1 /* MIT License
2 *
3 * Copyright (c) 2009 Daniel Stenberg
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a copy
6 * of this software and associated documentation files (the "Software"), to deal
7 * in the Software without restriction, including without limitation the rights
8 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 * copies of the Software, and to permit persons to whom the Software is
10 * furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 *
24 * SPDX-License-Identifier: MIT
25 */
26
27 #include "ares_private.h"
28 #include <stddef.h>
29 #include <assert.h>
30 #include "ares_data.h"
31
32 /*
33 ** ares_free_data() - c-ares external API function.
34 **
35 ** This function must be used by the application to free data memory that
36 ** has been internally allocated by some c-ares function and for which a
37 ** pointer has already been returned to the calling application. The list
38 ** of c-ares functions returning pointers that must be free'ed using this
39 ** function is:
40 **
41 ** ares_get_servers()
42 ** ares_parse_srv_reply()
43 ** ares_parse_txt_reply()
44 */
45
ares_free_data(void * dataptr)46 void ares_free_data(void *dataptr)
47 {
48 while (dataptr != NULL) {
49 struct ares_data *ptr;
50 void *next_data = NULL;
51
52 #ifdef __INTEL_COMPILER
53 # pragma warning(push)
54 # pragma warning(disable : 1684)
55 /* 1684: conversion from pointer to same-sized integral type */
56 #endif
57
58 ptr = (void *)((char *)dataptr - offsetof(struct ares_data, data));
59
60 #ifdef __INTEL_COMPILER
61 # pragma warning(pop)
62 #endif
63
64 if (ptr->mark != ARES_DATATYPE_MARK) {
65 return;
66 }
67
68 switch (ptr->type) {
69 case ARES_DATATYPE_MX_REPLY:
70 next_data = ptr->data.mx_reply.next;
71 ares_free(ptr->data.mx_reply.host);
72 break;
73
74 case ARES_DATATYPE_SRV_REPLY:
75 next_data = ptr->data.srv_reply.next;
76 ares_free(ptr->data.srv_reply.host);
77 break;
78
79 case ARES_DATATYPE_URI_REPLY:
80 next_data = ptr->data.uri_reply.next;
81 ares_free(ptr->data.uri_reply.uri);
82 break;
83
84 case ARES_DATATYPE_TXT_REPLY:
85 case ARES_DATATYPE_TXT_EXT:
86 next_data = ptr->data.txt_reply.next;
87 ares_free(ptr->data.txt_reply.txt);
88 break;
89
90 case ARES_DATATYPE_ADDR_NODE:
91 next_data = ptr->data.addr_node.next;
92 break;
93
94 case ARES_DATATYPE_ADDR_PORT_NODE:
95 next_data = ptr->data.addr_port_node.next;
96 break;
97
98 case ARES_DATATYPE_NAPTR_REPLY:
99 next_data = ptr->data.naptr_reply.next;
100 ares_free(ptr->data.naptr_reply.flags);
101 ares_free(ptr->data.naptr_reply.service);
102 ares_free(ptr->data.naptr_reply.regexp);
103 ares_free(ptr->data.naptr_reply.replacement);
104 break;
105
106 case ARES_DATATYPE_SOA_REPLY:
107 ares_free(ptr->data.soa_reply.nsname);
108 ares_free(ptr->data.soa_reply.hostmaster);
109 break;
110
111 case ARES_DATATYPE_CAA_REPLY:
112 next_data = ptr->data.caa_reply.next;
113 ares_free(ptr->data.caa_reply.property);
114 ares_free(ptr->data.caa_reply.value);
115 break;
116
117 default:
118 return;
119 }
120
121 ares_free(ptr);
122 dataptr = next_data;
123 }
124 }
125
126 /*
127 ** ares_malloc_data() - c-ares internal helper function.
128 **
129 ** This function allocates memory for a c-ares private ares_data struct
130 ** for the specified ares_datatype, initializes c-ares private fields
131 ** and zero initializes those which later might be used from the public
132 ** API. It returns an interior pointer which can be passed by c-ares
133 ** functions to the calling application, and that must be free'ed using
134 ** c-ares external API function ares_free_data().
135 */
136
ares_malloc_data(ares_datatype type)137 void *ares_malloc_data(ares_datatype type)
138 {
139 struct ares_data *ptr;
140
141 ptr = ares_malloc_zero(sizeof(*ptr));
142 if (!ptr) {
143 return NULL;
144 }
145
146 switch (type) {
147 case ARES_DATATYPE_MX_REPLY:
148 case ARES_DATATYPE_SRV_REPLY:
149 case ARES_DATATYPE_URI_REPLY:
150 case ARES_DATATYPE_TXT_EXT:
151 case ARES_DATATYPE_TXT_REPLY:
152 case ARES_DATATYPE_CAA_REPLY:
153 case ARES_DATATYPE_ADDR_NODE:
154 case ARES_DATATYPE_ADDR_PORT_NODE:
155 case ARES_DATATYPE_NAPTR_REPLY:
156 case ARES_DATATYPE_SOA_REPLY:
157 break;
158
159 default:
160 ares_free(ptr);
161 return NULL;
162 }
163
164 ptr->mark = ARES_DATATYPE_MARK;
165 ptr->type = type;
166
167 return &ptr->data;
168 }
169