diff options
Diffstat (limited to 'net/dccp/input.c')
| -rw-r--r-- | net/dccp/input.c | 44 |
1 files changed, 15 insertions, 29 deletions
diff --git a/net/dccp/input.c b/net/dccp/input.c index 782cdb7292fa..3b651701cfe4 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -280,6 +280,7 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk, if (dh->dccph_type == DCCP_PKT_RESPONSE) { const struct inet_connection_sock *icsk = inet_csk(sk); struct dccp_sock *dp = dccp_sk(sk); + long tstamp = dccp_timestamp(); /* Stop the REQUEST timer */ inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS); @@ -300,11 +301,10 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk, if (dccp_parse_options(sk, skb)) goto out_invalid_packet; - /* Obtain RTT sample from SYN exchange (used by CCID 3) */ - if (dp->dccps_options_received.dccpor_timestamp_echo) - dp->dccps_syn_rtt = dccp_sample_rtt(sk, - ktime_get_real(), - NULL); + /* Obtain usec RTT sample from SYN exchange (used by CCID 3) */ + if (likely(dp->dccps_options_received.dccpor_timestamp_echo)) + dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * (tstamp - + dp->dccps_options_received.dccpor_timestamp_echo)); if (dccp_msk(sk)->dccpms_send_ack_vector && dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, @@ -585,36 +585,22 @@ discard: EXPORT_SYMBOL_GPL(dccp_rcv_state_process); /** - * dccp_sample_rtt - Sample RTT from packet exchange - * - * @sk: connected dccp_sock - * @t_recv: receive timestamp of packet with timestamp echo - * @t_hist: packet history timestamp or NULL + * dccp_sample_rtt - Validate and finalise computation of RTT sample + * @delta: number of microseconds between packet and acknowledgment + * The routine is kept generic to work in different contexts. It should be + * called immediately when the ACK used for the RTT sample arrives. */ -u32 dccp_sample_rtt(struct sock *sk, ktime_t t_recv, ktime_t *t_hist) +u32 dccp_sample_rtt(struct sock *sk, long delta) { - struct dccp_sock *dp = dccp_sk(sk); - struct dccp_options_received *or = &dp->dccps_options_received; - s64 delta; - - if (t_hist == NULL) { - if (!or->dccpor_timestamp_echo) { - DCCP_WARN("packet without timestamp echo\n"); - return DCCP_SANE_RTT_MAX; - } - ktime_sub_us(t_recv, or->dccpor_timestamp_echo * 10); - delta = ktime_to_us(t_recv); - } else - delta = ktime_us_delta(t_recv, *t_hist); - - delta -= or->dccpor_elapsed_time * 10; /* either set or 0 */ + /* dccpor_elapsed_time is either zeroed out or set and > 0 */ + delta -= dccp_sk(sk)->dccps_options_received.dccpor_elapsed_time * 10; if (unlikely(delta <= 0)) { - DCCP_WARN("unusable RTT sample %ld, using min\n", (long)delta); + DCCP_WARN("unusable RTT sample %ld, using min\n", delta); return DCCP_SANE_RTT_MIN; } - if (unlikely(delta - (s64)DCCP_SANE_RTT_MAX > 0)) { - DCCP_WARN("RTT sample %ld too large, using max\n", (long)delta); + if (unlikely(delta > DCCP_SANE_RTT_MAX)) { + DCCP_WARN("RTT sample %ld too large, using max\n", delta); return DCCP_SANE_RTT_MAX; } |