diff --git a/plugin/protocol/http/include/internal/http_half.h b/plugin/protocol/http/include/internal/http_half.h
index fe762b9..86c8414 100644
--- a/plugin/protocol/http/include/internal/http_half.h
+++ b/plugin/protocol/http/include/internal/http_half.h
@@ -95,6 +95,8 @@ struct http_half_private
 
 	/* UPGRADE */
 	bool is_upgrade;
+	/* PASSTHROUGH */
+	bool is_passthrough;
 };
 
 struct http_half_private * hf_private_create(tfe_http_direction ht_dir, short major, short minor);
diff --git a/plugin/protocol/http/src/http_entry.cpp b/plugin/protocol/http/src/http_entry.cpp
index ccdcee4..8f42893 100644
--- a/plugin/protocol/http/src/http_entry.cpp
+++ b/plugin/protocol/http/src/http_entry.cpp
@@ -362,6 +362,11 @@ enum tfe_stream_action __http_connection_entry_on_request(const struct tfe_strea
 	}
 
 	/* Some kind of error happened, write log and detach the stream */
+	if (ret == -1 && hf_private_req_in->is_passthrough)
+	{
+		goto __errout;
+	}
+
 	if (ret == -1)
 	{
 		TFE_STREAM_LOG_ERROR(stream, "Failed at parsing stream as HTTP: %u, %s, %s",
@@ -475,6 +480,12 @@ enum tfe_stream_action __http_connection_entry_on_response(const struct tfe_stre
 		return hf_private_resp_in->stream_action;
 	}
 
+	/* Need to passthrough */
+	if (ret == -1 && hf_private_resp_in->is_passthrough)
+	{
+		goto __errout;
+	}
+
 	/* Some kind of error happened, write log and detach the stream */
 	if (ret == -1)
 	{
diff --git a/plugin/protocol/http/src/http_half.cpp b/plugin/protocol/http/src/http_half.cpp
index e2499af..a85374b 100644
--- a/plugin/protocol/http/src/http_half.cpp
+++ b/plugin/protocol/http/src/http_half.cpp
@@ -172,6 +172,8 @@ void __hf_public_req_fill_from_private(struct http_half_private * hf_private, st
 
 	/* accept-encoding, host is located in header's K-V structure */
 	hf_req_spec->method = (enum tfe_http_std_method) parser->method;
+	hf_private->method_or_status =  (enum tfe_http_std_method) parser->method;
+
 	const static struct http_field_name __host_field_name = {TFE_HTTP_HOST, NULL};
 	hf_req_spec->host = (char *) tfe_http_field_read(hf_public, &__host_field_name);
 
@@ -320,6 +322,16 @@ static int __parser_callback_on_headers_complete(http_parser * parser)
 		__hf_public_resp_fill_from_private(hf_private, parser);
 	}
 
+	/* for POST, must contains 'content-length' */
+	if (hf_direction == TFE_HTTP_REQUEST && hf_private->method_or_status == TFE_HTTP_METHOD_POST)
+	{
+		const static struct http_field_name __cont_encoding_field_name = {TFE_HTTP_CONT_LENGTH, NULL};
+		char * __str_content_length = (char *) tfe_http_field_read(hf_public, &__cont_encoding_field_name);
+
+		/* Does not contain a content-length, passthrough the whole TCP connection */
+		if (unlikely(__str_content_length == NULL)) { hf_private->is_passthrough = true; return -1;}
+	}
+
 	tfe_http_event event = (hf_direction == TFE_HTTP_REQUEST) ? EV_HTTP_REQ_HDR : EV_HTTP_RESP_HDR;
 	if (hf_private->event_cb)
 	{
@@ -334,8 +346,8 @@ static int __parser_callback_on_headers_complete(http_parser * parser)
 		hf_private->stream_action = hf_private->user_stream_action;
 	}
 
-		/* user's suspend tag is set, which indicate that the way to handle request/response
-         * cannot be determinate at now, need to defer */
+	/* user's suspend tag is set, which indicate that the way to handle request/response
+	 * cannot be determinate at now, need to defer */
 	else if (hs_private && hs_private->suspend_tag_user)
 	{
 		/* Pause parser, prevent to parse request/response body,
@@ -1095,9 +1107,14 @@ void __write_access_log(struct http_session_private * hs_private)
 	/* Upgrade Tag */
 	const char * __str_upgrade = response ? response->is_upgrade ? "UPGRADE" : "-" : "-";
 
+	/* PASSTHROUGH */
+	const char * __str_req_passthrough = request ? request->is_passthrough ? "PASS-THROUGH/REQ" : "-" : "-";
+	const char * __str_resp_passthrough = response ? response->is_passthrough ? "PASS-THROUGH/REP" : "-" : "-";
+
 	char * __access_log;
-	asprintf(&__access_log, "%d %s %s HTTP/%d.%d %s %s %s %s", hs_private->hs_public.session_id,  __str_method,
-		__str_url, request->major, request->minor, __str_resp_code, __str_cont_type, __str_cont_encoding, __str_upgrade);
+	asprintf(&__access_log, "%d %s %s HTTP/%d.%d %s %s %s %s %s %s", hs_private->hs_public.session_id,  __str_method,
+		__str_url, request->major, request->minor, __str_resp_code, __str_cont_type, __str_cont_encoding,
+		__str_upgrade, __str_req_passthrough, __str_resp_passthrough);
 
 	const struct tfe_stream * stream = hs_private->hc_private->stream;
 	tfe_stream_write_access_log(stream, RLOG_LV_INFO, "%s", __access_log);