Recreate upgrade headers for websocket request (#1592)

Co-authored-by: Alexander Krizhanovsky <[email protected]>
Signed-off-by: Aleksey Mikhaylov <[email protected]>

fw/http.c

@@ -2572,6 +2572,44 @@ tfw_http_set_hdr_date(TfwHttpMsg *hm)
 	return r;
 }
 
+/*
+ * Add 'Upgrade:' header for websocket upgrade messages
+ */
+static int
+tfw_http_set_hdr_upgrade(TfwHttpMsg *hm, bool is_resp)
+{
+	int r = 0;
+
+	if (test_bit(TFW_HTTP_B_UPGRADE_WEBSOCKET, hm->flags)) {
+		/*
+		 * RFC7230#section-6.7:
+		 * A server that sends a 101 (Switching Protocols) response
+		 * MUST send an Upgrade header field to indicate the new
+		 * protocol(s) to which the connection is being switched; if
+		 * multiple protocol layers are being switched, the sender MUST
+		 * list the protocols in layer-ascending order.
+		 *
+		 * We do expect neither upgrades besides 'websocket' nor
+		 * multilayer upgrades. So we consider extra options as error.
+		 */
+		if (is_resp && ((TfwHttpResp *)hm)->status == 101
+		    && test_bit(TFW_HTTP_B_UPGRADE_EXTRA, hm->flags))
+		{
+			T_ERR("Unable to add uncompliant 'Upgrade:' header "
+			      "to msg [%p]\n", hm);
+			return -EINVAL;
+		}
+		r = tfw_http_msg_hdr_xfrm(hm, "upgrade", SLEN("upgrade"),
+				  "websocket", SLEN("websocket"),
+				  TFW_HTTP_HDR_UPGRADE, 0);
+		if (r)
+			T_ERR("Unable to add Upgrade: header to msg [%p]\n", hm);
+		else
+			T_DBG2("Added Upgrade: header to msg [%p]\n", hm);
+	}
+	return r;
+}
+
 /*
  * Expand HTTP response with 'Date:' header field.
  */
@@ -2677,23 +2715,54 @@ tfw_http_expand_hbh(TfwHttpResp *resp, unsigned short status)
 static int
 tfw_http_set_hdr_connection(TfwHttpMsg *hm, unsigned long conn_flg)
 {
+	int r;
 	BUILD_BUG_ON(BIT_WORD(__TFW_HTTP_MSG_M_CONN) != 0);
 	if (((hm->flags[0] & __TFW_HTTP_MSG_M_CONN) == conn_flg)
 	    && (!TFW_STR_EMPTY(&hm->h_tbl->tbl[TFW_HTTP_HDR_CONNECTION]))
-	    && !test_bit(TFW_HTTP_B_CONN_EXTRA, hm->flags))
+	    && !test_bit(TFW_HTTP_B_CONN_EXTRA, hm->flags)
+	    && !test_bit(TFW_HTTP_B_CONN_UPGRADE, hm->flags))
+	{
 		return 0;
+	}
 
-	switch (conn_flg) {
-	case BIT(TFW_HTTP_B_CONN_CLOSE):
+	/*
+	 * We can see `TFW_HTTP_B_CONN_CLOSE` here only in case of 4XX
+	 * response with 'Connection: close' option.
+	 *
+	 * For requests conn_flg by default is TFW_HTTP_B_CONN_KA.
+	 */
+	if (unlikely(conn_flg == BIT(TFW_HTTP_B_CONN_CLOSE)))
 		return TFW_HTTP_MSG_HDR_XFRM(hm, "Connection", "close",
 					     TFW_HTTP_HDR_CONNECTION, 0);
-	case BIT(TFW_HTTP_B_CONN_KA):
-		return TFW_HTTP_MSG_HDR_XFRM(hm, "Connection", "keep-alive",
-					     TFW_HTTP_HDR_CONNECTION, 0);
-	default:
-		return TFW_HTTP_MSG_HDR_DEL(hm, "Connection",
-					    TFW_HTTP_HDR_CONNECTION);
+
+	if (conn_flg == BIT(TFW_HTTP_B_CONN_KA)) {
+		if (test_bit(TFW_HTTP_B_UPGRADE_WEBSOCKET, hm->flags)
+		    && test_bit(TFW_HTTP_B_CONN_UPGRADE, hm->flags))
+		{
+			r = TFW_HTTP_MSG_HDR_XFRM(hm, "Connection",
+						  "keep-alive, upgrade",
+						  TFW_HTTP_HDR_CONNECTION, 0);
+		}
+		else {
+			r = TFW_HTTP_MSG_HDR_XFRM(hm, "Connection",
+						  "keep-alive",
+						  TFW_HTTP_HDR_CONNECTION, 0);
+		}
+	} else {
+		if (test_bit(TFW_HTTP_B_UPGRADE_WEBSOCKET, hm->flags)
+		    && test_bit(TFW_HTTP_B_CONN_UPGRADE, hm->flags))
+		{
+			r = TFW_HTTP_MSG_HDR_XFRM(hm, "Connection",
+						  "upgrade",
+						  TFW_HTTP_HDR_CONNECTION, 0);
+		}
+		else {
+			r = TFW_HTTP_MSG_HDR_DEL(hm, "Connection",
+					         TFW_HTTP_HDR_CONNECTION);
+		}
 	}
+
+	return r;
 }
 
 /**
@@ -3072,6 +3141,10 @@ tfw_h1_adjust_req(TfwHttpReq *req)
 	if (r < 0)
 		return r;
 
+	r = tfw_http_set_hdr_upgrade(hm, false);
+	if (r < 0)
+		return r;
+
 	r = tfw_h1_set_loc_hdrs(hm, false, false);
 	if (r < 0)
 		return r;
@@ -3642,6 +3715,10 @@ tfw_http_adjust_resp(TfwHttpResp *resp)
 	if (r < 0)
 		return r;
 
+	r = tfw_http_set_hdr_upgrade(hm, true);
+	if (r < 0)
+		return r;
+
 	r = tfw_http_set_hdr_keep_alive(hm, conn_flg);
 	if (r < 0)
 		return r;

fw/http.h

@@ -242,8 +242,10 @@ enum {
 	TFW_HTTP_B_CONN_KA,
 	TFW_HTTP_B_CONN_UPGRADE,
 	TFW_HTTP_B_CONN_EXTRA,
-	/* Request is a websocket upgrade request */
+	/* Message is a websocket upgrade request */
 	TFW_HTTP_B_UPGRADE_WEBSOCKET,
+	/* Message upgrade header contains extra fields */
+	TFW_HTTP_B_UPGRADE_EXTRA,
 	/* Chunked is last transfer encoding. */
 	TFW_HTTP_B_CHUNKED,
 	/* Chunked in the middle of applied transfer encodings. */

fw/http_parser.c

@@ -3348,7 +3348,7 @@ STACK_FRAME_NON_STANDARD(__parse_pragma);
  * __FSM_I_MOVE_fixup()/__FSM_I_MATCH_fixup()/TRY_STR_fixup() everywhere.
  */
 static int
-__req_parse_upgrade(TfwHttpMsg *hm, unsigned char *data, size_t len)
+__parse_upgrade(TfwHttpMsg *hm, unsigned char *data, size_t len)
 {
 	int r = CSTR_NEQ;
 	__FSM_DECLARE_VARS(hm);
@@ -3382,6 +3382,8 @@ __req_parse_upgrade(TfwHttpMsg *hm, unsigned char *data, size_t len)
 			 */
 			return CSTR_NEQ;
 		}
+
+		__set_bit(TFW_HTTP_B_UPGRADE_EXTRA, msg->flags);
 		__FSM_I_JMP(I_UpgradeProtocolEnd);
 	}
 
@@ -3398,6 +3400,8 @@ __req_parse_upgrade(TfwHttpMsg *hm, unsigned char *data, size_t len)
 				__set_bit(TFW_HTTP_B_UPGRADE_WEBSOCKET,
 					  msg->flags);
 			}
+		} else {
+			__set_bit(TFW_HTTP_B_UPGRADE_EXTRA, msg->flags);
 		}
 
 		__FSM_I_JMP(I_UpgradeProtocolEnd);
@@ -3437,7 +3441,6 @@ __req_parse_upgrade(TfwHttpMsg *hm, unsigned char *data, size_t len)
 	 * At this state we know that we saw at least one character in
 	 * protocol version and now we can pass zero length token.
 	 */
-
 	__FSM_STATE(I_UpgradeVersion) {
 		__FSM_I_MATCH_MOVE_fixup(token, I_UpgradeVersion,
 					 TFW_STR_VALUE);
@@ -3477,7 +3480,7 @@ __req_parse_upgrade(TfwHttpMsg *hm, unsigned char *data, size_t len)
 done:
 	return r;
 }
-STACK_FRAME_NON_STANDARD(__req_parse_upgrade);
+STACK_FRAME_NON_STANDARD(__parse_upgrade);
 
 static int
 __req_parse_user_agent(TfwHttpMsg *hm, unsigned char *data, size_t len)
@@ -4479,7 +4482,7 @@ tfw_http_parse_req(void *req_data, unsigned char *data, size_t len,
 				   TFW_HTTP_HDR_USER_AGENT);
 
 	/* 'Upgrade:*OWS' is read, process field-value. */
-	__TFW_HTTP_PARSE_SPECHDR_VAL(Req_HdrUpgradeV, msg,__req_parse_upgrade,
+	__TFW_HTTP_PARSE_SPECHDR_VAL(Req_HdrUpgradeV, msg, __parse_upgrade,
 				     TFW_HTTP_HDR_UPGRADE, 0);
 
 	/* 'Cookie:*OWS' is read, process field-value. */
@@ -10057,6 +10060,17 @@ tfw_http_parse_resp(void *resp_data, unsigned char *data, size_t len,
 				__FSM_MOVE_hdr_fixup(RGen_LWS, 1);
 			}
 			__FSM_MOVE(Resp_HdrT);
+		case 'u':
+			if (likely(__data_available(p, 8)
+				   && C4_INT_LCM(p, 'u', 'p', 'g', 'r')
+				   && C4_INT3_LCM(p + 4, 'a', 'd', 'e', ':')))
+			{
+				__msg_hdr_chunk_fixup(data, __data_off(p + 7));
+				parser->_i_st = &&Resp_HdrUpgradeV;
+				p += 7;
+				__FSM_MOVE_hdr_fixup(RGen_LWS, 1);
+			}
+			__FSM_MOVE(Resp_HdrU);
 		case 'v':
 			if (likely(__data_available(p, 5)
 			           && C4_INT3_LCM(p + 1, 'a', 'r', 'y', ':')))
@@ -10229,6 +10243,10 @@ tfw_http_parse_resp(void *resp_data, unsigned char *data, size_t len,
 	/* 'Pragma:*OWS' is read, process field-value. */
 	__TFW_HTTP_PARSE_RAWHDR_VAL(Resp_HdrPragmaV, msg, __parse_pragma, 0);
 
+	/* 'Upgrade:*OWS' is read, process field-value. */
+	__TFW_HTTP_PARSE_SPECHDR_VAL(Resp_HdrUpgradeV, msg, __parse_upgrade,
+				     TFW_HTTP_HDR_UPGRADE, 0);
+
 	/* 'Server:*OWS' is read, process field-value. */
 	TFW_HTTP_PARSE_SPECHDR_VAL(Resp_HdrServerV, resp, __resp_parse_server,
 				   TFW_HTTP_HDR_SERVER);
@@ -10744,6 +10762,15 @@ tfw_http_parse_resp(void *resp_data, unsigned char *data, size_t len,
 	__FSM_TX_AF(Resp_HdrWWW_Authenticat, 'e', Resp_HdrWWW_Authenticate);
 	__FSM_TX_AF_OWS_HP(Resp_HdrWWW_Authenticate, RGen_HdrOtherV, 61);
 
+	/* Upgrade header processing. */
+	__FSM_TX_AF(Resp_HdrU, 'p', Resp_HdrUp);
+	__FSM_TX_AF(Resp_HdrUp, 'g', Resp_HdrUpg);
+	__FSM_TX_AF(Resp_HdrUpg, 'r', Resp_HdrUpgr);
+	__FSM_TX_AF(Resp_HdrUpgr, 'a', Resp_HdrUpgra);
+	__FSM_TX_AF(Resp_HdrUpgra, 'd', Resp_HdrUpgrad);
+	__FSM_TX_AF(Resp_HdrUpgrad, 'e', Resp_HdrUpgrade);
+	__FSM_TX_AF_OWS(Resp_HdrUpgrade, Resp_HdrUpgradeV);
+
 	__FSM_FINISH(resp);
 
 	return r;