1 /* MIT License
2 *
3 * Copyright (c) 2023 Brad House
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_setup.h"
28 #include "ares.h"
29 #include "ares_data.h"
30 #include "ares_private.h"
31
ares_parse_uri_reply(const unsigned char * abuf,int alen_int,struct ares_uri_reply ** uri_out)32 int ares_parse_uri_reply(const unsigned char *abuf, int alen_int,
33 struct ares_uri_reply **uri_out)
34 {
35 ares_status_t status;
36 size_t alen;
37 struct ares_uri_reply *uri_head = NULL;
38 struct ares_uri_reply *uri_last = NULL;
39 struct ares_uri_reply *uri_curr;
40 ares_dns_record_t *dnsrec = NULL;
41 size_t i;
42
43 *uri_out = NULL;
44
45 if (alen_int < 0) {
46 return ARES_EBADRESP;
47 }
48
49 alen = (size_t)alen_int;
50
51 status = ares_dns_parse(abuf, alen, 0, &dnsrec);
52 if (status != ARES_SUCCESS) {
53 goto done;
54 }
55
56 if (ares_dns_record_rr_cnt(dnsrec, ARES_SECTION_ANSWER) == 0) {
57 status = ARES_ENODATA;
58 goto done;
59 }
60
61 for (i = 0; i < ares_dns_record_rr_cnt(dnsrec, ARES_SECTION_ANSWER); i++) {
62 const ares_dns_rr_t *rr =
63 ares_dns_record_rr_get(dnsrec, ARES_SECTION_ANSWER, i);
64
65 if (rr == NULL) {
66 /* Shouldn't be possible */
67 status = ARES_EBADRESP;
68 goto done;
69 }
70
71 if (ares_dns_rr_get_class(rr) != ARES_CLASS_IN ||
72 ares_dns_rr_get_type(rr) != ARES_REC_TYPE_URI) {
73 continue;
74 }
75
76 /* Allocate storage for this URI answer appending it to the list */
77 uri_curr = ares_malloc_data(ARES_DATATYPE_URI_REPLY);
78 if (uri_curr == NULL) {
79 status = ARES_ENOMEM;
80 goto done;
81 }
82
83 /* Link in the record */
84 if (uri_last) {
85 uri_last->next = uri_curr;
86 } else {
87 uri_head = uri_curr;
88 }
89 uri_last = uri_curr;
90
91
92 uri_curr->priority = ares_dns_rr_get_u16(rr, ARES_RR_URI_PRIORITY);
93 uri_curr->weight = ares_dns_rr_get_u16(rr, ARES_RR_URI_WEIGHT);
94 uri_curr->uri = ares_strdup(ares_dns_rr_get_str(rr, ARES_RR_URI_TARGET));
95 uri_curr->ttl = (int)ares_dns_rr_get_ttl(rr);
96
97 if (uri_curr->uri == NULL) {
98 status = ARES_ENOMEM;
99 goto done;
100 }
101 }
102
103 done:
104 /* clean up on error */
105 if (status != ARES_SUCCESS) {
106 if (uri_head) {
107 ares_free_data(uri_head);
108 }
109 } else {
110 /* everything looks fine, return the data */
111 *uri_out = uri_head;
112 }
113 ares_dns_record_destroy(dnsrec);
114 return (int)status;
115 }
116