• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 using base::StringPrintf;
38 /*******************************************************************************
39  *             L O C A L    F U N C T I O N     P R O T O T Y P E S            *
40  ******************************************************************************/
41 static tGATT_ATTR& allocate_attr_in_db(tGATT_SVC_DB& db, const tBT_UUID& uuid,
42                                        tGATT_PERM perm);
43 static tGATT_STATUS gatts_send_app_read_request(
44     tGATT_TCB& tcb, uint8_t op_code, uint16_t handle, uint16_t offset,
45     uint32_t trans_id, bt_gatt_db_attribute_type_t gatt_type);
46 
47 /**
48  * Initialize a memory space to be a service database.
49  */
gatts_init_service_db(tGATT_SVC_DB & db,tBT_UUID * p_service,bool is_pri,uint16_t s_hdl,uint16_t num_handle)50 void gatts_init_service_db(tGATT_SVC_DB& db, tBT_UUID* p_service, bool is_pri,
51                            uint16_t s_hdl, uint16_t num_handle) {
52   db.attr_list.reserve(num_handle);
53 
54   VLOG(1) << StringPrintf("%s: s_hdl= %d num_handle= %d", __func__, s_hdl,
55                           num_handle);
56 
57   /* update service database information */
58   db.next_handle = s_hdl;
59   db.end_handle = s_hdl + num_handle;
60 
61   /* add service declration record */
62   tBT_UUID uuid = {LEN_UUID_16, {0}};
63   uuid.uu.uuid16 = is_pri ? GATT_UUID_PRI_SERVICE : GATT_UUID_SEC_SERVICE;
64   tGATT_ATTR& attr = allocate_attr_in_db(db, uuid, GATT_PERM_READ);
65   attr.p_value.reset((tGATT_ATTR_VALUE*)(new tBT_UUID));
66   memcpy(&attr.p_value->uuid, p_service, sizeof(tBT_UUID));
67 }
68 
gatts_get_service_uuid(tGATT_SVC_DB * p_db)69 tBT_UUID* gatts_get_service_uuid(tGATT_SVC_DB* p_db) {
70   if (!p_db || p_db->attr_list.empty()) {
71     LOG(ERROR) << "service DB empty";
72     return NULL;
73   } else {
74     return &p_db->attr_list[0].p_value->uuid;
75   }
76 }
77 
78 /** 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)79 static tGATT_STATUS gatts_check_attr_readability(const tGATT_ATTR& attr,
80                                                  UNUSED_ATTR uint16_t offset,
81                                                  bool read_long,
82                                                  tGATT_SEC_FLAG sec_flag,
83                                                  uint8_t key_size) {
84   uint16_t min_key_size;
85   tGATT_PERM perm = attr.permission;
86 
87   min_key_size = (((perm & GATT_ENCRYPT_KEY_SIZE_MASK) >> 12));
88   if (min_key_size != 0) {
89     min_key_size += 6;
90   }
91 
92   if (!(perm & GATT_READ_ALLOWED)) {
93     LOG(ERROR) << __func__ << ": GATT_READ_NOT_PERMIT";
94     return GATT_READ_NOT_PERMIT;
95   }
96 
97   if ((perm & GATT_READ_AUTH_REQUIRED) &&
98       !(sec_flag & GATT_SEC_FLAG_LKEY_UNAUTHED) &&
99       !(sec_flag & BTM_SEC_FLAG_ENCRYPTED)) {
100     LOG(ERROR) << __func__ << ": GATT_INSUF_AUTHENTICATION";
101     return GATT_INSUF_AUTHENTICATION;
102   }
103 
104   if ((perm & GATT_READ_MITM_REQUIRED) &&
105       !(sec_flag & GATT_SEC_FLAG_LKEY_AUTHED)) {
106     LOG(ERROR) << __func__ << ": GATT_INSUF_AUTHENTICATION: MITM Required";
107     return GATT_INSUF_AUTHENTICATION;
108   }
109 
110   if ((perm & GATT_READ_ENCRYPTED_REQUIRED) &&
111       !(sec_flag & GATT_SEC_FLAG_ENCRYPTED)) {
112     LOG(ERROR) << __func__ << ": GATT_INSUF_ENCRYPTION";
113     return GATT_INSUF_ENCRYPTION;
114   }
115 
116   if ((perm & GATT_READ_ENCRYPTED_REQUIRED) &&
117       (sec_flag & GATT_SEC_FLAG_ENCRYPTED) && (key_size < min_key_size)) {
118     LOG(ERROR) << __func__ << ": GATT_INSUF_KEY_SIZE";
119     return GATT_INSUF_KEY_SIZE;
120   }
121 
122   if (read_long && attr.uuid.len == LEN_UUID_16) {
123     switch (attr.uuid.uu.uuid16) {
124       case GATT_UUID_PRI_SERVICE:
125       case GATT_UUID_SEC_SERVICE:
126       case GATT_UUID_CHAR_DECLARE:
127       case GATT_UUID_INCLUDE_SERVICE:
128       case GATT_UUID_CHAR_EXT_PROP:
129       case GATT_UUID_CHAR_CLIENT_CONFIG:
130       case GATT_UUID_CHAR_SRVR_CONFIG:
131       case GATT_UUID_CHAR_PRESENT_FORMAT:
132         LOG(ERROR) << __func__ << ": GATT_NOT_LONG";
133         return GATT_NOT_LONG;
134 
135       default:
136         break;
137     }
138   }
139 
140   return GATT_SUCCESS;
141 }
142 
143 /*******************************************************************************
144  *
145  * Function         read_attr_value
146  *
147  * Description      Utility function to read an attribute value.
148  *
149  * Parameter        p_attr: pointer to the attribute to read.
150  *                  offset: read offset.
151  *                  p_value: output parameter to carry out the attribute value.
152  *                  p_len: output parameter to carry out the attribute length.
153  *                  read_long: this is a read blob request.
154  *                  mtu: MTU
155  *                  sec_flag: current link security status.
156  *                  key_size: encryption key size.
157  *
158  * Returns          status of operation.
159  *
160  ******************************************************************************/
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)161 static tGATT_STATUS read_attr_value(tGATT_ATTR& attr16, uint16_t offset,
162                                     uint8_t** p_data, bool read_long,
163                                     uint16_t mtu, uint16_t* p_len,
164                                     tGATT_SEC_FLAG sec_flag, uint8_t key_size) {
165   uint16_t len = 0, uuid16 = 0;
166   uint8_t* p = *p_data;
167 
168   VLOG(1)
169       << __func__
170       << StringPrintf(
171              " uuid=0x%04x perm=0x%02x sec_flag=0x%x offset=%d read_long=%d",
172              attr16.uuid.uu.uuid16, attr16.permission, sec_flag, offset,
173              read_long);
174 
175   tGATT_STATUS status = gatts_check_attr_readability(attr16, offset, read_long,
176                                                      sec_flag, key_size);
177 
178   if (status != GATT_SUCCESS) return status;
179 
180   if (attr16.uuid.len == LEN_UUID_16) uuid16 = attr16.uuid.uu.uuid16;
181 
182   status = GATT_NO_RESOURCES;
183 
184   if (uuid16 == GATT_UUID_PRI_SERVICE || uuid16 == GATT_UUID_SEC_SERVICE) {
185     len = attr16.p_value->uuid.len;
186     if (mtu >= attr16.p_value->uuid.len) {
187       gatt_build_uuid_to_stream(&p, attr16.p_value->uuid);
188       status = GATT_SUCCESS;
189     }
190   } else if (uuid16 == GATT_UUID_CHAR_DECLARE) {
191     tGATT_ATTR* val_attr = &attr16 + 1;
192     len = (val_attr->uuid.len == LEN_UUID_16) ? 5 : 19;
193 
194     if (mtu >= len) {
195       UINT8_TO_STREAM(p, attr16.p_value->char_decl.property);
196       UINT16_TO_STREAM(p, attr16.p_value->char_decl.char_val_handle);
197 
198       if (val_attr->uuid.len == LEN_UUID_16) {
199         UINT16_TO_STREAM(p, val_attr->uuid.uu.uuid16);
200       }
201       /* convert a 32bits UUID to 128 bits */
202       else if (val_attr->uuid.len == LEN_UUID_32) {
203         gatt_convert_uuid32_to_uuid128(p, val_attr->uuid.uu.uuid32);
204         p += LEN_UUID_128;
205       } else {
206         ARRAY_TO_STREAM(p, val_attr->uuid.uu.uuid128, LEN_UUID_128);
207       }
208       status = GATT_SUCCESS;
209     }
210 
211   } else if (uuid16 == GATT_UUID_INCLUDE_SERVICE) {
212     if (attr16.p_value->incl_handle.service_type.len == LEN_UUID_16)
213       len = 6;
214     else
215       len = 4;
216 
217     if (mtu >= len) {
218       UINT16_TO_STREAM(p, attr16.p_value->incl_handle.s_handle);
219       UINT16_TO_STREAM(p, attr16.p_value->incl_handle.e_handle);
220 
221       if (attr16.p_value->incl_handle.service_type.len == LEN_UUID_16) {
222         UINT16_TO_STREAM(p, attr16.p_value->incl_handle.service_type.uu.uuid16);
223       }
224       status = GATT_SUCCESS;
225     }
226   } else /* characteristic description or characteristic value */
227   {
228     status = GATT_PENDING;
229   }
230 
231   *p_len = len;
232   *p_data = p;
233   return status;
234 }
235 
236 /*******************************************************************************
237  *
238  * Function         gatts_db_read_attr_value_by_type
239  *
240  * Description      Query attribute value by attribute type.
241  *
242  * Parameter        p_db: pointer to the attribute database.
243  *                  p_rsp: Read By type response data.
244  *                  s_handle: starting handle of the range we are looking for.
245  *                  e_handle: ending handle of the range we are looking for.
246  *                  type: Attribute type.
247  *                  mtu: MTU.
248  *                  sec_flag: current link security status.
249  *                  key_size: encryption key size.
250  *
251  * Returns          Status of the operation.
252  *
253  ******************************************************************************/
gatts_db_read_attr_value_by_type(tGATT_TCB & 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)254 tGATT_STATUS gatts_db_read_attr_value_by_type(
255     tGATT_TCB& tcb, tGATT_SVC_DB* p_db, uint8_t op_code, BT_HDR* p_rsp,
256     uint16_t s_handle, uint16_t e_handle, tBT_UUID type, uint16_t* p_len,
257     tGATT_SEC_FLAG sec_flag, uint8_t key_size, uint32_t trans_id,
258     uint16_t* p_cur_handle) {
259   tGATT_STATUS status = GATT_NOT_FOUND;
260   uint16_t len = 0;
261   uint8_t* p = (uint8_t*)(p_rsp + 1) + p_rsp->len + L2CAP_MIN_OFFSET;
262 
263   if (p_db) {
264     for (tGATT_ATTR& attr : p_db->attr_list) {
265       tBT_UUID attr_uuid = attr.uuid;
266 
267       if (attr.handle >= s_handle && gatt_uuid_compare(type, attr_uuid)) {
268         if (*p_len <= 2) {
269           status = GATT_NO_RESOURCES;
270           break;
271         }
272 
273         UINT16_TO_STREAM(p, attr.handle);
274 
275         status = read_attr_value(attr, 0, &p, false, (uint16_t)(*p_len - 2),
276                                  &len, sec_flag, key_size);
277 
278         if (status == GATT_PENDING) {
279           status = gatts_send_app_read_request(tcb, op_code, attr.handle, 0,
280                                                trans_id, attr.gatt_type);
281 
282           /* one callback at a time */
283           break;
284         } else if (status == GATT_SUCCESS) {
285           if (p_rsp->offset == 0) p_rsp->offset = len + 2;
286 
287           if (p_rsp->offset == len + 2) {
288             p_rsp->len += (len + 2);
289             *p_len -= (len + 2);
290           } else {
291             LOG(ERROR) << "format mismatch";
292             status = GATT_NO_RESOURCES;
293             break;
294           }
295         } else {
296           *p_cur_handle = attr.handle;
297           break;
298         }
299       }
300     }
301   }
302 
303 #if (BLE_DELAY_REQUEST_ENC == TRUE)
304   uint8_t flag = 0;
305   if (BTM_GetSecurityFlags(tcb.peer_bda, &flag)) {
306     if ((tcb.att_lcid == L2CAP_ATT_CID) && (status == GATT_PENDING) &&
307         (type.uu.uuid16 == GATT_UUID_GAP_DEVICE_NAME)) {
308       if ((flag & (BTM_SEC_LINK_KEY_KNOWN | BTM_SEC_FLAG_ENCRYPTED)) ==
309           BTM_SEC_LINK_KEY_KNOWN) {
310         tACL_CONN* p = btm_bda_to_acl(tcb.peer_bda, BT_TRANSPORT_LE);
311         if ((p != NULL) && (p->link_role == BTM_ROLE_MASTER))
312           btm_ble_set_encryption(tcb.peer_bda, BTM_BLE_SEC_ENCRYPT,
313                                  p->link_role);
314       }
315     }
316   }
317 #endif
318   return status;
319 }
320 
321 /**
322  * This function adds an included service into a database.
323  *
324  * Parameter        db: database pointer.
325  *                  inc_srvc_type: included service type.
326  *
327  * Returns          Status of the operation.
328  *
329  */
gatts_add_included_service(tGATT_SVC_DB & db,uint16_t s_handle,uint16_t e_handle,tBT_UUID service)330 uint16_t gatts_add_included_service(tGATT_SVC_DB& db, uint16_t s_handle,
331                                     uint16_t e_handle, tBT_UUID service) {
332   tBT_UUID uuid = {LEN_UUID_16, {GATT_UUID_INCLUDE_SERVICE}};
333 
334   VLOG(1) << StringPrintf("%s: s_hdl = 0x%04x e_hdl = 0x%04x uuid = 0x%04x",
335                           __func__, s_handle, e_handle, service.uu.uuid16);
336 
337   if (service.len == 0 || s_handle == 0 || e_handle == 0) {
338     LOG(ERROR) << __func__ << ": Illegal Params.";
339     return 0;
340   }
341 
342   tGATT_ATTR& attr = allocate_attr_in_db(db, uuid, GATT_PERM_READ);
343 
344   attr.p_value.reset((tGATT_ATTR_VALUE*)(new tGATT_INCL_SRVC));
345   attr.p_value->incl_handle.s_handle = s_handle;
346   attr.p_value->incl_handle.e_handle = e_handle;
347   memcpy(&attr.p_value->incl_handle.service_type, &service, sizeof(tBT_UUID));
348 
349   return attr.handle;
350 }
351 
352 /*******************************************************************************
353  *
354  * Function         gatts_add_characteristic
355  *
356  * Description      This function add a characteristics and its descriptor into
357  *                  a servce identified by the service database pointer.
358  *
359  * Parameter        db: database.
360  *                  perm: permission (authentication and key size requirements)
361  *                  property: property of the characteristic.
362  *                  p_char: characteristic value information.
363  *
364  * Returns          Status of te operation.
365  *
366  ******************************************************************************/
gatts_add_characteristic(tGATT_SVC_DB & db,tGATT_PERM perm,tGATT_CHAR_PROP property,tBT_UUID & char_uuid)367 uint16_t gatts_add_characteristic(tGATT_SVC_DB& db, tGATT_PERM perm,
368                                   tGATT_CHAR_PROP property,
369                                   tBT_UUID& char_uuid) {
370   tBT_UUID uuid = {LEN_UUID_16, {GATT_UUID_CHAR_DECLARE}};
371 
372   VLOG(1) << StringPrintf("%s: perm=0x%0x property=0x%0x", __func__, perm,
373                           property);
374 
375   tGATT_ATTR& char_decl = allocate_attr_in_db(db, uuid, GATT_PERM_READ);
376   tGATT_ATTR& char_val = allocate_attr_in_db(db, char_uuid, perm);
377 
378   char_decl.p_value.reset((tGATT_ATTR_VALUE*)(new tGATT_CHAR_DECL));
379   char_decl.p_value->char_decl.property = property;
380   char_decl.p_value->char_decl.char_val_handle = char_val.handle;
381   char_val.gatt_type = BTGATT_DB_CHARACTERISTIC;
382   return char_val.handle;
383 }
384 
385 /*******************************************************************************
386  *
387  * Function         gatt_convertchar_descr_type
388  *
389  * Description      Convert a char descript UUID into descriptor type.
390  *
391  * Returns          descriptor type.
392  *
393  ******************************************************************************/
gatt_convertchar_descr_type(tBT_UUID * p_descr_uuid)394 uint8_t gatt_convertchar_descr_type(tBT_UUID* p_descr_uuid) {
395   tBT_UUID std_descr = {LEN_UUID_16, {GATT_UUID_CHAR_EXT_PROP}};
396 
397   if (gatt_uuid_compare(std_descr, *p_descr_uuid))
398     return GATT_DESCR_EXT_DSCPTOR;
399 
400   std_descr.uu.uuid16++;
401   if (gatt_uuid_compare(std_descr, *p_descr_uuid))
402     return GATT_DESCR_USER_DSCPTOR;
403 
404   std_descr.uu.uuid16++;
405   if (gatt_uuid_compare(std_descr, *p_descr_uuid)) return GATT_DESCR_CLT_CONFIG;
406 
407   std_descr.uu.uuid16++;
408   if (gatt_uuid_compare(std_descr, *p_descr_uuid)) return GATT_DESCR_SVR_CONFIG;
409 
410   std_descr.uu.uuid16++;
411   if (gatt_uuid_compare(std_descr, *p_descr_uuid))
412     return GATT_DESCR_PRES_FORMAT;
413 
414   std_descr.uu.uuid16++;
415   if (gatt_uuid_compare(std_descr, *p_descr_uuid))
416     return GATT_DESCR_AGGR_FORMAT;
417 
418   std_descr.uu.uuid16++;
419   if (gatt_uuid_compare(std_descr, *p_descr_uuid))
420     return GATT_DESCR_VALID_RANGE;
421 
422   return GATT_DESCR_UNKNOWN;
423 }
424 
425 /*******************************************************************************
426  *
427  * Function         gatts_add_char_descr
428  *
429  * Description      This function add a characteristics descriptor.
430  *
431  * Parameter        p_db: database pointer.
432  *                  perm: characteristic descriptor permission type.
433  *                  char_dscp_tpye: the characteristic descriptor masks.
434  *                  p_dscp_params: characteristic descriptors values.
435  *
436  * Returns          Status of the operation.
437  *
438  ******************************************************************************/
gatts_add_char_descr(tGATT_SVC_DB & db,tGATT_PERM perm,tBT_UUID & descr_uuid)439 uint16_t gatts_add_char_descr(tGATT_SVC_DB& db, tGATT_PERM perm,
440                               tBT_UUID& descr_uuid) {
441   VLOG(1) << StringPrintf("gatts_add_char_descr uuid=0x%04x",
442                           descr_uuid.uu.uuid16);
443 
444   /* Add characteristic descriptors */
445   tGATT_ATTR& char_dscptr = allocate_attr_in_db(db, descr_uuid, perm);
446   char_dscptr.gatt_type = BTGATT_DB_DESCRIPTOR;
447   return char_dscptr.handle;
448 }
449 
450 /******************************************************************************/
451 /* Service Attribute Database Query Utility Functions */
452 /******************************************************************************/
find_attr_by_handle(tGATT_SVC_DB * p_db,uint16_t handle)453 tGATT_ATTR* find_attr_by_handle(tGATT_SVC_DB* p_db, uint16_t handle) {
454   if (!p_db) return nullptr;
455 
456   for (auto& attr : p_db->attr_list) {
457     if (attr.handle == handle) return &attr;
458     if (attr.handle > handle) return nullptr;
459   }
460 
461   return nullptr;
462 }
463 
464 /*******************************************************************************
465  *
466  * Function         gatts_read_attr_value_by_handle
467  *
468  * Description      Query attribute value by attribute handle.
469  *
470  * Parameter        p_db: pointer to the attribute database.
471  *                  handle: Attribute handle to read.
472  *                  offset: Read offset.
473  *                  p_value: output parameter to carry out the attribute value.
474  *                  p_len: output parameter as attribute length read.
475  *                  read_long: this is a read blob request.
476  *                  mtu: MTU.
477  *                  sec_flag: current link security status.
478  *                  key_size: encryption key size
479  *
480  * Returns          Status of operation.
481  *
482  ******************************************************************************/
gatts_read_attr_value_by_handle(tGATT_TCB & 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)483 tGATT_STATUS gatts_read_attr_value_by_handle(
484     tGATT_TCB& tcb, tGATT_SVC_DB* p_db, uint8_t op_code, uint16_t handle,
485     uint16_t offset, uint8_t* p_value, uint16_t* p_len, uint16_t mtu,
486     tGATT_SEC_FLAG sec_flag, uint8_t key_size, uint32_t trans_id) {
487   tGATT_ATTR* p_attr = find_attr_by_handle(p_db, handle);
488   if (!p_attr) return GATT_NOT_FOUND;
489 
490   uint8_t* pp = p_value;
491   tGATT_STATUS status = read_attr_value(*p_attr, offset, &pp,
492                                         (bool)(op_code == GATT_REQ_READ_BLOB),
493                                         mtu, p_len, sec_flag, key_size);
494 
495   if (status == GATT_PENDING) {
496     status = gatts_send_app_read_request(tcb, op_code, p_attr->handle, offset,
497                                          trans_id, p_attr->gatt_type);
498   }
499   return status;
500 }
501 
502 /*******************************************************************************
503  *
504  * Function         gatts_read_attr_perm_check
505  *
506  * Description      Check attribute readability.
507  *
508  * Parameter        p_db: pointer to the attribute database.
509  *                  handle: Attribute handle to read.
510  *                  offset: Read offset.
511  *                  p_value: output parameter to carry out the attribute value.
512  *                  p_len: output parameter as attribute length read.
513  *                  read_long: this is a read blob request.
514  *                  mtu: MTU.
515  *                  sec_flag: current link security status.
516  *                  key_size: encryption key size
517  *
518  * Returns          Status of operation.
519  *
520  ******************************************************************************/
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)521 tGATT_STATUS gatts_read_attr_perm_check(tGATT_SVC_DB* p_db, bool is_long,
522                                         uint16_t handle,
523                                         tGATT_SEC_FLAG sec_flag,
524                                         uint8_t key_size) {
525   tGATT_ATTR* p_attr = find_attr_by_handle(p_db, handle);
526   if (!p_attr) return GATT_NOT_FOUND;
527 
528   return gatts_check_attr_readability(*p_attr, 0, is_long, sec_flag, key_size);
529 }
530 
531 /*******************************************************************************
532  *
533  * Function         gatts_write_attr_perm_check
534  *
535  * Description      Write attribute value into database.
536  *
537  * Parameter        p_db: pointer to the attribute database.
538  *                  op_code:op code of this write.
539  *                  handle: handle of the attribute to write.
540  *                  offset: Write offset if write op code is write blob.
541  *                  p_data: Attribute value to write.
542  *                  len: attribute data length.
543  *                  sec_flag: current link security status.
544  *                  key_size: encryption key size
545  *
546  * Returns          Status of the operation.
547  *
548  ******************************************************************************/
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)549 tGATT_STATUS gatts_write_attr_perm_check(tGATT_SVC_DB* p_db, uint8_t op_code,
550                                          uint16_t handle, uint16_t offset,
551                                          uint8_t* p_data, uint16_t len,
552                                          tGATT_SEC_FLAG sec_flag,
553                                          uint8_t key_size) {
554   VLOG(1) << StringPrintf(
555       "%s: op_code=0x%0x handle=0x%04x offset=%d len=%d sec_flag=0x%0x "
556       "key_size=%d",
557       __func__, op_code, handle, offset, len, sec_flag, key_size);
558 
559   tGATT_ATTR* p_attr = find_attr_by_handle(p_db, handle);
560   if (!p_attr) return GATT_NOT_FOUND;
561 
562   tGATT_PERM perm = p_attr->permission;
563   uint16_t min_key_size = (((perm & GATT_ENCRYPT_KEY_SIZE_MASK) >> 12));
564   if (min_key_size != 0) {
565     min_key_size += 6;
566   }
567   VLOG(1) << StringPrintf("%s: p_attr->permission =0x%04x min_key_size==0x%04x",
568                           __func__, p_attr->permission, min_key_size);
569 
570   if ((op_code == GATT_CMD_WRITE || op_code == GATT_REQ_WRITE) &&
571       (perm & GATT_WRITE_SIGNED_PERM)) {
572     /* use the rules for the mixed security see section 10.2.3*/
573     /* use security mode 1 level 2 when the following condition follows */
574     /* LE security mode 2 level 1 and LE security mode 1 level 2 */
575     if ((perm & GATT_PERM_WRITE_SIGNED) && (perm & GATT_PERM_WRITE_ENCRYPTED)) {
576       perm = GATT_PERM_WRITE_ENCRYPTED;
577     }
578     /* use security mode 1 level 3 when the following condition follows */
579     /* LE security mode 2 level 2 and security mode 1 and LE */
580     else if (((perm & GATT_PERM_WRITE_SIGNED_MITM) &&
581               (perm & GATT_PERM_WRITE_ENCRYPTED)) ||
582              /* LE security mode 2 and security mode 1 level 3 */
583              ((perm & GATT_WRITE_SIGNED_PERM) &&
584               (perm & GATT_PERM_WRITE_ENC_MITM))) {
585       perm = GATT_PERM_WRITE_ENC_MITM;
586     }
587   }
588 
589   tGATT_STATUS status = GATT_NOT_FOUND;
590   if ((op_code == GATT_SIGN_CMD_WRITE) && !(perm & GATT_WRITE_SIGNED_PERM)) {
591     status = GATT_WRITE_NOT_PERMIT;
592     VLOG(1) << __func__ << ": sign cmd write not allowed";
593   }
594   if ((op_code == GATT_SIGN_CMD_WRITE) &&
595       (sec_flag & GATT_SEC_FLAG_ENCRYPTED)) {
596     status = GATT_INVALID_PDU;
597     LOG(ERROR) << __func__
598                << ": Error!! sign cmd write sent on a encypted link";
599   } else if (!(perm & GATT_WRITE_ALLOWED)) {
600     status = GATT_WRITE_NOT_PERMIT;
601     LOG(ERROR) << __func__ << ": GATT_WRITE_NOT_PERMIT";
602   }
603   /* require authentication, but not been authenticated */
604   else if ((perm & GATT_WRITE_AUTH_REQUIRED) &&
605            !(sec_flag & GATT_SEC_FLAG_LKEY_UNAUTHED)) {
606     status = GATT_INSUF_AUTHENTICATION;
607     LOG(ERROR) << __func__ << ": GATT_INSUF_AUTHENTICATION";
608   } else if ((perm & GATT_WRITE_MITM_REQUIRED) &&
609              !(sec_flag & GATT_SEC_FLAG_LKEY_AUTHED)) {
610     status = GATT_INSUF_AUTHENTICATION;
611     LOG(ERROR) << __func__ << ": GATT_INSUF_AUTHENTICATION: MITM required";
612   } else if ((perm & GATT_WRITE_ENCRYPTED_PERM) &&
613              !(sec_flag & GATT_SEC_FLAG_ENCRYPTED)) {
614     status = GATT_INSUF_ENCRYPTION;
615     LOG(ERROR) << __func__ << ": GATT_INSUF_ENCRYPTION";
616   } else if ((perm & GATT_WRITE_ENCRYPTED_PERM) &&
617              (sec_flag & GATT_SEC_FLAG_ENCRYPTED) &&
618              (key_size < min_key_size)) {
619     status = GATT_INSUF_KEY_SIZE;
620     LOG(ERROR) << __func__ << ": GATT_INSUF_KEY_SIZE";
621   }
622   /* LE security mode 2 attribute  */
623   else if (perm & GATT_WRITE_SIGNED_PERM && op_code != GATT_SIGN_CMD_WRITE &&
624            !(sec_flag & GATT_SEC_FLAG_ENCRYPTED) &&
625            (perm & GATT_WRITE_ALLOWED) == 0) {
626     status = GATT_INSUF_AUTHENTICATION;
627     LOG(ERROR) << __func__
628                << ": GATT_INSUF_AUTHENTICATION: LE security mode 2 required";
629   } else /* writable: must be char value declaration or char descritpors
630             */
631   {
632     uint16_t max_size = 0;
633 
634     if (p_attr->uuid.len == LEN_UUID_16) {
635       switch (p_attr->uuid.uu.uuid16) {
636         case GATT_UUID_CHAR_PRESENT_FORMAT: /* should be readable only */
637         case GATT_UUID_CHAR_EXT_PROP:       /* should be readable only */
638         case GATT_UUID_CHAR_AGG_FORMAT:     /* should be readable only */
639         case GATT_UUID_CHAR_VALID_RANGE:
640           status = GATT_WRITE_NOT_PERMIT;
641           break;
642 
643         case GATT_UUID_CHAR_CLIENT_CONFIG:
644         /* fall through */
645         case GATT_UUID_CHAR_SRVR_CONFIG:
646           max_size = 2;
647         /* fall through */
648         case GATT_UUID_CHAR_DESCRIPTION:
649         default: /* any other must be character value declaration */
650           status = GATT_SUCCESS;
651           break;
652       }
653     } else if (p_attr->uuid.len == LEN_UUID_128 ||
654                p_attr->uuid.len == LEN_UUID_32) {
655       status = GATT_SUCCESS;
656     } else {
657       status = GATT_INVALID_PDU;
658     }
659 
660     if (p_data == NULL && len > 0) {
661       status = GATT_INVALID_PDU;
662     }
663     /* these attribute does not allow write blob */
664     else if ((p_attr->uuid.len == LEN_UUID_16) &&
665              (p_attr->uuid.uu.uuid16 == GATT_UUID_CHAR_CLIENT_CONFIG ||
666               p_attr->uuid.uu.uuid16 == GATT_UUID_CHAR_SRVR_CONFIG)) {
667       if (op_code == GATT_REQ_PREPARE_WRITE &&
668           offset != 0) /* does not allow write blob */
669       {
670         status = GATT_NOT_LONG;
671         LOG(ERROR) << __func__ << ": GATT_NOT_LONG";
672       } else if (len != max_size) /* data does not match the required format */
673       {
674         status = GATT_INVALID_ATTR_LEN;
675         LOG(ERROR) << __func__ << ": GATT_INVALID_PDU";
676       } else {
677         status = GATT_SUCCESS;
678       }
679     }
680   }
681 
682   return status;
683 }
684 
uuid_to_str(const tBT_UUID bt_uuid,char * str_buf,size_t buf_len)685 static void uuid_to_str(const tBT_UUID bt_uuid, char* str_buf, size_t buf_len) {
686   if (bt_uuid.len == LEN_UUID_16) {
687     snprintf(str_buf, buf_len, "0x%04x", bt_uuid.uu.uuid16);
688   } else if (bt_uuid.len == LEN_UUID_32) {
689     snprintf(str_buf, buf_len, "0x%08x", bt_uuid.uu.uuid32);
690   } else if (bt_uuid.len == LEN_UUID_128) {
691     int x = snprintf(str_buf, buf_len, "%02x%02x%02x%02x-%02x%02x-%02x%02x-",
692                      bt_uuid.uu.uuid128[15], bt_uuid.uu.uuid128[14],
693                      bt_uuid.uu.uuid128[13], bt_uuid.uu.uuid128[12],
694                      bt_uuid.uu.uuid128[11], bt_uuid.uu.uuid128[10],
695                      bt_uuid.uu.uuid128[9], bt_uuid.uu.uuid128[8]);
696     snprintf(&str_buf[x], buf_len - x, "%02x%02x-%02x%02x%02x%02x%02x%02x",
697              bt_uuid.uu.uuid128[7], bt_uuid.uu.uuid128[6],
698              bt_uuid.uu.uuid128[5], bt_uuid.uu.uuid128[4],
699              bt_uuid.uu.uuid128[3], bt_uuid.uu.uuid128[2],
700              bt_uuid.uu.uuid128[1], bt_uuid.uu.uuid128[0]);
701   } else
702     snprintf(str_buf, buf_len, "Unknown (len=%d)", bt_uuid.len);
703 }
704 
705 /**
706  * Description      Allocate a memory space for a new attribute, and link this
707  *                  attribute into the database attribute list.
708  *
709  *
710  * Parameter        p_db    : database pointer.
711  *                  uuid:     attribute UUID
712  *
713  * Returns          pointer to the newly allocated attribute.
714  *
715  */
allocate_attr_in_db(tGATT_SVC_DB & db,const tBT_UUID & uuid,tGATT_PERM perm)716 static tGATT_ATTR& allocate_attr_in_db(tGATT_SVC_DB& db, const tBT_UUID& uuid,
717                                        tGATT_PERM perm) {
718   if (db.next_handle >= db.end_handle) {
719     LOG(FATAL) << __func__
720                << " wrong number of handles! handle_max = " << +db.end_handle
721                << ", next_handle = " << +db.next_handle;
722   }
723 
724   db.attr_list.emplace_back();
725   tGATT_ATTR& attr = db.attr_list.back();
726   attr.handle = db.next_handle++;
727   attr.uuid = uuid;
728   attr.permission = perm;
729 
730   char uuid_str[37];
731   uuid_to_str(attr.uuid, uuid_str, sizeof(uuid_str));
732 
733   return attr;
734 }
735 
736 /*******************************************************************************
737  *
738  * Function         gatts_send_app_read_request
739  *
740  * Description      Send application read request callback
741  *
742  * Returns          status of operation.
743  *
744  ******************************************************************************/
gatts_send_app_read_request(tGATT_TCB & tcb,uint8_t op_code,uint16_t handle,uint16_t offset,uint32_t trans_id,bt_gatt_db_attribute_type_t gatt_type)745 static tGATT_STATUS gatts_send_app_read_request(
746     tGATT_TCB& tcb, uint8_t op_code, uint16_t handle, uint16_t offset,
747     uint32_t trans_id, bt_gatt_db_attribute_type_t gatt_type) {
748   tGATT_SRV_LIST_ELEM& el = *gatt_sr_find_i_rcb_by_handle(handle);
749   uint16_t conn_id = GATT_CREATE_CONN_ID(tcb.tcb_idx, el.gatt_if);
750 
751   if (trans_id == 0) {
752     trans_id = gatt_sr_enqueue_cmd(tcb, op_code, handle);
753     gatt_sr_update_cback_cnt(tcb, el.gatt_if, true, true);
754   }
755 
756   if (trans_id != 0) {
757     tGATTS_DATA sr_data;
758     memset(&sr_data, 0, sizeof(tGATTS_DATA));
759 
760     sr_data.read_req.handle = handle;
761     sr_data.read_req.is_long = (bool)(op_code == GATT_REQ_READ_BLOB);
762     sr_data.read_req.offset = offset;
763 
764     uint8_t opcode;
765     if (gatt_type == BTGATT_DB_DESCRIPTOR) {
766       opcode = GATTS_REQ_TYPE_READ_DESCRIPTOR;
767     } else if (gatt_type == BTGATT_DB_CHARACTERISTIC) {
768       opcode = GATTS_REQ_TYPE_READ_CHARACTERISTIC;
769     } else {
770       LOG(ERROR) << __func__
771                  << ": Attempt to read attribute that's not tied with "
772                     "characteristic or descriptor value.";
773       return GATT_ERROR;
774     }
775 
776     gatt_sr_send_req_callback(conn_id, trans_id, opcode, &sr_data);
777     return (tGATT_STATUS)GATT_PENDING;
778   } else
779     return (tGATT_STATUS)GATT_BUSY; /* max pending command, application error */
780 }
781