CURLOPT_DOH_URL - Online Linux Manual Page

Section : 3
Updated : November 26, 2021
Source : libcurl 7.82.0
Note : curl_easy_setopt options

NAME

CURLOPT_DOH_URL − provide the DNS-over-HTTPS URL

SYNOPSIS

#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DOH_URL, char *URL);

DESCRIPTION

Pass in a pointer to a URL

for the DoH server to use for name resolving. The parameter should be a char * to a null-terminated string which must be URL-encoded in the following format: "https://host:port/path". It MUST specify a HTTPS URL. libcurl does not validate the syntax or use this variable until the transfer is issued. Even if you set a crazy value here,

curl_easy_setopt(3)

will still return

CURLE_OK

. curl sends POST requests to the given DNS-over-HTTPS URL. To find the DoH server itself, which might be specified using a name, libcurl will use the default name lookup function. You can bootstrap that by providing the address for the DoH server with

CURLOPT_RESOLVE(3)

. Disable DoH use again by setting this option to NULL.

INHERIT OPTIONS

DoH lookups use SSL and some SSL settings from your transfer are inherited, like CURLOPT_SSL_CTX_FUNCTION(3)

. The hostname and peer certificate verification settings are not inherited but can be controlled separately via

CURLOPT_DOH_SSL_VERIFYHOST(3)

and

CURLOPT_DOH_SSL_VERIFYPEER(3)

. A set(3)

callback is not inherited.

DEFAULT

NULL - there is no default DoH URL. If this option is not set, libcurl will use the default name resolver.

PROTOCOLS

All

EXAMPLE

CURL *curl = curl_easy_init(); if(curl) { curl_easy_setopt(curl, CURLOPT_URL, "https://example.com"); curl_easy_setopt(curl, CURLOPT_DOH_URL, "https://dns.example.com"); curl_easy_perform(curl); }

AVAILABILITY

Added in 7.62.0

RETURN VALUE

Returns CURLE_OK on success or CURLE_OUT_OF_MEMORY if there was insufficient heap space. Note that curl_easy_setopt(3)

will not actually parse the given string so given a bad DoH URL, curl will not detect a problem until it tries to resolve a name with it.