From ba1c73d947389243b06bdf2920f742364fcc9943 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=2E=20K=C3=A4rkk=C3=A4inen?=
 <98187+Tronic@users.noreply.github.com>
Date: Wed, 28 Jul 2021 04:38:28 -0400
Subject: [PATCH] Fix issues with after request handling in HTTP pipelining
 (#2201)
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* Clean up after a request is complete, before the next pipelined request.

* Limit the size of request body consumed after handler has finished.

* Linter error.

* Add unit test re: bad headers

Co-authored-by: L. Kärkkäinen <tronic@users.noreply.github.com>
Co-authored-by: Adam Hopkins <admhpkns@gmail.com>
Co-authored-by: Adam Hopkins <adam@amhopkins.com>
---
 sanic/http.py            | 31 +++++++++++++++++++++++--------
 tests/test_pipelining.py | 25 ++++++++++++++++++++++++-
 2 files changed, 47 insertions(+), 9 deletions(-)

diff --git a/sanic/http.py b/sanic/http.py
index 16603c38..402238cb 100644
--- a/sanic/http.py
+++ b/sanic/http.py
@@ -95,19 +95,23 @@ class Http:
         self._receive_more = protocol.receive_more
         self.recv_buffer = protocol.recv_buffer
         self.protocol = protocol
-        self.expecting_continue: bool = False
+        self.keep_alive = True
         self.stage: Stage = Stage.IDLE
+        self.init_for_request()
+
+    def init_for_request(self):
+        """Init/reset all per-request variables."""
+        self.exception = None
+        self.expecting_continue: bool = False
+        self.head_only = None
         self.request_body = None
         self.request_bytes = None
         self.request_bytes_left = None
-        self.request_max_size = protocol.request_max_size
-        self.keep_alive = True
-        self.head_only = None
+        self.request_max_size = self.protocol.request_max_size
         self.request: Request = None
         self.response: BaseHTTPResponse = None
-        self.exception = None
-        self.url = None
         self.upgrade_websocket = False
+        self.url = None
 
     def __bool__(self):
         """Test if request handling is in progress"""
@@ -148,7 +152,10 @@ class Http:
             if self.request_body:
                 if self.response and 200 <= self.response.status < 300:
                     error_logger.error(f"{self.request} body not consumed.")
-
+                # Limit the size because the handler may have set it infinite
+                self.request_max_size = min(
+                    self.request_max_size, self.protocol.request_max_size
+                )
                 try:
                     async for _ in self:
                         pass
@@ -160,11 +167,19 @@ class Http:
                     await sleep(0.001)
                     self.keep_alive = False
 
+            # Clean up to free memory and for the next request
+            if self.request:
+                self.request.stream = None
+                if self.response:
+                    self.response.stream = None
+
+            self.init_for_request()
+
             # Exit and disconnect if no more requests can be taken
             if self.stage is not Stage.IDLE or not self.keep_alive:
                 break
 
-            # Wait for next request
+            # Wait for the next request
             if not self.recv_buffer:
                 await self._receive_more()
 
diff --git a/tests/test_pipelining.py b/tests/test_pipelining.py
index 689a787b..2bb29c52 100644
--- a/tests/test_pipelining.py
+++ b/tests/test_pipelining.py
@@ -1,7 +1,7 @@
 from httpx import AsyncByteStream
 from sanic_testing.reusable import ReusableClient
 
-from sanic.response import json
+from sanic.response import json, text
 
 
 def test_no_body_requests(app):
@@ -80,3 +80,26 @@ def test_streaming_body_requests(app):
     assert response1.json["data"] == response2.json["data"] == data
     assert response1.json["request_id"] != response2.json["request_id"]
     assert response1.json["connection_id"] == response2.json["connection_id"]
+
+
+def test_bad_headers(app):
+    @app.get("/")
+    async def handler(request):
+        return text("")
+
+    @app.on_response
+    async def reqid(request, response):
+        response.headers["x-request-id"] = request.id
+
+    client = ReusableClient(app, port=1234)
+    bad_headers = {"bad": "bad" * 5_000}
+
+    with client:
+        _, response1 = client.get("/")
+        _, response2 = client.get("/", headers=bad_headers)
+
+    assert response1.status == 200
+    assert response2.status == 413
+    assert (
+        response1.headers["x-request-id"] != response2.headers["x-request-id"]
+    )