
733  * Description      Send application read request callback
734  *
735  * Returns          status of operation.
736  *
737  ******************************************************************************/
gatts_send_app_read_request(tGATT_TCB * p_tcb,uint8_t op_code,uint16_t handle,uint16_t offset,uint32_t trans_id,bt_gatt_db_attribute_type_t gatt_type)738 static tGATT_STATUS gatts_send_app_read_request(
739     tGATT_TCB* p_tcb, uint8_t op_code, uint16_t handle, uint16_t offset,
740     uint32_t trans_id, bt_gatt_db_attribute_type_t gatt_type) {
741   tGATT_SRV_LIST_ELEM& el = *gatt_sr_find_i_rcb_by_handle(handle);
742   uint16_t conn_id = GATT_CREATE_CONN_ID(p_tcb->tcb_idx, el.gatt_if);
743 
744   if (trans_id == 0) {
745     trans_id = gatt_sr_enqueue_cmd(p_tcb, op_code, handle);
746     gatt_sr_update_cback_cnt(p_tcb, el.gatt_if, true, true);
747   }
748 
749   if (trans_id != 0) {
750     tGATTS_DATA sr_data;
751     memset(&sr_data, 0, sizeof(tGATTS_DATA));
752 
753     sr_data.read_req.handle = handle;
754     sr_data.read_req.is_long = (bool)(op_code == GATT_REQ_READ_BLOB);
755     sr_data.read_req.offset = offset;
756 
757     uint8_t opcode;
758     if (gatt_type == BTGATT_DB_DESCRIPTOR) {
759       opcode = GATTS_REQ_TYPE_READ_DESCRIPTOR;
760     } else if (gatt_type == BTGATT_DB_CHARACTERISTIC) {
761       opcode = GATTS_REQ_TYPE_READ_CHARACTERISTIC;
762     } else {
763       GATT_TRACE_ERROR(
764           "%s: Attempt to read attribute that's not tied with"
765           " characteristic or descriptor value.",
766           __func__);
767       return GATT_ERROR;
768     }
769 
770     gatt_sr_send_req_callback(conn_id, trans_id, opcode, &sr_data);
771     return (tGATT_STATUS)GATT_PENDING;
772   } else
773     return (tGATT_STATUS)GATT_BUSY; /* max pending command, application error */
774 }
775