From a8a73c78189c36669559a9d431083f44967484eb Mon Sep 17 00:00:00 2001
From: Anthony Ramine <nox@nox.paris>
Date: Mon, 15 Mar 2021 12:00:46 +0100
Subject: [PATCH] feat(http): introduce Error::is_header_section_too_large
 (fixes #2462)

We rename Parse::TooLarge into Parse::HeaderSectionTooLarge while at it.
---
 src/body/length.rs   |  2 +-
 src/error.rs         | 16 +++++++++++-----
 src/proto/h1/io.rs   |  4 ++--
 src/proto/h1/role.rs |  4 ++--
 tests/server.rs      |  2 +-
 5 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/src/body/length.rs b/src/body/length.rs
index aa9cf3dcd5..35d42b1dee 100644
--- a/src/body/length.rs
+++ b/src/body/length.rs
@@ -43,7 +43,7 @@ impl DecodedLength {
             Ok(DecodedLength(len))
         } else {
             warn!("content-length bigger than maximum: {} > {}", len, MAX_LEN);
-            Err(crate::error::Parse::TooLarge)
+            Err(crate::error::Parse::HeaderSectionTooLarge)
         }
     }
 
diff --git a/src/error.rs b/src/error.rs
index 663156e0a9..6217a0746b 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -71,7 +71,7 @@ pub(super) enum Parse {
     VersionH2,
     Uri,
     Header,
-    TooLarge,
+    HeaderSectionTooLarge,
     Status,
 }
 
@@ -132,6 +132,12 @@ impl Error {
         matches!(self.inner.kind, Kind::Parse(_))
     }
 
+    /// Returns true if this was an HTTP parse error about the header section
+    /// being too large.
+    pub fn is_header_section_too_large(&self) -> bool {
+        self.inner.kind == Kind::Parse(Parse::HeaderSectionTooLarge)
+    }
+
     /// Returns true if this error was caused by user code.
     pub fn is_user(&self) -> bool {
         matches!(self.inner.kind, Kind::User(_))
@@ -220,8 +226,8 @@ impl Error {
     }
 
     #[cfg(feature = "http1")]
-    pub(super) fn new_too_large() -> Error {
-        Error::new(Kind::Parse(Parse::TooLarge))
+    pub(super) fn new_header_section_too_large() -> Error {
+        Error::new(Kind::Parse(Parse::HeaderSectionTooLarge))
     }
 
     #[cfg(feature = "http1")]
@@ -361,7 +367,7 @@ impl Error {
             Kind::Parse(Parse::VersionH2) => "invalid HTTP version parsed (found HTTP2 preface)",
             Kind::Parse(Parse::Uri) => "invalid URI",
             Kind::Parse(Parse::Header) => "invalid HTTP header parsed",
-            Kind::Parse(Parse::TooLarge) => "message head is too large",
+            Kind::Parse(Parse::HeaderSectionTooLarge) => "message head is too large",
             Kind::Parse(Parse::Status) => "invalid HTTP status-code parsed",
             Kind::IncompleteMessage => "connection closed before message completed",
             #[cfg(feature = "http1")]
@@ -465,7 +471,7 @@ impl From<httparse::Error> for Parse {
             | httparse::Error::NewLine
             | httparse::Error::Token => Parse::Header,
             httparse::Error::Status => Parse::Status,
-            httparse::Error::TooManyHeaders => Parse::TooLarge,
+            httparse::Error::TooManyHeaders => Parse::HeaderSectionTooLarge,
             httparse::Error::Version => Parse::Version,
         }
     }
diff --git a/src/proto/h1/io.rs b/src/proto/h1/io.rs
index 5536b5d164..637b8adbb2 100644
--- a/src/proto/h1/io.rs
+++ b/src/proto/h1/io.rs
@@ -18,7 +18,7 @@ pub(crate) const INIT_BUFFER_SIZE: usize = 8192;
 pub(crate) const MINIMUM_MAX_BUFFER_SIZE: usize = INIT_BUFFER_SIZE;
 
 /// The default maximum read buffer size. If the buffer gets this big and
-/// a message is still not complete, a `TooLarge` error is triggered.
+/// a message is still not complete, a `HeaderSectionTooLarge` error is triggered.
 // Note: if this changes, update server::conn::Http::max_buf_size docs.
 pub(crate) const DEFAULT_MAX_BUFFER_SIZE: usize = 8192 + 4096 * 100;
 
@@ -171,7 +171,7 @@ where
                     let max = self.read_buf_strategy.max();
                     if self.read_buf.len() >= max {
                         debug!("max_buf_size ({}) reached, closing", max);
-                        return Poll::Ready(Err(crate::Error::new_too_large()));
+                        return Poll::Ready(Err(crate::Error::new_header_section_too_large()));
                     }
                 }
             }
diff --git a/src/proto/h1/role.rs b/src/proto/h1/role.rs
index a9f2f0074f..4765c05132 100644
--- a/src/proto/h1/role.rs
+++ b/src/proto/h1/role.rs
@@ -609,7 +609,7 @@ impl Http1Transaction for Server {
             | Kind::Parse(Parse::Header)
             | Kind::Parse(Parse::Uri)
             | Kind::Parse(Parse::Version) => StatusCode::BAD_REQUEST,
-            Kind::Parse(Parse::TooLarge) => StatusCode::REQUEST_HEADER_FIELDS_TOO_LARGE,
+            Kind::Parse(Parse::HeaderSectionTooLarge) => StatusCode::REQUEST_HEADER_FIELDS_TOO_LARGE,
             _ => return None,
         };
 
@@ -1077,7 +1077,7 @@ fn record_header_indices(
     for (header, indices) in headers.iter().zip(indices.iter_mut()) {
         if header.name.len() >= (1 << 16) {
             debug!("header name larger than 64kb: {:?}", header.name);
-            return Err(crate::error::Parse::TooLarge);
+            return Err(crate::error::Parse::HeaderSectionTooLarge);
         }
         let name_start = header.name.as_ptr() as usize - bytes_ptr;
         let name_end = name_start + header.name.len();
diff --git a/tests/server.rs b/tests/server.rs
index 72d2e459d8..174cd2a19b 100644
--- a/tests/server.rs
+++ b/tests/server.rs
@@ -1566,7 +1566,7 @@ async fn max_buf_size() {
         .max_buf_size(MAX)
         .serve_connection(socket, HelloWorld)
         .await
-        .expect_err("should TooLarge error");
+        .expect_err("should HeaderSectionTooLarge error");
 }
 
 #[cfg(feature = "stream")]