Websocket upgrade directive implementation

Contributes to tempesta-tech#755

Signed-off-by: Aleksey Mikhaylov <[email protected]>

Author: ttaym

fw/http.h

@@ -170,11 +170,11 @@ typedef struct {
  * Http headers table.
  *
  * Singular headers (in terms of RFC 7230 3.2.2) go first to protect header
- * repetition attacks. See __hdr_is_singular() and don't forget to
- * update the static headers array when add a new singular header here.
- * If the new header is hop-by-hop (must not be forwarded and cached by Tempesta)
- * it must be listed in tfw_http_init_parser_req()/tfw_http_init_parser_resp()
- * for unconditionally hop-by-hop header or in __parse_connection() otherwize.
+ * repetition attacks. See __hdr_is_singular() and don't forget to update the
+ * static headers array when add a new singular header here. If the new header
+ * is hop-by-hop (must not be forwarded and cached by Tempesta) it must be
+ * listed in tfw_http_init_parser_req()/tfw_http_init_parser_resp()
+ * for unconditionally hop-by-hop header or in __parse_connection() otherwise.
  * If the header is end-to-end it must be listed in __hbh_parser_add_data().
  *
  * Note: don't forget to update __http_msg_hdr_val() and
@@ -212,6 +212,7 @@ typedef enum {
 	TFW_HTTP_HDR_X_FORWARDED_FOR,
 	TFW_HTTP_HDR_KEEP_ALIVE,
 	TFW_HTTP_HDR_TRANSFER_ENCODING,
+	TFW_HTTP_HDR_UPGRADE,
 
 	/* Start of list of generic (raw) headers. */
 	TFW_HTTP_HDR_RAW,
@@ -239,7 +240,10 @@ enum {
 	 */
 	TFW_HTTP_B_CONN_CLOSE	= TFW_HTTP_FLAGS_COMMON,
 	TFW_HTTP_B_CONN_KA,
+	TFW_HTTP_B_CONN_UPGRADE,
 	TFW_HTTP_B_CONN_EXTRA,
+	/* Request is a websocket upgrade request */
+	TFW_HTTP_B_UPGRADE_WEBSOCKET,
 	/* Chunked is last transfer encoding. */
 	TFW_HTTP_B_CHUNKED,
 	/* Chunked in the middle of applied transfer encodings. */

fw/http_limits.c

@@ -564,6 +564,49 @@ frang_http_methods_override(const TfwHttpReq *req, FrangAcc *ra,
 	return TFW_PASS;
 }
 
+static int
+frang_http_upgrade_websocket(const TfwHttpReq *req, FrangAcc *ra,
+			     FrangVhostCfg *f_cfg)
+{
+	BUG_ON(!req);
+
+	switch (req->version) {
+	/*
+	 * TODO upgrade websocket checks for h2 as described in RFC8441
+	 */
+	case TFW_HTTP_VER_20:
+		break;
+	/*
+	 * Tempesta FW MUST block requests with Upgrade header but without
+	 * upgrade option in Connection header. Tempesta FW MUST ignore
+	 * Upgrade header for HTTP version less then HTTP/1.1.
+	 * See RFC7230#section-6.1.
+	 */
+	case TFW_HTTP_VER_11:
+	case TFW_HTTP_VER_10:
+	case TFW_HTTP_VER_09:
+		if (test_bit(TFW_HTTP_B_UPGRADE_WEBSOCKET, req->flags)
+		    && !test_bit(TFW_HTTP_B_CONN_UPGRADE, req->flags))
+		{
+			frang_msg("upgrade request without connection option",
+			  &FRANG_ACC2CLI(ra)->addr, ": protocol: %s\n",
+			  "websocket");
+			return TFW_BLOCK;
+		}
+		if (req->version == TFW_HTTP_VER_10
+		    || req->version == TFW_HTTP_VER_09)
+		{
+			clear_bit(TFW_HTTP_B_UPGRADE_WEBSOCKET,
+				  ((TfwHttpReq *)req)->flags);
+		}
+		break;
+	default:
+		return TFW_BLOCK;
+	}
+
+	return TFW_PASS;
+}
+
 static int
 frang_http_ct_check(const TfwHttpReq *req, FrangAcc *ra, FrangCtVals *ct_vals)
 {
@@ -1189,6 +1232,13 @@ frang_http_req_process(FrangAcc *ra, TfwConn *conn, TfwFsmData *data,
 		if (f_cfg->http_ct_required || f_cfg->http_ct_vals)
 			r = frang_http_ct_check(req, ra, f_cfg->http_ct_vals);
 
+		/* Do checks for websocket upgrade */
+		if (test_bit(TFW_HTTP_B_UPGRADE_WEBSOCKET, req->flags)
+		    && (r = frang_http_upgrade_websocket(req, ra, f_cfg)))
+		{
+			T_FSM_EXIT();
+		}
+
 		__FRANG_FSM_MOVE(Frang_Req_Body_Start);
 	}
 

fw/http_msg.c

@@ -155,6 +155,7 @@ tfw_http_msg_resp_spec_hid(const TfwStr *hdr)
 		TfwStrDefV("transfer-encoding:",TFW_HTTP_HDR_TRANSFER_ENCODING),
 		TfwStrDefV("x-forwarded-for:",	TFW_HTTP_HDR_X_FORWARDED_FOR),
 		TfwStrDefV("x-tempesta-cache:",	TFW_HTTP_HDR_X_TEMPESTA_CACHE),
+		TfwStrDefV("upgrade:",		TFW_HTTP_HDR_UPGRADE),
 	};
 
 	BUILD_BUG_ON(ARRAY_SIZE(resp_hdrs) !=
@@ -182,6 +183,7 @@ tfw_http_msg_req_spec_hid(const TfwStr *hdr)
 		TfwStrDefV("user-agent:",	TFW_HTTP_HDR_USER_AGENT),
 		TfwStrDefV("x-forwarded-for:",	TFW_HTTP_HDR_X_FORWARDED_FOR),
 		TfwStrDefV("x-tempesta-cache:",	TFW_HTTP_HDR_X_TEMPESTA_CACHE),
+		TfwStrDefV("upgrade:",		TFW_HTTP_HDR_UPGRADE),
 	};
 
 	BUILD_BUG_ON(ARRAY_SIZE(req_hdrs) !=
@@ -215,6 +217,7 @@ __http_msg_hdr_val(TfwStr *hdr, unsigned id, TfwStr *val, bool client)
 			[TFW_HTTP_HDR_SET_COOKIE]	= SLEN("Set-Cookie:"),
 			[TFW_HTTP_HDR_ETAG]		= SLEN("ETag:"),
 			[TFW_HTTP_HDR_REFERER]		= SLEN("Referer:"),
+			[TFW_HTTP_HDR_UPGRADE]		= SLEN("Upgrade:"),
 		},
 		(unsigned char []) {
 			[TFW_HTTP_HDR_HOST]		= SLEN("Host:"),
@@ -229,6 +232,7 @@ __http_msg_hdr_val(TfwStr *hdr, unsigned id, TfwStr *val, bool client)
 			[TFW_HTTP_HDR_COOKIE]		= SLEN("Cookie:"),
 			[TFW_HTTP_HDR_IF_NONE_MATCH]	= SLEN("If-None-Match:"),
 			[TFW_HTTP_HDR_REFERER]		= SLEN("Referer:"),
+			[TFW_HTTP_HDR_UPGRADE]		= SLEN("Upgrade:"),
 		},
 	};
 	TfwStr *c, *end;