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 #ifdef USE_HTTPSRR 30 # include <stdint.h> 31 #endif 32 33 #ifndef CURL_DISABLE_DOH 34 35 typedef enum { 36 DOH_OK, 37 DOH_DNS_BAD_LABEL, /* 1 */ 38 DOH_DNS_OUT_OF_RANGE, /* 2 */ 39 DOH_DNS_LABEL_LOOP, /* 3 */ 40 DOH_TOO_SMALL_BUFFER, /* 4 */ 41 DOH_OUT_OF_MEM, /* 5 */ 42 DOH_DNS_RDATA_LEN, /* 6 */ 43 DOH_DNS_MALFORMAT, /* 7 */ 44 DOH_DNS_BAD_RCODE, /* 8 - no such name */ 45 DOH_DNS_UNEXPECTED_TYPE, /* 9 */ 46 DOH_DNS_UNEXPECTED_CLASS, /* 10 */ 47 DOH_NO_CONTENT, /* 11 */ 48 DOH_DNS_BAD_ID, /* 12 */ 49 DOH_DNS_NAME_TOO_LONG /* 13 */ 50 } DOHcode; 51 52 typedef enum { 53 DNS_TYPE_A = 1, 54 DNS_TYPE_NS = 2, 55 DNS_TYPE_CNAME = 5, 56 DNS_TYPE_AAAA = 28, 57 DNS_TYPE_DNAME = 39, /* RFC6672 */ 58 DNS_TYPE_HTTPS = 65 59 } DNStype; 60 61 /* one of these for each DoH request */ 62 struct doh_probe { 63 curl_off_t easy_mid; /* multi id of easy handle doing the lookup */ 64 DNStype dnstype; 65 unsigned char req_body[512]; 66 size_t req_body_len; 67 struct dynbuf resp_body; 68 }; 69 70 enum doh_slot_num { 71 /* Explicit values for first two symbols so as to match hard-coded 72 * constants in existing code 73 */ 74 DOH_SLOT_IPV4 = 0, /* make 'V4' stand out for readability */ 75 DOH_SLOT_IPV6 = 1, /* 'V6' likewise */ 76 77 /* Space here for (possibly build-specific) additional slot definitions */ 78 #ifdef USE_HTTPSRR 79 DOH_SLOT_HTTPS_RR = 2, /* for HTTPS RR */ 80 #endif 81 82 /* for example */ 83 /* #ifdef WANT_DOH_FOOBAR_TXT */ 84 /* DOH_PROBE_SLOT_FOOBAR_TXT, */ 85 /* #endif */ 86 87 /* AFTER all slot definitions, establish how many we have */ 88 DOH_SLOT_COUNT 89 }; 90 91 struct doh_probes { 92 struct curl_slist *req_hds; 93 struct doh_probe probe[DOH_SLOT_COUNT]; 94 unsigned int pending; /* still outstanding probes */ 95 int port; 96 const char *host; 97 }; 98 99 /* 100 * Curl_doh() resolve a name using DoH (DNS-over-HTTPS). It resolves a name 101 * and returns a 'Curl_addrinfo *' with the address information. 102 */ 103 104 struct Curl_addrinfo *Curl_doh(struct Curl_easy *data, 105 const char *hostname, 106 int port, 107 int *waitp); 108 109 CURLcode Curl_doh_is_resolved(struct Curl_easy *data, 110 struct Curl_dns_entry **dns); 111 112 #define DOH_MAX_ADDR 24 113 #define DOH_MAX_CNAME 4 114 #define DOH_MAX_HTTPS 4 115 116 struct dohaddr { 117 int type; 118 union { 119 unsigned char v4[4]; /* network byte order */ 120 unsigned char v6[16]; 121 } ip; 122 }; 123 124 #ifdef USE_HTTPSRR 125 126 /* 127 * These are the code points for DNS wire format SvcParams as 128 * per draft-ietf-dnsop-svcb-https 129 * Not all are supported now, and even those that are may need 130 * more work in future to fully support the spec. 131 */ 132 #define HTTPS_RR_CODE_ALPN 0x01 133 #define HTTPS_RR_CODE_NO_DEF_ALPN 0x02 134 #define HTTPS_RR_CODE_PORT 0x03 135 #define HTTPS_RR_CODE_IPV4 0x04 136 #define HTTPS_RR_CODE_ECH 0x05 137 #define HTTPS_RR_CODE_IPV6 0x06 138 139 /* 140 * These may need escaping when found within an ALPN string 141 * value. 142 */ 143 #define COMMA_CHAR ',' 144 #define BACKSLASH_CHAR '\\' 145 146 struct dohhttps_rr { 147 uint16_t len; /* raw encoded length */ 148 unsigned char *val; /* raw encoded octets */ 149 }; 150 #endif 151 152 struct dohentry { 153 struct dynbuf cname[DOH_MAX_CNAME]; 154 struct dohaddr addr[DOH_MAX_ADDR]; 155 int numaddr; 156 unsigned int ttl; 157 int numcname; 158 #ifdef USE_HTTPSRR 159 struct dohhttps_rr https_rrs[DOH_MAX_HTTPS]; 160 int numhttps_rrs; 161 #endif 162 }; 163 164 void Curl_doh_close(struct Curl_easy *data); 165 void Curl_doh_cleanup(struct Curl_easy *data); 166 167 #ifdef UNITTESTS 168 UNITTEST DOHcode doh_req_encode(const char *host, 169 DNStype dnstype, 170 unsigned char *dnsp, /* buffer */ 171 size_t len, /* buffer size */ 172 size_t *olen); /* output length */ 173 UNITTEST DOHcode doh_resp_decode(const unsigned char *doh, 174 size_t dohlen, 175 DNStype dnstype, 176 struct dohentry *d); 177 178 UNITTEST void de_init(struct dohentry *d); 179 UNITTEST void de_cleanup(struct dohentry *d); 180 #endif 181 182 extern struct curl_trc_feat Curl_doh_trc; 183 184 #else /* if DoH is disabled */ 185 #define Curl_doh(a,b,c,d) NULL 186 #define Curl_doh_is_resolved(x,y) CURLE_COULDNT_RESOLVE_HOST 187 #endif 188 189 #endif /* HEADER_CURL_DOH_H */ 190
