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Diffstat (limited to 'net/ipv4/tcp_metrics.c')
-rw-r--r--net/ipv4/tcp_metrics.c83
1 files changed, 49 insertions, 34 deletions
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index d547075d8300..dcaf72f10216 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -33,6 +33,11 @@ struct tcp_fastopen_metrics {
struct tcp_fastopen_cookie cookie;
};
+/* TCP_METRIC_MAX includes 2 extra fields for userspace compatibility
+ * Kernel only stores RTT and RTTVAR in usec resolution
+ */
+#define TCP_METRIC_MAX_KERNEL (TCP_METRIC_MAX - 2)
+
struct tcp_metrics_block {
struct tcp_metrics_block __rcu *tcpm_next;
struct inetpeer_addr tcpm_saddr;
@@ -41,7 +46,7 @@ struct tcp_metrics_block {
u32 tcpm_ts;
u32 tcpm_ts_stamp;
u32 tcpm_lock;
- u32 tcpm_vals[TCP_METRIC_MAX + 1];
+ u32 tcpm_vals[TCP_METRIC_MAX_KERNEL + 1];
struct tcp_fastopen_metrics tcpm_fastopen;
struct rcu_head rcu_head;
@@ -59,12 +64,6 @@ static u32 tcp_metric_get(struct tcp_metrics_block *tm,
return tm->tcpm_vals[idx];
}
-static u32 tcp_metric_get_jiffies(struct tcp_metrics_block *tm,
- enum tcp_metric_index idx)
-{
- return msecs_to_jiffies(tm->tcpm_vals[idx]);
-}
-
static void tcp_metric_set(struct tcp_metrics_block *tm,
enum tcp_metric_index idx,
u32 val)
@@ -72,13 +71,6 @@ static void tcp_metric_set(struct tcp_metrics_block *tm,
tm->tcpm_vals[idx] = val;
}
-static void tcp_metric_set_msecs(struct tcp_metrics_block *tm,
- enum tcp_metric_index idx,
- u32 val)
-{
- tm->tcpm_vals[idx] = jiffies_to_msecs(val);
-}
-
static bool addr_same(const struct inetpeer_addr *a,
const struct inetpeer_addr *b)
{
@@ -101,9 +93,11 @@ struct tcpm_hash_bucket {
static DEFINE_SPINLOCK(tcp_metrics_lock);
-static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst,
+static void tcpm_suck_dst(struct tcp_metrics_block *tm,
+ const struct dst_entry *dst,
bool fastopen_clear)
{
+ u32 msval;
u32 val;
tm->tcpm_stamp = jiffies;
@@ -121,8 +115,11 @@ static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst,
val |= 1 << TCP_METRIC_REORDERING;
tm->tcpm_lock = val;
- tm->tcpm_vals[TCP_METRIC_RTT] = dst_metric_raw(dst, RTAX_RTT);
- tm->tcpm_vals[TCP_METRIC_RTTVAR] = dst_metric_raw(dst, RTAX_RTTVAR);
+ msval = dst_metric_raw(dst, RTAX_RTT);
+ tm->tcpm_vals[TCP_METRIC_RTT] = msval * USEC_PER_MSEC;
+
+ msval = dst_metric_raw(dst, RTAX_RTTVAR);
+ tm->tcpm_vals[TCP_METRIC_RTTVAR] = msval * USEC_PER_MSEC;
tm->tcpm_vals[TCP_METRIC_SSTHRESH] = dst_metric_raw(dst, RTAX_SSTHRESH);
tm->tcpm_vals[TCP_METRIC_CWND] = dst_metric_raw(dst, RTAX_CWND);
tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING);
@@ -384,7 +381,7 @@ void tcp_update_metrics(struct sock *sk)
dst_confirm(dst);
rcu_read_lock();
- if (icsk->icsk_backoff || !tp->srtt) {
+ if (icsk->icsk_backoff || !tp->srtt_us) {
/* This session failed to estimate rtt. Why?
* Probably, no packets returned in time. Reset our
* results.
@@ -399,8 +396,8 @@ void tcp_update_metrics(struct sock *sk)
if (!tm)
goto out_unlock;
- rtt = tcp_metric_get_jiffies(tm, TCP_METRIC_RTT);
- m = rtt - tp->srtt;
+ rtt = tcp_metric_get(tm, TCP_METRIC_RTT);
+ m = rtt - tp->srtt_us;
/* If newly calculated rtt larger than stored one, store new
* one. Otherwise, use EWMA. Remember, rtt overestimation is
@@ -408,10 +405,10 @@ void tcp_update_metrics(struct sock *sk)
*/
if (!tcp_metric_locked(tm, TCP_METRIC_RTT)) {
if (m <= 0)
- rtt = tp->srtt;
+ rtt = tp->srtt_us;
else
rtt -= (m >> 3);
- tcp_metric_set_msecs(tm, TCP_METRIC_RTT, rtt);
+ tcp_metric_set(tm, TCP_METRIC_RTT, rtt);
}
if (!tcp_metric_locked(tm, TCP_METRIC_RTTVAR)) {
@@ -422,16 +419,16 @@ void tcp_update_metrics(struct sock *sk)
/* Scale deviation to rttvar fixed point */
m >>= 1;
- if (m < tp->mdev)
- m = tp->mdev;
+ if (m < tp->mdev_us)
+ m = tp->mdev_us;
- var = tcp_metric_get_jiffies(tm, TCP_METRIC_RTTVAR);
+ var = tcp_metric_get(tm, TCP_METRIC_RTTVAR);
if (m >= var)
var = m;
else
var -= (var - m) >> 2;
- tcp_metric_set_msecs(tm, TCP_METRIC_RTTVAR, var);
+ tcp_metric_set(tm, TCP_METRIC_RTTVAR, var);
}
if (tcp_in_initial_slowstart(tp)) {
@@ -528,7 +525,7 @@ void tcp_init_metrics(struct sock *sk)
tp->reordering = val;
}
- crtt = tcp_metric_get_jiffies(tm, TCP_METRIC_RTT);
+ crtt = tcp_metric_get(tm, TCP_METRIC_RTT);
rcu_read_unlock();
reset:
/* The initial RTT measurement from the SYN/SYN-ACK is not ideal
@@ -551,18 +548,20 @@ reset:
* to low value, and then abruptly stops to do it and starts to delay
* ACKs, wait for troubles.
*/
- if (crtt > tp->srtt) {
+ if (crtt > tp->srtt_us) {
/* Set RTO like tcp_rtt_estimator(), but from cached RTT. */
- crtt >>= 3;
+ crtt /= 8 * USEC_PER_MSEC;
inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk));
- } else if (tp->srtt == 0) {
+ } else if (tp->srtt_us == 0) {
/* RFC6298: 5.7 We've failed to get a valid RTT sample from
* 3WHS. This is most likely due to retransmission,
* including spurious one. Reset the RTO back to 3secs
* from the more aggressive 1sec to avoid more spurious
* retransmission.
*/
- tp->mdev = tp->mdev_max = tp->rttvar = TCP_TIMEOUT_FALLBACK;
+ tp->rttvar_us = jiffies_to_usecs(TCP_TIMEOUT_FALLBACK);
+ tp->mdev_us = tp->mdev_max_us = tp->rttvar_us;
+
inet_csk(sk)->icsk_rto = TCP_TIMEOUT_FALLBACK;
}
/* Cut cwnd down to 1 per RFC5681 if SYN or SYN-ACK has been
@@ -809,10 +808,26 @@ static int tcp_metrics_fill_info(struct sk_buff *msg,
nest = nla_nest_start(msg, TCP_METRICS_ATTR_VALS);
if (!nest)
goto nla_put_failure;
- for (i = 0; i < TCP_METRIC_MAX + 1; i++) {
- if (!tm->tcpm_vals[i])
+ for (i = 0; i < TCP_METRIC_MAX_KERNEL + 1; i++) {
+ u32 val = tm->tcpm_vals[i];
+
+ if (!val)
continue;
- if (nla_put_u32(msg, i + 1, tm->tcpm_vals[i]) < 0)
+ if (i == TCP_METRIC_RTT) {
+ if (nla_put_u32(msg, TCP_METRIC_RTT_US + 1,
+ val) < 0)
+ goto nla_put_failure;
+ n++;
+ val = max(val / 1000, 1U);
+ }
+ if (i == TCP_METRIC_RTTVAR) {
+ if (nla_put_u32(msg, TCP_METRIC_RTTVAR_US + 1,
+ val) < 0)
+ goto nla_put_failure;
+ n++;
+ val = max(val / 1000, 1U);
+ }
+ if (nla_put_u32(msg, i + 1, val) < 0)
goto nla_put_failure;
n++;
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.