tcp: rstreason: fully support in tcp_ack()

Based on the existing skb drop reason, updating the rstreason map can
help us finish the rstreason job in this function.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
Link: https://lore.kernel.org/r/20240510122502.27850-3-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: JasonXing

include/net/rstreason.h

@@ -10,6 +10,8 @@
 	FN(NO_SOCKET)			\
 	FN(TCP_INVALID_ACK_SEQUENCE)	\
 	FN(TCP_RFC7323_PAWS)		\
+	FN(TCP_TOO_OLD_ACK)		\
+	FN(TCP_ACK_UNSENT_DATA)		\
 	FN(MPTCP_RST_EUNSPEC)		\
 	FN(MPTCP_RST_EMPTCP)		\
 	FN(MPTCP_RST_ERESOURCE)		\
@@ -50,6 +52,13 @@ enum sk_rst_reason {
 	 * LINUX_MIB_PAWSESTABREJECTED, LINUX_MIB_PAWSACTIVEREJECTED
 	 */
 	SK_RST_REASON_TCP_RFC7323_PAWS,
+	/** @SK_RST_REASON_TCP_TOO_OLD_ACK: TCP ACK is too old */
+	SK_RST_REASON_TCP_TOO_OLD_ACK,
+	/**
+	 * @SK_RST_REASON_TCP_ACK_UNSENT_DATA: TCP ACK for data we haven't
+	 * sent yet
+	 */
+	SK_RST_REASON_TCP_ACK_UNSENT_DATA,
 
 	/* Copy from include/uapi/linux/mptcp.h.
 	 * These reset fields will not be changed since they adhere to
@@ -130,6 +139,10 @@ sk_rst_convert_drop_reason(enum skb_drop_reason reason)
 		return SK_RST_REASON_TCP_INVALID_ACK_SEQUENCE;
 	case SKB_DROP_REASON_TCP_RFC7323_PAWS:
 		return SK_RST_REASON_TCP_RFC7323_PAWS;
+	case SKB_DROP_REASON_TCP_TOO_OLD_ACK:
+		return SK_RST_REASON_TCP_TOO_OLD_ACK;
+	case SKB_DROP_REASON_TCP_ACK_UNSENT_DATA:
+		return SK_RST_REASON_TCP_ACK_UNSENT_DATA;
 	default:
 		/* If we don't have our own corresponding reason */
 		return SK_RST_REASON_NOT_SPECIFIED;