quickjs-tart

quickjs-based runtime for wallet-core logic
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ares_parse_mx_reply.c (3451B)

      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_mx_reply(const unsigned char *abuf, int alen_int,
     31                         struct ares_mx_reply **mx_out)
     32 {
     33   ares_status_t         status;
     34   size_t                alen;
     35   struct ares_mx_reply *mx_head = NULL;
     36   struct ares_mx_reply *mx_last = NULL;
     37   struct ares_mx_reply *mx_curr;
     38   ares_dns_record_t    *dnsrec = NULL;
     39   size_t                i;
     40 
     41   *mx_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_MX) {
     71       continue;
     72     }
     73 
     74     /* Allocate storage for this MX answer appending it to the list */
     75     mx_curr = ares_malloc_data(ARES_DATATYPE_MX_REPLY);
     76     if (mx_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 (mx_last) {
     83       mx_last->next = mx_curr;
     84     } else {
     85       mx_head = mx_curr;
     86     }
     87     mx_last = mx_curr;
     88 
     89     mx_curr->priority = ares_dns_rr_get_u16(rr, ARES_RR_MX_PREFERENCE);
     90     mx_curr->host = ares_strdup(ares_dns_rr_get_str(rr, ARES_RR_MX_EXCHANGE));
     91 
     92     if (mx_curr->host == NULL) {
     93       status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */
     94       goto done;            /* LCOV_EXCL_LINE: OutOfMemory */
     95     }
     96   }
     97 
     98 done:
     99   /* clean up on error */
    100   if (status != ARES_SUCCESS) {
    101     if (mx_head) {
    102       ares_free_data(mx_head);
    103     }
    104   } else {
    105     /* everything looks fine, return the data */
    106     *mx_out = mx_head;
    107   }
    108   ares_dns_record_destroy(dnsrec);
    109   return (int)status;
    110 }