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tcp: new helper tcp_timeout_mark_lost 

Refactor using a new helper, tcp_timeout_mark_loss(), that marks packets
lost upon RTO.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Priyaranjan Jha <priyarjha@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Yuchung Cheng 2018-05-16 16:40:14 -07:00 committed by David S. Miller
parent d716bfdb10
commit 2ad55f5660
1 changed files with 29 additions and 21 deletions
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50
net/ipv4/tcp_input.c
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@ -1917,18 +1917,43 @@ static inline void tcp_init_undo(struct tcp_sock *tp)
tp->undo_retrans = tp->retrans_out ? : -1;
}
/* Enter Loss state. If we detect SACK reneging, forget all SACK information
/* If we detect SACK reneging, forget all SACK information
* and reset tags completely, otherwise preserve SACKs. If receiver
* dropped its ofo queue, we will know this due to reneging detection.
*/
static void tcp_timeout_mark_lost(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
struct sk_buff *skb;
bool is_reneg; /* is receiver reneging on SACKs? */
skb = tcp_rtx_queue_head(sk);
is_reneg = skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED);
if (is_reneg) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSACKRENEGING);
tp->sacked_out = 0;
/* Mark SACK reneging until we recover from this loss event. */
tp->is_sack_reneg = 1;
} else if (tcp_is_reno(tp)) {
tcp_reset_reno_sack(tp);
}
skb_rbtree_walk_from(skb) {
if (is_reneg)
TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_ACKED;
tcp_mark_skb_lost(sk, skb);
}
tcp_verify_left_out(tp);
tcp_clear_all_retrans_hints(tp);
}
/* Enter Loss state. */
void tcp_enter_loss(struct sock *sk)
{
const struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
struct net *net = sock_net(sk);
struct sk_buff *skb;
bool new_recovery = icsk->icsk_ca_state < TCP_CA_Recovery;
bool is_reneg; /* is receiver reneging on SACKs? */
/* Reduce ssthresh if it has not yet been made inside this window. */
if (icsk->icsk_ca_state <= TCP_CA_Disorder ||
@ -1944,24 +1969,7 @@ void tcp_enter_loss(struct sock *sk)
tp->snd_cwnd_cnt = 0;
tp->snd_cwnd_stamp = tcp_jiffies32;
if (tcp_is_reno(tp))
tcp_reset_reno_sack(tp);
skb = tcp_rtx_queue_head(sk);
is_reneg = skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED);
if (is_reneg) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSACKRENEGING);
tp->sacked_out = 0;
/* Mark SACK reneging until we recover from this loss event. */
tp->is_sack_reneg = 1;
}
skb_rbtree_walk_from(skb) {
if (is_reneg)
TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_ACKED;
tcp_mark_skb_lost(sk, skb);
}
tcp_verify_left_out(tp);
tcp_clear_all_retrans_hints(tp);
tcp_timeout_mark_lost(sk);
/* Timeout in disordered state after receiving substantial DUPACKs
* suggests that the degree of reordering is over-estimated.