mirror of https://gitee.com/openkylin/linux.git
tcp: remove one indentation level in tcp_rcv_state_process()
Remove one level of indentation 'introduced' in commit
c3ae62af8e (tcp: should drop incoming frames without ACK flag set)
if (true) {
...
}
@acceptable variable is a boolean.
This patch is a pure cleanup.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
David S. Miller
parent
42e52bf9e3
commit
1f6afc8108
|
|
@ -5536,6 +5536,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
|
|||
struct inet_connection_sock *icsk = inet_csk(sk);
|
||||
struct request_sock *req;
|
||||
int queued = 0;
|
||||
bool acceptable;
|
||||
|
||||
tp->rx_opt.saw_tstamp = 0;
|
||||
|
||||
|
|
@ -5606,157 +5607,153 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
|
|||
return 0;
|
||||
|
||||
/* step 5: check the ACK field */
|
||||
if (true) {
|
||||
int acceptable = tcp_ack(sk, skb, FLAG_SLOWPATH |
|
||||
FLAG_UPDATE_TS_RECENT) > 0;
|
||||
acceptable = tcp_ack(sk, skb, FLAG_SLOWPATH |
|
||||
FLAG_UPDATE_TS_RECENT) > 0;
|
||||
|
||||
switch (sk->sk_state) {
|
||||
case TCP_SYN_RECV:
|
||||
if (acceptable) {
|
||||
/* Once we leave TCP_SYN_RECV, we no longer
|
||||
* need req so release it.
|
||||
*/
|
||||
if (req) {
|
||||
tcp_synack_rtt_meas(sk, req);
|
||||
tp->total_retrans = req->num_retrans;
|
||||
|
||||
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);
|
||||
|
||||
/* Note, that this wakeup is only for marginal
|
||||
* crossed SYN case. Passively open sockets
|
||||
* are not waked up, because sk->sk_sleep ==
|
||||
* NULL and sk->sk_socket == NULL.
|
||||
*/
|
||||
if (sk->sk_socket)
|
||||
sk_wake_async(sk,
|
||||
SOCK_WAKE_IO, POLL_OUT);
|
||||
|
||||
tp->snd_una = TCP_SKB_CB(skb)->ack_seq;
|
||||
tp->snd_wnd = ntohs(th->window) <<
|
||||
tp->rx_opt.snd_wscale;
|
||||
tcp_init_wl(tp, TCP_SKB_CB(skb)->seq);
|
||||
|
||||
if (tp->rx_opt.tstamp_ok)
|
||||
tp->advmss -= TCPOLEN_TSTAMP_ALIGNED;
|
||||
|
||||
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_initialize_rcv_mss(sk);
|
||||
tcp_fast_path_on(tp);
|
||||
} else {
|
||||
return 1;
|
||||
}
|
||||
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.
|
||||
switch (sk->sk_state) {
|
||||
case TCP_SYN_RECV:
|
||||
if (acceptable) {
|
||||
/* Once we leave TCP_SYN_RECV, we no longer
|
||||
* need req so release it.
|
||||
*/
|
||||
if (req != NULL) {
|
||||
/* Return RST if ack_seq is invalid.
|
||||
* Note that RFC793 only says to generate a
|
||||
* DUPACK for it but for TCP Fast Open it seems
|
||||
* better to treat this case like TCP_SYN_RECV
|
||||
* above.
|
||||
*/
|
||||
if (!acceptable)
|
||||
return 1;
|
||||
/* We no longer need the request sock. */
|
||||
if (req) {
|
||||
tcp_synack_rtt_meas(sk, req);
|
||||
tp->total_retrans = req->num_retrans;
|
||||
|
||||
reqsk_fastopen_remove(sk, req, false);
|
||||
tcp_rearm_rto(sk);
|
||||
} 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;
|
||||
}
|
||||
if (tp->snd_una == tp->write_seq) {
|
||||
struct dst_entry *dst;
|
||||
smp_mb();
|
||||
tcp_set_state(sk, TCP_ESTABLISHED);
|
||||
sk->sk_state_change(sk);
|
||||
|
||||
tcp_set_state(sk, TCP_FIN_WAIT2);
|
||||
sk->sk_shutdown |= SEND_SHUTDOWN;
|
||||
/* Note, that this wakeup is only for marginal
|
||||
* crossed SYN case. Passively open sockets
|
||||
* are not waked up, because sk->sk_sleep ==
|
||||
* NULL and sk->sk_socket == NULL.
|
||||
*/
|
||||
if (sk->sk_socket)
|
||||
sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
|
||||
|
||||
dst = __sk_dst_get(sk);
|
||||
if (dst)
|
||||
dst_confirm(dst);
|
||||
tp->snd_una = TCP_SKB_CB(skb)->ack_seq;
|
||||
tp->snd_wnd = ntohs(th->window) <<
|
||||
tp->rx_opt.snd_wscale;
|
||||
tcp_init_wl(tp, TCP_SKB_CB(skb)->seq);
|
||||
|
||||
if (!sock_flag(sk, SOCK_DEAD))
|
||||
/* Wake up lingering close() */
|
||||
sk->sk_state_change(sk);
|
||||
else {
|
||||
int tmo;
|
||||
if (tp->rx_opt.tstamp_ok)
|
||||
tp->advmss -= TCPOLEN_TSTAMP_ALIGNED;
|
||||
|
||||
if (tp->linger2 < 0 ||
|
||||
(TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq &&
|
||||
after(TCP_SKB_CB(skb)->end_seq - th->fin, tp->rcv_nxt))) {
|
||||
tcp_done(sk);
|
||||
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
|
||||
return 1;
|
||||
}
|
||||
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 retransmitting any data sooner based
|
||||
* on when they are sent out.
|
||||
*/
|
||||
tcp_rearm_rto(sk);
|
||||
} else
|
||||
tcp_init_metrics(sk);
|
||||
|
||||
tmo = tcp_fin_time(sk);
|
||||
if (tmo > TCP_TIMEWAIT_LEN) {
|
||||
inet_csk_reset_keepalive_timer(sk, tmo - TCP_TIMEWAIT_LEN);
|
||||
} else if (th->fin || sock_owned_by_user(sk)) {
|
||||
/* Bad case. We could lose such FIN otherwise.
|
||||
* It is not a big problem, but it looks confusing
|
||||
* and not so rare event. We still can lose it now,
|
||||
* if it spins in bh_lock_sock(), but it is really
|
||||
* marginal case.
|
||||
*/
|
||||
inet_csk_reset_keepalive_timer(sk, tmo);
|
||||
} else {
|
||||
tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
|
||||
goto discard;
|
||||
}
|
||||
/* Prevent spurious tcp_cwnd_restart() on
|
||||
* first data packet.
|
||||
*/
|
||||
tp->lsndtime = tcp_time_stamp;
|
||||
|
||||
tcp_initialize_rcv_mss(sk);
|
||||
tcp_fast_path_on(tp);
|
||||
} else {
|
||||
return 1;
|
||||
}
|
||||
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 (req != NULL) {
|
||||
/* Return RST if ack_seq is invalid.
|
||||
* Note that RFC793 only says to generate a
|
||||
* DUPACK for it but for TCP Fast Open it seems
|
||||
* better to treat this case like TCP_SYN_RECV
|
||||
* above.
|
||||
*/
|
||||
if (!acceptable)
|
||||
return 1;
|
||||
/* 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;
|
||||
|
||||
tcp_set_state(sk, TCP_FIN_WAIT2);
|
||||
sk->sk_shutdown |= SEND_SHUTDOWN;
|
||||
|
||||
dst = __sk_dst_get(sk);
|
||||
if (dst)
|
||||
dst_confirm(dst);
|
||||
|
||||
if (!sock_flag(sk, SOCK_DEAD)) {
|
||||
/* Wake up lingering close() */
|
||||
sk->sk_state_change(sk);
|
||||
} else {
|
||||
int tmo;
|
||||
|
||||
if (tp->linger2 < 0 ||
|
||||
(TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq &&
|
||||
after(TCP_SKB_CB(skb)->end_seq - th->fin, tp->rcv_nxt))) {
|
||||
tcp_done(sk);
|
||||
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
|
||||
return 1;
|
||||
}
|
||||
|
||||
tmo = tcp_fin_time(sk);
|
||||
if (tmo > TCP_TIMEWAIT_LEN) {
|
||||
inet_csk_reset_keepalive_timer(sk, tmo - TCP_TIMEWAIT_LEN);
|
||||
} else if (th->fin || sock_owned_by_user(sk)) {
|
||||
/* Bad case. We could lose such FIN otherwise.
|
||||
* It is not a big problem, but it looks confusing
|
||||
* and not so rare event. We still can lose it now,
|
||||
* if it spins in bh_lock_sock(), but it is really
|
||||
* marginal case.
|
||||
*/
|
||||
inet_csk_reset_keepalive_timer(sk, tmo);
|
||||
} else {
|
||||
tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
|
||||
goto discard;
|
||||
}
|
||||
}
|
||||
break;
|
||||
|
||||
case TCP_CLOSING:
|
||||
if (tp->snd_una == tp->write_seq) {
|
||||
tcp_time_wait(sk, TCP_TIME_WAIT, 0);
|
||||
goto discard;
|
||||
}
|
||||
break;
|
||||
|
||||
case TCP_LAST_ACK:
|
||||
if (tp->snd_una == tp->write_seq) {
|
||||
tcp_update_metrics(sk);
|
||||
tcp_done(sk);
|
||||
goto discard;
|
||||
}
|
||||
break;
|
||||
}
|
||||
break;
|
||||
|
||||
case TCP_CLOSING:
|
||||
if (tp->snd_una == tp->write_seq) {
|
||||
tcp_time_wait(sk, TCP_TIME_WAIT, 0);
|
||||
goto discard;
|
||||
}
|
||||
break;
|
||||
|
||||
case TCP_LAST_ACK:
|
||||
if (tp->snd_una == tp->write_seq) {
|
||||
tcp_update_metrics(sk);
|
||||
tcp_done(sk);
|
||||
goto discard;
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
/* step 6: check the URG bit */
|
||||
|
|
|
|||
Loading…
Reference in New Issue