1 /******************************************************************************
2  *
3  *  Copyright (C) 2014 Google, Inc.
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 #include <assert.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 
24 #include "btcore/include/uuid.h"
25 #include "osi/include/allocator.h"
26 
27 static const size_t UUID_WELL_FORMED_STRING_LEN = 36;
28 static const size_t UUID_WELL_FORMED_STRING_LEN_WITH_NULL = 36 + 1;
29 
30 typedef struct uuid_string_t {
31   char string[0];
32 } uuid_string_t;
33 
34 static const bt_uuid_t empty_uuid = {{ 0 }};
35 
36 // The base UUID is used for calculating 128-bit UUIDs from 16 and
37 // 32 bit UUIDs as described in the SDP specification.
38 static const bt_uuid_t base_uuid = {
39   { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
40     0x80, 0x00, 0x00, 0x80, 0x5f, 0x9b, 0x34, 0xfb, }};
41 
42 static bool uuid_is_base(const bt_uuid_t *uuid);
43 
uuid_string_new(void)44 uuid_string_t *uuid_string_new(void) {
45   return osi_calloc(UUID_WELL_FORMED_STRING_LEN_WITH_NULL);
46 }
47 
uuid_string_free(uuid_string_t * uuid_string)48 void uuid_string_free(uuid_string_t *uuid_string) {
49   osi_free(uuid_string);
50 }
51 
uuid_string_data(const uuid_string_t * uuid_string)52 const char *uuid_string_data(const uuid_string_t *uuid_string) {
53   assert(uuid_string != NULL);
54   return (const char *)uuid_string->string;
55 }
56 
uuid_new(const char * uuid_string)57 bt_uuid_t *uuid_new(const char *uuid_string) {
58   assert(uuid_string != NULL);
59 
60   if (strlen(uuid_string) < UUID_WELL_FORMED_STRING_LEN)
61     return NULL;
62   if (uuid_string[8] != '-' || uuid_string[13] != '-' || uuid_string[18] != '-' || uuid_string[23] != '-')
63     return NULL;
64 
65   bt_uuid_t *uuid = osi_calloc(sizeof(bt_uuid_t));
66 
67   const char *s = uuid_string;
68   for (size_t i = 0; i < sizeof(bt_uuid_t); ++i, s+=2) {
69     char buf[3] = {0};
70     buf[0] = s[0];
71     buf[1] = s[1];
72     uuid->uu[i] = strtoul(buf, NULL, 16);
73     // Adjust by skipping the dashes
74     switch(i) {
75       case 3:
76       case 5:
77       case 7:
78       case 9:
79         s++;
80         break;
81     }
82   }
83   return uuid;
84 }
85 
uuid_free(bt_uuid_t * uuid)86 void uuid_free(bt_uuid_t *uuid) {
87   osi_free(uuid);
88 }
89 
uuid_is_empty(const bt_uuid_t * uuid)90 bool uuid_is_empty(const bt_uuid_t *uuid) {
91   return !uuid || !memcmp(uuid, &empty_uuid, sizeof(bt_uuid_t));
92 }
93 
uuid_is_equal(const bt_uuid_t * first,const bt_uuid_t * second)94 bool uuid_is_equal(const bt_uuid_t *first, const bt_uuid_t *second) {
95   assert(first != NULL);
96   assert(second != NULL);
97   return !memcmp(first, second, sizeof(bt_uuid_t));
98 }
99 
uuid_copy(bt_uuid_t * dest,const bt_uuid_t * src)100 bt_uuid_t *uuid_copy(bt_uuid_t *dest, const bt_uuid_t *src) {
101   assert(dest != NULL);
102   assert(src != NULL);
103   return (bt_uuid_t *)memcpy(dest, src, sizeof(bt_uuid_t));
104 }
105 
uuid_128_to_16(const bt_uuid_t * uuid,uint16_t * uuid16)106 bool uuid_128_to_16(const bt_uuid_t *uuid, uint16_t *uuid16) {
107   assert(uuid != NULL);
108   assert(uuid16 != NULL);
109 
110   if (!uuid_is_base(uuid))
111     return false;
112 
113   *uuid16 = (uuid->uu[2] << 8) + uuid->uu[3];
114   return true;
115 }
116 
uuid_128_to_32(const bt_uuid_t * uuid,uint32_t * uuid32)117 bool uuid_128_to_32(const bt_uuid_t *uuid, uint32_t *uuid32) {
118   assert(uuid != NULL);
119   assert(uuid32 != NULL);
120 
121   if (!uuid_is_base(uuid))
122     return false;
123 
124   *uuid32 = (uuid->uu[0] << 24) + (uuid->uu[1] << 16) + (uuid->uu[2] << 8) + uuid->uu[3];
125   return true;
126 }
127 
uuid_to_string(const bt_uuid_t * uuid,uuid_string_t * uuid_string)128 void uuid_to_string(const bt_uuid_t *uuid, uuid_string_t *uuid_string) {
129   assert(uuid != NULL);
130   assert(uuid_string != NULL);
131 
132   char *string = uuid_string->string;
133 
134   for (int i = 0; i < 4; i++) {
135     string += sprintf(string, "%02x", uuid->uu[i]);
136   }
137   string += sprintf(string, "-");
138   for (int i = 4; i < 6; i++) {
139     string += sprintf(string, "%02x", uuid->uu[i]);
140   }
141   string += sprintf(string, "-");
142   for (int i = 6; i < 8; i++) {
143     string += sprintf(string, "%02x", uuid->uu[i]);
144   }
145   string += sprintf(string, "-");
146   for (int i = 8; i < 10; i++) {
147     string += sprintf(string, "%02x", uuid->uu[i]);
148   }
149   string += sprintf(string, "-");
150   for (int i = 10; i < 16; i++) {
151     string += sprintf(string, "%02x", uuid->uu[i]);
152   }
153 }
154 
uuid_is_base(const bt_uuid_t * uuid)155 static bool uuid_is_base(const bt_uuid_t *uuid) {
156   if (!uuid)
157     return false;
158 
159   for (int i = 4; i < 16; i++) {
160     if (uuid->uu[i] != base_uuid.uu[i])
161       return false;
162   }
163   return true;
164 }
165