Add rewrite_path()

src/types/request.rs

@@ -4,6 +4,7 @@ use std::convert::TryInto;
 use std::{
     collections::HashMap,
     convert::TryFrom,
+    path::Path,
 };
 use anyhow::*;
 use percent_encoding::percent_decode_str;
@@ -25,6 +26,8 @@ pub struct Request {
     manager: UserManager,
     #[cfg(feature = "scgi_srv")]
     headers: HashMap<String, String>,
+    #[cfg(feature = "scgi_srv")]
+    script_path: Option<String>,
 }
 
 impl Request {
@@ -37,7 +40,7 @@ impl Request {
         manager: UserManager,
     ) -> Result<Self> {
         #[cfg(feature = "scgi_srv")]
-        let (mut uri, certificate) = (
+        let (mut uri, certificate, script_path) = (
             URIReference::try_from(
                 format!(
                     "{}{}",
@@ -58,6 +61,9 @@ impl Request {
                         .try_into()
                         .expect("Received certificate fingerprint of invalid lenght from upstream")
                 }),
+            headers.get("SCRIPT_PATH")
+                .or_else(|| headers.get("SCRIPT_NAME"))
+                .cloned()
         );
 
         uri.normalize();
@@ -83,6 +89,8 @@ impl Request {
             trailing_segments: None,
             #[cfg(feature = "scgi_srv")]
             headers,
+            #[cfg(feature = "scgi_srv")]
+            script_path,
             #[cfg(feature="user_management")]
             manager,
         })
@@ -192,6 +200,40 @@ impl Request {
     pub fn user_manager(&self) -> &UserManager {
         &self.manager
     }
+
+    /// Attempt to rewrite an absolute URL against the base path of the SCGI script
+    ///
+    /// When writing an SCGI script, you cannot assume that your script is mounted on the
+    /// base path of "/".  For example, a request to the gemini server for "/app/path"
+    /// might be received by your script as "/path" if your script is mounted on "/app/".
+    /// In this situation, if you linked to "/", you would be sending users to "/", which
+    /// is not handled by your app, instead of "/app/", where you probably intended to
+    /// send the user.
+    ///
+    /// This method attempts to infer where the script is mounted, and rewrite an absolute
+    /// url relative to that.  For example, if the application was mounted on "/app/", and
+    /// you passed "/path", the result would be "/app/path".
+    ///
+    /// When running in `gemini_srv` mode, the application is always mounted at the base
+    /// path, so this will always return the path unchanged.
+    ///
+    /// Not all SCGI clients will correctly report the application's path, so this may
+    /// fail if unable to infer the correct path.  If this is the case, None will be
+    /// returned.  Currently, the SCGI headers checked are:
+    ///
+    /// * `SCRIPT_PATH` (Used by mollybrown)
+    /// * `SCRIPT_NAME` (Used by GLV-1.12556)
+    pub fn rewrite_path(&self, path: impl AsRef<str>) -> Option<String> {
+        #[cfg(feature = "scgi_srv")] {
+            self.script_path.as_ref().map(|base| {
+                let base: &Path = base.as_ref();
+                base.join(path.as_ref()).display().to_string()
+            })
+        }
+        #[cfg(feature = "gemini_srv")] {
+            Some(path.to_string())
+        }
+    }
 }
 
 impl ops::Deref for Request {