CURLOPT_REDIR_PROTOCOLS

Section: curl_easy_setopt options (3)
Updated: November 04, 2020
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NAME

CURLOPT_REDIR_PROTOCOLS - set protocols allowed to redirect to

SYNOPSIS

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_REDIR_PROTOCOLS, long bitmask);

DESCRIPTION

Pass a long that holds a bitmask of CURLPROTO_* defines. If used, this bitmask limits what protocols libcurl may use in a transfer that it follows to in a redirect when CURLOPT_FOLLOWLOCATION(3) is enabled. This allows you to limit specific transfers to only be allowed to use a subset of protocols in redirections.

Protocols denied by CURLOPT_PROTOCOLS(3) are not overridden by this option.

By default libcurl will allow HTTP, HTTPS, FTP and FTPS on redirect (7.65.2). Older versions of libcurl allowed all protocols on redirect except several disabled for security reasons: Since 7.19.4 FILE and SCP are disabled, and since 7.40.0 SMB and SMBS are also disabled. CURLPROTO_ALL enables all protocols on redirect, including those disabled for security.

These are the available protocol defines:

CURLPROTO_DICT
CURLPROTO_FILE
CURLPROTO_FTP
CURLPROTO_FTPS
CURLPROTO_GOPHER
CURLPROTO_HTTP
CURLPROTO_HTTPS
CURLPROTO_IMAP
CURLPROTO_IMAPS
CURLPROTO_LDAP
CURLPROTO_LDAPS
CURLPROTO_POP3
CURLPROTO_POP3S
CURLPROTO_RTMP
CURLPROTO_RTMPE
CURLPROTO_RTMPS
CURLPROTO_RTMPT
CURLPROTO_RTMPTE
CURLPROTO_RTMPTS
CURLPROTO_RTSP
CURLPROTO_SCP
CURLPROTO_SFTP
CURLPROTO_SMB
CURLPROTO_SMBS
CURLPROTO_SMTP
CURLPROTO_SMTPS
CURLPROTO_TELNET
CURLPROTO_TFTP

DEFAULT

HTTP, HTTPS, FTP and FTPS (Since 7.65.2).

Older versions defaulted to all protocols except FILE, SCP and since 7.40.0 SMB and SMBS.

PROTOCOLS

All

EXAMPLE

curl = curl_easy_init();
if(curl) {
  /* pass in the URL from an external source */
  curl_easy_setopt(curl, CURLOPT_URL, argv[1]);

  /* only allow redirects to HTTP and HTTPS URLs */
  curl_easy_setopt(curl, CURLOPT_REDIR_PROTOCOLS,
                   CURLPROTO_HTTP | CURLPROTO_HTTPS);

  /* Perform the request */
  curl_easy_perform(curl);
}

AVAILABILITY

Added in 7.19.4, before then it would follow all protocols.

RETURN VALUE

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.