curl/docs/libcurl/opts/CURLOPT_FTP_SKIP_PASV_IP.md
Daniel Stenberg e694c8284a
docs/libcurl/opts: clarify the return values
Expand a little.

- mention the type name of the return code
- avoid stating which exact return codes that might be returned, as that
  varies over time, builds and conditions
- avoid stating some always return OK
- refer to the manpage documenting all the return codes

Closes #15900
2025-01-02 17:13:33 +01:00

1.7 KiB

c SPDX-License-Identifier Title Section Source Protocol See-also Added-in
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. curl CURLOPT_FTP_SKIP_PASV_IP 3 libcurl
FTP
CURLOPT_FTPPORT (3)
CURLOPT_FTP_USE_EPRT (3)
7.15.0

NAME

CURLOPT_FTP_SKIP_PASV_IP - ignore the IP address in the PASV response

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_SKIP_PASV_IP, long skip);

DESCRIPTION

Pass a long. If skip is set to 1, it instructs libcurl to not use the IP address the server suggests in its 227-response to libcurl's PASV command when libcurl connects the data connection. Instead libcurl reuses the same IP address it already uses for the control connection. It still uses the port number from the 227-response.

This option allows libcurl to work around broken server installations or funny network setups that due to NATs, firewalls or incompetence report the wrong IP address. Setting this option also reduces the risk for various sorts of client abuse by malicious servers.

This option has no effect if PORT, EPRT or EPSV is used instead of PASV.

DEFAULT

1 since 7.74.0, was 0 before then.

%PROTOCOLS%

EXAMPLE

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/file.txt");

    /* please ignore the IP in the PASV response */
    curl_easy_setopt(curl, CURLOPT_FTP_SKIP_PASV_IP, 1L);
    res = curl_easy_perform(curl);

    curl_easy_cleanup(curl);
  }
}

%AVAILABILITY%

RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).