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Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c90
1 files changed, 67 insertions, 23 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index bcfccc5cb8d..8c304a40079 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -378,7 +378,7 @@ static void tcp_fixup_rcvbuf(struct sock *sk)
/* 4. Try to fixup all. It is made immediately after connection enters
* established state.
*/
-static void tcp_init_buffer_space(struct sock *sk)
+void tcp_init_buffer_space(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
int maxwin;
@@ -2930,13 +2930,14 @@ static void tcp_enter_recovery(struct sock *sk, bool ece_ack)
* tcp_xmit_retransmit_queue().
*/
static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked,
- int newly_acked_sacked, bool is_dupack,
+ int prior_sacked, bool is_dupack,
int flag)
{
struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
int do_lost = is_dupack || ((flag & FLAG_DATA_SACKED) &&
(tcp_fackets_out(tp) > tp->reordering));
+ int newly_acked_sacked = 0;
int fast_rexmit = 0;
if (WARN_ON(!tp->packets_out && tp->sacked_out))
@@ -2996,6 +2997,7 @@ static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked,
tcp_add_reno_sack(sk);
} else
do_lost = tcp_try_undo_partial(sk, pkts_acked);
+ newly_acked_sacked = pkts_acked + tp->sacked_out - prior_sacked;
break;
case TCP_CA_Loss:
if (flag & FLAG_DATA_ACKED)
@@ -3017,6 +3019,7 @@ static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked,
if (is_dupack)
tcp_add_reno_sack(sk);
}
+ newly_acked_sacked = pkts_acked + tp->sacked_out - prior_sacked;
if (icsk->icsk_ca_state <= TCP_CA_Disorder)
tcp_try_undo_dsack(sk);
@@ -3124,6 +3127,12 @@ void tcp_rearm_rto(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
+ /* If the retrans timer is currently being used by Fast Open
+ * for SYN-ACK retrans purpose, stay put.
+ */
+ if (tp->fastopen_rsk)
+ return;
+
if (!tp->packets_out) {
inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
} else {
@@ -3594,7 +3603,6 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
int prior_packets;
int prior_sacked = tp->sacked_out;
int pkts_acked = 0;
- int newly_acked_sacked = 0;
bool frto_cwnd = false;
/* If the ack is older than previous acks
@@ -3670,8 +3678,6 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
flag |= tcp_clean_rtx_queue(sk, prior_fackets, prior_snd_una);
pkts_acked = prior_packets - tp->packets_out;
- newly_acked_sacked = (prior_packets - prior_sacked) -
- (tp->packets_out - tp->sacked_out);
if (tp->frto_counter)
frto_cwnd = tcp_process_frto(sk, flag);
@@ -3685,7 +3691,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
tcp_may_raise_cwnd(sk, flag))
tcp_cong_avoid(sk, ack, prior_in_flight);
is_dupack = !(flag & (FLAG_SND_UNA_ADVANCED | FLAG_NOT_DUP));
- tcp_fastretrans_alert(sk, pkts_acked, newly_acked_sacked,
+ tcp_fastretrans_alert(sk, pkts_acked, prior_sacked,
is_dupack, flag);
} else {
if ((flag & FLAG_DATA_ACKED) && !frto_cwnd)
@@ -3702,7 +3708,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
no_queue:
/* If data was DSACKed, see if we can undo a cwnd reduction. */
if (flag & FLAG_DSACKING_ACK)
- tcp_fastretrans_alert(sk, pkts_acked, newly_acked_sacked,
+ tcp_fastretrans_alert(sk, pkts_acked, prior_sacked,
is_dupack, flag);
/* If this ack opens up a zero window, clear backoff. It was
* being used to time the probes, and is probably far higher than
@@ -3722,8 +3728,7 @@ old_ack:
*/
if (TCP_SKB_CB(skb)->sacked) {
flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una);
- newly_acked_sacked = tp->sacked_out - prior_sacked;
- tcp_fastretrans_alert(sk, pkts_acked, newly_acked_sacked,
+ tcp_fastretrans_alert(sk, pkts_acked, prior_sacked,
is_dupack, flag);
}
@@ -4039,7 +4044,7 @@ static inline bool tcp_sequence(const struct tcp_sock *tp, u32 seq, u32 end_seq)
}
/* When we get a reset we do this. */
-static void tcp_reset(struct sock *sk)
+void tcp_reset(struct sock *sk)
{
/* We want the right error as BSD sees it (and indeed as we do). */
switch (sk->sk_state) {
@@ -5896,7 +5901,9 @@ discard:
tcp_send_synack(sk);
#if 0
/* Note, we could accept data and URG from this segment.
- * There are no obstacles to make this.
+ * There are no obstacles to make this (except that we must
+ * either change tcp_recvmsg() to prevent it from returning data
+ * before 3WHS completes per RFC793, or employ TCP Fast Open).
*
* However, if we ignore data in ACKless segments sometimes,
* we have no reasons to accept it sometimes.
@@ -5936,6 +5943,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
{
struct tcp_sock *tp = tcp_sk(sk);
struct inet_connection_sock *icsk = inet_csk(sk);
+ struct request_sock *req;
int queued = 0;
tp->rx_opt.saw_tstamp = 0;
@@ -5991,7 +5999,14 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
return 0;
}
- if (!tcp_validate_incoming(sk, skb, th, 0))
+ req = tp->fastopen_rsk;
+ if (req != NULL) {
+ BUG_ON(sk->sk_state != TCP_SYN_RECV &&
+ sk->sk_state != TCP_FIN_WAIT1);
+
+ if (tcp_check_req(sk, skb, req, NULL, true) == NULL)
+ goto discard;
+ } else if (!tcp_validate_incoming(sk, skb, th, 0))
return 0;
/* step 5: check the ACK field */
@@ -6001,7 +6016,22 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
switch (sk->sk_state) {
case TCP_SYN_RECV:
if (acceptable) {
- tp->copied_seq = tp->rcv_nxt;
+ /* Once we leave TCP_SYN_RECV, we no longer
+ * need req so release it.
+ */
+ if (req) {
+ reqsk_fastopen_remove(sk, req, false);
+ } else {
+ /* Make sure socket is routed, for
+ * correct metrics.
+ */
+ icsk->icsk_af_ops->rebuild_header(sk);
+ tcp_init_congestion_control(sk);
+
+ tcp_mtup_init(sk);
+ tcp_init_buffer_space(sk);
+ tp->copied_seq = tp->rcv_nxt;
+ }
smp_mb();
tcp_set_state(sk, TCP_ESTABLISHED);
sk->sk_state_change(sk);
@@ -6023,23 +6053,27 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
if (tp->rx_opt.tstamp_ok)
tp->advmss -= TCPOLEN_TSTAMP_ALIGNED;
- /* Make sure socket is routed, for
- * correct metrics.
- */
- icsk->icsk_af_ops->rebuild_header(sk);
-
- tcp_init_metrics(sk);
-
- tcp_init_congestion_control(sk);
+ if (req) {
+ /* Re-arm the timer because data may
+ * have been sent out. This is similar
+ * to the regular data transmission case
+ * when new data has just been ack'ed.
+ *
+ * (TFO) - we could try to be more
+ * aggressive and retranmitting any data
+ * sooner based on when they were sent
+ * out.
+ */
+ tcp_rearm_rto(sk);
+ } else
+ tcp_init_metrics(sk);
/* Prevent spurious tcp_cwnd_restart() on
* first data packet.
*/
tp->lsndtime = tcp_time_stamp;
- tcp_mtup_init(sk);
tcp_initialize_rcv_mss(sk);
- tcp_init_buffer_space(sk);
tcp_fast_path_on(tp);
} else {
return 1;
@@ -6047,6 +6081,16 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
break;
case TCP_FIN_WAIT1:
+ /* If we enter the TCP_FIN_WAIT1 state and we are a
+ * Fast Open socket and this is the first acceptable
+ * ACK we have received, this would have acknowledged
+ * our SYNACK so stop the SYNACK timer.
+ */
+ if (acceptable && req != NULL) {
+ /* We no longer need the request sock. */
+ reqsk_fastopen_remove(sk, req, false);
+ tcp_rearm_rto(sk);
+ }
if (tp->snd_una == tp->write_seq) {
struct dst_entry *dst;
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-05 18:34:07 +0000