What causes "entity header:%s" in XX-net/XX-Net?

Inspect the logged line to see what the client actually sent

entity header:%s

Error message

entity header:%s

What it means

While reading a chunked HTTP request body in proxy_handler.py, the parser encountered header-like lines after a chunk instead of the terminating CRLF (or inside the trailer). This indicates the upstream client sent a malformed chunked encoding, so the handler skips and logs each unexpected line. It is a protocol-parsing warning, not an exception.

Source

Thrown at code/default/gae_proxy/local/proxy_handler.py:324

            except NetWorkIOError as e:
                xlog.error('handle_method_urlfetch read payload failed:%s', e)
                return
        elif b'Transfer-Encoding' in self.headers:
            # chunked, used by facebook android client
            payload = ""
            while True:
                chunk_size_str = self.rfile.readline(65537)
                chunk_size_list = chunk_size_str.split(b";")
                chunk_size = int(b"0x"+chunk_size_list[0], 0)
                if len(chunk_size_list) > 1 and chunk_size_list[1] != b"\r\n":
                    xlog.warn("chunk ext: %s", chunk_size_str)
                if chunk_size == 0:
                    while True:
                        line = self.rfile.readline(65537)
                        if line == b"\r\n":
                            break
                        else:
                            xlog.warn("entity header:%s", line)
                    break
                payload += self.rfile.read(chunk_size)
                get_crlf(self.rfile)

        self.req_payload = payload
        return payload

# called by smart_router
def wrap_ssl(sock, host, port, client_address):
    certfile = CertUtil.get_cert(host or b'www.google.com')
    ssl_sock = ssl.wrap_socket(sock, keyfile=CertUtil.cert_keyfile,
                               certfile=certfile, server_side=True)
    return ssl_sock

View on GitHub (pinned to cfa5bc17b6)

Solutions

Inspect the logged line to see what the client actually sent
Fix the client/middlebox to emit spec-compliant chunked encoding (size CRLF data CRLF, 0 CRLF CRLF)
If trailers are expected, extend the parser to handle them explicitly

Defensive patterns

Strategy: validation

Validate before calling

// Ensure chunked requests are well-formed before proxying: send size CRLF data CRLF and terminate with '0\r\n\r\n'

Prevention

Use standard HTTP libraries to produce chunked bodies
Test clients against the proxy with valid chunked samples

When it happens

Trigger: A client sends a chunked request where a chunk is followed by data other than CRLF (e.g. chunk size with extensions, trailers, or raw bytes), causing readline() to return non-empty lines until a blank line is found.

Common situations: Non-conforming HTTP clients or middleboxes rewriting chunked bodies; debugging tools sending hand-crafted chunked requests; a chunk_size of 0 with trailing entity headers.

Related errors

AI-assisted analysis of XX-net/XX-Net@cfa5bc17b6 (2026-08-27). Data as JSON: /api/errors/4e65d9f97afa3637. Report an issue: GitHub.