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Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c51
1 files changed, 31 insertions, 20 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 90de838a2745..df7b13f0e5e0 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -202,23 +202,17 @@ static void bpf_skops_established(struct sock *sk, int bpf_op,
}
#endif
-static void tcp_gro_dev_warn(struct sock *sk, const struct sk_buff *skb,
- unsigned int len)
+static __cold void tcp_gro_dev_warn(const struct sock *sk, const struct sk_buff *skb,
+ unsigned int len)
{
- static bool __once __read_mostly;
+ struct net_device *dev;
- if (!__once) {
- struct net_device *dev;
-
- __once = true;
-
- rcu_read_lock();
- dev = dev_get_by_index_rcu(sock_net(sk), skb->skb_iif);
- if (!dev || len >= dev->mtu)
- pr_warn("%s: Driver has suspect GRO implementation, TCP performance may be compromised.\n",
- dev ? dev->name : "Unknown driver");
- rcu_read_unlock();
- }
+ rcu_read_lock();
+ dev = dev_get_by_index_rcu(sock_net(sk), skb->skb_iif);
+ if (!dev || len >= READ_ONCE(dev->mtu))
+ pr_warn("%s: Driver has suspect GRO implementation, TCP performance may be compromised.\n",
+ dev ? dev->name : "Unknown driver");
+ rcu_read_unlock();
}
/* Adapt the MSS value used to make delayed ack decision to the
@@ -250,9 +244,8 @@ static void tcp_measure_rcv_mss(struct sock *sk, const struct sk_buff *skb)
icsk->icsk_ack.rcv_mss = min_t(unsigned int, len,
tcp_sk(sk)->advmss);
/* Account for possibly-removed options */
- if (unlikely(len > icsk->icsk_ack.rcv_mss +
- MAX_TCP_OPTION_SPACE))
- tcp_gro_dev_warn(sk, skb, len);
+ DO_ONCE_LITE_IF(len > icsk->icsk_ack.rcv_mss + MAX_TCP_OPTION_SPACE,
+ tcp_gro_dev_warn, sk, skb, len);
/* If the skb has a len of exactly 1*MSS and has the PSH bit
* set then it is likely the end of an application write. So
* more data may not be arriving soon, and yet the data sender
@@ -4368,6 +4361,23 @@ EXPORT_SYMBOL(tcp_do_parse_auth_options);
* up to bandwidth of 18Gigabit/sec. 8) ]
*/
+/* Estimates max number of increments of remote peer TSval in
+ * a replay window (based on our current RTO estimation).
+ */
+static u32 tcp_tsval_replay(const struct sock *sk)
+{
+ /* If we use usec TS resolution,
+ * then expect the remote peer to use the same resolution.
+ */
+ if (tcp_sk(sk)->tcp_usec_ts)
+ return inet_csk(sk)->icsk_rto * (USEC_PER_SEC / HZ);
+
+ /* RFC 7323 recommends a TSval clock between 1ms and 1sec.
+ * We know that some OS (including old linux) can use 1200 Hz.
+ */
+ return inet_csk(sk)->icsk_rto * 1200 / HZ;
+}
+
static int tcp_disordered_ack(const struct sock *sk, const struct sk_buff *skb)
{
const struct tcp_sock *tp = tcp_sk(sk);
@@ -4375,7 +4385,7 @@ static int tcp_disordered_ack(const struct sock *sk, const struct sk_buff *skb)
u32 seq = TCP_SKB_CB(skb)->seq;
u32 ack = TCP_SKB_CB(skb)->ack_seq;
- return (/* 1. Pure ACK with correct sequence number. */
+ return /* 1. Pure ACK with correct sequence number. */
(th->ack && seq == TCP_SKB_CB(skb)->end_seq && seq == tp->rcv_nxt) &&
/* 2. ... and duplicate ACK. */
@@ -4385,7 +4395,8 @@ static int tcp_disordered_ack(const struct sock *sk, const struct sk_buff *skb)
!tcp_may_update_window(tp, ack, seq, ntohs(th->window) << tp->rx_opt.snd_wscale) &&
/* 4. ... and sits in replay window. */
- (s32)(tp->rx_opt.ts_recent - tp->rx_opt.rcv_tsval) <= (inet_csk(sk)->icsk_rto * 1024) / HZ);
+ (s32)(tp->rx_opt.ts_recent - tp->rx_opt.rcv_tsval) <=
+ tcp_tsval_replay(sk);
}
static inline bool tcp_paws_discard(const struct sock *sk,