Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

real_ip: Remove Heroku router workaround #10249

Merged
merged 1 commit into from
Dec 20, 2024
Merged

real_ip: Remove Heroku router workaround #10249

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
63 changes: 17 additions & 46 deletions src/real_ip.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -38,50 +38,21 @@ fn is_cloud_front_ip(ip: &IpAddr) -> bool {
.any(|trusted_proxy| trusted_proxy.contains(*ip))
}

/// Extracts the client IP address from the `X-Forwarded-For` header.
///
/// This function will return the last valid non-CloudFront IP address in the
/// `X-Forwarded-For` header, if any.
pub fn process_xff_headers(headers: &HeaderMap) -> Option<IpAddr> {
let mut xff_iter = headers.get_all(X_FORWARDED_FOR).iter();
let Some(first_header) = xff_iter.next() else {
debug!(target: "real_ip", "No X-Forwarded-For header found");
return None;
};

let has_more_headers = xff_iter.next().is_some();
if has_more_headers {
// This only happens for requests going directly to crates-io.herokuapp.com,
// since AWS CloudFront automatically merges these headers into one.
//
// The Heroku router has a bug where it currently (2023-10-25) appends
// the connecting IP to the **first** header instead of the last.
//
// In this specific scenario we will read the IP from the first header,
// instead of the last, to work around the Heroku bug. We also don't
// have to care about the trusted proxies, since the request was
// apparently sent to Heroku directly.

debug!(target: "real_ip", ?first_header, "Multiple X-Forwarded-For headers found, using the first one due to Heroku bug");

parse_xff_header(first_header)
.into_iter()
.filter_map(|r| r.ok())
.next_back()
} else {
// If the request came in through CloudFront we only get a single,
// merged header.
//
// If the request came in through Heroku and only had a single header
// originally, then we also only get a single header.
//
// In this case return the right-most IP address that is not in the list
// of IPs from trusted proxies (i.e. CloudFront).

debug!(target: "real_ip", ?first_header, "Single X-Forwarded-For header found");

parse_xff_header(first_header)
.into_iter()
.filter_map(|r| r.ok())
.filter(|ip| !is_cloud_front_ip(ip))
.next_back()
}
headers
.get_all(X_FORWARDED_FOR)
.iter()
.flat_map(|header| {
parse_xff_header(header)
.into_iter()
.filter_map(|r| r.ok())
.filter(|ip| !is_cloud_front_ip(ip))
})
.next_back()
}

/// Parses the content of an `X-Forwarded-For` header into a
Expand Down Expand Up @@ -142,11 +113,11 @@ mod tests {
test(vec![b"1.1.1.1, 130.176.118.147"], Some("1.1.1.1"));
test(vec![b"1.1.1.1, 2.2.2.2, 130.176.118.147"], Some("2.2.2.2"));

// Heroku workaround
test(vec![b"1.1.1.1, 2.2.2.2", b"3.3.3.3"], Some("2.2.2.2"));
// Multiple headers behavior
test(vec![b"1.1.1.1, 2.2.2.2", b"3.3.3.3"], Some("3.3.3.3"));
test(
vec![b"1.1.1.1, 130.176.118.147", b"3.3.3.3"],
Some("130.176.118.147"),
Some("3.3.3.3"),
);
}

Expand Down