--- zzzz-none-000/linux-4.19.183/net/ipv4/tcp_timer.c	2021-03-24 10:07:39.000000000 +0000
+++ bcm63-7530ax-756/linux-4.19.183/net/ipv4/tcp_timer.c	2023-06-28 08:54:21.000000000 +0000
@@ -20,6 +20,9 @@
 
 #include <linux/module.h>
 #include <linux/gfp.h>
+#if defined(CONFIG_BCM_KF_MPTCP) && defined(CONFIG_BCM_MPTCP)
+#include <net/mptcp.h>
+#endif
 #include <net/tcp.h>
 
 static u32 tcp_retransmit_stamp(const struct sock *sk)
@@ -58,7 +61,11 @@
  *  Returns: Nothing (void)
  */
 
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 static void tcp_write_err(struct sock *sk)
+#else
+void tcp_write_err(struct sock *sk)
+#endif
 {
 	sk->sk_err = sk->sk_err_soft ? : ETIMEDOUT;
 	sk->sk_error_report(sk);
@@ -114,7 +121,11 @@
 		    (!tp->snd_wnd && !tp->packets_out))
 			do_reset = true;
 		if (do_reset)
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 			tcp_send_active_reset(sk, GFP_ATOMIC);
+#else
+			tp->ops->send_active_reset(sk, GFP_ATOMIC);
+#endif
 		tcp_done(sk);
 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONMEMORY);
 		return 1;
@@ -186,9 +197,15 @@
  * after "boundary" unsuccessful, exponentially backed-off
  * retransmissions with an initial RTO of TCP_RTO_MIN.
  */
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 static bool retransmits_timed_out(struct sock *sk,
 				  unsigned int boundary,
 				  unsigned int timeout)
+#else
+bool retransmits_timed_out(struct sock *sk,
+			   unsigned int boundary,
+			   unsigned int timeout)
+#endif
 {
 	const unsigned int rto_base = TCP_RTO_MIN;
 	unsigned int linear_backoff_thresh, start_ts;
@@ -214,7 +231,11 @@
 }
 
 /* A write timeout has occurred. Process the after effects. */
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 static int tcp_write_timeout(struct sock *sk)
+#else
+int tcp_write_timeout(struct sock *sk)
+#endif
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
@@ -229,6 +250,19 @@
 			sk_rethink_txhash(sk);
 		}
 		retry_until = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
+#if defined(CONFIG_BCM_KF_MPTCP) && defined(CONFIG_BCM_MPTCP)
+
+#ifdef CONFIG_MPTCP
+		/* Stop retransmitting MP_CAPABLE options in SYN if timed out. */
+		if (tcp_sk(sk)->request_mptcp &&
+		    icsk->icsk_retransmits >= sysctl_mptcp_syn_retries) {
+			tcp_sk(sk)->request_mptcp = 0;
+
+			MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLERETRANSFALLBACK);
+		}
+#endif /* CONFIG_MPTCP */
+
+#endif
 		expired = icsk->icsk_retransmits >= retry_until;
 	} else {
 		if (retransmits_timed_out(sk, net->ipv4.sysctl_tcp_retries1, 0)) {
@@ -324,18 +358,39 @@
 	struct inet_connection_sock *icsk =
 			from_timer(icsk, t, icsk_delack_timer);
 	struct sock *sk = &icsk->icsk_inet.sk;
+#if defined(CONFIG_BCM_KF_MPTCP) && defined(CONFIG_BCM_MPTCP)
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sock *meta_sk = mptcp(tp) ? mptcp_meta_sk(sk) : sk;
+#endif
 
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 	bh_lock_sock(sk);
 	if (!sock_owned_by_user(sk)) {
+#else
+	bh_lock_sock(meta_sk);
+	if (!sock_owned_by_user(meta_sk)) {
+#endif
 		tcp_delack_timer_handler(sk);
 	} else {
 		icsk->icsk_ack.blocked = 1;
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOCKED);
+#else
+		__NET_INC_STATS(sock_net(meta_sk), LINUX_MIB_DELAYEDACKLOCKED);
+#endif
 		/* deleguate our work to tcp_release_cb() */
 		if (!test_and_set_bit(TCP_DELACK_TIMER_DEFERRED, &sk->sk_tsq_flags))
 			sock_hold(sk);
+#if defined(CONFIG_BCM_KF_MPTCP) && defined(CONFIG_BCM_MPTCP)
+		if (mptcp(tp))
+			mptcp_tsq_flags(sk);
+#endif
 	}
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 	bh_unlock_sock(sk);
+#else
+	bh_unlock_sock(meta_sk);
+#endif
 	sock_put(sk);
 }
 
@@ -379,7 +434,16 @@
 	}
 
 	if (icsk->icsk_probes_out >= max_probes) {
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 abort:		tcp_write_err(sk);
+#else
+abort:
+		tcp_write_err(sk);
+		if (is_meta_sk(sk) &&
+		    mptcp_in_infinite_mapping_weak(tp->mpcb)) {
+			mptcp_sub_force_close_all(tp->mpcb, NULL);
+		}
+#endif
 	} else {
 		/* Only send another probe if we didn't close things up. */
 		tcp_send_probe0(sk);
@@ -595,7 +659,11 @@
 		break;
 	case ICSK_TIME_RETRANS:
 		icsk->icsk_pending = 0;
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 		tcp_retransmit_timer(sk);
+#else
+		tcp_sk(sk)->ops->retransmit_timer(sk);
+#endif
 		break;
 	case ICSK_TIME_PROBE0:
 		icsk->icsk_pending = 0;
@@ -612,16 +680,32 @@
 	struct inet_connection_sock *icsk =
 			from_timer(icsk, t, icsk_retransmit_timer);
 	struct sock *sk = &icsk->icsk_inet.sk;
+#if defined(CONFIG_BCM_KF_MPTCP) && defined(CONFIG_BCM_MPTCP)
+	struct sock *meta_sk = mptcp(tcp_sk(sk)) ? mptcp_meta_sk(sk) : sk;
+#endif
 
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 	bh_lock_sock(sk);
 	if (!sock_owned_by_user(sk)) {
+#else
+	bh_lock_sock(meta_sk);
+	if (!sock_owned_by_user(meta_sk)) {
+#endif
 		tcp_write_timer_handler(sk);
 	} else {
 		/* delegate our work to tcp_release_cb() */
 		if (!test_and_set_bit(TCP_WRITE_TIMER_DEFERRED, &sk->sk_tsq_flags))
 			sock_hold(sk);
+#if defined(CONFIG_BCM_KF_MPTCP) && defined(CONFIG_BCM_MPTCP)
+		if (mptcp(tcp_sk(sk)))
+			mptcp_tsq_flags(sk);
+#endif
 	}
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 	bh_unlock_sock(sk);
+#else
+	bh_unlock_sock(meta_sk);
+#endif
 	sock_put(sk);
 }
 
@@ -651,11 +735,19 @@
 	struct sock *sk = from_timer(sk, t, sk_timer);
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
+#if defined(CONFIG_BCM_KF_MPTCP) && defined(CONFIG_BCM_MPTCP)
+	struct sock *meta_sk = mptcp(tp) ? mptcp_meta_sk(sk) : sk;
+#endif
 	u32 elapsed;
 
 	/* Only process if socket is not in use. */
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 	bh_lock_sock(sk);
 	if (sock_owned_by_user(sk)) {
+#else
+	bh_lock_sock(meta_sk);
+	if (sock_owned_by_user(meta_sk)) {
+#endif
 		/* Try again later. */
 		inet_csk_reset_keepalive_timer (sk, HZ/20);
 		goto out;
@@ -667,16 +759,41 @@
 	}
 
 	tcp_mstamp_refresh(tp);
+#if defined(CONFIG_BCM_KF_MPTCP) && defined(CONFIG_BCM_MPTCP)
+
+	if (tp->send_mp_fclose) {
+		if (icsk->icsk_retransmits >= MPTCP_FASTCLOSE_RETRIES) {
+			tcp_write_err(sk);
+			goto out;
+		}
+
+		tcp_send_ack(sk);
+		icsk->icsk_retransmits++;
+
+		icsk->icsk_rto = min(icsk->icsk_rto << 1, TCP_RTO_MAX);
+		elapsed = icsk->icsk_rto;
+		goto resched;
+	}
+
+#endif
 	if (sk->sk_state == TCP_FIN_WAIT2 && sock_flag(sk, SOCK_DEAD)) {
 		if (tp->linger2 >= 0) {
 			const int tmo = tcp_fin_time(sk) - TCP_TIMEWAIT_LEN;
 
 			if (tmo > 0) {
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
+#else
+				tp->ops->time_wait(sk, TCP_FIN_WAIT2, tmo);
+#endif
 				goto out;
 			}
 		}
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 		tcp_send_active_reset(sk, GFP_ATOMIC);
+#else
+		tp->ops->send_active_reset(sk, GFP_ATOMIC);
+#endif
 		goto death;
 	}
 
@@ -701,11 +818,19 @@
 		    icsk->icsk_probes_out > 0) ||
 		    (icsk->icsk_user_timeout == 0 &&
 		    icsk->icsk_probes_out >= keepalive_probes(tp))) {
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 			tcp_send_active_reset(sk, GFP_ATOMIC);
+#else
+			tp->ops->send_active_reset(sk, GFP_ATOMIC);
+#endif
 			tcp_write_err(sk);
 			goto out;
 		}
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 		if (tcp_write_wakeup(sk, LINUX_MIB_TCPKEEPALIVE) <= 0) {
+#else
+		if (tp->ops->write_wakeup(sk, LINUX_MIB_TCPKEEPALIVE) <= 0) {
+#endif
 			icsk->icsk_probes_out++;
 			elapsed = keepalive_intvl_when(tp);
 		} else {
@@ -729,7 +854,11 @@
 	tcp_done(sk);
 
 out:
+#if !defined(CONFIG_BCM_KF_MPTCP) || !defined(CONFIG_BCM_MPTCP)
 	bh_unlock_sock(sk);
+#else
+	bh_unlock_sock(meta_sk);
+#endif
 	sock_put(sk);
 }