1
2 /* Copyright (C) 2009-2010 by Daniel Stenberg
3 *
4 * Permission to use, copy, modify, and distribute this
5 * software and its documentation for any purpose and without
6 * fee is hereby granted, provided that the above copyright
7 * notice appear in all copies and that both that copyright
8 * notice and this permission notice appear in supporting
9 * documentation, and that the name of M.I.T. not be used in
10 * advertising or publicity pertaining to distribution of the
11 * software without specific, written prior permission.
12 * M.I.T. makes no representations about the suitability of
13 * this software for any purpose. It is provided "as is"
14 * without express or implied warranty.
15 */
16
17
18 #include "ares_setup.h"
19
20 #include <stddef.h>
21
22 #include "ares.h"
23 #include "ares_data.h"
24 #include "ares_private.h"
25
26
27 /*
28 ** ares_free_data() - c-ares external API function.
29 **
30 ** This function must be used by the application to free data memory that
31 ** has been internally allocated by some c-ares function and for which a
32 ** pointer has already been returned to the calling application. The list
33 ** of c-ares functions returning pointers that must be free'ed using this
34 ** function is:
35 **
36 ** ares_get_servers()
37 ** ares_parse_srv_reply()
38 ** ares_parse_txt_reply()
39 */
40
ares_free_data(void * dataptr)41 void ares_free_data(void *dataptr)
42 {
43 struct ares_data *ptr;
44
45 if (!dataptr)
46 return;
47
48 #ifdef __INTEL_COMPILER
49 # pragma warning(push)
50 # pragma warning(disable:1684)
51 /* 1684: conversion from pointer to same-sized integral type */
52 #endif
53
54 ptr = (void *)((char *)dataptr - offsetof(struct ares_data, data));
55
56 #ifdef __INTEL_COMPILER
57 # pragma warning(pop)
58 #endif
59
60 if (ptr->mark != ARES_DATATYPE_MARK)
61 return;
62
63 switch (ptr->type)
64 {
65 case ARES_DATATYPE_MX_REPLY:
66
67 if (ptr->data.mx_reply.next)
68 ares_free_data(ptr->data.mx_reply.next);
69 if (ptr->data.mx_reply.host)
70 free(ptr->data.mx_reply.host);
71 break;
72
73 case ARES_DATATYPE_SRV_REPLY:
74
75 if (ptr->data.srv_reply.next)
76 ares_free_data(ptr->data.srv_reply.next);
77 if (ptr->data.srv_reply.host)
78 free(ptr->data.srv_reply.host);
79 break;
80
81 case ARES_DATATYPE_TXT_REPLY:
82
83 if (ptr->data.txt_reply.next)
84 ares_free_data(ptr->data.txt_reply.next);
85 if (ptr->data.txt_reply.txt)
86 free(ptr->data.txt_reply.txt);
87 break;
88
89 case ARES_DATATYPE_ADDR_NODE:
90
91 if (ptr->data.addr_node.next)
92 ares_free_data(ptr->data.addr_node.next);
93 break;
94
95 default:
96 return;
97 }
98
99 free(ptr);
100 }
101
102
103 /*
104 ** ares_malloc_data() - c-ares internal helper function.
105 **
106 ** This function allocates memory for a c-ares private ares_data struct
107 ** for the specified ares_datatype, initializes c-ares private fields
108 ** and zero initializes those which later might be used from the public
109 ** API. It returns an interior pointer which can be passed by c-ares
110 ** functions to the calling application, and that must be free'ed using
111 ** c-ares external API function ares_free_data().
112 */
113
ares_malloc_data(ares_datatype type)114 void *ares_malloc_data(ares_datatype type)
115 {
116 struct ares_data *ptr;
117
118 ptr = malloc(sizeof(struct ares_data));
119 if (!ptr)
120 return NULL;
121
122 switch (type)
123 {
124 case ARES_DATATYPE_MX_REPLY:
125 ptr->data.mx_reply.next = NULL;
126 ptr->data.mx_reply.host = NULL;
127 ptr->data.mx_reply.priority = 0;
128 break;
129
130 case ARES_DATATYPE_SRV_REPLY:
131 ptr->data.srv_reply.next = NULL;
132 ptr->data.srv_reply.host = NULL;
133 ptr->data.srv_reply.priority = 0;
134 ptr->data.srv_reply.weight = 0;
135 ptr->data.srv_reply.port = 0;
136 break;
137
138 case ARES_DATATYPE_TXT_REPLY:
139 ptr->data.txt_reply.next = NULL;
140 ptr->data.txt_reply.txt = NULL;
141 ptr->data.txt_reply.length = 0;
142 break;
143
144 case ARES_DATATYPE_ADDR_NODE:
145 ptr->data.addr_node.next = NULL;
146 ptr->data.addr_node.family = 0;
147 memset(&ptr->data.addr_node.addrV6, 0,
148 sizeof(ptr->data.addr_node.addrV6));
149 break;
150
151 default:
152 free(ptr);
153 return NULL;
154 }
155
156 ptr->mark = ARES_DATATYPE_MARK;
157 ptr->type = type;
158
159 return &ptr->data;
160 }
161
162
163 /*
164 ** ares_get_datatype() - c-ares internal helper function.
165 **
166 ** This function returns the ares_datatype of the data stored in a
167 ** private ares_data struct when given the public API pointer.
168 */
169
ares_get_datatype(void * dataptr)170 ares_datatype ares_get_datatype(void * dataptr)
171 {
172 struct ares_data *ptr;
173
174 #ifdef __INTEL_COMPILER
175 # pragma warning(push)
176 # pragma warning(disable:1684)
177 /* 1684: conversion from pointer to same-sized integral type */
178 #endif
179
180 ptr = (void *)((char *)dataptr - offsetof(struct ares_data, data));
181
182 #ifdef __INTEL_COMPILER
183 # pragma warning(pop)
184 #endif
185
186 if (ptr->mark == ARES_DATATYPE_MARK)
187 return ptr->type;
188
189 return ARES_DATATYPE_UNKNOWN;
190 }
191