aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/c-ares/src/lib/legacy/ares_parse_caa_reply.c
blob: f74358f456696520de45be2340020b0c182dc00e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/* MIT License
 *
 * Copyright (c) 2023 Brad House
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * SPDX-License-Identifier: MIT
 */

#include "ares_private.h"
#include "ares_data.h"

int ares_parse_caa_reply(const unsigned char *abuf, int alen_int,
                         struct ares_caa_reply **caa_out)
{
  ares_status_t          status;
  size_t                 alen;
  struct ares_caa_reply *caa_head = NULL;
  struct ares_caa_reply *caa_last = NULL;
  struct ares_caa_reply *caa_curr;
  ares_dns_record_t     *dnsrec = NULL;
  size_t                 i;

  *caa_out = NULL;

  if (alen_int < 0) {
    return ARES_EBADRESP;
  }

  alen = (size_t)alen_int;

  status = ares_dns_parse(abuf, alen, 0, &dnsrec);
  if (status != ARES_SUCCESS) {
    goto done;
  }

  if (ares_dns_record_rr_cnt(dnsrec, ARES_SECTION_ANSWER) == 0) {
    status = ARES_ENODATA;
    goto done;
  }

  for (i = 0; i < ares_dns_record_rr_cnt(dnsrec, ARES_SECTION_ANSWER); i++) {
    const unsigned char *ptr;
    size_t               ptr_len;
    const ares_dns_rr_t *rr =
      ares_dns_record_rr_get(dnsrec, ARES_SECTION_ANSWER, i);

    if (rr == NULL) {
      /* Shouldn't be possible */
      status = ARES_EBADRESP; /* LCOV_EXCL_LINE: DefensiveCoding */
      goto done;              /* LCOV_EXCL_LINE: DefensiveCoding */
    }

    /* XXX: Why do we allow Chaos class? */
    if (ares_dns_rr_get_class(rr) != ARES_CLASS_IN &&
        ares_dns_rr_get_class(rr) != ARES_CLASS_CHAOS) {
      continue;
    }

    /* Only looking for CAA records */
    if (ares_dns_rr_get_type(rr) != ARES_REC_TYPE_CAA) {
      continue;
    }

    /* Allocate storage for this CAA answer appending it to the list */
    caa_curr = ares_malloc_data(ARES_DATATYPE_CAA_REPLY);
    if (caa_curr == NULL) {
      status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */
      goto done;            /* LCOV_EXCL_LINE: OutOfMemory */
    }

    /* Link in the record */
    if (caa_last) {
      caa_last->next = caa_curr;
    } else {
      caa_head = caa_curr;
    }
    caa_last = caa_curr;

    caa_curr->critical = ares_dns_rr_get_u8(rr, ARES_RR_CAA_CRITICAL);
    caa_curr->property =
      (unsigned char *)ares_strdup(ares_dns_rr_get_str(rr, ARES_RR_CAA_TAG));
    if (caa_curr->property == NULL) {
      status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */
      break;                /* LCOV_EXCL_LINE: OutOfMemory */
    }
    /* RFC6844 says this can only be ascii, so not sure why we're recording a
     * length */
    caa_curr->plength = ares_strlen((const char *)caa_curr->property);

    ptr = ares_dns_rr_get_bin(rr, ARES_RR_CAA_VALUE, &ptr_len);
    if (ptr == NULL) {
      status = ARES_EBADRESP; /* LCOV_EXCL_LINE: DefensiveCoding */
      goto done;              /* LCOV_EXCL_LINE: DefensiveCoding */
    }

    /* Wants NULL termination for some reason */
    caa_curr->value = ares_malloc(ptr_len + 1);
    if (caa_curr->value == NULL) {
      status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */
      goto done;            /* LCOV_EXCL_LINE: OutOfMemory */
    }
    memcpy(caa_curr->value, ptr, ptr_len);
    caa_curr->value[ptr_len] = 0;
    caa_curr->length         = ptr_len;
  }

done:
  /* clean up on error */
  if (status != ARES_SUCCESS) {
    if (caa_head) {
      ares_free_data(caa_head);
    }
  } else {
    /* everything looks fine, return the data */
    *caa_out = caa_head;
  }
  ares_dns_record_destroy(dnsrec);
  return (int)status;
}