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#ifndef HEADER_CURL_DOH_H
#define HEADER_CURL_DOH_H
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "urldata.h"
#include "curl_addrinfo.h"
#ifdef USE_HTTPSRR
# include <stdint.h>
#endif
#ifndef CURL_DISABLE_DOH
typedef enum {
DOH_OK,
DOH_DNS_BAD_LABEL, /* 1 */
DOH_DNS_OUT_OF_RANGE, /* 2 */
DOH_DNS_LABEL_LOOP, /* 3 */
DOH_TOO_SMALL_BUFFER, /* 4 */
DOH_OUT_OF_MEM, /* 5 */
DOH_DNS_RDATA_LEN, /* 6 */
DOH_DNS_MALFORMAT, /* 7 */
DOH_DNS_BAD_RCODE, /* 8 - no such name */
DOH_DNS_UNEXPECTED_TYPE, /* 9 */
DOH_DNS_UNEXPECTED_CLASS, /* 10 */
DOH_NO_CONTENT, /* 11 */
DOH_DNS_BAD_ID, /* 12 */
DOH_DNS_NAME_TOO_LONG /* 13 */
} DOHcode;
typedef enum {
DNS_TYPE_A = 1,
DNS_TYPE_NS = 2,
DNS_TYPE_CNAME = 5,
DNS_TYPE_AAAA = 28,
DNS_TYPE_DNAME = 39, /* RFC6672 */
DNS_TYPE_HTTPS = 65
} DNStype;
/* one of these for each DoH request */
struct doh_probe {
curl_off_t easy_mid; /* multi id of easy handle doing the lookup */
DNStype dnstype;
unsigned char req_body[512];
size_t req_body_len;
struct dynbuf resp_body;
};
enum doh_slot_num {
/* Explicit values for first two symbols so as to match hard-coded
* constants in existing code
*/
DOH_SLOT_IPV4 = 0, /* make 'V4' stand out for readability */
DOH_SLOT_IPV6 = 1, /* 'V6' likewise */
/* Space here for (possibly build-specific) additional slot definitions */
#ifdef USE_HTTPSRR
DOH_SLOT_HTTPS_RR = 2, /* for HTTPS RR */
#endif
/* for example */
/* #ifdef WANT_DOH_FOOBAR_TXT */
/* DOH_PROBE_SLOT_FOOBAR_TXT, */
/* #endif */
/* AFTER all slot definitions, establish how many we have */
DOH_SLOT_COUNT
};
struct doh_probes {
struct curl_slist *req_hds;
struct doh_probe probe[DOH_SLOT_COUNT];
unsigned int pending; /* still outstanding probes */
int port;
const char *host;
};
/*
* Curl_doh() resolve a name using DoH (DNS-over-HTTPS). It resolves a name
* and returns a 'Curl_addrinfo *' with the address information.
*/
struct Curl_addrinfo *Curl_doh(struct Curl_easy *data,
const char *hostname,
int port,
int *waitp);
CURLcode Curl_doh_is_resolved(struct Curl_easy *data,
struct Curl_dns_entry **dns);
#define DOH_MAX_ADDR 24
#define DOH_MAX_CNAME 4
#define DOH_MAX_HTTPS 4
struct dohaddr {
int type;
union {
unsigned char v4[4]; /* network byte order */
unsigned char v6[16];
} ip;
};
#ifdef USE_HTTPSRR
/*
* These are the code points for DNS wire format SvcParams as
* per draft-ietf-dnsop-svcb-https
* Not all are supported now, and even those that are may need
* more work in future to fully support the spec.
*/
#define HTTPS_RR_CODE_ALPN 0x01
#define HTTPS_RR_CODE_NO_DEF_ALPN 0x02
#define HTTPS_RR_CODE_PORT 0x03
#define HTTPS_RR_CODE_IPV4 0x04
#define HTTPS_RR_CODE_ECH 0x05
#define HTTPS_RR_CODE_IPV6 0x06
/*
* These may need escaping when found within an ALPN string
* value.
*/
#define COMMA_CHAR ','
#define BACKSLASH_CHAR '\\'
struct dohhttps_rr {
uint16_t len; /* raw encoded length */
unsigned char *val; /* raw encoded octets */
};
#endif
struct dohentry {
struct dynbuf cname[DOH_MAX_CNAME];
struct dohaddr addr[DOH_MAX_ADDR];
int numaddr;
unsigned int ttl;
int numcname;
#ifdef USE_HTTPSRR
struct dohhttps_rr https_rrs[DOH_MAX_HTTPS];
int numhttps_rrs;
#endif
};
void Curl_doh_close(struct Curl_easy *data);
void Curl_doh_cleanup(struct Curl_easy *data);
#ifdef UNITTESTS
UNITTEST DOHcode doh_req_encode(const char *host,
DNStype dnstype,
unsigned char *dnsp, /* buffer */
size_t len, /* buffer size */
size_t *olen); /* output length */
UNITTEST DOHcode doh_resp_decode(const unsigned char *doh,
size_t dohlen,
DNStype dnstype,
struct dohentry *d);
UNITTEST void de_init(struct dohentry *d);
UNITTEST void de_cleanup(struct dohentry *d);
#endif
extern struct curl_trc_feat Curl_doh_trc;
#else /* if DoH is disabled */
#define Curl_doh(a,b,c,d) NULL
#define Curl_doh_is_resolved(x,y) CURLE_COULDNT_RESOLVE_HOST
#endif
#endif /* HEADER_CURL_DOH_H */
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