totally refactored

src/proxy/utils_headers.rs

@@ -0,0 +1,112 @@
+use super::{Upstream, UpstreamOption};
+use crate::{error::*, log::*, utils::*};
+use hyper::{
+  header::{self, HeaderMap, HeaderValue},
+  Uri,
+};
+use std::net::SocketAddr;
+
+////////////////////////////////////////////////////
+// Functions to manipulate headers
+
+pub(super) fn apply_upstream_options_to_header(
+  headers: &mut HeaderMap,
+  _client_addr: SocketAddr,
+  upstream_scheme_host: &Uri,
+  upstream: &Upstream,
+) -> Result<()> {
+  for opt in upstream.opts.iter() {
+    match opt {
+      UpstreamOption::OverrideHost => {
+        let upstream_host = upstream_scheme_host.host().ok_or_else(|| anyhow!("none"))?;
+        headers
+          .insert(header::HOST, HeaderValue::from_str(upstream_host)?)
+          .ok_or_else(|| anyhow!("none"))?;
+      }
+    }
+  }
+
+  Ok(())
+}
+
+pub(super) fn append_header_entry(
+  headers: &mut HeaderMap,
+  key: &'static str,
+  value: &str,
+) -> Result<()> {
+  match headers.entry(key) {
+    header::Entry::Vacant(entry) => {
+      entry.insert(value.parse::<HeaderValue>()?);
+    }
+    header::Entry::Occupied(mut entry) => {
+      entry.append(value.parse::<HeaderValue>()?);
+    }
+  }
+
+  Ok(())
+}
+
+pub(super) fn add_forwarding_header(
+  headers: &mut HeaderMap,
+  client_addr: SocketAddr,
+) -> Result<()> {
+  // default process
+  // optional process defined by upstream_option is applied in fn apply_upstream_options
+  append_header_entry(
+    headers,
+    "x-forwarded-for",
+    &client_addr.to_canonical().ip().to_string(),
+  )?;
+
+  Ok(())
+}
+
+pub(super) fn remove_connection_header(headers: &mut HeaderMap) {
+  if let Some(values) = headers.get(header::CONNECTION) {
+    if let Ok(v) = values.clone().to_str() {
+      for m in v.split(',') {
+        if !m.is_empty() {
+          headers.remove(m.trim());
+        }
+      }
+    }
+  }
+}
+
+const HOP_HEADERS: &[&str] = &[
+  "connection",
+  "te",
+  "trailer",
+  "keep-alive",
+  "proxy-connection",
+  "proxy-authenticate",
+  "proxy-authorization",
+  "transfer-encoding",
+  "upgrade",
+];
+
+pub(super) fn remove_hop_header(headers: &mut HeaderMap) {
+  HOP_HEADERS.iter().for_each(|key| {
+    headers.remove(*key);
+  });
+}
+
+pub(super) fn extract_upgrade(headers: &HeaderMap) -> Option<String> {
+  if let Some(c) = headers.get(header::CONNECTION) {
+    if c
+      .to_str()
+      .unwrap_or("")
+      .split(',')
+      .into_iter()
+      .any(|w| w.trim().to_ascii_lowercase() == header::UPGRADE.as_str().to_ascii_lowercase())
+    {
+      if let Some(u) = headers.get(header::UPGRADE) {
+        if let Ok(m) = u.to_str() {
+          debug!("Upgrade in request header: {}", m);
+          return Some(m.to_owned());
+        }
+      }
+    }
+  }
+  None
+}