diff --git a/platform/src/kni_acceptor.cpp b/platform/src/kni_acceptor.cpp
index 3855a7b..2c4268c 100644
--- a/platform/src/kni_acceptor.cpp
+++ b/platform/src/kni_acceptor.cpp
@@ -236,8 +236,15 @@ void __kni_event_cb(evutil_socket_t fd, short what, void * user)
 	__cmsghdr = CMSG_FIRSTHDR(&__msghdr);
 	__fds = (int *) (CMSG_DATA(__cmsghdr));
 
-	if(__kni_parse_tlv_data(__ctx, &__accept_para, __buffer, (size_t)rd) < 0)
+	if (unlikely(__fds == NULL))
 	{
+		TFE_LOG_ERROR(__ctx->logger, "Failed at fetch CMSG_DATA() from incoming fds, close KNI connection.");
+		goto __close_kni_connection;
+	}
+
+	if(unlikely(__kni_parse_tlv_data(__ctx, &__accept_para, __buffer, (size_t)rd) < 0))
+	{
+		TFE_LOG_ERROR(__ctx->logger, "Failed at parsing TLV format, close KNI connection.");
 		goto __close_kni_connection;
 	}
 
diff --git a/plugin/protocol/http/include/internal/http_half.h b/plugin/protocol/http/include/internal/http_half.h
index 665b764..fe762b9 100644
--- a/plugin/protocol/http/include/internal/http_half.h
+++ b/plugin/protocol/http/include/internal/http_half.h
@@ -92,6 +92,9 @@ struct http_half_private
 	struct evbuffer * evbuf_body;
 	struct evbuffer * evbuf_raw;
 	struct tfe_stream_write_ctx * write_ctx;
+
+	/* UPGRADE */
+	bool is_upgrade;
 };
 
 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 2ec4348..4a1bf31 100644
--- a/plugin/protocol/http/src/http_entry.cpp
+++ b/plugin/protocol/http/src/http_entry.cpp
@@ -436,8 +436,7 @@ enum tfe_stream_action __http_connection_entry_on_response(const struct tfe_stre
 		hf_private_set_session(hf_private_resp_in, hs_private);
 
 		/* Closure, catch stream, session and thread_id */
-		struct user_event_dispatch_closure * __closure = ALLOC(
-			struct user_event_dispatch_closure, 1);
+		struct user_event_dispatch_closure * __closure = ALLOC(struct user_event_dispatch_closure, 1);
 		__closure->thread_id = thread_id;
 		__closure->stream = stream;
 		__closure->session = to_hs_public(hs_private);
@@ -478,6 +477,13 @@ enum tfe_stream_action __http_connection_entry_on_response(const struct tfe_stre
 		goto __errout;
 	}
 
+	/* Upgrade, passthrough the connection and close this session */
+	if (hf_private_resp_in->is_upgrade)
+	{
+		tfe_stream_detach(stream);
+		hf_private_resp_in->stream_action = ACTION_FORWARD_DATA;
+	}
+
 	hf_private_resp_user = hs_private->hf_private_resp_user;
 	if (hf_private_resp_user != NULL)
 	{
diff --git a/plugin/protocol/http/src/http_half.cpp b/plugin/protocol/http/src/http_half.cpp
index a916113..3ef8b2b 100644
--- a/plugin/protocol/http/src/http_half.cpp
+++ b/plugin/protocol/http/src/http_half.cpp
@@ -775,6 +775,11 @@ int hf_private_parse(struct http_half_private * hf_private, const unsigned char
 		__is_paused = true;
 	}
 
+	if (hf_private->parse_object->upgrade)
+	{
+		hf_private->is_upgrade = true;
+	}
+
 	if (sz_parsed == __len_with_offset)
 	{
 		hf_private->parse_cursor += sz_parsed;
@@ -1091,10 +1096,12 @@ void __write_access_log(struct http_session_private * hs_private)
 	const char * __str_cont_length = resp_spec ? resp_spec->content_length : "-";
 	/* Content Encoding */
 	const char * __str_cont_encoding = resp_spec ? resp_spec->content_encoding : "-";
+	/* Upgrade Tag */
+	const char * __str_upgrade = response->is_upgrade ? "UPGRADE" : "-";
 
 	char * __access_log;
-	asprintf(&__access_log, "%s %s %s %s %s %s", __str_method,
-		__str_url, __str_resp_code, __str_cont_type, __str_cont_length, __str_cont_encoding);
+	asprintf(&__access_log, "%s %s %s %s %s %s %s", __str_method,
+		__str_url, __str_resp_code, __str_cont_type, __str_cont_length, __str_cont_encoding, __str_upgrade);
 
 	const struct tfe_stream * stream = hs_private->hc_private->stream;
 	tfe_stream_write_access_log(stream, RLOG_LV_INFO, "%s", __access_log);