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Merged
merged 4 commits into from
Oct 26, 2023
Merged

Implement X-Forwarded-For header processing #7359

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a7d62ec
Implement `parse_xff_header()` fn
Turbo87 Oct 25, 2023
29d92ed
Implement basic `process_xff_headers()` fn
Turbo87 Oct 25, 2023
7f59175
Complicate `process_xff_headers()` fn
Turbo87 Oct 25, 2023
1bf0e2d
middleware/log_request: Add logging for processed `X-Forwarded-For` h…
Turbo87 Oct 25, 2023
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1 change: 1 addition & 0 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -59,6 +59,7 @@ pub mod auth;
pub mod controllers;
mod licenses;
pub mod models;
mod real_ip;
mod router;
pub mod sentry;
pub mod storage;
Expand Down
23 changes: 19 additions & 4 deletions src/middleware/log_request.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -4,13 +4,15 @@
use crate::controllers::util::RequestPartsExt;
use crate::headers::{XRealIp, XRequestId};
use crate::middleware::normalize_path::OriginalPath;
use crate::real_ip::process_xff_headers;
use axum::headers::UserAgent;
use axum::middleware::Next;
use axum::response::IntoResponse;
use axum::{Extension, TypedHeader};
use http::{Method, Request, StatusCode, Uri};
use parking_lot::Mutex;
use std::fmt::{self, Display, Formatter};
use std::net::IpAddr;
use std::ops::Deref;
use std::sync::Arc;
use std::time::{Duration, Instant};
Expand Down Expand Up @@ -39,6 +41,7 @@ pub struct Metadata<'a> {
cause: Option<&'a CauseField>,
error: Option<&'a ErrorField>,
duration: Duration,
real_ip: Option<IpAddr>,
custom_metadata: RequestLog,
}

Expand Down Expand Up @@ -71,10 +74,19 @@ impl Display for Metadata<'_> {
};
}

match &self.request.real_ip {
Some(header) => line.add_quoted_field("fwd", header.as_str())?,
None => line.add_quoted_field("fwd", "")?,
};
let real_ip = self.real_ip.map(|ip| ip.to_string()).unwrap_or_default();
line.add_quoted_field("ip", &real_ip)?;

let x_real_ip = self.request.real_ip.as_ref();
let x_real_ip = x_real_ip
.map(|ip| ip.as_str().to_string())
.unwrap_or_default();
line.add_quoted_field("fwd", &x_real_ip)?;

// TODO: Remove this once production traffic has shown that `ip == fwd`
if real_ip != x_real_ip {
line.add_marker("ip!=fwd")?;
}

let response_time_in_ms = self.duration.as_millis();
if !is_download_redirect || response_time_in_ms > 0 {
Expand Down Expand Up @@ -122,6 +134,8 @@ pub async fn log_requests<B>(
let custom_metadata = RequestLog::default();
req.extensions_mut().insert(custom_metadata.clone());

let real_ip = process_xff_headers(req.headers());

let response = next.run(req).await;

let metadata = Metadata {
Expand All @@ -130,6 +144,7 @@ pub async fn log_requests<B>(
cause: response.extensions().get(),
error: response.extensions().get(),
duration: start_instant.elapsed(),
real_ip,
custom_metadata,
};

Expand Down
299 changes: 299 additions & 0 deletions src/real_ip.rs
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Original file line number Diff line number Diff line change
@@ -0,0 +1,299 @@
use http::{HeaderMap, HeaderValue};
use ipnetwork::IpNetwork;
use once_cell::sync::Lazy;
use std::iter::Iterator;
use std::net::IpAddr;
use std::str::from_utf8;

const X_FORWARDED_FOR: &str = "X-Forwarded-For";

const CLOUD_FRONT_STRS: &[&str] = &[
// CloudFront IP addresses from http://d7uri8nf7uskq.cloudfront.net/tools/list-cloudfront-ips
// Last updated: 2022-03-26
"3.10.17.128/25",
"3.11.53.0/24",
"3.35.130.128/25",
"3.101.158.0/23",
"3.128.93.0/24",
"3.134.215.0/24",
"3.231.2.0/25",
"3.234.232.224/27",
"3.236.48.0/23",
"3.236.169.192/26",
"13.32.0.0/15",
"13.35.0.0/16",
"13.48.32.0/24",
"13.54.63.128/26",
"13.59.250.0/26",
"13.113.196.64/26",
"13.113.203.0/24",
"13.124.199.0/24",
"13.210.67.128/26",
"13.224.0.0/14",
"13.228.69.0/24",
"13.233.177.192/26",
"13.249.0.0/16",
"15.158.0.0/16",
"15.188.184.0/24",
"15.207.13.128/25",
"15.207.213.128/25",
"18.64.0.0/14",
"18.154.0.0/15",
"18.160.0.0/15",
"18.164.0.0/15",
"18.172.0.0/15",
"18.192.142.0/23",
"18.200.212.0/23",
"18.216.170.128/25",
"18.229.220.192/26",
"18.238.0.0/15",
"18.244.0.0/15",
"34.195.252.0/24",
"34.216.51.0/25",
"34.223.12.224/27",
"34.223.80.192/26",
"34.226.14.0/24",
"35.158.136.0/24",
"35.162.63.192/26",
"35.167.191.128/26",
"36.103.232.0/25",
"36.103.232.128/26",
"44.227.178.0/24",
"44.234.90.252/30",
"44.234.108.128/25",
"52.15.127.128/26",
"52.46.0.0/18",
"52.47.139.0/24",
"52.52.191.128/26",
"52.56.127.0/25",
"52.57.254.0/24",
"52.66.194.128/26",
"52.78.247.128/26",
"52.82.128.0/19",
"52.84.0.0/15",
"52.124.128.0/17",
"52.199.127.192/26",
"52.212.248.0/26",
"52.220.191.0/26",
"52.222.128.0/17",
"54.182.0.0/16",
"54.192.0.0/16",
"54.230.0.0/17",
"54.230.128.0/18",
"54.230.200.0/21",
"54.230.208.0/20",
"54.230.224.0/19",
"54.233.255.128/26",
"54.239.128.0/18",
"54.239.192.0/19",
"54.240.128.0/18",
"58.254.138.0/25",
"58.254.138.128/26",
"64.252.64.0/18",
"64.252.128.0/18",
"65.8.0.0/16",
"65.9.0.0/17",
"65.9.128.0/18",
"70.132.0.0/18",
"71.152.0.0/17",
"99.79.169.0/24",
"99.84.0.0/16",
"99.86.0.0/16",
"108.138.0.0/15",
"108.156.0.0/14",
"116.129.226.0/25",
"116.129.226.128/26",
"118.193.97.64/26",
"118.193.97.128/25",
"119.147.182.0/25",
"119.147.182.128/26",
"120.52.12.64/26",
"120.52.22.96/27",
"120.52.39.128/27",
"120.52.153.192/26",
"120.232.236.0/25",
"120.232.236.128/26",
"120.253.240.192/26",
"120.253.241.160/27",
"120.253.245.128/26",
"120.253.245.192/27",
"130.176.0.0/17",
"130.176.128.0/18",
"130.176.192.0/19",
"130.176.224.0/20",
"143.204.0.0/16",
"144.220.0.0/16",
"180.163.57.0/25",
"180.163.57.128/26",
"204.246.164.0/22",
"204.246.168.0/22",
"204.246.172.0/24",
"204.246.173.0/24",
"204.246.174.0/23",
"204.246.176.0/20",
"205.251.200.0/21",
"205.251.208.0/20",
"205.251.249.0/24",
"205.251.250.0/23",
"205.251.252.0/23",
"205.251.254.0/24",
"216.137.32.0/19",
"223.71.11.0/27",
"223.71.71.96/27",
"223.71.71.128/25",
];

static CLOUD_FRONT_NETWORKS: Lazy<Vec<IpNetwork>> = Lazy::new(|| {
CLOUD_FRONT_STRS
.iter()
.map(|s| s.parse().unwrap())
.collect()
});

fn is_cloud_front_ip(ip: &IpAddr) -> bool {
CLOUD_FRONT_NETWORKS
.iter()
.any(|trusted_proxy| trusted_proxy.contains(*ip))
}

pub fn process_xff_headers(headers: &HeaderMap) -> Option<IpAddr> {
let mut xff_iter = headers.get_all(X_FORWARDED_FOR).iter();
let first_header = xff_iter.next()?;

let has_more_headers = xff_iter.next().is_some();
return 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.
Comment on lines +168 to +169
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for context: heroku/roadmap#238

//
// 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.

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).

parse_xff_header(first_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
/// `Vec<Result<IpAddr, &[u8]>>`.
fn parse_xff_header(header: &HeaderValue) -> Vec<Result<IpAddr, &[u8]>> {
let bytes = header.as_bytes();
if bytes.is_empty() {
return vec![];
}

bytes
.split(|&byte| byte == b',')
.map(|bytes| parse_ip_addr(bytes))
.collect()
}

fn parse_ip_addr(bytes: &[u8]) -> Result<IpAddr, &[u8]> {
from_utf8(bytes)
.map_err(|_| bytes)?
.trim()
.parse()
.map_err(|_| bytes)
}

#[cfg(test)]
mod tests {
use super::*;
use http::HeaderValue;

#[test]
fn test_process_xff_headers() {
#[track_caller]
fn test(input: Vec<&[u8]>, expectation: Option<&str>) {
let mut headers = HeaderMap::new();
for value in input {
let value = HeaderValue::from_bytes(value).unwrap();
headers.append(X_FORWARDED_FOR, value);
}

let expectation: Option<IpAddr> = expectation.map(|ip| ip.parse().unwrap());

assert_eq!(process_xff_headers(&headers), expectation)
}

// Generic behavior
test(vec![], None);
test(vec![b""], None);
test(vec![b"1.1.1.1"], Some("1.1.1.1"));
test(vec![b"1.1.1.1, 2.2.2.2"], Some("2.2.2.2"));
test(vec![b"1.1.1.1, 2.2.2.2, 3.3.3.3"], Some("3.3.3.3"));
test(
vec![b"oh, hi,,127.0.0.1,,,,, 12.34.56.78 "],
Some("12.34.56.78"),
);

// CloudFront behavior
test(vec![b"130.176.118.147"], None);
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"));
test(
vec![b"1.1.1.1, 130.176.118.147", b"3.3.3.3"],
Some("130.176.118.147"),
);
}

#[test]
fn test_parse_xff_header() {
#[track_caller]
fn test(input: &'static [u8], expectation: Vec<Result<&str, &[u8]>>) {
let header = HeaderValue::from_bytes(input).unwrap();

let expectation: Vec<Result<IpAddr, &[u8]>> = expectation
.into_iter()
.map(|ip| ip.map(|ip| ip.parse().unwrap()))
.collect();

assert_eq!(parse_xff_header(&header), expectation)
}

test(b"", vec![]);
test(b"1.2.3.4", vec![Ok("1.2.3.4")]);
test(
b"1.2.3.4, 11.22.33.44",
vec![Ok("1.2.3.4"), Ok("11.22.33.44")],
);
test(
b"oh, hi,,127.0.0.1,,,,, 12.34.56.78 ",
vec![
Err(b"oh"),
Err(b" hi"),
Err(b""),
Ok("127.0.0.1"),
Err(b""),
Err(b""),
Err(b""),
Err(b""),
Ok("12.34.56.78"),
],
);
}
}