ares_parse_uri_reply.c (3523B)
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_private.h" 28 #include "ares_data.h" 29 30 int ares_parse_uri_reply(const unsigned char *abuf, int alen_int, 31 struct ares_uri_reply **uri_out) 32 { 33 ares_status_t status; 34 size_t alen; 35 struct ares_uri_reply *uri_head = NULL; 36 struct ares_uri_reply *uri_last = NULL; 37 struct ares_uri_reply *uri_curr; 38 ares_dns_record_t *dnsrec = NULL; 39 size_t i; 40 41 *uri_out = NULL; 42 43 if (alen_int < 0) { 44 return ARES_EBADRESP; 45 } 46 47 alen = (size_t)alen_int; 48 49 status = ares_dns_parse(abuf, alen, 0, &dnsrec); 50 if (status != ARES_SUCCESS) { 51 goto done; 52 } 53 54 if (ares_dns_record_rr_cnt(dnsrec, ARES_SECTION_ANSWER) == 0) { 55 status = ARES_ENODATA; 56 goto done; 57 } 58 59 for (i = 0; i < ares_dns_record_rr_cnt(dnsrec, ARES_SECTION_ANSWER); i++) { 60 const ares_dns_rr_t *rr = 61 ares_dns_record_rr_get(dnsrec, ARES_SECTION_ANSWER, i); 62 63 if (rr == NULL) { 64 /* Shouldn't be possible */ 65 status = ARES_EBADRESP; /* LCOV_EXCL_LINE: DefensiveCoding */ 66 goto done; /* LCOV_EXCL_LINE: DefensiveCoding */ 67 } 68 69 if (ares_dns_rr_get_class(rr) != ARES_CLASS_IN || 70 ares_dns_rr_get_type(rr) != ARES_REC_TYPE_URI) { 71 continue; 72 } 73 74 /* Allocate storage for this URI answer appending it to the list */ 75 uri_curr = ares_malloc_data(ARES_DATATYPE_URI_REPLY); 76 if (uri_curr == NULL) { 77 status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */ 78 goto done; /* LCOV_EXCL_LINE: OutOfMemory */ 79 } 80 81 /* Link in the record */ 82 if (uri_last) { 83 uri_last->next = uri_curr; 84 } else { 85 uri_head = uri_curr; 86 } 87 uri_last = uri_curr; 88 89 90 uri_curr->priority = ares_dns_rr_get_u16(rr, ARES_RR_URI_PRIORITY); 91 uri_curr->weight = ares_dns_rr_get_u16(rr, ARES_RR_URI_WEIGHT); 92 uri_curr->uri = ares_strdup(ares_dns_rr_get_str(rr, ARES_RR_URI_TARGET)); 93 uri_curr->ttl = (int)ares_dns_rr_get_ttl(rr); 94 95 if (uri_curr->uri == NULL) { 96 status = ARES_ENOMEM; 97 goto done; 98 } 99 } 100 101 done: 102 /* clean up on error */ 103 if (status != ARES_SUCCESS) { 104 if (uri_head) { 105 ares_free_data(uri_head); 106 } 107 } else { 108 /* everything looks fine, return the data */ 109 *uri_out = uri_head; 110 } 111 ares_dns_record_destroy(dnsrec); 112 return (int)status; 113 }