Commit ab56222a authored by Vijay Subramanian's avatar Vijay Subramanian Committed by David S. Miller
Browse files

tcp: Replace constants with #define macros 



to record the state of SACK/FACK and DSACK for better readability and maintenance.

Signed-off-by: default avatarVijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 08f4fc9d

include/linux/tcp.h

+5 −0
Original line number Diff line number Diff line
@@ -238,6 +238,11 @@ struct tcp_sack_block { 
	u32	end_seq;

};



/*These are used to set the sack_ok field in struct tcp_options_received */

#define TCP_SACK_SEEN     (1 << 0)   /*1 = peer is SACK capable, */

#define TCP_FACK_ENABLED  (1 << 1)   /*1 = FACK is enabled locally*/

#define TCP_DSACK_SEEN    (1 << 2)   /*1 = DSACK was received from peer*/



struct tcp_options_received {

/*	PAWS/RTTM data	*/

	long	ts_recent_stamp;/* Time we stored ts_recent (for aging) */

include/net/tcp.h

+2 −2
Original line number Diff line number Diff line
@@ -773,12 +773,12 @@ static inline int tcp_is_reno(const struct tcp_sock *tp) 


static inline int tcp_is_fack(const struct tcp_sock *tp)

{

	return tp->rx_opt.sack_ok & 2;

	return tp->rx_opt.sack_ok & TCP_FACK_ENABLED;

}



static inline void tcp_enable_fack(struct tcp_sock *tp)

{

	tp->rx_opt.sack_ok |= 2;

	tp->rx_opt.sack_ok |= TCP_FACK_ENABLED;

}



static inline unsigned int tcp_left_out(const struct tcp_sock *tp)

net/ipv4/syncookies.c

+1 −1
Original line number Diff line number Diff line
@@ -245,7 +245,7 @@ bool cookie_check_timestamp(struct tcp_options_received *tcp_opt, bool *ecn_ok) 
	if (!sysctl_tcp_timestamps)

		return false;



	tcp_opt->sack_ok = (options >> 4) & 0x1;

	tcp_opt->sack_ok = (options & (1 << 4)) ? TCP_SACK_SEEN : 0;

	*ecn_ok = (options >> 5) & 1;

	if (*ecn_ok && !sysctl_tcp_ecn)

		return false;

net/ipv4/tcp_input.c

+3 −3
Original line number Diff line number Diff line
@@ -865,13 +865,13 @@ static void tcp_disable_fack(struct tcp_sock *tp) 
	/* RFC3517 uses different metric in lost marker => reset on change */

	if (tcp_is_fack(tp))

		tp->lost_skb_hint = NULL;

	tp->rx_opt.sack_ok &= ~2;

	tp->rx_opt.sack_ok &= ~TCP_FACK_ENABLED;

}



/* Take a notice that peer is sending D-SACKs */

static void tcp_dsack_seen(struct tcp_sock *tp)

{

	tp->rx_opt.sack_ok |= 4;

	tp->rx_opt.sack_ok |= TCP_DSACK_SEEN;

}



/* Initialize metrics on socket. */
@@ -3878,7 +3878,7 @@ void tcp_parse_options(const struct sk_buff *skb, struct tcp_options_received *o 
			case TCPOPT_SACK_PERM:

				if (opsize == TCPOLEN_SACK_PERM && th->syn &&

				    !estab && sysctl_tcp_sack) {

					opt_rx->sack_ok = 1;

					opt_rx->sack_ok = TCP_SACK_SEEN;

					tcp_sack_reset(opt_rx);

				}

				break;