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#include <linux/tcp.h>
#include <net/tcp.h>
/* Record the most recently (re)sent time among the (s)acked packets */
void tcp_rack_advance(struct tcp_sock *tp,
const struct skb_mstamp *xmit_time, u8 sacked)
{
if (tp->rack.mstamp.v64 &&
!skb_mstamp_after(xmit_time, &tp->rack.mstamp))
return;
if (sacked & TCPCB_RETRANS) {
struct skb_mstamp now;
/* If the sacked packet was retransmitted, it's ambiguous
* whether the retransmission or the original (or the prior
* retransmission) was sacked.
*
* If the original is lost, there is no ambiguity. Otherwise
* we assume the original can be delayed up to aRTT + min_rtt.
* the aRTT term is bounded by the fast recovery or timeout,
* so it's at least one RTT (i.e., retransmission is at least
* an RTT later).
*/
skb_mstamp_get(&now);
if (skb_mstamp_us_delta(&now, xmit_time) < tcp_min_rtt(tp))
return;
}
tp->rack.mstamp = *xmit_time;
tp->rack.advanced = 1;
}
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