1 
2 /* Copyright (C) 2009-2013 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   while (dataptr != NULL) {
44     struct ares_data *ptr;
45     void *next_data = NULL;
46 
47 #ifdef __INTEL_COMPILER
48 #  pragma warning(push)
49 #  pragma warning(disable:1684)
50    /* 1684: conversion from pointer to same-sized integral type */
51 #endif
52 
53     ptr = (void *)((char *)dataptr - offsetof(struct ares_data, data));
54 
55 #ifdef __INTEL_COMPILER
56 #  pragma warning(pop)
57 #endif
58 
59     if (ptr->mark != ARES_DATATYPE_MARK)
60       return;
61 
62     switch (ptr->type)
63       {
64         case ARES_DATATYPE_MX_REPLY:
65 
66           if (ptr->data.mx_reply.next)
67             next_data = ptr->data.mx_reply.next;
68           if (ptr->data.mx_reply.host)
69             ares_free(ptr->data.mx_reply.host);
70           break;
71 
72         case ARES_DATATYPE_SRV_REPLY:
73 
74           if (ptr->data.srv_reply.next)
75             next_data = ptr->data.srv_reply.next;
76           if (ptr->data.srv_reply.host)
77             ares_free(ptr->data.srv_reply.host);
78           break;
79 
80         case ARES_DATATYPE_TXT_REPLY:
81         case ARES_DATATYPE_TXT_EXT:
82 
83           if (ptr->data.txt_reply.next)
84             next_data = ptr->data.txt_reply.next;
85           if (ptr->data.txt_reply.txt)
86             ares_free(ptr->data.txt_reply.txt);
87           break;
88 
89         case ARES_DATATYPE_ADDR_NODE:
90 
91           if (ptr->data.addr_node.next)
92             next_data = ptr->data.addr_node.next;
93           break;
94 
95         case ARES_DATATYPE_ADDR_PORT_NODE:
96 
97           if (ptr->data.addr_port_node.next)
98             next_data = ptr->data.addr_port_node.next;
99           break;
100 
101         case ARES_DATATYPE_NAPTR_REPLY:
102 
103           if (ptr->data.naptr_reply.next)
104             next_data = ptr->data.naptr_reply.next;
105           if (ptr->data.naptr_reply.flags)
106             ares_free(ptr->data.naptr_reply.flags);
107           if (ptr->data.naptr_reply.service)
108             ares_free(ptr->data.naptr_reply.service);
109           if (ptr->data.naptr_reply.regexp)
110             ares_free(ptr->data.naptr_reply.regexp);
111           if (ptr->data.naptr_reply.replacement)
112             ares_free(ptr->data.naptr_reply.replacement);
113           break;
114 
115         case ARES_DATATYPE_SOA_REPLY:
116           if (ptr->data.soa_reply.nsname)
117             ares_free(ptr->data.soa_reply.nsname);
118           if (ptr->data.soa_reply.hostmaster)
119             ares_free(ptr->data.soa_reply.hostmaster);
120           break;
121 
122         case ARES_DATATYPE_CAA_REPLY:
123 
124           if (ptr->data.caa_reply.next)
125             next_data = ptr->data.caa_reply.next;
126           if (ptr->data.caa_reply.property)
127             ares_free(ptr->data.caa_reply.property);
128           if (ptr->data.caa_reply.value)
129             ares_free(ptr->data.caa_reply.value);
130           break;
131 
132         default:
133           return;
134       }
135 
136     ares_free(ptr);
137     dataptr = next_data;
138   }
139 }
140 
141 
142 /*
143 ** ares_malloc_data() - c-ares internal helper function.
144 **
145 ** This function allocates memory for a c-ares private ares_data struct
146 ** for the specified ares_datatype, initializes c-ares private fields
147 ** and zero initializes those which later might be used from the public
148 ** API. It returns an interior pointer which can be passed by c-ares
149 ** functions to the calling application, and that must be free'ed using
150 ** c-ares external API function ares_free_data().
151 */
152 
ares_malloc_data(ares_datatype type)153 void *ares_malloc_data(ares_datatype type)
154 {
155   struct ares_data *ptr;
156 
157   ptr = ares_malloc(sizeof(struct ares_data));
158   if (!ptr)
159     return NULL;
160 
161   switch (type)
162     {
163       case ARES_DATATYPE_MX_REPLY:
164         ptr->data.mx_reply.next = NULL;
165         ptr->data.mx_reply.host = NULL;
166         ptr->data.mx_reply.priority = 0;
167         break;
168 
169       case ARES_DATATYPE_SRV_REPLY:
170         ptr->data.srv_reply.next = NULL;
171         ptr->data.srv_reply.host = NULL;
172         ptr->data.srv_reply.priority = 0;
173         ptr->data.srv_reply.weight = 0;
174         ptr->data.srv_reply.port = 0;
175         break;
176 
177       case ARES_DATATYPE_TXT_EXT:
178         ptr->data.txt_ext.record_start = 0;
179         /* FALLTHROUGH */
180 
181       case ARES_DATATYPE_TXT_REPLY:
182         ptr->data.txt_reply.next = NULL;
183         ptr->data.txt_reply.txt = NULL;
184         ptr->data.txt_reply.length = 0;
185         break;
186 
187       case ARES_DATATYPE_CAA_REPLY:
188         ptr->data.caa_reply.next = NULL;
189         ptr->data.caa_reply.plength = 0;
190         ptr->data.caa_reply.property = NULL;
191         ptr->data.caa_reply.length = 0;
192         ptr->data.caa_reply.value = NULL;
193         break;
194 
195       case ARES_DATATYPE_ADDR_NODE:
196         ptr->data.addr_node.next = NULL;
197         ptr->data.addr_node.family = 0;
198         memset(&ptr->data.addr_node.addrV6, 0,
199                sizeof(ptr->data.addr_node.addrV6));
200         break;
201 
202       case ARES_DATATYPE_ADDR_PORT_NODE:
203         ptr->data.addr_port_node.next = NULL;
204         ptr->data.addr_port_node.family = 0;
205         ptr->data.addr_port_node.udp_port = 0;
206         ptr->data.addr_port_node.tcp_port = 0;
207         memset(&ptr->data.addr_port_node.addrV6, 0,
208                sizeof(ptr->data.addr_port_node.addrV6));
209         break;
210 
211       case ARES_DATATYPE_NAPTR_REPLY:
212         ptr->data.naptr_reply.next = NULL;
213         ptr->data.naptr_reply.flags = NULL;
214         ptr->data.naptr_reply.service = NULL;
215         ptr->data.naptr_reply.regexp = NULL;
216         ptr->data.naptr_reply.replacement = NULL;
217         ptr->data.naptr_reply.order = 0;
218         ptr->data.naptr_reply.preference = 0;
219         break;
220 
221       case ARES_DATATYPE_SOA_REPLY:
222         ptr->data.soa_reply.nsname = NULL;
223         ptr->data.soa_reply.hostmaster = NULL;
224         ptr->data.soa_reply.serial = 0;
225         ptr->data.soa_reply.refresh = 0;
226         ptr->data.soa_reply.retry = 0;
227         ptr->data.soa_reply.expire = 0;
228         ptr->data.soa_reply.minttl = 0;
229 	break;
230 
231       default:
232         ares_free(ptr);
233         return NULL;
234     }
235 
236   ptr->mark = ARES_DATATYPE_MARK;
237   ptr->type = type;
238 
239   return &ptr->data;
240 }
241