Re: [PATCH v2 1/3] tcp: Rename "retrans" to "retries"

[David Gibson <david@gibson.dropbear.id.au>]

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On Fri, Oct 10, 2025 at 03:46:58PM +0800, Yumei Huang wrote:
> Rename "retrans" to "retries" so it can be used for SYN retries.
> 
> Signed-off-by: Yumei Huang <yuhuang@redhat.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

I think the new name is clearer, although AFAICT the RFCs mostly seem
to refer to both data retransmits and SYN retries as "retransmits".

> ---
>  tcp.c      | 12 ++++++------
>  tcp_conn.h | 12 ++++++------
>  2 files changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/tcp.c b/tcp.c
> index 0f9e9b3..2ec4b0c 100644
> --- a/tcp.c
> +++ b/tcp.c
> @@ -186,7 +186,7 @@
>   * - ACK_TIMEOUT: if no ACK segment was received from tap/guest, after sending
>   *   data (flag ACK_FROM_TAP_DUE with ESTABLISHED event), re-send data from the
>   *   socket and reset sequence to what was acknowledged. If this persists for
> - *   more than TCP_MAX_RETRANS times in a row, reset the connection
> + *   more than TCP_MAX_RETRIES times in a row, reset the connection
>   *
>   * - FIN_TIMEOUT: if a FIN segment was sent to tap/guest (flag ACK_FROM_TAP_DUE
>   *   with TAP_FIN_SENT event), and no ACK is received within this time, reset
> @@ -1127,7 +1127,7 @@ static void tcp_update_seqack_from_tap(const struct ctx *c,
>  		if (SEQ_LT(seq, conn->seq_to_tap))
>  			conn_flag(c, conn, ACK_FROM_TAP_DUE);
>  
> -		conn->retrans = 0;
> +		conn->retries = 0;
>  		conn->seq_ack_from_tap = seq;
>  	}
>  }
> @@ -2414,7 +2414,7 @@ void tcp_timer_handler(const struct ctx *c, union epoll_ref ref)
>  		} else if (CONN_HAS(conn, SOCK_FIN_SENT | TAP_FIN_ACKED)) {
>  			flow_dbg(conn, "FIN timeout");
>  			tcp_rst(c, conn);
> -		} else if (conn->retrans == TCP_MAX_RETRANS) {
> +		} else if (conn->retries == TCP_MAX_RETRIES) {
>  			flow_dbg(conn, "retransmissions count exceeded");
>  			tcp_rst(c, conn);
>  		} else {
> @@ -2423,7 +2423,7 @@ void tcp_timer_handler(const struct ctx *c, union epoll_ref ref)
>  			if (!conn->wnd_from_tap)
>  				conn->wnd_from_tap = 1; /* Zero-window probe */
>  
> -			conn->retrans++;
> +			conn->retries++;
>  			if (tcp_rewind_seq(c, conn))
>  				return;
>  
> @@ -3382,7 +3382,7 @@ static int tcp_flow_repair_opt(const struct tcp_tap_conn *conn,
>  int tcp_flow_migrate_source(int fd, struct tcp_tap_conn *conn)
>  {
>  	struct tcp_tap_transfer t = {
> -		.retrans		= conn->retrans,
> +		.retries		= conn->retries,
>  		.ws_from_tap		= conn->ws_from_tap,
>  		.ws_to_tap		= conn->ws_to_tap,
>  		.events			= conn->events,
> @@ -3662,7 +3662,7 @@ int tcp_flow_migrate_target(struct ctx *c, int fd)
>  	memcpy(&flow->f.side, &t.side, sizeof(flow->f.side));
>  	conn = FLOW_SET_TYPE(flow, FLOW_TCP, tcp);
>  
> -	conn->retrans			= t.retrans;
> +	conn->retries			= t.retries;
>  	conn->ws_from_tap		= t.ws_from_tap;
>  	conn->ws_to_tap			= t.ws_to_tap;
>  	conn->events			= t.events;
> diff --git a/tcp_conn.h b/tcp_conn.h
> index 38b5c54..e5c8146 100644
> --- a/tcp_conn.h
> +++ b/tcp_conn.h
> @@ -13,7 +13,7 @@
>   * struct tcp_tap_conn - Descriptor for a TCP connection (not spliced)
>   * @f:			Generic flow information
>   * @in_epoll:		Is the connection in the epoll set?
> - * @retrans:		Number of retransmissions occurred due to ACK_TIMEOUT
> + * @retries:		Number of retries occurred due to timeouts
>   * @ws_from_tap:	Window scaling factor advertised from tap/guest
>   * @ws_to_tap:		Window scaling factor advertised to tap/guest
>   * @tap_mss:		MSS advertised by tap/guest, rounded to 2 ^ TCP_MSS_BITS
> @@ -38,9 +38,9 @@ struct tcp_tap_conn {
>  
>  	bool		in_epoll	:1;
>  
> -#define TCP_RETRANS_BITS		3
> -	unsigned int	retrans		:TCP_RETRANS_BITS;
> -#define TCP_MAX_RETRANS			MAX_FROM_BITS(TCP_RETRANS_BITS)
> +#define TCP_RETRIES_BITS		3
> +	unsigned int	retries		:TCP_RETRIES_BITS;
> +#define TCP_MAX_RETRIES			MAX_FROM_BITS(TCP_RETRIES_BITS)
>  
>  #define TCP_WS_BITS			4	/* RFC 7323 */
>  #define TCP_WS_MAX			14
> @@ -102,7 +102,7 @@ struct tcp_tap_conn {
>   * struct tcp_tap_transfer - Migrated TCP data, flow table part, network order
>   * @pif:		Interfaces for each side of the flow
>   * @side:		Addresses and ports for each side of the flow
> - * @retrans:		Number of retransmissions occurred due to ACK_TIMEOUT
> + * @retries:		Number of retries occurred due to timeouts
>   * @ws_from_tap:	Window scaling factor advertised from tap/guest
>   * @ws_to_tap:		Window scaling factor advertised to tap/guest
>   * @events:		Connection events, implying connection states
> @@ -122,7 +122,7 @@ struct tcp_tap_transfer {
>  	uint8_t		pif[SIDES];
>  	struct flowside	side[SIDES];
>  
> -	uint8_t		retrans;
> +	uint8_t		retries;
>  	uint8_t		ws_from_tap;
>  	uint8_t		ws_to_tap;
>  	uint8_t		events;
> -- 
> 2.47.0
> 

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson

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