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Commit e60402d0 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by David S. Miller
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[TCP]: Move sack_ok access to obviously named funcs & cleanup 



Previously code had IsReno/IsFack defined as macros that were
local to tcp_input.c though sack_ok field has user elsewhere too
for the same purpose. This changes them to static inlines as
preferred according the current coding style and unifies the
access to sack_ok across multiple files. Magic bitops of sack_ok
for FACK and DSACK are also abstracted to functions with
appropriate names.

Note:
- One sack_ok = 1 remains but that's self explanary, i.e., it
  enables sack
- Couple of !IsReno cases are changed to tcp_is_sack
- There were no users for IsDSack => I dropped it

Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b9c4595b

include/net/tcp.h

+28 −0
Original line number Diff line number Diff line
@@ -719,6 +719,34 @@ static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) 
		icsk->icsk_ca_ops->cwnd_event(sk, event);

}



/* These functions determine how the current flow behaves in respect of SACK

 * handling. SACK is negotiated with the peer, and therefore it can vary

 * between different flows.

 *

 * tcp_is_sack - SACK enabled

 * tcp_is_reno - No SACK

 * tcp_is_fack - FACK enabled, implies SACK enabled

 */

static inline int tcp_is_sack(const struct tcp_sock *tp)

{

	return tp->rx_opt.sack_ok;

}



static inline int tcp_is_reno(const struct tcp_sock *tp)

{

	return !tcp_is_sack(tp);

}



static inline int tcp_is_fack(const struct tcp_sock *tp)

{

	return tp->rx_opt.sack_ok & 2;

}



static inline void tcp_enable_fack(struct tcp_sock *tp)

{

	tp->rx_opt.sack_ok |= 2;

}



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

{

	return tp->sacked_out + tp->lost_out;

net/ipv4/tcp.c

+1 −1
Original line number Diff line number Diff line
@@ -2014,7 +2014,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) 


	if (tp->rx_opt.tstamp_ok)

		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;

	if (tp->rx_opt.sack_ok)

	if (tcp_is_sack(tp))

		info->tcpi_options |= TCPI_OPT_SACK;

	if (tp->rx_opt.wscale_ok) {

		info->tcpi_options |= TCPI_OPT_WSCALE;

net/ipv4/tcp_input.c

+46 −36
Original line number Diff line number Diff line
@@ -111,10 +111,6 @@ int sysctl_tcp_abc __read_mostly; 
#define FLAG_FORWARD_PROGRESS	(FLAG_ACKED|FLAG_DATA_SACKED)

#define FLAG_ANY_PROGRESS	(FLAG_FORWARD_PROGRESS|FLAG_SND_UNA_ADVANCED)



#define IsReno(tp) ((tp)->rx_opt.sack_ok == 0)

#define IsFack(tp) ((tp)->rx_opt.sack_ok & 2)

#define IsDSack(tp) ((tp)->rx_opt.sack_ok & 4)



#define IsSackFrto() (sysctl_tcp_frto == 0x2)



#define TCP_REMNANT (TCP_FLAG_FIN|TCP_FLAG_URG|TCP_FLAG_SYN|TCP_FLAG_PSH)
@@ -860,6 +856,21 @@ void tcp_enter_cwr(struct sock *sk, const int set_ssthresh) 
	}

}



/*

 * Packet counting of FACK is based on in-order assumptions, therefore TCP

 * disables it when reordering is detected

 */

static void tcp_disable_fack(struct tcp_sock *tp)

{

	tp->rx_opt.sack_ok &= ~2;

}



/* Take a notice that peer is sending DSACKs */

static void tcp_dsack_seen(struct tcp_sock *tp)

{

	tp->rx_opt.sack_ok |= 4;

}



/* Initialize metrics on socket. */



static void tcp_init_metrics(struct sock *sk)
@@ -881,7 +892,7 @@ static void tcp_init_metrics(struct sock *sk) 
	}

	if (dst_metric(dst, RTAX_REORDERING) &&

	    tp->reordering != dst_metric(dst, RTAX_REORDERING)) {

		tp->rx_opt.sack_ok &= ~2;

		tcp_disable_fack(tp);

		tp->reordering = dst_metric(dst, RTAX_REORDERING);

	}
@@ -943,9 +954,9 @@ static void tcp_update_reordering(struct sock *sk, const int metric, 
		/* This exciting event is worth to be remembered. 8) */

		if (ts)

			NET_INC_STATS_BH(LINUX_MIB_TCPTSREORDER);

		else if (IsReno(tp))

		else if (tcp_is_reno(tp))

			NET_INC_STATS_BH(LINUX_MIB_TCPRENOREORDER);

		else if (IsFack(tp))

		else if (tcp_is_fack(tp))

			NET_INC_STATS_BH(LINUX_MIB_TCPFACKREORDER);

		else

			NET_INC_STATS_BH(LINUX_MIB_TCPSACKREORDER);
@@ -957,8 +968,7 @@ static void tcp_update_reordering(struct sock *sk, const int metric, 
		       tp->sacked_out,

		       tp->undo_marker ? tp->undo_retrans : 0);

#endif

		/* Disable FACK yet. */

		tp->rx_opt.sack_ok &= ~2;

		tcp_disable_fack(tp);

	}

}
@@ -1020,7 +1030,7 @@ static int tcp_check_dsack(struct tcp_sock *tp, struct sk_buff *ack_skb, 


	if (before(start_seq_0, TCP_SKB_CB(ack_skb)->ack_seq)) {

		dup_sack = 1;

		tp->rx_opt.sack_ok |= 4;

		tcp_dsack_seen(tp);

		NET_INC_STATS_BH(LINUX_MIB_TCPDSACKRECV);

	} else if (num_sacks > 1) {

		u32 end_seq_1 = ntohl(get_unaligned(&sp[1].end_seq));
@@ -1029,7 +1039,7 @@ static int tcp_check_dsack(struct tcp_sock *tp, struct sk_buff *ack_skb, 
		if (!after(end_seq_0, end_seq_1) &&

		    !before(start_seq_0, start_seq_1)) {

			dup_sack = 1;

			tp->rx_opt.sack_ok |= 4;

			tcp_dsack_seen(tp);

			NET_INC_STATS_BH(LINUX_MIB_TCPDSACKOFORECV);

		}

	}
@@ -1326,7 +1336,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ 
				continue;

			if ((TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_RETRANS) &&

			    after(lost_retrans, TCP_SKB_CB(skb)->ack_seq) &&

			    (IsFack(tp) ||

			    (tcp_is_fack(tp) ||

			     !before(lost_retrans,

				     TCP_SKB_CB(skb)->ack_seq + tp->reordering *

				     tp->mss_cache))) {
@@ -1526,7 +1536,7 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag) 


	tp->lost_out = 0;

	tp->retrans_out = 0;

	if (IsReno(tp))

	if (tcp_is_reno(tp))

		tcp_reset_reno_sack(tp);



	tcp_for_write_queue(skb, sk) {
@@ -1668,7 +1678,7 @@ static int tcp_check_sack_reneging(struct sock *sk) 


static inline int tcp_fackets_out(struct tcp_sock *tp)

{

	return IsReno(tp) ? tp->sacked_out+1 : tp->fackets_out;

	return tcp_is_reno(tp) ? tp->sacked_out+1 : tp->fackets_out;

}



static inline int tcp_skb_timedout(struct sock *sk, struct sk_buff *skb)
@@ -1872,7 +1882,7 @@ static void tcp_update_scoreboard(struct sock *sk) 
{

	struct tcp_sock *tp = tcp_sk(sk);



	if (IsFack(tp)) {

	if (tcp_is_fack(tp)) {

		int lost = tp->fackets_out - tp->reordering;

		if (lost <= 0)

			lost = 1;
@@ -1886,7 +1896,7 @@ static void tcp_update_scoreboard(struct sock *sk) 
	 * Hence, we can detect timed out packets during fast

	 * retransmit without falling to slow start.

	 */

	if (!IsReno(tp) && tcp_head_timedout(sk)) {

	if (!tcp_is_reno(tp) && tcp_head_timedout(sk)) {

		struct sk_buff *skb;



		skb = tp->scoreboard_skb_hint ? tp->scoreboard_skb_hint
@@ -1938,7 +1948,7 @@ static void tcp_cwnd_down(struct sock *sk, int flag) 
	int decr = tp->snd_cwnd_cnt + 1;



	if ((flag&(FLAG_ANY_PROGRESS|FLAG_DSACKING_ACK)) ||

	    (IsReno(tp) && !(flag&FLAG_NOT_DUP))) {

	    (tcp_is_reno(tp) && !(flag&FLAG_NOT_DUP))) {

		tp->snd_cwnd_cnt = decr&1;

		decr >>= 1;
@@ -2029,7 +2039,7 @@ static int tcp_try_undo_recovery(struct sock *sk) 
			NET_INC_STATS_BH(LINUX_MIB_TCPFULLUNDO);

		tp->undo_marker = 0;

	}

	if (tp->snd_una == tp->high_seq && IsReno(tp)) {

	if (tp->snd_una == tp->high_seq && tcp_is_reno(tp)) {

		/* Hold old state until something *above* high_seq

		 * is ACKed. For Reno it is MUST to prevent false

		 * fast retransmits (RFC2582). SACK TCP is safe. */
@@ -2059,7 +2069,7 @@ static int tcp_try_undo_partial(struct sock *sk, int acked) 
{

	struct tcp_sock *tp = tcp_sk(sk);

	/* Partial ACK arrived. Force Hoe's retransmit. */

	int failed = IsReno(tp) || tp->fackets_out>tp->reordering;

	int failed = tcp_is_reno(tp) || tp->fackets_out>tp->reordering;



	if (tcp_may_undo(tp)) {

		/* Plain luck! Hole if filled with delayed
@@ -2104,7 +2114,7 @@ static int tcp_try_undo_loss(struct sock *sk) 
		NET_INC_STATS_BH(LINUX_MIB_TCPLOSSUNDO);

		inet_csk(sk)->icsk_retransmits = 0;

		tp->undo_marker = 0;

		if (!IsReno(tp))

		if (tcp_is_sack(tp))

			tcp_set_ca_state(sk, TCP_CA_Open);

		return 1;

	}
@@ -2251,14 +2261,14 @@ tcp_fastretrans_alert(struct sock *sk, int pkts_acked, int flag) 
			if (!tp->undo_marker ||

			    /* For SACK case do not Open to allow to undo

			     * catching for all duplicate ACKs. */

			    IsReno(tp) || tp->snd_una != tp->high_seq) {

			    tcp_is_reno(tp) || tp->snd_una != tp->high_seq) {

				tp->undo_marker = 0;

				tcp_set_ca_state(sk, TCP_CA_Open);

			}

			break;



		case TCP_CA_Recovery:

			if (IsReno(tp))

			if (tcp_is_reno(tp))

				tcp_reset_reno_sack(tp);

			if (tcp_try_undo_recovery(sk))

				return;
@@ -2271,7 +2281,7 @@ tcp_fastretrans_alert(struct sock *sk, int pkts_acked, int flag) 
	switch (icsk->icsk_ca_state) {

	case TCP_CA_Recovery:

		if (!(flag & FLAG_SND_UNA_ADVANCED)) {

			if (IsReno(tp) && is_dupack)

			if (tcp_is_reno(tp) && is_dupack)

				tcp_add_reno_sack(sk);

		} else

			do_lost = tcp_try_undo_partial(sk, pkts_acked);
@@ -2288,7 +2298,7 @@ tcp_fastretrans_alert(struct sock *sk, int pkts_acked, int flag) 
			return;

		/* Loss is undone; fall through to processing in Open state. */

	default:

		if (IsReno(tp)) {

		if (tcp_is_reno(tp)) {

			if (flag & FLAG_SND_UNA_ADVANCED)

				tcp_reset_reno_sack(tp);

			if (is_dupack)
@@ -2316,7 +2326,7 @@ tcp_fastretrans_alert(struct sock *sk, int pkts_acked, int flag) 


		/* Otherwise enter Recovery state */



		if (IsReno(tp))

		if (tcp_is_reno(tp))

			NET_INC_STATS_BH(LINUX_MIB_TCPRENORECOVERY);

		else

			NET_INC_STATS_BH(LINUX_MIB_TCPSACKRECOVERY);
@@ -2573,7 +2583,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) 
		tcp_ack_update_rtt(sk, acked, seq_rtt);

		tcp_ack_packets_out(sk);



		if (IsReno(tp))

		if (tcp_is_reno(tp))

			tcp_remove_reno_sacks(sk, pkts_acked);



		if (ca_ops->pkts_acked) {
@@ -2599,7 +2609,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, __s32 *seq_rtt_p) 
	BUG_TRAP((int)tp->sacked_out >= 0);

	BUG_TRAP((int)tp->lost_out >= 0);

	BUG_TRAP((int)tp->retrans_out >= 0);

	if (!tp->packets_out && tp->rx_opt.sack_ok) {

	if (!tp->packets_out && tcp_is_sack(tp)) {

		const struct inet_connection_sock *icsk = inet_csk(sk);

		if (tp->lost_out) {

			printk(KERN_DEBUG "Leak l=%u %d\n",
@@ -2779,7 +2789,7 @@ static int tcp_process_frto(struct sock *sk, int flag) 
		return 1;

	}



	if (!IsSackFrto() || IsReno(tp)) {

	if (!IsSackFrto() || tcp_is_reno(tp)) {

		/* RFC4138 shortcoming in step 2; should also have case c):

		 * ACK isn't duplicate nor advances window, e.g., opposite dir

		 * data, winupdate
@@ -3263,7 +3273,7 @@ static void tcp_fin(struct sk_buff *skb, struct sock *sk, struct tcphdr *th) 
	 * Probably, we should reset in this case. For now drop them.

	 */

	__skb_queue_purge(&tp->out_of_order_queue);

	if (tp->rx_opt.sack_ok)

	if (tcp_is_sack(tp))

		tcp_sack_reset(&tp->rx_opt);

	sk_stream_mem_reclaim(sk);
@@ -3293,7 +3303,7 @@ static inline int tcp_sack_extend(struct tcp_sack_block *sp, u32 seq, u32 end_se 


static void tcp_dsack_set(struct tcp_sock *tp, u32 seq, u32 end_seq)

{

	if (tp->rx_opt.sack_ok && sysctl_tcp_dsack) {

	if (tcp_is_sack(tp) && sysctl_tcp_dsack) {

		if (before(seq, tp->rcv_nxt))

			NET_INC_STATS_BH(LINUX_MIB_TCPDSACKOLDSENT);

		else
@@ -3323,7 +3333,7 @@ static void tcp_send_dupack(struct sock *sk, struct sk_buff *skb) 
		NET_INC_STATS_BH(LINUX_MIB_DELAYEDACKLOST);

		tcp_enter_quickack_mode(sk);



		if (tp->rx_opt.sack_ok && sysctl_tcp_dsack) {

		if (tcp_is_sack(tp) && sysctl_tcp_dsack) {

			u32 end_seq = TCP_SKB_CB(skb)->end_seq;



			if (after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))
@@ -3639,7 +3649,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) 


	if (!skb_peek(&tp->out_of_order_queue)) {

		/* Initial out of order segment, build 1 SACK. */

		if (tp->rx_opt.sack_ok) {

		if (tcp_is_sack(tp)) {

			tp->rx_opt.num_sacks = 1;

			tp->rx_opt.dsack     = 0;

			tp->rx_opt.eff_sacks = 1;
@@ -3704,7 +3714,7 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) 
		}



add_sack:

		if (tp->rx_opt.sack_ok)

		if (tcp_is_sack(tp))

			tcp_sack_new_ofo_skb(sk, seq, end_seq);

	}

}
@@ -3893,7 +3903,7 @@ static int tcp_prune_queue(struct sock *sk) 
		 * is in a sad state like this, we care only about integrity

		 * of the connection not performance.

		 */

		if (tp->rx_opt.sack_ok)

		if (tcp_is_sack(tp))

			tcp_sack_reset(&tp->rx_opt);

		sk_stream_mem_reclaim(sk);

	}
@@ -4594,8 +4604,8 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, 
			tp->tcp_header_len = sizeof(struct tcphdr);

		}



		if (tp->rx_opt.sack_ok && sysctl_tcp_fack)

			tp->rx_opt.sack_ok |= 2;

		if (tcp_is_sack(tp) && sysctl_tcp_fack)

			tcp_enable_fack(tp);



		tcp_mtup_init(sk);

		tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);

net/ipv4/tcp_minisocks.c

+1 −1
Original line number Diff line number Diff line
@@ -445,7 +445,7 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req, 
		newtp->rx_opt.tstamp_ok = ireq->tstamp_ok;

		if ((newtp->rx_opt.sack_ok = ireq->sack_ok) != 0) {

			if (sysctl_tcp_fack)

				newtp->rx_opt.sack_ok |= 2;

				tcp_enable_fack(newtp);

		}

		newtp->window_clamp = req->window_clamp;

		newtp->rcv_ssthresh = req->rcv_wnd;

net/ipv4/tcp_output.c

+3 −3
Original line number Diff line number Diff line
@@ -737,7 +737,7 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, unsigned int mss 


		if (diff > 0) {

			/* Adjust Reno SACK estimate. */

			if (!tp->rx_opt.sack_ok) {

			if (tcp_is_reno(tp)) {

				tcp_dec_pcount_approx_int(&tp->sacked_out, diff);

				tcp_verify_left_out(tp);

			}
@@ -1728,7 +1728,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb, int m 
		if (TCP_SKB_CB(next_skb)->sacked&TCPCB_LOST)

			tp->lost_out -= tcp_skb_pcount(next_skb);

		/* Reno case is special. Sigh... */

		if (!tp->rx_opt.sack_ok && tp->sacked_out)

		if (tcp_is_reno(tp) && tp->sacked_out)

			tcp_dec_pcount_approx(&tp->sacked_out, next_skb);



		/* Not quite right: it can be > snd.fack, but
@@ -1976,7 +1976,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk) 
		return;



	/* No forward retransmissions in Reno are possible. */

	if (!tp->rx_opt.sack_ok)

	if (tcp_is_reno(tp))

		return;



	/* Yeah, we have to make difficult choice between forward transmission