http_ip/

lib.rs

//! Utilities to determine HTTP client's IP
//!
//! ## Features
//!
//! - `http` - Enables filter implementation using http's header map;
//! - `axum08` - Enables `axum` extractor implementation for `0.8.x`;
//! - `tonic014` - Enables `tonic` extension implementation for `0.14.x`.
//!
//! ## Example
//!
//! A very simple example to extract IP from given header value using CIDR filtering to determine client's IP
//!
//! This is different from a very common approach selecting leftmost IP as client's IP
//! Instead you can search starting through the right, filtering out your cloud's CIDRs to guarantee you get client's real external IP.
//! In complicated network environments individual clients are rarely having static IPs and
//! most likely hidden by corporate proxy that shields company's network, which often inserts extra IP in between you and client.
//!
//! This in-between IP is more often than not, what you'd want to get and use, rather than leftmost
//! (which may be client IP, but it is not client IP from perspective of public network)
//!
//!```rust
//!
//!const IPS: &str = "203.0.113.195,2001:db8:85a3:8d3:1319:8a2e:370:7348,198.51.100.178";
//!const CIDR: http_ip::filter::Cidr = match http_ip::filter::Cidr::from_text("198.51.100.0/24") {
//!    Ok(cidr) => cidr,
//!    Err(_) => panic!("I cannot fail"),
//!};
//!
//!//Get ips in reverse (from right) order to filter out proxy IPs manually until we reach client's IP
//!let ips = http_ip::forwarded::parse_x_forwarded_for_rev(IPS);
//!let client_ip = http_ip::find_next_ip_after_filter(ips, &CIDR).expect("to find ip");
//!assert_eq!(client_ip, core::net::IpAddr::V6(core::net::Ipv6Addr::new(0x2001, 0xdb8, 0x85a3, 0x8d3, 0x1319, 0x8a2e, 0x370, 0x7348)));
//!```

#![no_std]
#![warn(missing_docs)]
#![allow(clippy::style)]

use core::net::IpAddr;

#[cfg(any(feature = "tonic014", feature = "http"))]
mod shared;
pub mod forwarded;
pub mod filter;
#[cfg(feature = "http")]
pub mod http;
#[cfg(feature = "axum08")]
pub mod axum08;
#[cfg(feature = "tonic014")]
pub mod tonic014;

#[inline]
///Determines next IP among `nodes` iterator after applying filter
///
///If `node` is not IP address, then search is aborted, as it is impossible to correctly apply filter
pub fn find_next_ip_after_filter<'a>(nodes: impl Iterator<Item = forwarded::ForwardedNode<'a>>, filter: &impl filter::Filter) -> Option<IpAddr> {

    for node in nodes {
        match node {
            forwarded::ForwardedNode::Ip(ip) => if filter.is_match(ip) {
                continue
            } else {
                return Some(ip);
            },
            _ => return None,
        }
    }

    None
}