1 /* MIT License
2  *
3  * Copyright (c) 1998 Massachusetts Institute of Technology
4  * Copyright (c) 2019 Andrew Selivanov
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the next
14  * paragraph) shall be included in all copies or substantial portions of the
15  * Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23  * SOFTWARE.
24  *
25  * SPDX-License-Identifier: MIT
26  */
27 
28 #include "ares_setup.h"
29 
30 #ifdef HAVE_NETINET_IN_H
31 #  include <netinet/in.h>
32 #endif
33 #ifdef HAVE_NETDB_H
34 #  include <netdb.h>
35 #endif
36 #ifdef HAVE_ARPA_INET_H
37 #  include <arpa/inet.h>
38 #endif
39 
40 #include "ares_nameser.h"
41 
42 #ifdef HAVE_STRINGS_H
43 #  include <strings.h>
44 #endif
45 
46 #ifdef HAVE_LIMITS_H
47 #  include <limits.h>
48 #endif
49 
50 #include "ares.h"
51 #include "ares_dns.h"
52 #include "ares_private.h"
53 
ares_parse_a_reply(const unsigned char *abuf, int alen, struct hostent **host, struct ares_addrttl *addrttls, int *naddrttls)54 int ares_parse_a_reply(const unsigned char *abuf, int alen,
55                        struct hostent **host, struct ares_addrttl *addrttls,
56                        int *naddrttls)
57 {
58   struct ares_addrinfo ai;
59   char                *question_hostname = NULL;
60   ares_status_t        status;
61   size_t               req_naddrttls = 0;
62 
63   if (alen < 0) {
64     return ARES_EBADRESP;
65   }
66 
67   if (naddrttls) {
68     req_naddrttls = (size_t)*naddrttls;
69     *naddrttls    = 0;
70   }
71 
72   memset(&ai, 0, sizeof(ai));
73 
74   status = ares__parse_into_addrinfo(abuf, (size_t)alen, 0, 0, &ai);
75   if (status != ARES_SUCCESS && status != ARES_ENODATA) {
76     goto fail;
77   }
78 
79   if (host != NULL) {
80     status = ares__addrinfo2hostent(&ai, AF_INET, host);
81     if (status != ARES_SUCCESS && status != ARES_ENODATA) {
82       goto fail;
83     }
84   }
85 
86   if (addrttls != NULL && req_naddrttls) {
87     size_t temp_naddrttls = 0;
88     ares__addrinfo2addrttl(&ai, AF_INET, req_naddrttls, addrttls, NULL,
89                            &temp_naddrttls);
90     *naddrttls = (int)temp_naddrttls;
91   }
92 
93 
94 fail:
95   ares__freeaddrinfo_cnames(ai.cnames);
96   ares__freeaddrinfo_nodes(ai.nodes);
97   ares_free(ai.name);
98   ares_free(question_hostname);
99 
100   return (int)status;
101 }
102