CURLOPT_RESOLVE - provide custom host name to IP address resolves
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_RESOLVE,
struct curl_slist *hosts);
Pass a pointer to a linked list of strings with host name resolve information to
use for requests with this handle. The linked list should be a fully valid
list of
struct curl_slist structs properly filled in. Use
curl_slist_append(3) to create the list and
curl_slist_free_all(3) to clean up an entire list.
Each resolve rule to add should be written using the format
[+]HOST:PORT:ADDRESS[,ADDRESS]
... where HOST is the name libcurl will try to resolve, PORT is the port number
of the service where libcurl wants to connect to the HOST and ADDRESS is one
or more numerical IP addresses. If you specify multiple IP addresses they need
to be separated by comma. If libcurl is built to support IPv6, each of the
ADDRESS entries can of course be either IPv4 or IPv6 style addressing.
This option effectively pre-populates the DNS cache with entries for the
host+port pair so redirects and everything that operations against the
HOST+PORT will instead use your provided ADDRESS.
The optional leading "+" specifies that the new entry should time-out.
Entries added without the leading plus character will never time-out whereas
entries added with "+HOST:..." will time-out just like ordinary DNS
cache entries.
If the DNS cache already has an entry for the given host+port pair, the new
entry will override the former one.
An ADDRESS provided by this option will only be used if not restricted by the
setting of
CURLOPT_IPRESOLVE(3) to a different IP version.
To remove names from the DNS cache again, to stop providing these fake resolves,
include a string in the linked list that uses the format
-HOST:PORT
The entry to remove must be prefixed with a dash, and the host name and port
number must exactly match what was added previously.
NULL
All
CURL *curl;
struct curl_slist *host = NULL;
host = curl_slist_append(NULL, "example.com:443:127.0.0.1");
curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_RESOLVE, host);
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
curl_easy_perform(curl);
/* always cleanup */
curl_easy_cleanup(curl);
}
curl_slist_free_all(host);
Added in 7.21.3. Removal support added in 7.42.0.
Support for providing the ADDRESS within [brackets] was added in 7.57.0.
Support for providing multiple IP addresses per entry was added in 7.59.0.
Support for adding non-permanent entries by using the "+" prefix was
added in 7.75.0.
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
CURLOPT_IPRESOLVE(3),
CURLOPT_DNS_CACHE_TIMEOUT(3),
CURLOPT_CONNECT_TO(3),