From a987a201688307f972d7f13a314fba84d6e4eeb2 Mon Sep 17 00:00:00 2001
From: Jeong YunWon <jeong.yunwon@navercorp.com>
Date: Fri, 30 Jun 2017 21:46:19 +0900
Subject: [PATCH] A buffer which helps httptools not to corrupt requests

---
 sanic/server.py           | 54 ++++++++++++++++++++++++++++++++++-----
 tests/test_bad_request.py |  2 +-
 tests/test_requests.py    | 10 ++++++++
 3 files changed, 59 insertions(+), 7 deletions(-)

diff --git a/sanic/server.py b/sanic/server.py
index fd31680e..7d33e44f 100644
--- a/sanic/server.py
+++ b/sanic/server.py
@@ -56,6 +56,40 @@ class CIDict(dict):
         return super().__contains__(key.casefold())
 
 
+class RequestBuffer:
+    def __init__(self):
+        self.saved = b''
+        self.passed_header = False
+        self.received = b''
+
+    def put(self, data):
+        if not self.passed_header:
+            self.saved += data
+            if b'\r\n\r\n' in self.saved:
+                data = self.saved
+                self.saved = None
+                self.passed_header = True
+            else:
+                try:
+                    i = self.saved.rindex(b'\r\n')
+                except ValueError:
+                    data = None
+                else:
+                    data = self.saved[:i]
+                    self.saved = self.saved[i:]
+        if data:
+            self.received += data
+
+    def pop(self):
+        received = self.received
+        self.received = b''
+        return received
+
+    def finalize(self):
+        if self.saved:
+            self.received += self.saved
+
+
 class HttpProtocol(asyncio.Protocol):
     __slots__ = (
         # event loop, connection
@@ -99,6 +133,7 @@ class HttpProtocol(asyncio.Protocol):
         self._request_handler_task = None
         self._request_stream_task = None
         self._keep_alive = keep_alive
+        self._buffer = None
         self.state = state if state else {}
         if 'requests_count' not in self.state:
             self.state['requests_count'] = 0
@@ -146,6 +181,18 @@ class HttpProtocol(asyncio.Protocol):
     # -------------------------------------------- #
 
     def data_received(self, data):
+        # Create parser if this is the first time we're receiving data
+        if self.parser is None:
+            assert self.request is None
+            self.headers = []
+            self.parser = HttpRequestParser(self)
+            self._buffer = RequestBuffer()
+
+        self._buffer.put(data)
+        data = self._buffer.pop()
+        if not data:
+            return
+
         # Check for the request itself getting too large and exceeding
         # memory limits
         self._total_request_size += len(data)
@@ -153,12 +200,6 @@ class HttpProtocol(asyncio.Protocol):
             exception = PayloadTooLarge('Payload Too Large')
             self.write_error(exception)
 
-        # Create parser if this is the first time we're receiving data
-        if self.parser is None:
-            assert self.request is None
-            self.headers = []
-            self.parser = HttpRequestParser(self)
-
         # requests count
         self.state['requests_count'] = self.state['requests_count'] + 1
 
@@ -357,6 +398,7 @@ class HttpProtocol(asyncio.Protocol):
         self._request_stream_task = None
         self._total_request_size = 0
         self._is_stream_handler = False
+        self._buffer = None
 
     def close_if_idle(self):
         """Close the connection if a request is not being sent or received
diff --git a/tests/test_bad_request.py b/tests/test_bad_request.py
index bf595085..f951b096 100644
--- a/tests/test_bad_request.py
+++ b/tests/test_bad_request.py
@@ -9,7 +9,7 @@ def test_bad_request_response():
     async def _request(sanic, loop):
         connect = asyncio.open_connection('127.0.0.1', 42101)
         reader, writer = await connect
-        writer.write(b'not http')
+        writer.write(b'not http\r\n\r\n')
         while True:
             line = await reader.readline()
             if not line:
diff --git a/tests/test_requests.py b/tests/test_requests.py
index 81fe1a5c..01c60ec3 100644
--- a/tests/test_requests.py
+++ b/tests/test_requests.py
@@ -9,6 +9,7 @@ from sanic import Sanic
 from sanic.exceptions import ServerError
 from sanic.response import json, text
 from sanic.request import DEFAULT_HTTP_CONTENT_TYPE
+from sanic.server import RequestBuffer
 from sanic.testing import HOST, PORT
 
 
@@ -336,3 +337,12 @@ def test_url_attributes_with_ssl(path, query, expected_url):
     assert parsed.path == request.path
     assert parsed.query == request.query_string
     assert parsed.netloc == request.host
+
+
+def test_request_buffer():
+    request = b'''GET /ping/ HTTP/1.1\r\nHost: github.com\r\nConnection: keep-alive\r\nCache-Control: max-age=0\r\nUpgrade-Insecure-Requests: 1\r\nUser-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8\r\nAccept-Encoding: gzip, deflate\r\nAccept-Language: ko-KR,ko;q=0.8,en-US;q=0.6,en;q=0.4\r\n\r\n'''
+    buffer = RequestBuffer()
+    for i, byte in enumerate(request):
+        buffer.put(request[i:i+1])
+    buffer.finalize()
+    assert request == buffer.pop()
\ No newline at end of file