983 строки
28 KiB
C
983 строки
28 KiB
C
/***************************************************************************
|
|
* _ _ ____ _
|
|
* Project ___| | | | _ \| |
|
|
* / __| | | | |_) | |
|
|
* | (__| |_| | _ <| |___
|
|
* \___|\___/|_| \_\_____|
|
|
*
|
|
* Copyright (C) 2018 - 2022, 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 "curl_setup.h"
|
|
|
|
#ifndef CURL_DISABLE_DOH
|
|
|
|
#include "urldata.h"
|
|
#include "curl_addrinfo.h"
|
|
#include "doh.h"
|
|
|
|
#include "sendf.h"
|
|
#include "multiif.h"
|
|
#include "url.h"
|
|
#include "share.h"
|
|
#include "curl_base64.h"
|
|
#include "connect.h"
|
|
#include "strdup.h"
|
|
#include "dynbuf.h"
|
|
/* The last 3 #include files should be in this order */
|
|
#include "curl_printf.h"
|
|
#include "curl_memory.h"
|
|
#include "memdebug.h"
|
|
|
|
#define DNS_CLASS_IN 0x01
|
|
|
|
#ifndef CURL_DISABLE_VERBOSE_STRINGS
|
|
static const char * const errors[]={
|
|
"",
|
|
"Bad label",
|
|
"Out of range",
|
|
"Label loop",
|
|
"Too small",
|
|
"Out of memory",
|
|
"RDATA length",
|
|
"Malformat",
|
|
"Bad RCODE",
|
|
"Unexpected TYPE",
|
|
"Unexpected CLASS",
|
|
"No content",
|
|
"Bad ID",
|
|
"Name too long"
|
|
};
|
|
|
|
static const char *doh_strerror(DOHcode code)
|
|
{
|
|
if((code >= DOH_OK) && (code <= DOH_DNS_NAME_TOO_LONG))
|
|
return errors[code];
|
|
return "bad error code";
|
|
}
|
|
#endif
|
|
|
|
/* @unittest 1655
|
|
*/
|
|
UNITTEST DOHcode doh_encode(const char *host,
|
|
DNStype dnstype,
|
|
unsigned char *dnsp, /* buffer */
|
|
size_t len, /* buffer size */
|
|
size_t *olen) /* output length */
|
|
{
|
|
const size_t hostlen = strlen(host);
|
|
unsigned char *orig = dnsp;
|
|
const char *hostp = host;
|
|
|
|
/* The expected output length is 16 bytes more than the length of
|
|
* the QNAME-encoding of the host name.
|
|
*
|
|
* A valid DNS name may not contain a zero-length label, except at
|
|
* the end. For this reason, a name beginning with a dot, or
|
|
* containing a sequence of two or more consecutive dots, is invalid
|
|
* and cannot be encoded as a QNAME.
|
|
*
|
|
* If the host name ends with a trailing dot, the corresponding
|
|
* QNAME-encoding is one byte longer than the host name. If (as is
|
|
* also valid) the hostname is shortened by the omission of the
|
|
* trailing dot, then its QNAME-encoding will be two bytes longer
|
|
* than the host name.
|
|
*
|
|
* Each [ label, dot ] pair is encoded as [ length, label ],
|
|
* preserving overall length. A final [ label ] without a dot is
|
|
* also encoded as [ length, label ], increasing overall length
|
|
* by one. The encoding is completed by appending a zero byte,
|
|
* representing the zero-length root label, again increasing
|
|
* the overall length by one.
|
|
*/
|
|
|
|
size_t expected_len;
|
|
DEBUGASSERT(hostlen);
|
|
expected_len = 12 + 1 + hostlen + 4;
|
|
if(host[hostlen-1]!='.')
|
|
expected_len++;
|
|
|
|
if(expected_len > (256 + 16)) /* RFCs 1034, 1035 */
|
|
return DOH_DNS_NAME_TOO_LONG;
|
|
|
|
if(len < expected_len)
|
|
return DOH_TOO_SMALL_BUFFER;
|
|
|
|
*dnsp++ = 0; /* 16 bit id */
|
|
*dnsp++ = 0;
|
|
*dnsp++ = 0x01; /* |QR| Opcode |AA|TC|RD| Set the RD bit */
|
|
*dnsp++ = '\0'; /* |RA| Z | RCODE | */
|
|
*dnsp++ = '\0';
|
|
*dnsp++ = 1; /* QDCOUNT (number of entries in the question section) */
|
|
*dnsp++ = '\0';
|
|
*dnsp++ = '\0'; /* ANCOUNT */
|
|
*dnsp++ = '\0';
|
|
*dnsp++ = '\0'; /* NSCOUNT */
|
|
*dnsp++ = '\0';
|
|
*dnsp++ = '\0'; /* ARCOUNT */
|
|
|
|
/* encode each label and store it in the QNAME */
|
|
while(*hostp) {
|
|
size_t labellen;
|
|
char *dot = strchr(hostp, '.');
|
|
if(dot)
|
|
labellen = dot - hostp;
|
|
else
|
|
labellen = strlen(hostp);
|
|
if((labellen > 63) || (!labellen)) {
|
|
/* label is too long or too short, error out */
|
|
*olen = 0;
|
|
return DOH_DNS_BAD_LABEL;
|
|
}
|
|
/* label is non-empty, process it */
|
|
*dnsp++ = (unsigned char)labellen;
|
|
memcpy(dnsp, hostp, labellen);
|
|
dnsp += labellen;
|
|
hostp += labellen;
|
|
/* advance past dot, but only if there is one */
|
|
if(dot)
|
|
hostp++;
|
|
} /* next label */
|
|
|
|
*dnsp++ = 0; /* append zero-length label for root */
|
|
|
|
/* There are assigned TYPE codes beyond 255: use range [1..65535] */
|
|
*dnsp++ = (unsigned char)(255 & (dnstype>>8)); /* upper 8 bit TYPE */
|
|
*dnsp++ = (unsigned char)(255 & dnstype); /* lower 8 bit TYPE */
|
|
|
|
*dnsp++ = '\0'; /* upper 8 bit CLASS */
|
|
*dnsp++ = DNS_CLASS_IN; /* IN - "the Internet" */
|
|
|
|
*olen = dnsp - orig;
|
|
|
|
/* verify that our estimation of length is valid, since
|
|
* this has led to buffer overflows in this function */
|
|
DEBUGASSERT(*olen == expected_len);
|
|
return DOH_OK;
|
|
}
|
|
|
|
static size_t
|
|
doh_write_cb(const void *contents, size_t size, size_t nmemb, void *userp)
|
|
{
|
|
size_t realsize = size * nmemb;
|
|
struct dynbuf *mem = (struct dynbuf *)userp;
|
|
|
|
if(Curl_dyn_addn(mem, contents, realsize))
|
|
return 0;
|
|
|
|
return realsize;
|
|
}
|
|
|
|
/* called from multi.c when this DoH transfer is complete */
|
|
static int doh_done(struct Curl_easy *doh, CURLcode result)
|
|
{
|
|
struct Curl_easy *data = doh->set.dohfor;
|
|
struct dohdata *dohp = data->req.doh;
|
|
/* so one of the DoH request done for the 'data' transfer is now complete! */
|
|
dohp->pending--;
|
|
infof(data, "a DoH request is completed, %u to go", dohp->pending);
|
|
if(result)
|
|
infof(data, "DoH request %s", curl_easy_strerror(result));
|
|
|
|
if(!dohp->pending) {
|
|
/* DoH completed */
|
|
curl_slist_free_all(dohp->headers);
|
|
dohp->headers = NULL;
|
|
Curl_expire(data, 0, EXPIRE_RUN_NOW);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#define ERROR_CHECK_SETOPT(x,y) \
|
|
do { \
|
|
result = curl_easy_setopt(doh, x, y); \
|
|
if(result && \
|
|
result != CURLE_NOT_BUILT_IN && \
|
|
result != CURLE_UNKNOWN_OPTION) \
|
|
goto error; \
|
|
} while(0)
|
|
|
|
static CURLcode dohprobe(struct Curl_easy *data,
|
|
struct dnsprobe *p, DNStype dnstype,
|
|
const char *host,
|
|
const char *url, CURLM *multi,
|
|
struct curl_slist *headers)
|
|
{
|
|
struct Curl_easy *doh = NULL;
|
|
char *nurl = NULL;
|
|
CURLcode result = CURLE_OK;
|
|
timediff_t timeout_ms;
|
|
DOHcode d = doh_encode(host, dnstype, p->dohbuffer, sizeof(p->dohbuffer),
|
|
&p->dohlen);
|
|
if(d) {
|
|
failf(data, "Failed to encode DoH packet [%d]", d);
|
|
return CURLE_OUT_OF_MEMORY;
|
|
}
|
|
|
|
p->dnstype = dnstype;
|
|
Curl_dyn_init(&p->serverdoh, DYN_DOH_RESPONSE);
|
|
|
|
timeout_ms = Curl_timeleft(data, NULL, TRUE);
|
|
if(timeout_ms <= 0) {
|
|
result = CURLE_OPERATION_TIMEDOUT;
|
|
goto error;
|
|
}
|
|
/* Curl_open() is the internal version of curl_easy_init() */
|
|
result = Curl_open(&doh);
|
|
if(!result) {
|
|
/* pass in the struct pointer via a local variable to please coverity and
|
|
the gcc typecheck helpers */
|
|
struct dynbuf *resp = &p->serverdoh;
|
|
ERROR_CHECK_SETOPT(CURLOPT_URL, url);
|
|
ERROR_CHECK_SETOPT(CURLOPT_DEFAULT_PROTOCOL, "https");
|
|
ERROR_CHECK_SETOPT(CURLOPT_WRITEFUNCTION, doh_write_cb);
|
|
ERROR_CHECK_SETOPT(CURLOPT_WRITEDATA, resp);
|
|
ERROR_CHECK_SETOPT(CURLOPT_POSTFIELDS, p->dohbuffer);
|
|
ERROR_CHECK_SETOPT(CURLOPT_POSTFIELDSIZE, (long)p->dohlen);
|
|
ERROR_CHECK_SETOPT(CURLOPT_HTTPHEADER, headers);
|
|
#ifdef USE_HTTP2
|
|
ERROR_CHECK_SETOPT(CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2TLS);
|
|
#endif
|
|
#ifndef CURLDEBUG
|
|
/* enforce HTTPS if not debug */
|
|
ERROR_CHECK_SETOPT(CURLOPT_PROTOCOLS, CURLPROTO_HTTPS);
|
|
#else
|
|
/* in debug mode, also allow http */
|
|
ERROR_CHECK_SETOPT(CURLOPT_PROTOCOLS, CURLPROTO_HTTP|CURLPROTO_HTTPS);
|
|
#endif
|
|
ERROR_CHECK_SETOPT(CURLOPT_TIMEOUT_MS, (long)timeout_ms);
|
|
ERROR_CHECK_SETOPT(CURLOPT_SHARE, data->share);
|
|
if(data->set.err && data->set.err != stderr)
|
|
ERROR_CHECK_SETOPT(CURLOPT_STDERR, data->set.err);
|
|
if(data->set.verbose)
|
|
ERROR_CHECK_SETOPT(CURLOPT_VERBOSE, 1L);
|
|
if(data->set.no_signal)
|
|
ERROR_CHECK_SETOPT(CURLOPT_NOSIGNAL, 1L);
|
|
|
|
ERROR_CHECK_SETOPT(CURLOPT_SSL_VERIFYHOST,
|
|
data->set.doh_verifyhost ? 2L : 0L);
|
|
ERROR_CHECK_SETOPT(CURLOPT_SSL_VERIFYPEER,
|
|
data->set.doh_verifypeer ? 1L : 0L);
|
|
ERROR_CHECK_SETOPT(CURLOPT_SSL_VERIFYSTATUS,
|
|
data->set.doh_verifystatus ? 1L : 0L);
|
|
|
|
/* Inherit *some* SSL options from the user's transfer. This is a
|
|
best-guess as to which options are needed for compatibility. #3661
|
|
|
|
Note DoH does not inherit the user's proxy server so proxy SSL settings
|
|
have no effect and are not inherited. If that changes then two new
|
|
options should be added to check doh proxy insecure separately,
|
|
CURLOPT_DOH_PROXY_SSL_VERIFYHOST and CURLOPT_DOH_PROXY_SSL_VERIFYPEER.
|
|
*/
|
|
if(data->set.ssl.falsestart)
|
|
ERROR_CHECK_SETOPT(CURLOPT_SSL_FALSESTART, 1L);
|
|
if(data->set.str[STRING_SSL_CAFILE]) {
|
|
ERROR_CHECK_SETOPT(CURLOPT_CAINFO,
|
|
data->set.str[STRING_SSL_CAFILE]);
|
|
}
|
|
if(data->set.blobs[BLOB_CAINFO]) {
|
|
ERROR_CHECK_SETOPT(CURLOPT_CAINFO_BLOB,
|
|
data->set.blobs[BLOB_CAINFO]);
|
|
}
|
|
if(data->set.str[STRING_SSL_CAPATH]) {
|
|
ERROR_CHECK_SETOPT(CURLOPT_CAPATH,
|
|
data->set.str[STRING_SSL_CAPATH]);
|
|
}
|
|
if(data->set.str[STRING_SSL_CRLFILE]) {
|
|
ERROR_CHECK_SETOPT(CURLOPT_CRLFILE,
|
|
data->set.str[STRING_SSL_CRLFILE]);
|
|
}
|
|
if(data->set.ssl.certinfo)
|
|
ERROR_CHECK_SETOPT(CURLOPT_CERTINFO, 1L);
|
|
if(data->set.ssl.fsslctx)
|
|
ERROR_CHECK_SETOPT(CURLOPT_SSL_CTX_FUNCTION, data->set.ssl.fsslctx);
|
|
if(data->set.ssl.fsslctxp)
|
|
ERROR_CHECK_SETOPT(CURLOPT_SSL_CTX_DATA, data->set.ssl.fsslctxp);
|
|
if(data->set.str[STRING_SSL_EC_CURVES]) {
|
|
ERROR_CHECK_SETOPT(CURLOPT_SSL_EC_CURVES,
|
|
data->set.str[STRING_SSL_EC_CURVES]);
|
|
}
|
|
|
|
{
|
|
long mask =
|
|
(data->set.ssl.enable_beast ?
|
|
CURLSSLOPT_ALLOW_BEAST : 0) |
|
|
(data->set.ssl.no_revoke ?
|
|
CURLSSLOPT_NO_REVOKE : 0) |
|
|
(data->set.ssl.no_partialchain ?
|
|
CURLSSLOPT_NO_PARTIALCHAIN : 0) |
|
|
(data->set.ssl.revoke_best_effort ?
|
|
CURLSSLOPT_REVOKE_BEST_EFFORT : 0) |
|
|
(data->set.ssl.native_ca_store ?
|
|
CURLSSLOPT_NATIVE_CA : 0) |
|
|
(data->set.ssl.auto_client_cert ?
|
|
CURLSSLOPT_AUTO_CLIENT_CERT : 0);
|
|
|
|
(void)curl_easy_setopt(doh, CURLOPT_SSL_OPTIONS, mask);
|
|
}
|
|
|
|
doh->set.fmultidone = doh_done;
|
|
doh->set.dohfor = data; /* identify for which transfer this is done */
|
|
p->easy = doh;
|
|
|
|
/* DoH private_data must be null because the user must have a way to
|
|
distinguish their transfer's handle from DoH handles in user
|
|
callbacks (ie SSL CTX callback). */
|
|
DEBUGASSERT(!doh->set.private_data);
|
|
|
|
if(curl_multi_add_handle(multi, doh))
|
|
goto error;
|
|
}
|
|
else
|
|
goto error;
|
|
free(nurl);
|
|
return CURLE_OK;
|
|
|
|
error:
|
|
free(nurl);
|
|
Curl_close(&doh);
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Curl_doh() resolves a name using DoH. 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 result = CURLE_OK;
|
|
int slot;
|
|
struct dohdata *dohp;
|
|
struct connectdata *conn = data->conn;
|
|
*waitp = TRUE; /* this never returns synchronously */
|
|
(void)hostname;
|
|
(void)port;
|
|
|
|
DEBUGASSERT(!data->req.doh);
|
|
DEBUGASSERT(conn);
|
|
|
|
/* start clean, consider allocating this struct on demand */
|
|
dohp = data->req.doh = calloc(sizeof(struct dohdata), 1);
|
|
if(!dohp)
|
|
return NULL;
|
|
|
|
conn->bits.doh = TRUE;
|
|
dohp->host = hostname;
|
|
dohp->port = port;
|
|
dohp->headers =
|
|
curl_slist_append(NULL,
|
|
"Content-Type: application/dns-message");
|
|
if(!dohp->headers)
|
|
goto error;
|
|
|
|
/* create IPv4 DoH request */
|
|
result = dohprobe(data, &dohp->probe[DOH_PROBE_SLOT_IPADDR_V4],
|
|
DNS_TYPE_A, hostname, data->set.str[STRING_DOH],
|
|
data->multi, dohp->headers);
|
|
if(result)
|
|
goto error;
|
|
dohp->pending++;
|
|
|
|
if((conn->ip_version != CURL_IPRESOLVE_V4) && Curl_ipv6works(data)) {
|
|
/* create IPv6 DoH request */
|
|
result = dohprobe(data, &dohp->probe[DOH_PROBE_SLOT_IPADDR_V6],
|
|
DNS_TYPE_AAAA, hostname, data->set.str[STRING_DOH],
|
|
data->multi, dohp->headers);
|
|
if(result)
|
|
goto error;
|
|
dohp->pending++;
|
|
}
|
|
return NULL;
|
|
|
|
error:
|
|
curl_slist_free_all(dohp->headers);
|
|
data->req.doh->headers = NULL;
|
|
for(slot = 0; slot < DOH_PROBE_SLOTS; slot++) {
|
|
Curl_close(&dohp->probe[slot].easy);
|
|
}
|
|
Curl_safefree(data->req.doh);
|
|
return NULL;
|
|
}
|
|
|
|
static DOHcode skipqname(const unsigned char *doh, size_t dohlen,
|
|
unsigned int *indexp)
|
|
{
|
|
unsigned char length;
|
|
do {
|
|
if(dohlen < (*indexp + 1))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
length = doh[*indexp];
|
|
if((length & 0xc0) == 0xc0) {
|
|
/* name pointer, advance over it and be done */
|
|
if(dohlen < (*indexp + 2))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
*indexp += 2;
|
|
break;
|
|
}
|
|
if(length & 0xc0)
|
|
return DOH_DNS_BAD_LABEL;
|
|
if(dohlen < (*indexp + 1 + length))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
*indexp += 1 + length;
|
|
} while(length);
|
|
return DOH_OK;
|
|
}
|
|
|
|
static unsigned short get16bit(const unsigned char *doh, int index)
|
|
{
|
|
return (unsigned short)((doh[index] << 8) | doh[index + 1]);
|
|
}
|
|
|
|
static unsigned int get32bit(const unsigned char *doh, int index)
|
|
{
|
|
/* make clang and gcc optimize this to bswap by incrementing
|
|
the pointer first. */
|
|
doh += index;
|
|
|
|
/* avoid undefined behavior by casting to unsigned before shifting
|
|
24 bits, possibly into the sign bit. codegen is same, but
|
|
ub sanitizer won't be upset */
|
|
return ( (unsigned)doh[0] << 24) | (doh[1] << 16) |(doh[2] << 8) | doh[3];
|
|
}
|
|
|
|
static DOHcode store_a(const unsigned char *doh, int index, struct dohentry *d)
|
|
{
|
|
/* silently ignore addresses over the limit */
|
|
if(d->numaddr < DOH_MAX_ADDR) {
|
|
struct dohaddr *a = &d->addr[d->numaddr];
|
|
a->type = DNS_TYPE_A;
|
|
memcpy(&a->ip.v4, &doh[index], 4);
|
|
d->numaddr++;
|
|
}
|
|
return DOH_OK;
|
|
}
|
|
|
|
static DOHcode store_aaaa(const unsigned char *doh,
|
|
int index,
|
|
struct dohentry *d)
|
|
{
|
|
/* silently ignore addresses over the limit */
|
|
if(d->numaddr < DOH_MAX_ADDR) {
|
|
struct dohaddr *a = &d->addr[d->numaddr];
|
|
a->type = DNS_TYPE_AAAA;
|
|
memcpy(&a->ip.v6, &doh[index], 16);
|
|
d->numaddr++;
|
|
}
|
|
return DOH_OK;
|
|
}
|
|
|
|
static DOHcode store_cname(const unsigned char *doh,
|
|
size_t dohlen,
|
|
unsigned int index,
|
|
struct dohentry *d)
|
|
{
|
|
struct dynbuf *c;
|
|
unsigned int loop = 128; /* a valid DNS name can never loop this much */
|
|
unsigned char length;
|
|
|
|
if(d->numcname == DOH_MAX_CNAME)
|
|
return DOH_OK; /* skip! */
|
|
|
|
c = &d->cname[d->numcname++];
|
|
do {
|
|
if(index >= dohlen)
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
length = doh[index];
|
|
if((length & 0xc0) == 0xc0) {
|
|
int newpos;
|
|
/* name pointer, get the new offset (14 bits) */
|
|
if((index + 1) >= dohlen)
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
|
|
/* move to the new index */
|
|
newpos = (length & 0x3f) << 8 | doh[index + 1];
|
|
index = newpos;
|
|
continue;
|
|
}
|
|
else if(length & 0xc0)
|
|
return DOH_DNS_BAD_LABEL; /* bad input */
|
|
else
|
|
index++;
|
|
|
|
if(length) {
|
|
if(Curl_dyn_len(c)) {
|
|
if(Curl_dyn_addn(c, STRCONST(".")))
|
|
return DOH_OUT_OF_MEM;
|
|
}
|
|
if((index + length) > dohlen)
|
|
return DOH_DNS_BAD_LABEL;
|
|
|
|
if(Curl_dyn_addn(c, &doh[index], length))
|
|
return DOH_OUT_OF_MEM;
|
|
index += length;
|
|
}
|
|
} while(length && --loop);
|
|
|
|
if(!loop)
|
|
return DOH_DNS_LABEL_LOOP;
|
|
return DOH_OK;
|
|
}
|
|
|
|
static DOHcode rdata(const unsigned char *doh,
|
|
size_t dohlen,
|
|
unsigned short rdlength,
|
|
unsigned short type,
|
|
int index,
|
|
struct dohentry *d)
|
|
{
|
|
/* RDATA
|
|
- A (TYPE 1): 4 bytes
|
|
- AAAA (TYPE 28): 16 bytes
|
|
- NS (TYPE 2): N bytes */
|
|
DOHcode rc;
|
|
|
|
switch(type) {
|
|
case DNS_TYPE_A:
|
|
if(rdlength != 4)
|
|
return DOH_DNS_RDATA_LEN;
|
|
rc = store_a(doh, index, d);
|
|
if(rc)
|
|
return rc;
|
|
break;
|
|
case DNS_TYPE_AAAA:
|
|
if(rdlength != 16)
|
|
return DOH_DNS_RDATA_LEN;
|
|
rc = store_aaaa(doh, index, d);
|
|
if(rc)
|
|
return rc;
|
|
break;
|
|
case DNS_TYPE_CNAME:
|
|
rc = store_cname(doh, dohlen, index, d);
|
|
if(rc)
|
|
return rc;
|
|
break;
|
|
case DNS_TYPE_DNAME:
|
|
/* explicit for clarity; just skip; rely on synthesized CNAME */
|
|
break;
|
|
default:
|
|
/* unsupported type, just skip it */
|
|
break;
|
|
}
|
|
return DOH_OK;
|
|
}
|
|
|
|
UNITTEST void de_init(struct dohentry *de)
|
|
{
|
|
int i;
|
|
memset(de, 0, sizeof(*de));
|
|
de->ttl = INT_MAX;
|
|
for(i = 0; i < DOH_MAX_CNAME; i++)
|
|
Curl_dyn_init(&de->cname[i], DYN_DOH_CNAME);
|
|
}
|
|
|
|
|
|
UNITTEST DOHcode doh_decode(const unsigned char *doh,
|
|
size_t dohlen,
|
|
DNStype dnstype,
|
|
struct dohentry *d)
|
|
{
|
|
unsigned char rcode;
|
|
unsigned short qdcount;
|
|
unsigned short ancount;
|
|
unsigned short type = 0;
|
|
unsigned short rdlength;
|
|
unsigned short nscount;
|
|
unsigned short arcount;
|
|
unsigned int index = 12;
|
|
DOHcode rc;
|
|
|
|
if(dohlen < 12)
|
|
return DOH_TOO_SMALL_BUFFER; /* too small */
|
|
if(!doh || doh[0] || doh[1])
|
|
return DOH_DNS_BAD_ID; /* bad ID */
|
|
rcode = doh[3] & 0x0f;
|
|
if(rcode)
|
|
return DOH_DNS_BAD_RCODE; /* bad rcode */
|
|
|
|
qdcount = get16bit(doh, 4);
|
|
while(qdcount) {
|
|
rc = skipqname(doh, dohlen, &index);
|
|
if(rc)
|
|
return rc; /* bad qname */
|
|
if(dohlen < (index + 4))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
index += 4; /* skip question's type and class */
|
|
qdcount--;
|
|
}
|
|
|
|
ancount = get16bit(doh, 6);
|
|
while(ancount) {
|
|
unsigned short class;
|
|
unsigned int ttl;
|
|
|
|
rc = skipqname(doh, dohlen, &index);
|
|
if(rc)
|
|
return rc; /* bad qname */
|
|
|
|
if(dohlen < (index + 2))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
|
|
type = get16bit(doh, index);
|
|
if((type != DNS_TYPE_CNAME) /* may be synthesized from DNAME */
|
|
&& (type != DNS_TYPE_DNAME) /* if present, accept and ignore */
|
|
&& (type != dnstype))
|
|
/* Not the same type as was asked for nor CNAME nor DNAME */
|
|
return DOH_DNS_UNEXPECTED_TYPE;
|
|
index += 2;
|
|
|
|
if(dohlen < (index + 2))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
class = get16bit(doh, index);
|
|
if(DNS_CLASS_IN != class)
|
|
return DOH_DNS_UNEXPECTED_CLASS; /* unsupported */
|
|
index += 2;
|
|
|
|
if(dohlen < (index + 4))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
|
|
ttl = get32bit(doh, index);
|
|
if(ttl < d->ttl)
|
|
d->ttl = ttl;
|
|
index += 4;
|
|
|
|
if(dohlen < (index + 2))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
|
|
rdlength = get16bit(doh, index);
|
|
index += 2;
|
|
if(dohlen < (index + rdlength))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
|
|
rc = rdata(doh, dohlen, rdlength, type, index, d);
|
|
if(rc)
|
|
return rc; /* bad rdata */
|
|
index += rdlength;
|
|
ancount--;
|
|
}
|
|
|
|
nscount = get16bit(doh, 8);
|
|
while(nscount) {
|
|
rc = skipqname(doh, dohlen, &index);
|
|
if(rc)
|
|
return rc; /* bad qname */
|
|
|
|
if(dohlen < (index + 8))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
|
|
index += 2 + 2 + 4; /* type, class and ttl */
|
|
|
|
if(dohlen < (index + 2))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
|
|
rdlength = get16bit(doh, index);
|
|
index += 2;
|
|
if(dohlen < (index + rdlength))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
index += rdlength;
|
|
nscount--;
|
|
}
|
|
|
|
arcount = get16bit(doh, 10);
|
|
while(arcount) {
|
|
rc = skipqname(doh, dohlen, &index);
|
|
if(rc)
|
|
return rc; /* bad qname */
|
|
|
|
if(dohlen < (index + 8))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
|
|
index += 2 + 2 + 4; /* type, class and ttl */
|
|
|
|
if(dohlen < (index + 2))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
|
|
rdlength = get16bit(doh, index);
|
|
index += 2;
|
|
if(dohlen < (index + rdlength))
|
|
return DOH_DNS_OUT_OF_RANGE;
|
|
index += rdlength;
|
|
arcount--;
|
|
}
|
|
|
|
if(index != dohlen)
|
|
return DOH_DNS_MALFORMAT; /* something is wrong */
|
|
|
|
if((type != DNS_TYPE_NS) && !d->numcname && !d->numaddr)
|
|
/* nothing stored! */
|
|
return DOH_NO_CONTENT;
|
|
|
|
return DOH_OK; /* ok */
|
|
}
|
|
|
|
#ifndef CURL_DISABLE_VERBOSE_STRINGS
|
|
static void showdoh(struct Curl_easy *data,
|
|
const struct dohentry *d)
|
|
{
|
|
int i;
|
|
infof(data, "TTL: %u seconds", d->ttl);
|
|
for(i = 0; i < d->numaddr; i++) {
|
|
const struct dohaddr *a = &d->addr[i];
|
|
if(a->type == DNS_TYPE_A) {
|
|
infof(data, "DoH A: %u.%u.%u.%u",
|
|
a->ip.v4[0], a->ip.v4[1],
|
|
a->ip.v4[2], a->ip.v4[3]);
|
|
}
|
|
else if(a->type == DNS_TYPE_AAAA) {
|
|
int j;
|
|
char buffer[128];
|
|
char *ptr;
|
|
size_t len;
|
|
msnprintf(buffer, 128, "DoH AAAA: ");
|
|
ptr = &buffer[10];
|
|
len = 118;
|
|
for(j = 0; j < 16; j += 2) {
|
|
size_t l;
|
|
msnprintf(ptr, len, "%s%02x%02x", j?":":"", d->addr[i].ip.v6[j],
|
|
d->addr[i].ip.v6[j + 1]);
|
|
l = strlen(ptr);
|
|
len -= l;
|
|
ptr += l;
|
|
}
|
|
infof(data, "%s", buffer);
|
|
}
|
|
}
|
|
for(i = 0; i < d->numcname; i++) {
|
|
infof(data, "CNAME: %s", Curl_dyn_ptr(&d->cname[i]));
|
|
}
|
|
}
|
|
#else
|
|
#define showdoh(x,y)
|
|
#endif
|
|
|
|
/*
|
|
* doh2ai()
|
|
*
|
|
* This function returns a pointer to the first element of a newly allocated
|
|
* Curl_addrinfo struct linked list filled with the data from a set of DoH
|
|
* lookups. Curl_addrinfo is meant to work like the addrinfo struct does for
|
|
* a IPv6 stack, but usable also for IPv4, all hosts and environments.
|
|
*
|
|
* The memory allocated by this function *MUST* be free'd later on calling
|
|
* Curl_freeaddrinfo(). For each successful call to this function there
|
|
* must be an associated call later to Curl_freeaddrinfo().
|
|
*/
|
|
|
|
static struct Curl_addrinfo *
|
|
doh2ai(const struct dohentry *de, const char *hostname, int port)
|
|
{
|
|
struct Curl_addrinfo *ai;
|
|
struct Curl_addrinfo *prevai = NULL;
|
|
struct Curl_addrinfo *firstai = NULL;
|
|
struct sockaddr_in *addr;
|
|
#ifdef ENABLE_IPV6
|
|
struct sockaddr_in6 *addr6;
|
|
#endif
|
|
CURLcode result = CURLE_OK;
|
|
int i;
|
|
size_t hostlen = strlen(hostname) + 1; /* include null-terminator */
|
|
|
|
if(!de)
|
|
/* no input == no output! */
|
|
return NULL;
|
|
|
|
for(i = 0; i < de->numaddr; i++) {
|
|
size_t ss_size;
|
|
CURL_SA_FAMILY_T addrtype;
|
|
if(de->addr[i].type == DNS_TYPE_AAAA) {
|
|
#ifndef ENABLE_IPV6
|
|
/* we can't handle IPv6 addresses */
|
|
continue;
|
|
#else
|
|
ss_size = sizeof(struct sockaddr_in6);
|
|
addrtype = AF_INET6;
|
|
#endif
|
|
}
|
|
else {
|
|
ss_size = sizeof(struct sockaddr_in);
|
|
addrtype = AF_INET;
|
|
}
|
|
|
|
ai = calloc(1, sizeof(struct Curl_addrinfo) + ss_size + hostlen);
|
|
if(!ai) {
|
|
result = CURLE_OUT_OF_MEMORY;
|
|
break;
|
|
}
|
|
ai->ai_addr = (void *)((char *)ai + sizeof(struct Curl_addrinfo));
|
|
ai->ai_canonname = (void *)((char *)ai->ai_addr + ss_size);
|
|
memcpy(ai->ai_canonname, hostname, hostlen);
|
|
|
|
if(!firstai)
|
|
/* store the pointer we want to return from this function */
|
|
firstai = ai;
|
|
|
|
if(prevai)
|
|
/* make the previous entry point to this */
|
|
prevai->ai_next = ai;
|
|
|
|
ai->ai_family = addrtype;
|
|
|
|
/* we return all names as STREAM, so when using this address for TFTP
|
|
the type must be ignored and conn->socktype be used instead! */
|
|
ai->ai_socktype = SOCK_STREAM;
|
|
|
|
ai->ai_addrlen = (curl_socklen_t)ss_size;
|
|
|
|
/* leave the rest of the struct filled with zero */
|
|
|
|
switch(ai->ai_family) {
|
|
case AF_INET:
|
|
addr = (void *)ai->ai_addr; /* storage area for this info */
|
|
DEBUGASSERT(sizeof(struct in_addr) == sizeof(de->addr[i].ip.v4));
|
|
memcpy(&addr->sin_addr, &de->addr[i].ip.v4, sizeof(struct in_addr));
|
|
addr->sin_family = addrtype;
|
|
addr->sin_port = htons((unsigned short)port);
|
|
break;
|
|
|
|
#ifdef ENABLE_IPV6
|
|
case AF_INET6:
|
|
addr6 = (void *)ai->ai_addr; /* storage area for this info */
|
|
DEBUGASSERT(sizeof(struct in6_addr) == sizeof(de->addr[i].ip.v6));
|
|
memcpy(&addr6->sin6_addr, &de->addr[i].ip.v6, sizeof(struct in6_addr));
|
|
addr6->sin6_family = addrtype;
|
|
addr6->sin6_port = htons((unsigned short)port);
|
|
break;
|
|
#endif
|
|
}
|
|
|
|
prevai = ai;
|
|
}
|
|
|
|
if(result) {
|
|
Curl_freeaddrinfo(firstai);
|
|
firstai = NULL;
|
|
}
|
|
|
|
return firstai;
|
|
}
|
|
|
|
#ifndef CURL_DISABLE_VERBOSE_STRINGS
|
|
static const char *type2name(DNStype dnstype)
|
|
{
|
|
return (dnstype == DNS_TYPE_A)?"A":"AAAA";
|
|
}
|
|
#endif
|
|
|
|
UNITTEST void de_cleanup(struct dohentry *d)
|
|
{
|
|
int i = 0;
|
|
for(i = 0; i < d->numcname; i++) {
|
|
Curl_dyn_free(&d->cname[i]);
|
|
}
|
|
}
|
|
|
|
CURLcode Curl_doh_is_resolved(struct Curl_easy *data,
|
|
struct Curl_dns_entry **dnsp)
|
|
{
|
|
CURLcode result;
|
|
struct dohdata *dohp = data->req.doh;
|
|
*dnsp = NULL; /* defaults to no response */
|
|
if(!dohp)
|
|
return CURLE_OUT_OF_MEMORY;
|
|
|
|
if(!dohp->probe[DOH_PROBE_SLOT_IPADDR_V4].easy &&
|
|
!dohp->probe[DOH_PROBE_SLOT_IPADDR_V6].easy) {
|
|
failf(data, "Could not DoH-resolve: %s", data->state.async.hostname);
|
|
return CONN_IS_PROXIED(data->conn)?CURLE_COULDNT_RESOLVE_PROXY:
|
|
CURLE_COULDNT_RESOLVE_HOST;
|
|
}
|
|
else if(!dohp->pending) {
|
|
DOHcode rc[DOH_PROBE_SLOTS] = {
|
|
DOH_OK, DOH_OK
|
|
};
|
|
struct dohentry de;
|
|
int slot;
|
|
/* remove DoH handles from multi handle and close them */
|
|
for(slot = 0; slot < DOH_PROBE_SLOTS; slot++) {
|
|
curl_multi_remove_handle(data->multi, dohp->probe[slot].easy);
|
|
Curl_close(&dohp->probe[slot].easy);
|
|
}
|
|
/* parse the responses, create the struct and return it! */
|
|
de_init(&de);
|
|
for(slot = 0; slot < DOH_PROBE_SLOTS; slot++) {
|
|
struct dnsprobe *p = &dohp->probe[slot];
|
|
if(!p->dnstype)
|
|
continue;
|
|
rc[slot] = doh_decode(Curl_dyn_uptr(&p->serverdoh),
|
|
Curl_dyn_len(&p->serverdoh),
|
|
p->dnstype,
|
|
&de);
|
|
Curl_dyn_free(&p->serverdoh);
|
|
if(rc[slot]) {
|
|
infof(data, "DoH: %s type %s for %s", doh_strerror(rc[slot]),
|
|
type2name(p->dnstype), dohp->host);
|
|
}
|
|
} /* next slot */
|
|
|
|
result = CURLE_COULDNT_RESOLVE_HOST; /* until we know better */
|
|
if(!rc[DOH_PROBE_SLOT_IPADDR_V4] || !rc[DOH_PROBE_SLOT_IPADDR_V6]) {
|
|
/* we have an address, of one kind or other */
|
|
struct Curl_dns_entry *dns;
|
|
struct Curl_addrinfo *ai;
|
|
|
|
infof(data, "DoH Host name: %s", dohp->host);
|
|
showdoh(data, &de);
|
|
|
|
ai = doh2ai(&de, dohp->host, dohp->port);
|
|
if(!ai) {
|
|
de_cleanup(&de);
|
|
return CURLE_OUT_OF_MEMORY;
|
|
}
|
|
|
|
if(data->share)
|
|
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
|
|
|
|
/* we got a response, store it in the cache */
|
|
dns = Curl_cache_addr(data, ai, dohp->host, dohp->port);
|
|
|
|
if(data->share)
|
|
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
|
|
|
|
if(!dns) {
|
|
/* returned failure, bail out nicely */
|
|
Curl_freeaddrinfo(ai);
|
|
}
|
|
else {
|
|
data->state.async.dns = dns;
|
|
*dnsp = dns;
|
|
result = CURLE_OK; /* address resolution OK */
|
|
}
|
|
} /* address processing done */
|
|
|
|
/* Now process any build-specific attributes retrieved from DNS */
|
|
|
|
/* All done */
|
|
de_cleanup(&de);
|
|
Curl_safefree(data->req.doh);
|
|
return result;
|
|
|
|
} /* !dohp->pending */
|
|
|
|
/* else wait for pending DoH transactions to complete */
|
|
return CURLE_OK;
|
|
}
|
|
|
|
#endif /* CURL_DISABLE_DOH */
|