xref: /third_party/curl/lib/doh.h (revision 13498266) 
1#ifndef HEADER_CURL_DOH_H
2#define HEADER_CURL_DOH_H
3/***************************************************************************
4 *                                  _   _ ____  _
5 *  Project                     ___| | | |  _ \| |
6 *                             / __| | | | |_) | |
7 *                            | (__| |_| |  _ <| |___
8 *                             \___|\___/|_| \_\_____|
9 *
10 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
11 *
12 * This software is licensed as described in the file COPYING, which
13 * you should have received as part of this distribution. The terms
14 * are also available at https://curl.se/docs/copyright.html.
15 *
16 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
17 * copies of the Software, and permit persons to whom the Software is
18 * furnished to do so, under the terms of the COPYING file.
19 *
20 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
21 * KIND, either express or implied.
22 *
23 * SPDX-License-Identifier: curl
24 *
25 ***************************************************************************/
26
27#include "urldata.h"
28#include "curl_addrinfo.h"
29
30#ifndef CURL_DISABLE_DOH
31
32typedef enum {
33  DOH_OK,
34  DOH_DNS_BAD_LABEL,    /* 1 */
35  DOH_DNS_OUT_OF_RANGE, /* 2 */
36  DOH_DNS_LABEL_LOOP,   /* 3 */
37  DOH_TOO_SMALL_BUFFER, /* 4 */
38  DOH_OUT_OF_MEM,       /* 5 */
39  DOH_DNS_RDATA_LEN,    /* 6 */
40  DOH_DNS_MALFORMAT,    /* 7 */
41  DOH_DNS_BAD_RCODE,    /* 8 - no such name */
42  DOH_DNS_UNEXPECTED_TYPE,  /* 9 */
43  DOH_DNS_UNEXPECTED_CLASS, /* 10 */
44  DOH_NO_CONTENT,           /* 11 */
45  DOH_DNS_BAD_ID,           /* 12 */
46  DOH_DNS_NAME_TOO_LONG     /* 13 */
47} DOHcode;
48
49typedef enum {
50  DNS_TYPE_A = 1,
51  DNS_TYPE_NS = 2,
52  DNS_TYPE_CNAME = 5,
53  DNS_TYPE_AAAA = 28,
54  DNS_TYPE_DNAME = 39           /* RFC6672 */
55} DNStype;
56
57/* one of these for each DoH request */
58struct dnsprobe {
59  CURL *easy;
60  DNStype dnstype;
61  unsigned char dohbuffer[512];
62  size_t dohlen;
63  struct dynbuf serverdoh;
64};
65
66struct dohdata {
67  struct curl_slist *headers;
68  struct dnsprobe probe[DOH_PROBE_SLOTS];
69  unsigned int pending; /* still outstanding requests */
70  int port;
71  const char *host;
72};
73
74/*
75 * Curl_doh() resolve a name using DoH (DNS-over-HTTPS). It resolves a name
76 * and returns a 'Curl_addrinfo *' with the address information.
77 */
78
79struct Curl_addrinfo *Curl_doh(struct Curl_easy *data,
80                               const char *hostname,
81                               int port,
82                               int *waitp);
83
84CURLcode Curl_doh_is_resolved(struct Curl_easy *data,
85                              struct Curl_dns_entry **dns);
86
87int Curl_doh_getsock(struct connectdata *conn, curl_socket_t *socks);
88
89#define DOH_MAX_ADDR 24
90#define DOH_MAX_CNAME 4
91
92struct dohaddr {
93  int type;
94  union {
95    unsigned char v4[4]; /* network byte order */
96    unsigned char v6[16];
97  } ip;
98};
99
100struct dohentry {
101  struct dynbuf cname[DOH_MAX_CNAME];
102  struct dohaddr addr[DOH_MAX_ADDR];
103  int numaddr;
104  unsigned int ttl;
105  int numcname;
106};
107
108
109#ifdef DEBUGBUILD
110DOHcode doh_encode(const char *host,
111                   DNStype dnstype,
112                   unsigned char *dnsp, /* buffer */
113                   size_t len,  /* buffer size */
114                   size_t *olen); /* output length */
115DOHcode doh_decode(const unsigned char *doh,
116                   size_t dohlen,
117                   DNStype dnstype,
118                   struct dohentry *d);
119void de_init(struct dohentry *d);
120void de_cleanup(struct dohentry *d);
121#endif
122
123#else /* if DoH is disabled */
124#define Curl_doh(a,b,c,d) NULL
125#define Curl_doh_is_resolved(x,y) CURLE_COULDNT_RESOLVE_HOST
126#endif
127
128#endif /* HEADER_CURL_DOH_H */
129