X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/5ba3f43ea354af8ad55bea84372a2bc834d8757c..cb3231590a3c94ab4375e2228bd5e86b0cf1ad7e:/bsd/netinet/tcp_usrreq.c

diff --git a/bsd/netinet/tcp_usrreq.c b/bsd/netinet/tcp_usrreq.c
index 0f0dc353e..92c445448 100644
--- a/bsd/netinet/tcp_usrreq.c
+++ b/bsd/netinet/tcp_usrreq.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2017 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2019 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  *
@@ -73,6 +73,7 @@
 #if !CONFIG_EMBEDDED
 #include <sys/kasl.h>
 #endif
+#include <sys/priv.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
 #include <sys/protosw.h>
@@ -82,6 +83,7 @@
 #include <net/route.h>
 #include <net/ntstat.h>
 #include <net/content_filter.h>
+#include <net/multi_layer_pkt_log.h>
 
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
@@ -104,6 +106,7 @@
 #include <netinet/tcp_var.h>
 #include <netinet/tcpip.h>
 #include <netinet/tcp_cc.h>
+#include <netinet/tcp_log.h>
 #include <mach/sdt.h>
 #if TCPDEBUG
 #include <netinet/tcp_debug.h>
@@ -122,40 +125,39 @@
 
 errno_t tcp_fill_info_for_info_tuple(struct info_tuple *, struct tcp_info *);
 
-int tcp_sysctl_info(struct sysctl_oid *, void *, int , struct sysctl_req *);
+int tcp_sysctl_info(struct sysctl_oid *, void *, int, struct sysctl_req *);
 static void tcp_connection_fill_info(struct tcpcb *tp,
     struct tcp_connection_info *tci);
+static int tcp_get_mpkl_send_info(struct mbuf *, struct so_mpkl_send_info *);
 
 /*
  * TCP protocol interface to socket abstraction.
  */
-extern	char *tcpstates[];	/* XXX ??? */
-
-static int	tcp_attach(struct socket *, struct proc *);
-static int	tcp_connect(struct tcpcb *, struct sockaddr *, struct proc *);
+static int      tcp_attach(struct socket *, struct proc *);
+static int      tcp_connect(struct tcpcb *, struct sockaddr *, struct proc *);
 #if INET6
-static int	tcp6_connect(struct tcpcb *, struct sockaddr *, struct proc *);
-static int	tcp6_usr_connect(struct socket *, struct sockaddr *,
-		    struct proc *);
+static int      tcp6_connect(struct tcpcb *, struct sockaddr *, struct proc *);
+static int      tcp6_usr_connect(struct socket *, struct sockaddr *,
+    struct proc *);
 #endif /* INET6 */
 static struct tcpcb *tcp_disconnect(struct tcpcb *);
 static struct tcpcb *tcp_usrclosed(struct tcpcb *);
 extern void tcp_sbrcv_trim(struct tcpcb *tp, struct sockbuf *sb);
 
 #if TCPDEBUG
-#define	TCPDEBUG0	int ostate = 0
-#define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
-#define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
-				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
+#define TCPDEBUG0       int ostate = 0
+#define TCPDEBUG1()     ostate = tp ? tp->t_state : 0
+#define TCPDEBUG2(req)  if (tp && (so->so_options & SO_DEBUG)) \
+	                        tcp_trace(TA_USER, ostate, tp, 0, 0, req)
 #else
-#define	TCPDEBUG0
-#define	TCPDEBUG1()
-#define	TCPDEBUG2(req)
+#define TCPDEBUG0
+#define TCPDEBUG1()
+#define TCPDEBUG2(req)
 #endif
 
 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, info,
     CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_ANYBODY | CTLFLAG_KERN,
-    0 , 0, tcp_sysctl_info, "S", "TCP info per tuple");
+    0, 0, tcp_sysctl_info, "S", "TCP info per tuple");
 
 /*
  * TCP attaches to socket via pru_attach(), reserving space,
@@ -182,11 +184,13 @@ tcp_usr_attach(struct socket *so, __unused int proto, struct proc *p)
 	}
 
 	error = tcp_attach(so, p);
-	if (error)
+	if (error) {
 		goto out;
+	}
 
-	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
+	if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
 		so->so_linger = TCP_LINGERTIME * hz;
+	}
 	tp = sototcpcb(so);
 out:
 	TCPDEBUG2(PRU_ATTACH);
@@ -209,13 +213,14 @@ tcp_usr_detach(struct socket *so)
 	TCPDEBUG0;
 
 	if (inp == 0 || (inp->inp_state == INPCB_STATE_DEAD)) {
-		return EINVAL;	/* XXX */
+		return EINVAL;  /* XXX */
 	}
 	socket_lock_assert_owned(so);
 	tp = intotcpcb(inp);
 	/* In case we got disconnected from the peer */
-        if (tp == NULL)
+	if (tp == NULL) {
 		goto out;
+	}
 	TCPDEBUG1();
 
 	calculate_tcp_clock();
@@ -227,28 +232,28 @@ out:
 }
 
 #if NECP
-#define	COMMON_START()	TCPDEBUG0;					\
-do {									\
-	if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD)		\
-		return (EINVAL);					\
-	if (necp_socket_should_use_flow_divert(inp))			\
-		return (EPROTOTYPE);					\
-	tp = intotcpcb(inp);						\
-	TCPDEBUG1();							\
-	calculate_tcp_clock();						\
+#define COMMON_START()  TCPDEBUG0;                                      \
+do {                                                                    \
+	if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD)          \
+	        return (EINVAL);                                        \
+	if (necp_socket_should_use_flow_divert(inp))                    \
+	        return (EPROTOTYPE);                                    \
+	tp = intotcpcb(inp);                                            \
+	TCPDEBUG1();                                                    \
+	calculate_tcp_clock();                                          \
 } while (0)
 #else /* NECP */
-#define	COMMON_START()	TCPDEBUG0;					\
-do {									\
-	if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD)		\
-		return (EINVAL);					\
-	tp = intotcpcb(inp);						\
-	TCPDEBUG1();							\
-	calculate_tcp_clock();						\
+#define COMMON_START()  TCPDEBUG0;                                      \
+do {                                                                    \
+	if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD)          \
+	        return (EINVAL);                                        \
+	tp = intotcpcb(inp);                                            \
+	TCPDEBUG1();                                                    \
+	calculate_tcp_clock();                                          \
 } while (0)
 #endif /* !NECP */
 
-#define COMMON_END(req)	out: TCPDEBUG2(req); return error; goto out
+#define COMMON_END(req) out: TCPDEBUG2(req); return error; goto out
 
 
 /*
@@ -291,13 +296,14 @@ tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
 		goto out;
 	}
 	error = in_pcbbind(inp, nam, p);
-	if (error)
+	if (error) {
 		goto out;
+	}
 
 #if NECP
 	/* Update NECP client with bind result if not in middle of connect */
 	if ((inp->inp_flags2 & INP2_CONNECT_IN_PROGRESS) &&
-		!uuid_is_null(inp->necp_client_uuid)) {
+	    !uuid_is_null(inp->necp_client_uuid)) {
 		socket_unlock(so, 0);
 		necp_client_assign_from_socket(so->last_pid, inp->necp_client_uuid, inp);
 		socket_lock(so, 0);
@@ -305,7 +311,6 @@ tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
 #endif /* NECP */
 
 	COMMON_END(PRU_BIND);
-
 }
 
 #if INET6
@@ -337,9 +342,9 @@ tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
 	inp->inp_vflag &= ~INP_IPV4;
 	inp->inp_vflag |= INP_IPV6;
 	if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
-		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
+		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr)) {
 			inp->inp_vflag |= INP_IPV4;
-		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
+		} else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
 			struct sockaddr_in sin;
 
 			in6_sin6_2_sin(&sin, sin6p);
@@ -350,8 +355,9 @@ tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
 		}
 	}
 	error = in6_pcbbind(inp, nam, p);
-	if (error)
+	if (error) {
 		goto out;
+	}
 	COMMON_END(PRU_BIND);
 }
 #endif /* INET6 */
@@ -377,10 +383,13 @@ tcp_usr_listen(struct socket *so, struct proc *p)
 	struct tcpcb *tp;
 
 	COMMON_START();
-	if (inp->inp_lport == 0)
+	if (inp->inp_lport == 0) {
 		error = in_pcbbind(inp, NULL, p);
-	if (error == 0)
+	}
+	if (error == 0) {
 		tp->t_state = TCPS_LISTEN;
+	}
+	TCP_LOG_LISTEN(tp, error);
 	COMMON_END(PRU_LISTEN);
 }
 
@@ -395,12 +404,15 @@ tcp6_usr_listen(struct socket *so, struct proc *p)
 	COMMON_START();
 	if (inp->inp_lport == 0) {
 		inp->inp_vflag &= ~INP_IPV4;
-		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
+		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 			inp->inp_vflag |= INP_IPV4;
+		}
 		error = in6_pcbbind(inp, NULL, p);
 	}
-	if (error == 0)
+	if (error == 0) {
 		tp->t_state = TCPS_LISTEN;
+	}
+	TCP_LOG_LISTEN(tp, error);
 	COMMON_END(PRU_LISTEN);
 }
 #endif /* INET6 */
@@ -412,28 +424,31 @@ tcp_connect_complete(struct socket *so)
 	struct inpcb *inp = sotoinpcb(so);
 	int error = 0;
 
-#if NECP
-	/* Update NECP client with connected five-tuple */
-	if (!uuid_is_null(inp->necp_client_uuid)) {
-		socket_unlock(so, 0);
-		necp_client_assign_from_socket(so->last_pid, inp->necp_client_uuid, inp);
-		socket_lock(so, 0);
-	}
-#endif /* NECP */
-
 	/* TFO delays the tcp_output until later, when the app calls write() */
 	if (so->so_flags1 & SOF1_PRECONNECT_DATA) {
-		if (!necp_socket_is_allowed_to_send_recv(sotoinpcb(so), NULL, NULL))
-			return (EHOSTUNREACH);
+		if (!necp_socket_is_allowed_to_send_recv(sotoinpcb(so), NULL, NULL, NULL, NULL)) {
+			TCP_LOG_DROP_NECP(NULL, NULL, tp, true);
+			return EHOSTUNREACH;
+		}
 
 		/* Initialize enough state so that we can actually send data */
 		tcp_mss(tp, -1, IFSCOPE_NONE);
 		tp->snd_wnd = tp->t_maxseg;
+		tp->max_sndwnd = tp->snd_wnd;
 	} else {
 		error = tcp_output(tp);
 	}
 
-	return (error);
+#if NECP
+	/* Update NECP client with connected five-tuple */
+	if (error == 0 && !uuid_is_null(inp->necp_client_uuid)) {
+		socket_unlock(so, 0);
+		necp_client_assign_from_socket(so->last_pid, inp->necp_client_uuid, inp);
+		socket_lock(so, 0);
+	}
+#endif /* NECP */
+
+	return error;
 }
 
 /*
@@ -459,12 +474,19 @@ tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
 			error = so->so_error;
 			so->so_error = 0;
 			return error;
-		} else
+		} else {
 			return EINVAL;
+		}
 	}
 #if NECP
+#if CONTENT_FILTER
+	error = cfil_sock_attach(so, NULL, nam, CFS_CONNECTION_DIR_OUT);
+	if (error != 0) {
+		return error;
+	}
+#endif /* CONTENT_FILTER */
 #if FLOW_DIVERT
-	else if (necp_socket_should_use_flow_divert(inp)) {
+	if (necp_socket_should_use_flow_divert(inp)) {
 		uint32_t fd_ctl_unit = necp_socket_get_flow_divert_control_unit(inp);
 		if (fd_ctl_unit > 0) {
 			error = flow_divert_pcb_init(so, fd_ctl_unit);
@@ -478,11 +500,6 @@ tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
 		return error;
 	}
 #endif /* FLOW_DIVERT */
-#if CONTENT_FILTER
-	error = cfil_sock_attach(so);
-	if (error != 0)
-		return error;
-#endif /* CONTENT_FILTER */
 #endif /* NECP */
 	tp = intotcpcb(inp);
 	TCPDEBUG1();
@@ -503,11 +520,15 @@ tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
 		goto out;
 	}
 
-	if ((error = tcp_connect(tp, nam, p)) != 0)
+	if ((error = tcp_connect(tp, nam, p)) != 0) {
+		TCP_LOG_CONNECT(tp, true, error);
 		goto out;
+	}
 
 	error = tcp_connect_complete(so);
 
+	TCP_LOG_CONNECT(tp, true, error);
+
 	COMMON_END(PRU_CONNECT);
 }
 
@@ -523,8 +544,9 @@ tcp_usr_connectx_common(struct socket *so, int af,
 	int error = 0;
 	user_ssize_t datalen = 0;
 
-	if (inp == NULL)
-		return (EINVAL);
+	if (inp == NULL) {
+		return EINVAL;
+	}
 
 	VERIFY(dst != NULL);
 
@@ -536,18 +558,19 @@ tcp_usr_connectx_common(struct socket *so, int af,
 #endif /* NECP */
 
 	if ((so->so_flags1 & SOF1_DATA_IDEMPOTENT) &&
-	    (tcp_fastopen & TCP_FASTOPEN_CLIENT))
+	    (tcp_fastopen & TCP_FASTOPEN_CLIENT)) {
 		sototcpcb(so)->t_flagsext |= TF_FASTOPEN;
+	}
 
 	/* bind socket to the specified interface, if requested */
 	if (ifscope != IFSCOPE_NONE &&
-		(error = inp_bindif(inp, ifscope, NULL)) != 0) {
+	    (error = inp_bindif(inp, ifscope, NULL)) != 0) {
 		goto done;
 	}
 
 	/* if source address and/or port is specified, bind to it */
 	if (src != NULL) {
-		error = sobindlock(so, src, 0);	/* already locked */
+		error = sobindlock(so, src, 0); /* already locked */
 		if (error != 0) {
 			goto done;
 		}
@@ -579,11 +602,12 @@ tcp_usr_connectx_common(struct socket *so, int af,
 
 		datalen = uio_resid(auio);
 		error = so->so_proto->pr_usrreqs->pru_sosend(so, NULL,
-	            (uio_t)auio, NULL, NULL, 0);
+		    (uio_t)auio, NULL, NULL, 0);
 		socket_lock(so, 0);
 
-		if (error == 0 || error == EWOULDBLOCK)
+		if (error == 0 || error == EWOULDBLOCK) {
 			*bytes_written = datalen - uio_resid(auio);
+		}
 
 		/*
 		 * sosend returns EWOULDBLOCK if it's a non-blocking
@@ -593,16 +617,21 @@ tcp_usr_connectx_common(struct socket *so, int af,
 		 * However, connectx() returns EINPROGRESS in case of a
 		 * blocking socket. So we change the return value here.
 		 */
-		if (error == EWOULDBLOCK)
+		if (error == EWOULDBLOCK) {
 			error = EINPROGRESS;
+		}
 	}
 
-	if (error == 0 && pcid != NULL)
+	if (error == 0 && pcid != NULL) {
 		*pcid = 1; /* there is only one connection in regular TCP */
-
+	}
 done:
+	if (error && error != EINPROGRESS) {
+		so->so_flags1 &= ~SOF1_PRECONNECT_DATA;
+	}
+
 	inp->inp_flags2 &= ~INP2_CONNECT_IN_PROGRESS;
-	return (error);
+	return error;
 }
 
 static int
@@ -611,8 +640,8 @@ tcp_usr_connectx(struct socket *so, struct sockaddr *src,
     sae_associd_t aid, sae_connid_t *pcid, uint32_t flags, void *arg,
     uint32_t arglen, struct uio *uio, user_ssize_t *bytes_written)
 {
-	return (tcp_usr_connectx_common(so, AF_INET, src, dst, p, ifscope, aid,
-	    pcid, flags, arg, arglen, uio, bytes_written));
+	return tcp_usr_connectx_common(so, AF_INET, src, dst, p, ifscope, aid,
+	           pcid, flags, arg, arglen, uio, bytes_written);
 }
 
 #if INET6
@@ -632,12 +661,19 @@ tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
 			error = so->so_error;
 			so->so_error = 0;
 			return error;
-		} else
+		} else {
 			return EINVAL;
+		}
 	}
 #if NECP
+#if CONTENT_FILTER
+	error = cfil_sock_attach(so, NULL, nam, CFS_CONNECTION_DIR_OUT);
+	if (error != 0) {
+		return error;
+	}
+#endif /* CONTENT_FILTER */
 #if FLOW_DIVERT
-	else if (necp_socket_should_use_flow_divert(inp)) {
+	if (necp_socket_should_use_flow_divert(inp)) {
 		uint32_t fd_ctl_unit = necp_socket_get_flow_divert_control_unit(inp);
 		if (fd_ctl_unit > 0) {
 			error = flow_divert_pcb_init(so, fd_ctl_unit);
@@ -651,11 +687,6 @@ tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
 		return error;
 	}
 #endif /* FLOW_DIVERT */
-#if CONTENT_FILTER
-	error = cfil_sock_attach(so);
-	if (error != 0)
-		return error;
-#endif /* CONTENT_FILTER */
 #endif /* NECP */
 
 	tp = intotcpcb(inp);
@@ -681,24 +712,32 @@ tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
 	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
 		struct sockaddr_in sin;
 
-		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)
-			return (EINVAL);
+		if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
+			return EINVAL;
+		}
 
 		in6_sin6_2_sin(&sin, sin6p);
 		inp->inp_vflag |= INP_IPV4;
 		inp->inp_vflag &= ~INP_IPV6;
-		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, p)) != 0)
+		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, p)) != 0) {
+			TCP_LOG_CONNECT(tp, true, error);
 			goto out;
+		}
 
 		error = tcp_connect_complete(so);
 		goto out;
 	}
 	inp->inp_vflag &= ~INP_IPV4;
 	inp->inp_vflag |= INP_IPV6;
-	if ((error = tcp6_connect(tp, nam, p)) != 0)
+	if ((error = tcp6_connect(tp, nam, p)) != 0) {
+		TCP_LOG_CONNECT(tp, true, error);
 		goto out;
+	}
 
 	error = tcp_connect_complete(so);
+
+	TCP_LOG_CONNECT(tp, true, error);
+
 	COMMON_END(PRU_CONNECT);
 }
 
@@ -708,8 +747,8 @@ tcp6_usr_connectx(struct socket *so, struct sockaddr*src,
     sae_associd_t aid, sae_connid_t *pcid, uint32_t flags, void *arg,
     uint32_t arglen, struct uio *uio, user_ssize_t *bytes_written)
 {
-	return (tcp_usr_connectx_common(so, AF_INET6, src, dst, p, ifscope, aid,
-	    pcid, flags, arg, arglen, uio, bytes_written));
+	return tcp_usr_connectx_common(so, AF_INET6, src, dst, p, ifscope, aid,
+	           pcid, flags, arg, arglen, uio, bytes_written);
 }
 #endif /* INET6 */
 
@@ -733,9 +772,10 @@ tcp_usr_disconnect(struct socket *so)
 
 	socket_lock_assert_owned(so);
 	COMMON_START();
-        /* In case we got disconnected from the peer */
-        if (tp == NULL)
+	/* In case we got disconnected from the peer */
+	if (tp == NULL) {
 		goto out;
+	}
 	tp = tcp_disconnect(tp);
 	COMMON_END(PRU_DISCONNECT);
 }
@@ -747,10 +787,11 @@ static int
 tcp_usr_disconnectx(struct socket *so, sae_associd_t aid, sae_connid_t cid)
 {
 #pragma unused(cid)
-	if (aid != SAE_ASSOCID_ANY && aid != SAE_ASSOCID_ALL)
-		return (EINVAL);
+	if (aid != SAE_ASSOCID_ANY && aid != SAE_ASSOCID_ALL) {
+		return EINVAL;
+	}
 
-	return (tcp_usr_disconnect(so));
+	return tcp_usr_disconnect(so);
 }
 
 /*
@@ -772,21 +813,21 @@ tcp_usr_accept(struct socket *so, struct sockaddr **nam)
 		error = ECONNABORTED;
 		goto out;
 	}
-	if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD)
-		return (EINVAL);
+	if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD) {
+		return EINVAL;
+	}
 #if NECP
-	else if (necp_socket_should_use_flow_divert(inp))
-		return (EPROTOTYPE);
-#if CONTENT_FILTER
-	error = cfil_sock_attach(so);
-	if (error != 0)
-		return (error);
-#endif /* CONTENT_FILTER */
+	else if (necp_socket_should_use_flow_divert(inp)) {
+		return EPROTOTYPE;
+	}
+
 #endif /* NECP */
 
 	tp = intotcpcb(inp);
 	TCPDEBUG1();
 
+	TCP_LOG_ACCEPT(tp, 0);
+
 	calculate_tcp_clock();
 
 	COMMON_END(PRU_ACCEPT);
@@ -805,21 +846,21 @@ tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
 		error = ECONNABORTED;
 		goto out;
 	}
-	if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD)
-		return (EINVAL);
+	if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD) {
+		return EINVAL;
+	}
 #if NECP
-	else if (necp_socket_should_use_flow_divert(inp))
-		return (EPROTOTYPE);
-#if CONTENT_FILTER
-	error = cfil_sock_attach(so);
-	if (error != 0)
-		return (error);
-#endif /* CONTENT_FILTER */
+	else if (necp_socket_should_use_flow_divert(inp)) {
+		return EPROTOTYPE;
+	}
+
 #endif /* NECP */
 
 	tp = intotcpcb(inp);
 	TCPDEBUG1();
 
+	TCP_LOG_ACCEPT(tp, 0);
+
 	calculate_tcp_clock();
 
 	in6_mapped_peeraddr(so, nam);
@@ -852,12 +893,13 @@ tcp_usr_shutdown(struct socket *so)
 	struct tcpcb *tp;
 
 	TCPDEBUG0;
-	if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD)
-		return (EINVAL);
+	if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD) {
+		return EINVAL;
+	}
 
 	socantsendmore(so);
 
-        /*
+	/*
 	 * In case we got disconnected from the peer, or if this is
 	 * a socket that is to be flow-diverted (but not yet).
 	 */
@@ -866,11 +908,12 @@ tcp_usr_shutdown(struct socket *so)
 
 	if (tp == NULL
 #if NECP
-		|| (necp_socket_should_use_flow_divert(inp))
+	    || (necp_socket_should_use_flow_divert(inp))
 #endif /* NECP */
-		) {
-		if (tp != NULL)
+	    ) {
+		if (tp != NULL) {
 			error = EPROTOTYPE;
+		}
 		goto out;
 	}
 
@@ -887,11 +930,13 @@ tcp_usr_shutdown(struct socket *so)
 #if CONTENT_FILTER
 	/* Don't send a FIN yet */
 	if (tp && !(so->so_state & SS_ISDISCONNECTED) &&
-		cfil_sock_data_pending(&so->so_snd))
+	    cfil_sock_data_pending(&so->so_snd)) {
 		goto out;
+	}
 #endif /* CONTENT_FILTER */
-	if (tp)
+	if (tp) {
 		error = tcp_output(tp);
+	}
 	COMMON_END(PRU_SHUTDOWN);
 }
 
@@ -906,9 +951,10 @@ tcp_usr_rcvd(struct socket *so, __unused int flags)
 	struct tcpcb *tp;
 
 	COMMON_START();
-        /* In case we got disconnected from the peer */
-        if (tp == NULL)
+	/* In case we got disconnected from the peer */
+	if (tp == NULL) {
 		goto out;
+	}
 	tcp_sbrcv_trim(tp, &so->so_rcv);
 
 	/*
@@ -916,8 +962,9 @@ tcp_usr_rcvd(struct socket *so, __unused int flags)
 	 * However, we really do not want these window-updates while we
 	 * are still in SYN_SENT or SYN_RECEIVED.
 	 */
-	if (TCPS_HAVEESTABLISHED(tp->t_state))
+	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
 		tcp_output(tp);
+	}
 
 #if CONTENT_FILTER
 	cfil_sock_buf_update(&so->so_rcv);
@@ -959,12 +1006,16 @@ tcp_usr_rcvd(struct socket *so, __unused int flags)
  */
 static int
 tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
-     struct sockaddr *nam, struct mbuf *control, struct proc *p)
+    struct sockaddr *nam, struct mbuf *control, struct proc *p)
 {
 	int error = 0;
 	struct inpcb *inp = sotoinpcb(so);
 	struct tcpcb *tp;
 	uint32_t msgpri = MSG_PRI_DEFAULT;
+	uint32_t mpkl_len = 0; /* length of mbuf chain */
+	uint32_t mpkl_seq; /* sequence number where new data is added */
+	struct so_mpkl_send_info mpkl_send_info = {};
+
 #if INET6
 	int isipv6;
 #endif
@@ -972,25 +1023,27 @@ tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
 
 	if (inp == NULL || inp->inp_state == INPCB_STATE_DEAD
 #if NECP
-		|| (necp_socket_should_use_flow_divert(inp))
+	    || (necp_socket_should_use_flow_divert(inp))
 #endif /* NECP */
-		) {
+	    ) {
 		/*
 		 * OOPS! we lost a race, the TCP session got reset after
 		 * we checked SS_CANTSENDMORE, eg: while doing uiomove or a
 		 * network interrupt in the non-splnet() section of sosend().
 		 */
-		if (m != NULL)
+		if (m != NULL) {
 			m_freem(m);
+		}
 		if (control != NULL) {
 			m_freem(control);
 			control = NULL;
 		}
 
-		if (inp == NULL)
-			error = ECONNRESET;	/* XXX EPIPE? */
-		else
+		if (inp == NULL) {
+			error = ECONNRESET;     /* XXX EPIPE? */
+		} else {
 			error = EPROTOTYPE;
+		}
 		tp = NULL;
 		TCPDEBUG1();
 		goto out;
@@ -1003,33 +1056,54 @@ tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
 
 	calculate_tcp_clock();
 
+	if (net_mpklog_enabled) {
+		mpkl_seq = tp->snd_una + so->so_snd.sb_cc;
+		if (m) {
+			mpkl_len = m_length(m);
+		}
+		if (so->so_flags1 & SOF1_MPKL_SEND_INFO) {
+			uuid_copy(mpkl_send_info.mpkl_uuid, so->so_mpkl_send_uuid);
+			mpkl_send_info.mpkl_proto = so->so_mpkl_send_proto;
+		}
+	}
+
 	if (control != NULL) {
 		if (so->so_flags & SOF_ENABLE_MSGS) {
 			/* Get the msg priority from control mbufs */
 			error = tcp_get_msg_priority(control, &msgpri);
 			if (error) {
 				m_freem(control);
-				if (m != NULL)
+				if (m != NULL) {
 					m_freem(m);
+				}
 				control = NULL;
 				m = NULL;
 				goto out;
 			}
-			m_freem(control);
-			control = NULL;
-		} else if (control->m_len) {
+		}
+		if (control->m_len > 0 && net_mpklog_enabled) {
+			error = tcp_get_mpkl_send_info(control, &mpkl_send_info);
 			/*
-			 * if not unordered, TCP should not have
-			 * control mbufs
+			 * Intepretation of the returned code:
+			 *  0: client wants us to use value passed in SCM_MPKL_SEND_INFO
+			 *  1: SCM_MPKL_SEND_INFO was not present
+			 *  other: failure
 			 */
-			m_freem(control);
-			if (m != NULL)
-				m_freem(m);
-			control = NULL;
-			m = NULL;
-			error = EINVAL;
-			goto out;
+			if (error != 0 && error != ENOMSG) {
+				m_freem(control);
+				if (m != NULL) {
+					m_freem(m);
+				}
+				control = NULL;
+				m = NULL;
+				goto out;
+			}
 		}
+		/*
+		 * Silently drop unsupported ancillary data messages
+		 */
+		m_freem(control);
+		control = NULL;
 	}
 
 	if (so->so_flags & SOF_ENABLE_MSGS) {
@@ -1041,15 +1115,15 @@ tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
 	VERIFY(!(so->so_flags & SOF_MP_SUBFLOW) ||
 	    (so->so_snd.sb_flags & SB_NOCOMPRESS));
 
-	if(!(flags & PRUS_OOB) || (so->so_flags1 & SOF1_PRECONNECT_DATA)) {
+	if (!(flags & PRUS_OOB) || (so->so_flags1 & SOF1_PRECONNECT_DATA)) {
 		/* Call msg send if message delivery is enabled */
-		if (so->so_flags & SOF_ENABLE_MSGS)
+		if (so->so_flags & SOF_ENABLE_MSGS) {
 			sbappendmsg_snd(&so->so_snd, m);
-		else
+		} else {
 			sbappendstream(&so->so_snd, m);
+		}
 
 		if (nam && tp->t_state < TCPS_SYN_SENT) {
-
 			/*
 			 * Do implied connect if not yet connected,
 			 * initialize window to default value, and
@@ -1057,15 +1131,23 @@ tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
 			 * MSS.
 			 */
 #if INET6
-			if (isipv6)
+			if (isipv6) {
 				error = tcp6_connect(tp, nam, p);
-			else
+			} else
 #endif /* INET6 */
-				error = tcp_connect(tp, nam, p);
-			if (error)
+			error = tcp_connect(tp, nam, p);
+			if (error) {
+				TCP_LOG_CONNECT(tp, true, error);
 				goto out;
+			}
 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
+			tp->max_sndwnd = tp->snd_wnd;
 			tcp_mss(tp, -1, IFSCOPE_NONE);
+
+			TCP_LOG_CONNECT(tp, true, error);
+
+			/* The sequence number of the data is past the SYN */
+			mpkl_seq = tp->iss + 1;
 		}
 
 		if (flags & PRUS_EOF) {
@@ -1077,11 +1159,13 @@ tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
 			tp = tcp_usrclosed(tp);
 		}
 		if (tp != NULL) {
-			if (flags & PRUS_MORETOCOME)
+			if (flags & PRUS_MORETOCOME) {
 				tp->t_flags |= TF_MORETOCOME;
+			}
 			error = tcp_output(tp);
-			if (flags & PRUS_MORETOCOME)
+			if (flags & PRUS_MORETOCOME) {
 				tp->t_flags &= ~TF_MORETOCOME;
+			}
 		}
 	} else {
 		if (sbspace(&so->so_snd) == 0) {
@@ -1108,15 +1192,20 @@ tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
 			 * MSS.
 			 */
 #if INET6
-			if (isipv6)
+			if (isipv6) {
 				error = tcp6_connect(tp, nam, p);
-			else
+			} else
 #endif /* INET6 */
 			error = tcp_connect(tp, nam, p);
-			if (error)
+			if (error) {
+				TCP_LOG_CONNECT(tp, true, error);
 				goto out;
+			}
 			tp->snd_wnd = TTCP_CLIENT_SND_WND;
+			tp->max_sndwnd = tp->snd_wnd;
 			tcp_mss(tp, -1, IFSCOPE_NONE);
+
+			TCP_LOG_CONNECT(tp, true, error);
 		}
 		tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
 		tp->t_flagsext |= TF_FORCE;
@@ -1124,20 +1213,32 @@ tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
 		tp->t_flagsext &= ~TF_FORCE;
 	}
 
+	if (net_mpklog_enabled && (inp = tp->t_inpcb) != NULL &&
+	    ((inp->inp_last_outifp != NULL &&
+	    (inp->inp_last_outifp->if_xflags & IFXF_MPK_LOG)) ||
+	    (inp->inp_boundifp != NULL &&
+	    (inp->inp_boundifp->if_xflags & IFXF_MPK_LOG)))) {
+		MPKL_TCP_SEND(tcp_mpkl_log_object,
+		    mpkl_send_info.mpkl_proto, mpkl_send_info.mpkl_uuid,
+		    ntohs(inp->inp_lport), ntohs(inp->inp_fport),
+		    mpkl_seq, mpkl_len,
+		    so->last_pid, so->so_log_seqn++);
+	}
 
 	/*
 	 * We wait for the socket to successfully connect before returning.
 	 * This allows us to signal a timeout to the application.
 	 */
 	if (so->so_state & SS_ISCONNECTING) {
-		if (so->so_state & SS_NBIO)
+		if (so->so_state & SS_NBIO) {
 			error = EWOULDBLOCK;
-		else
+		} else {
 			error = sbwait(&so->so_snd);
+		}
 	}
 
 	COMMON_END((flags & PRUS_OOB) ? PRU_SENDOOB :
-		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
+	    ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
 }
 
 /*
@@ -1151,9 +1252,10 @@ tcp_usr_abort(struct socket *so)
 	struct tcpcb *tp;
 
 	COMMON_START();
-        /* In case we got disconnected from the peer */
-        if (tp == NULL)
+	/* In case we got disconnected from the peer */
+	if (tp == NULL) {
 		goto out;
+	}
 	tp = tcp_drop(tp, ECONNABORTED);
 	VERIFY(so->so_usecount > 0);
 	so->so_usecount--;
@@ -1177,7 +1279,7 @@ tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
 
 	COMMON_START();
 	if ((so->so_oobmark == 0 &&
-	     (so->so_state & SS_RCVATMARK) == 0) ||
+	    (so->so_state & SS_RCVATMARK) == 0) ||
 	    so->so_options & SO_OOBINLINE ||
 	    tp->t_oobflags & TCPOOB_HADDATA) {
 		error = EINVAL;
@@ -1190,8 +1292,9 @@ tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
 	m->m_len = 1;
 	*mtod(m, caddr_t) = tp->t_iobc;
 	so->so_state &= ~SS_RCVATMARK;
-	if ((flags & MSG_PEEK) == 0)
+	if ((flags & MSG_PEEK) == 0) {
 		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
+	}
 	COMMON_END(PRU_RCVOOB);
 }
 
@@ -1220,50 +1323,50 @@ tcp_usr_preconnect(struct socket *so)
 
 /* xxx - should be const */
 struct pr_usrreqs tcp_usrreqs = {
-	.pru_abort =		tcp_usr_abort,
-	.pru_accept =		tcp_usr_accept,
-	.pru_attach =		tcp_usr_attach,
-	.pru_bind =		tcp_usr_bind,
-	.pru_connect =		tcp_usr_connect,
-	.pru_connectx =		tcp_usr_connectx,
-	.pru_control =		in_control,
-	.pru_detach =		tcp_usr_detach,
-	.pru_disconnect =	tcp_usr_disconnect,
-	.pru_disconnectx =	tcp_usr_disconnectx,
-	.pru_listen =		tcp_usr_listen,
-	.pru_peeraddr =		in_getpeeraddr,
-	.pru_rcvd =		tcp_usr_rcvd,
-	.pru_rcvoob =		tcp_usr_rcvoob,
-	.pru_send =		tcp_usr_send,
-	.pru_shutdown =		tcp_usr_shutdown,
-	.pru_sockaddr =		in_getsockaddr,
-	.pru_sosend =		sosend,
-	.pru_soreceive =	soreceive,
-	.pru_preconnect =	tcp_usr_preconnect,
+	.pru_abort =            tcp_usr_abort,
+	.pru_accept =           tcp_usr_accept,
+	.pru_attach =           tcp_usr_attach,
+	.pru_bind =             tcp_usr_bind,
+	.pru_connect =          tcp_usr_connect,
+	.pru_connectx =         tcp_usr_connectx,
+	.pru_control =          in_control,
+	.pru_detach =           tcp_usr_detach,
+	.pru_disconnect =       tcp_usr_disconnect,
+	.pru_disconnectx =      tcp_usr_disconnectx,
+	.pru_listen =           tcp_usr_listen,
+	.pru_peeraddr =         in_getpeeraddr,
+	.pru_rcvd =             tcp_usr_rcvd,
+	.pru_rcvoob =           tcp_usr_rcvoob,
+	.pru_send =             tcp_usr_send,
+	.pru_shutdown =         tcp_usr_shutdown,
+	.pru_sockaddr =         in_getsockaddr,
+	.pru_sosend =           sosend,
+	.pru_soreceive =        soreceive,
+	.pru_preconnect =       tcp_usr_preconnect,
 };
 
 #if INET6
 struct pr_usrreqs tcp6_usrreqs = {
-	.pru_abort =		tcp_usr_abort,
-	.pru_accept =		tcp6_usr_accept,
-	.pru_attach =		tcp_usr_attach,
-	.pru_bind =		tcp6_usr_bind,
-	.pru_connect =		tcp6_usr_connect,
-	.pru_connectx =		tcp6_usr_connectx,
-	.pru_control =		in6_control,
-	.pru_detach =		tcp_usr_detach,
-	.pru_disconnect =	tcp_usr_disconnect,
-	.pru_disconnectx =	tcp_usr_disconnectx,
-	.pru_listen =		tcp6_usr_listen,
-	.pru_peeraddr =		in6_mapped_peeraddr,
-	.pru_rcvd =		tcp_usr_rcvd,
-	.pru_rcvoob =		tcp_usr_rcvoob,
-	.pru_send =		tcp_usr_send,
-	.pru_shutdown =		tcp_usr_shutdown,
-	.pru_sockaddr =		in6_mapped_sockaddr,
-	.pru_sosend =		sosend,
-	.pru_soreceive =	soreceive,
-	.pru_preconnect =	tcp_usr_preconnect,
+	.pru_abort =            tcp_usr_abort,
+	.pru_accept =           tcp6_usr_accept,
+	.pru_attach =           tcp_usr_attach,
+	.pru_bind =             tcp6_usr_bind,
+	.pru_connect =          tcp6_usr_connect,
+	.pru_connectx =         tcp6_usr_connectx,
+	.pru_control =          in6_control,
+	.pru_detach =           tcp_usr_detach,
+	.pru_disconnect =       tcp_usr_disconnect,
+	.pru_disconnectx =      tcp_usr_disconnectx,
+	.pru_listen =           tcp6_usr_listen,
+	.pru_peeraddr =         in6_mapped_peeraddr,
+	.pru_rcvd =             tcp_usr_rcvd,
+	.pru_rcvoob =           tcp_usr_rcvoob,
+	.pru_send =             tcp_usr_send,
+	.pru_shutdown =         tcp_usr_shutdown,
+	.pru_sockaddr =         in6_mapped_sockaddr,
+	.pru_sosend =           sosend,
+	.pru_soreceive =        soreceive,
+	.pru_preconnect =       tcp_usr_preconnect,
 };
 #endif /* INET6 */
 
@@ -1304,8 +1407,9 @@ tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct proc *p)
 
 	if (inp->inp_lport == 0) {
 		error = in_pcbbind(inp, NULL, p);
-		if (error)
+		if (error) {
 			goto done;
+		}
 	}
 
 	/*
@@ -1314,22 +1418,25 @@ tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct proc *p)
 	 * TIME_WAIT state, creating an ADDRINUSE error.
 	 */
 	error = in_pcbladdr(inp, nam, &laddr, IFSCOPE_NONE, &outif, 0);
-	if (error)
+	if (error) {
 		goto done;
+	}
 
 	socket_unlock(inp->inp_socket, 0);
 	oinp = in_pcblookup_hash(inp->inp_pcbinfo,
 	    sin->sin_addr, sin->sin_port,
 	    inp->inp_laddr.s_addr != INADDR_ANY ? inp->inp_laddr : laddr,
-	    inp->inp_lport,  0, NULL);
+	    inp->inp_lport, 0, NULL);
 
 	socket_lock(inp->inp_socket, 0);
 	if (oinp) {
-		if (oinp != inp) /* 4143933: avoid deadlock if inp == oinp */
+		if (oinp != inp) { /* 4143933: avoid deadlock if inp == oinp */
 			socket_lock(oinp->inp_socket, 1);
+		}
 		if (in_pcb_checkstate(oinp, WNT_RELEASE, 1) == WNT_STOPUSING) {
-			if (oinp != inp)
+			if (oinp != inp) {
 				socket_unlock(oinp->inp_socket, 1);
+			}
 			goto skip_oinp;
 		}
 
@@ -1341,13 +1448,15 @@ tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct proc *p)
 		} else {
 			printf("tcp_connect: inp=0x%llx err=EADDRINUSE\n",
 			    (uint64_t)VM_KERNEL_ADDRPERM(inp));
-			if (oinp != inp)
+			if (oinp != inp) {
 				socket_unlock(oinp->inp_socket, 1);
+			}
 			error = EADDRINUSE;
 			goto done;
 		}
-		if (oinp != inp)
+		if (oinp != inp) {
 			socket_unlock(oinp->inp_socket, 1);
+		}
 	}
 skip_oinp:
 	if ((inp->inp_laddr.s_addr == INADDR_ANY ? laddr.s_addr :
@@ -1374,10 +1483,11 @@ skip_oinp:
 	in_pcbrehash(inp);
 	lck_rw_done(inp->inp_pcbinfo->ipi_lock);
 
-	if (inp->inp_flowhash == 0)
+	if (inp->inp_flowhash == 0) {
 		inp->inp_flowhash = inp_calc_flowhash(inp);
+	}
 
-	tcp_set_max_rwinscale(tp, so, TCP_AUTORCVBUF_MAX(outif));
+	tcp_set_max_rwinscale(tp, so, outif);
 
 	soisconnecting(so);
 	tcpstat.tcps_connattempt++;
@@ -1385,14 +1495,17 @@ skip_oinp:
 	tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, TCP_CONN_KEEPINIT(tp));
 	tp->iss = tcp_new_isn(tp);
 	tcp_sendseqinit(tp);
-	if (nstat_collect)
+	tp->t_connect_time = tcp_now;
+	if (nstat_collect) {
 		nstat_route_connect_attempt(inp->inp_route.ro_rt);
+	}
 
 done:
-	if (outif != NULL)
+	if (outif != NULL) {
 		ifnet_release(outif);
+	}
 
-	return (error);
+	return error;
 }
 
 #if INET6
@@ -1409,8 +1522,9 @@ tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct proc *p)
 
 	if (inp->inp_lport == 0) {
 		error = in6_pcbbind(inp, NULL, p);
-		if (error)
+		if (error) {
 			goto done;
+		}
 	}
 
 	/*
@@ -1423,15 +1537,16 @@ tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct proc *p)
 	 * whenever it's non-NULL.
 	 */
 	error = in6_pcbladdr(inp, nam, &addr6, &outif);
-	if (error)
+	if (error) {
 		goto done;
+	}
 	socket_unlock(inp->inp_socket, 0);
 	oinp = in6_pcblookup_hash(inp->inp_pcbinfo,
-				  &sin6->sin6_addr, sin6->sin6_port,
-				  IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)
-				  ? &addr6
-				  : &inp->in6p_laddr,
-				  inp->inp_lport,  0, NULL);
+	    &sin6->sin6_addr, sin6->sin6_port,
+	    IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)
+	    ? &addr6
+	    : &inp->in6p_laddr,
+	    inp->inp_lport, 0, NULL);
 	socket_lock(inp->inp_socket, 0);
 	if (oinp) {
 		if (oinp != inp && (otp = intotcpcb(oinp)) != NULL &&
@@ -1452,18 +1567,20 @@ tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct proc *p)
 	}
 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 		inp->in6p_laddr = addr6;
-		inp->in6p_last_outifp = outif;	/* no reference needed */
+		inp->in6p_last_outifp = outif;  /* no reference needed */
 		inp->in6p_flags |= INP_IN6ADDR_ANY;
 	}
 	inp->in6p_faddr = sin6->sin6_addr;
 	inp->inp_fport = sin6->sin6_port;
-	if ((sin6->sin6_flowinfo & IPV6_FLOWINFO_MASK) != 0)
+	if ((sin6->sin6_flowinfo & IPV6_FLOWINFO_MASK) != 0) {
 		inp->inp_flow = sin6->sin6_flowinfo;
+	}
 	in_pcbrehash(inp);
 	lck_rw_done(inp->inp_pcbinfo->ipi_lock);
 
-	if (inp->inp_flowhash == 0)
+	if (inp->inp_flowhash == 0) {
 		inp->inp_flowhash = inp_calc_flowhash(inp);
+	}
 	/* update flowinfo - RFC 6437 */
 	if (inp->inp_flow == 0 && inp->in6p_flags & IN6P_AUTOFLOWLABEL) {
 		inp->inp_flow &= ~IPV6_FLOWLABEL_MASK;
@@ -1471,23 +1588,26 @@ tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct proc *p)
 		    (htonl(inp->inp_flowhash) & IPV6_FLOWLABEL_MASK);
 	}
 
-	tcp_set_max_rwinscale(tp, so, TCP_AUTORCVBUF_MAX(outif));
+	tcp_set_max_rwinscale(tp, so, outif);
 
 	soisconnecting(so);
 	tcpstat.tcps_connattempt++;
 	tp->t_state = TCPS_SYN_SENT;
 	tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp,
-		TCP_CONN_KEEPINIT(tp));
+	    TCP_CONN_KEEPINIT(tp));
 	tp->iss = tcp_new_isn(tp);
 	tcp_sendseqinit(tp);
-	if (nstat_collect)
+	tp->t_connect_time = tcp_now;
+	if (nstat_collect) {
 		nstat_route_connect_attempt(inp->inp_route.ro_rt);
+	}
 
 done:
-	if (outif != NULL)
+	if (outif != NULL) {
 		ifnet_release(outif);
+	}
 
-	return (error);
+	return error;
 }
 #endif /* INET6 */
 
@@ -1505,24 +1625,29 @@ tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
 	ti->tcpi_flowhash = inp->inp_flowhash;
 
 	if (tp->t_state > TCPS_LISTEN) {
-		if (TSTMP_SUPPORTED(tp))
+		if (TSTMP_SUPPORTED(tp)) {
 			ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
-		if (SACK_ENABLED(tp))
+		}
+		if (SACK_ENABLED(tp)) {
 			ti->tcpi_options |= TCPI_OPT_SACK;
+		}
 		if (TCP_WINDOW_SCALE_ENABLED(tp)) {
 			ti->tcpi_options |= TCPI_OPT_WSCALE;
 			ti->tcpi_snd_wscale = tp->snd_scale;
 			ti->tcpi_rcv_wscale = tp->rcv_scale;
 		}
-		if (TCP_ECN_ENABLED(tp))
+		if (TCP_ECN_ENABLED(tp)) {
 			ti->tcpi_options |= TCPI_OPT_ECN;
+		}
 
 		/* Are we in retranmission episode */
-		if (IN_FASTRECOVERY(tp) || tp->t_rxtshift > 0)
+		if (IN_FASTRECOVERY(tp) || tp->t_rxtshift > 0) {
 			ti->tcpi_flags |= TCPI_FLAG_LOSSRECOVERY;
+		}
 
-		if (tp->t_flags & TF_STREAMING_ON)
+		if (tp->t_flags & TF_STREAMING_ON) {
 			ti->tcpi_flags |= TCPI_FLAG_STREAMING_ON;
+		}
 
 		ti->tcpi_rto = tp->t_timer[TCPT_REXMT] ? tp->t_rxtcur : 0;
 		ti->tcpi_snd_mss = tp->t_maxseg;
@@ -1545,8 +1670,8 @@ tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
 
 		/* convert bytes/msec to bits/sec */
 		if ((tp->t_flagsext & TF_MEASURESNDBW) != 0 &&
-			tp->t_bwmeas != NULL) {
-			ti->tcpi_snd_bw	= (tp->t_bwmeas->bw_sndbw * 8000);
+		    tp->t_bwmeas != NULL) {
+			ti->tcpi_snd_bw = (tp->t_bwmeas->bw_sndbw * 8000);
 		}
 
 		ti->tcpi_last_outif = (tp->t_inpcb->inp_last_outifp == NULL) ? 0 :
@@ -1566,7 +1691,7 @@ tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
 		ti->tcpi_rxoutoforderbytes = tp->t_stat.rxoutoforderbytes;
 
 		if (tp->t_state > TCPS_LISTEN) {
-			ti->tcpi_synrexmits = tp->t_stat.synrxtshift;
+			ti->tcpi_synrexmits = tp->t_stat.rxmitsyns;
 		}
 		ti->tcpi_cell_rxpackets = inp->inp_cstat->rxpackets;
 		ti->tcpi_cell_rxbytes = inp->inp_cstat->rxbytes;
@@ -1610,22 +1735,29 @@ tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
 		ti->tcpi_local_peer = !!(tp->t_flags & TF_LOCAL);
 
 		if (tp->t_inpcb->inp_last_outifp != NULL) {
-			if (IFNET_IS_CELLULAR(tp->t_inpcb->inp_last_outifp))
+			if (IFNET_IS_CELLULAR(tp->t_inpcb->inp_last_outifp)) {
 				ti->tcpi_if_cell = 1;
-			if (IFNET_IS_WIFI(tp->t_inpcb->inp_last_outifp))
+			}
+			if (IFNET_IS_WIFI(tp->t_inpcb->inp_last_outifp)) {
 				ti->tcpi_if_wifi = 1;
-			if (IFNET_IS_WIRED(tp->t_inpcb->inp_last_outifp))
+			}
+			if (IFNET_IS_WIRED(tp->t_inpcb->inp_last_outifp)) {
 				ti->tcpi_if_wired = 1;
-			if (IFNET_IS_WIFI_INFRA(tp->t_inpcb->inp_last_outifp))
+			}
+			if (IFNET_IS_WIFI_INFRA(tp->t_inpcb->inp_last_outifp)) {
 				ti->tcpi_if_wifi_infra = 1;
-			if (tp->t_inpcb->inp_last_outifp->if_eflags & IFEF_AWDL)
+			}
+			if (tp->t_inpcb->inp_last_outifp->if_eflags & IFEF_AWDL) {
 				ti->tcpi_if_wifi_awdl = 1;
+			}
 		}
-		if (tp->tcp_cc_index == TCP_CC_ALGO_BACKGROUND_INDEX)
+		if (tp->tcp_cc_index == TCP_CC_ALGO_BACKGROUND_INDEX) {
 			ti->tcpi_snd_background = 1;
+		}
 		if (tcp_recv_bg == 1 ||
-		    IS_TCP_RECV_BG(tp->t_inpcb->inp_socket))
+		    IS_TCP_RECV_BG(tp->t_inpcb->inp_socket)) {
 			ti->tcpi_rcv_background = 1;
+		}
 
 		ti->tcpi_ecn_recv_ce = tp->t_ecn_recv_ce;
 		ti->tcpi_ecn_recv_cwr = tp->t_ecn_recv_cwr;
@@ -1647,45 +1779,49 @@ tcp_fill_info_for_info_tuple(struct info_tuple *itpl, struct tcp_info *ti)
 	struct socket *so;
 	struct tcpcb *tp;
 
-	if (itpl->itpl_proto == IPPROTO_TCP)
+	if (itpl->itpl_proto == IPPROTO_TCP) {
 		pcbinfo = &tcbinfo;
-	else
+	} else {
 		return EINVAL;
+	}
 
 	if (itpl->itpl_local_sa.sa_family == AF_INET &&
-		itpl->itpl_remote_sa.sa_family == AF_INET) {
+	    itpl->itpl_remote_sa.sa_family == AF_INET) {
 		inp = in_pcblookup_hash(pcbinfo,
-			itpl->itpl_remote_sin.sin_addr,
-			itpl->itpl_remote_sin.sin_port,
-			itpl->itpl_local_sin.sin_addr,
-			itpl->itpl_local_sin.sin_port,
-			0, NULL);
+		    itpl->itpl_remote_sin.sin_addr,
+		    itpl->itpl_remote_sin.sin_port,
+		    itpl->itpl_local_sin.sin_addr,
+		    itpl->itpl_local_sin.sin_port,
+		    0, NULL);
 	} else if (itpl->itpl_local_sa.sa_family == AF_INET6 &&
-		itpl->itpl_remote_sa.sa_family == AF_INET6) {
+	    itpl->itpl_remote_sa.sa_family == AF_INET6) {
 		struct in6_addr ina6_local;
 		struct in6_addr ina6_remote;
 
 		ina6_local = itpl->itpl_local_sin6.sin6_addr;
 		if (IN6_IS_SCOPE_LINKLOCAL(&ina6_local) &&
-			itpl->itpl_local_sin6.sin6_scope_id)
+		    itpl->itpl_local_sin6.sin6_scope_id) {
 			ina6_local.s6_addr16[1] = htons(itpl->itpl_local_sin6.sin6_scope_id);
+		}
 
 		ina6_remote = itpl->itpl_remote_sin6.sin6_addr;
 		if (IN6_IS_SCOPE_LINKLOCAL(&ina6_remote) &&
-			itpl->itpl_remote_sin6.sin6_scope_id)
+		    itpl->itpl_remote_sin6.sin6_scope_id) {
 			ina6_remote.s6_addr16[1] = htons(itpl->itpl_remote_sin6.sin6_scope_id);
+		}
 
 		inp = in6_pcblookup_hash(pcbinfo,
-			&ina6_remote,
-			itpl->itpl_remote_sin6.sin6_port,
-			&ina6_local,
-			itpl->itpl_local_sin6.sin6_port,
-			0, NULL);
+		    &ina6_remote,
+		    itpl->itpl_remote_sin6.sin6_port,
+		    &ina6_local,
+		    itpl->itpl_local_sin6.sin6_port,
+		    0, NULL);
 	} else {
 		return EINVAL;
 	}
-	if (inp == NULL || (so = inp->inp_socket) == NULL)
+	if (inp == NULL || (so = inp->inp_socket) == NULL) {
 		return ENOENT;
+	}
 
 	socket_lock(so, 0);
 	if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) {
@@ -1708,23 +1844,28 @@ tcp_connection_fill_info(struct tcpcb *tp, struct tcp_connection_info *tci)
 	bzero(tci, sizeof(*tci));
 	tci->tcpi_state = tp->t_state;
 	if (tp->t_state > TCPS_LISTEN) {
-		if (TSTMP_SUPPORTED(tp))
+		if (TSTMP_SUPPORTED(tp)) {
 			tci->tcpi_options |= TCPCI_OPT_TIMESTAMPS;
-		if (SACK_ENABLED(tp))
+		}
+		if (SACK_ENABLED(tp)) {
 			tci->tcpi_options |= TCPCI_OPT_SACK;
+		}
 		if (TCP_WINDOW_SCALE_ENABLED(tp)) {
 			tci->tcpi_options |= TCPCI_OPT_WSCALE;
 			tci->tcpi_snd_wscale = tp->snd_scale;
 			tci->tcpi_rcv_wscale = tp->rcv_scale;
 		}
-		if (TCP_ECN_ENABLED(tp))
+		if (TCP_ECN_ENABLED(tp)) {
 			tci->tcpi_options |= TCPCI_OPT_ECN;
-		if (IN_FASTRECOVERY(tp) || tp->t_rxtshift > 0)
+		}
+		if (IN_FASTRECOVERY(tp) || tp->t_rxtshift > 0) {
 			tci->tcpi_flags |= TCPCI_FLAG_LOSSRECOVERY;
-		if (tp->t_flagsext & TF_PKTS_REORDERED)
+		}
+		if (tp->t_flagsext & TF_PKTS_REORDERED) {
 			tci->tcpi_flags |= TCPCI_FLAG_REORDERING_DETECTED;
+		}
 		tci->tcpi_rto = (tp->t_timer[TCPT_REXMT] > 0) ?
-			tp->t_rxtcur : 0;
+		    tp->t_rxtcur : 0;
 		tci->tcpi_maxseg = tp->t_maxseg;
 		tci->tcpi_snd_ssthresh = tp->snd_ssthresh;
 		tci->tcpi_snd_cwnd = tp->snd_cwnd;
@@ -1765,45 +1906,8 @@ __private_extern__ int
 tcp_sysctl_info(__unused struct sysctl_oid *oidp, __unused void *arg1, __unused int arg2, struct sysctl_req *req)
 {
 	int error;
-	struct tcp_info ti;
+	struct tcp_info ti = {};
 	struct info_tuple itpl;
-#if !CONFIG_EMBEDDED
-	proc_t caller = PROC_NULL;
-	proc_t caller_parent = PROC_NULL;
-	char command_name[MAXCOMLEN + 1] = "";
-	char parent_name[MAXCOMLEN + 1] = "";
-
-	if ((caller = proc_self()) != PROC_NULL) {
-		/* get process name */
-		strlcpy(command_name, caller->p_comm, sizeof(command_name));
-
-		/* get parent process name if possible */
-		if ((caller_parent = proc_find(caller->p_ppid)) != PROC_NULL) {
-			strlcpy(parent_name, caller_parent->p_comm,
-			    sizeof(parent_name));
-			proc_rele(caller_parent);
-		}
-
-		if ((escape_str(command_name, strlen(command_name),
-		    sizeof(command_name)) == 0) &&
-		    (escape_str(parent_name, strlen(parent_name),
-		    sizeof(parent_name)) == 0)) {
-			kern_asl_msg(LOG_DEBUG, "messagetracer",
-			    5,
-			    "com.apple.message.domain",
-			    "com.apple.kernel.tcpstat", /* 1 */
-			    "com.apple.message.signature",
-			    "tcpinfo", /* 2 */
-			    "com.apple.message.signature2", command_name, /* 3 */
-			    "com.apple.message.signature3", parent_name, /* 4 */
-			    "com.apple.message.summarize", "YES", /* 5 */
-			    NULL);
-		}
-	}
-
-	if (caller != PROC_NULL)
-		proc_rele(caller);
-#endif /* !CONFIG_EMBEDDED */
 
 	if (req->newptr == USER_ADDR_NULL) {
 		return EINVAL;
@@ -1832,36 +1936,38 @@ tcp_lookup_peer_pid_locked(struct socket *so, pid_t *out_pid)
 {
 	int error = EHOSTUNREACH;
 	*out_pid = -1;
-	if ((so->so_state & SS_ISCONNECTED) == 0) return ENOTCONN;
+	if ((so->so_state & SS_ISCONNECTED) == 0) {
+		return ENOTCONN;
+	}
 
-	struct inpcb	*inp = (struct inpcb*)so->so_pcb;
-	uint16_t		lport = inp->inp_lport;
-	uint16_t		fport = inp->inp_fport;
-	struct inpcb	*finp = NULL;
+	struct inpcb    *inp = (struct inpcb*)so->so_pcb;
+	uint16_t                lport = inp->inp_lport;
+	uint16_t                fport = inp->inp_fport;
+	struct inpcb    *finp = NULL;
+	struct  in6_addr laddr6, faddr6;
+	struct in_addr laddr4, faddr4;
 
 	if (inp->inp_vflag & INP_IPV6) {
-		struct	in6_addr	laddr6 = inp->in6p_laddr;
-		struct	in6_addr	faddr6 = inp->in6p_faddr;
-		socket_unlock(so, 0);
+		laddr6 = inp->in6p_laddr;
+		faddr6 = inp->in6p_faddr;
+	} else if (inp->inp_vflag & INP_IPV4) {
+		laddr4 = inp->inp_laddr;
+		faddr4 = inp->inp_faddr;
+	}
+
+	socket_unlock(so, 0);
+	if (inp->inp_vflag & INP_IPV6) {
 		finp = in6_pcblookup_hash(&tcbinfo, &laddr6, lport, &faddr6, fport, 0, NULL);
-		socket_lock(so, 0);
 	} else if (inp->inp_vflag & INP_IPV4) {
-		struct	in_addr	laddr4 = inp->inp_laddr;
-		struct	in_addr	faddr4 = inp->inp_faddr;
-		socket_unlock(so, 0);
 		finp = in_pcblookup_hash(&tcbinfo, laddr4, lport, faddr4, fport, 0, NULL);
-		socket_lock(so, 0);
 	}
 
 	if (finp) {
 		*out_pid = finp->inp_socket->last_pid;
 		error = 0;
-		/* Avoid deadlock due to same inpcb for loopback socket */
-		if (inp == finp)
-			in_pcb_checkstate(finp, WNT_RELEASE, 1);
-		else
-			in_pcb_checkstate(finp, WNT_RELEASE, 0);
+		in_pcb_checkstate(finp, WNT_RELEASE, 0);
 	}
+	socket_lock(so, 0);
 
 	return error;
 }
@@ -1873,6 +1979,90 @@ tcp_getconninfo(struct socket *so, struct conninfo_tcp *tcp_ci)
 	tcp_fill_info(sototcpcb(so), &tcp_ci->tcpci_tcp_info);
 }
 
+void
+tcp_clear_keep_alive_offload(struct socket *so)
+{
+	struct inpcb *inp;
+	struct ifnet *ifp;
+
+	inp = sotoinpcb(so);
+	if (inp == NULL) {
+		return;
+	}
+
+	if ((inp->inp_flags2 & INP2_KEEPALIVE_OFFLOAD) == 0) {
+		return;
+	}
+
+	ifp = inp->inp_boundifp != NULL ? inp->inp_boundifp :
+	    inp->inp_last_outifp;
+	if (ifp == NULL) {
+		panic("%s: so %p inp %p ifp NULL",
+		    __func__, so, inp);
+	}
+
+	ifnet_lock_exclusive(ifp);
+
+	if (ifp->if_tcp_kao_cnt == 0) {
+		panic("%s: so %p inp %p ifp %p if_tcp_kao_cnt == 0",
+		    __func__, so, inp, ifp);
+	}
+	ifp->if_tcp_kao_cnt--;
+	inp->inp_flags2 &= ~INP2_KEEPALIVE_OFFLOAD;
+
+	ifnet_lock_done(ifp);
+}
+
+static int
+tcp_set_keep_alive_offload(struct socket *so, struct proc *proc)
+{
+	int error = 0;
+	struct inpcb *inp;
+	struct ifnet *ifp;
+
+	inp = sotoinpcb(so);
+	if (inp == NULL) {
+		return ECONNRESET;
+	}
+	if ((inp->inp_flags2 & INP2_KEEPALIVE_OFFLOAD) != 0) {
+		return 0;
+	}
+
+	ifp = inp->inp_boundifp != NULL ? inp->inp_boundifp :
+	    inp->inp_last_outifp;
+	if (ifp == NULL) {
+		error = ENXIO;
+		os_log_info(OS_LOG_DEFAULT,
+		    "%s: error %d for proc %s[%u] out ifp is not set\n",
+		    __func__, error,
+		    proc != NULL ? proc->p_comm : "kernel",
+		    proc != NULL ? proc->p_pid : 0);
+		return ENXIO;
+	}
+
+	error = if_get_tcp_kao_max(ifp);
+	if (error != 0) {
+		return error;
+	}
+
+	ifnet_lock_exclusive(ifp);
+	if (ifp->if_tcp_kao_cnt < ifp->if_tcp_kao_max) {
+		ifp->if_tcp_kao_cnt++;
+		inp->inp_flags2 |= INP2_KEEPALIVE_OFFLOAD;
+	} else {
+		error = ETOOMANYREFS;
+		os_log_info(OS_LOG_DEFAULT,
+		    "%s: error %d for proc %s[%u] if_tcp_kao_max %u\n",
+		    __func__, error,
+		    proc != NULL ? proc->p_comm : "kernel",
+		    proc != NULL ? proc->p_pid : 0,
+		    ifp->if_tcp_kao_max);
+	}
+	ifnet_lock_done(ifp);
+
+	return error;
+}
+
 /*
  * The new sockopt interface makes it possible for us to block in the
  * copyin/out step (if we take a page fault).  Taking a page fault at
@@ -1883,30 +2073,29 @@ tcp_getconninfo(struct socket *so, struct conninfo_tcp *tcp_ci)
 int
 tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 {
-	int	error, opt, optval;
-	struct	inpcb *inp;
-	struct	tcpcb *tp;
+	int     error = 0, opt = 0, optval = 0;
+	struct  inpcb *inp;
+	struct  tcpcb *tp;
 
-	error = 0;
 	inp = sotoinpcb(so);
 	if (inp == NULL) {
-		return (ECONNRESET);
+		return ECONNRESET;
 	}
 	/* Allow <SOL_SOCKET,SO_FLUSH/SO_TRAFFIC_MGT_BACKGROUND> at this level */
 	if (sopt->sopt_level != IPPROTO_TCP &&
 	    !(sopt->sopt_level == SOL_SOCKET && (sopt->sopt_name == SO_FLUSH ||
 	    sopt->sopt_name == SO_TRAFFIC_MGT_BACKGROUND))) {
 #if INET6
-		if (SOCK_CHECK_DOM(so, PF_INET6))
+		if (SOCK_CHECK_DOM(so, PF_INET6)) {
 			error = ip6_ctloutput(so, sopt);
-		else
+		} else
 #endif /* INET6 */
 		error = ip_ctloutput(so, sopt);
-		return (error);
+		return error;
 	}
 	tp = intotcpcb(inp);
 	if (tp == NULL) {
-		return (ECONNRESET);
+		return ECONNRESET;
 	}
 
 	calculate_tcp_clock();
@@ -1918,9 +2107,10 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 		case TCP_NOOPT:
 		case TCP_NOPUSH:
 			error = sooptcopyin(sopt, &optval, sizeof optval,
-					    sizeof optval);
-			if (error)
+			    sizeof optval);
+			if (error) {
 				break;
+			}
 
 			switch (sopt->sopt_name) {
 			case TCP_NODELAY:
@@ -1937,17 +2127,19 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 				break;
 			}
 
-			if (optval)
+			if (optval) {
 				tp->t_flags |= opt;
-			else
+			} else {
 				tp->t_flags &= ~opt;
+			}
 			break;
 		case TCP_RXT_FINDROP:
 		case TCP_NOTIMEWAIT:
 			error = sooptcopyin(sopt, &optval, sizeof optval,
-				sizeof optval);
-			if (error)
+			    sizeof optval);
+			if (error) {
 				break;
+			}
 			switch (sopt->sopt_name) {
 			case TCP_RXT_FINDROP:
 				opt = TF_RXTFINDROP;
@@ -1959,16 +2151,18 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 				opt = 0;
 				break;
 			}
-			if (optval)
+			if (optval) {
 				tp->t_flagsext |= opt;
-			else
+			} else {
 				tp->t_flagsext &= ~opt;
+			}
 			break;
 		case TCP_MEASURE_SND_BW:
 			error = sooptcopyin(sopt, &optval, sizeof optval,
-				sizeof optval);
-			if (error)
+			    sizeof optval);
+			if (error) {
 				break;
+			}
 			opt = TF_MEASURESNDBW;
 			if (optval) {
 				if (tp->t_bwmeas == NULL) {
@@ -1994,18 +2188,19 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			bzero(&in, sizeof(in));
 
 			error = sooptcopyin(sopt, &in, sizeof(in),
-				sizeof(in));
-			if (error)
+			    sizeof(in));
+			if (error) {
 				break;
+			}
 			if ((tp->t_flagsext & TF_MEASURESNDBW) == 0 ||
-				tp->t_bwmeas == NULL) {
+			    tp->t_bwmeas == NULL) {
 				error = EINVAL;
 				break;
 			}
 			minpkts = (in.min_burst_size != 0) ? in.min_burst_size :
-				tp->t_bwmeas->bw_minsizepkts;
+			    tp->t_bwmeas->bw_minsizepkts;
 			maxpkts = (in.max_burst_size != 0) ? in.max_burst_size :
-				tp->t_bwmeas->bw_maxsizepkts;
+			    tp->t_bwmeas->bw_maxsizepkts;
 			if (minpkts > maxpkts) {
 				error = EINVAL;
 				break;
@@ -2018,46 +2213,50 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 		}
 		case TCP_MAXSEG:
 			error = sooptcopyin(sopt, &optval, sizeof optval,
-					    sizeof optval);
-			if (error)
+			    sizeof optval);
+			if (error) {
 				break;
+			}
 
 			if (optval > 0 && optval <= tp->t_maxseg &&
-			    optval + 40 >= tcp_minmss)
+			    optval + 40 >= tcp_minmss) {
 				tp->t_maxseg = optval;
-			else
+			} else {
 				error = EINVAL;
+			}
 			break;
 
 		case TCP_KEEPALIVE:
 			error = sooptcopyin(sopt, &optval, sizeof optval,
-						sizeof optval);
-			if (error)
+			    sizeof optval);
+			if (error) {
 				break;
-			if (optval < 0 || optval > UINT32_MAX/TCP_RETRANSHZ) {
+			}
+			if (optval < 0 || optval > UINT32_MAX / TCP_RETRANSHZ) {
 				error = EINVAL;
 			} else {
 				tp->t_keepidle = optval * TCP_RETRANSHZ;
 				/* reset the timer to new value */
 				tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp,
-					TCP_CONN_KEEPIDLE(tp));
+				    TCP_CONN_KEEPIDLE(tp));
 				tcp_check_timer_state(tp);
 			}
-                        break;
+			break;
 
 		case TCP_CONNECTIONTIMEOUT:
 			error = sooptcopyin(sopt, &optval, sizeof optval,
-						sizeof optval);
-			if (error)
+			    sizeof optval);
+			if (error) {
 				break;
-			if (optval < 0 || optval > UINT32_MAX/TCP_RETRANSHZ) {
+			}
+			if (optval < 0 || optval > UINT32_MAX / TCP_RETRANSHZ) {
 				error = EINVAL;
 			} else {
 				tp->t_keepinit = optval * TCP_RETRANSHZ;
 				if (tp->t_state == TCPS_SYN_RECEIVED ||
-					tp->t_state == TCPS_SYN_SENT) {
+				    tp->t_state == TCPS_SYN_SENT) {
 					tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp,
-						TCP_CONN_KEEPINIT(tp));
+					    TCP_CONN_KEEPINIT(tp));
 					tcp_check_timer_state(tp);
 				}
 			}
@@ -2065,17 +2264,18 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 
 		case TCP_KEEPINTVL:
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
-				sizeof(optval));
-			if (error)
+			    sizeof(optval));
+			if (error) {
 				break;
-			if (optval < 0 || optval > UINT32_MAX/TCP_RETRANSHZ) {
+			}
+			if (optval < 0 || optval > UINT32_MAX / TCP_RETRANSHZ) {
 				error = EINVAL;
 			} else {
 				tp->t_keepintvl = optval * TCP_RETRANSHZ;
 				if (tp->t_state == TCPS_FIN_WAIT_2 &&
-					TCP_CONN_MAXIDLE(tp) > 0) {
+				    TCP_CONN_MAXIDLE(tp) > 0) {
 					tp->t_timer[TCPT_2MSL] = OFFSET_FROM_START(tp,
-						TCP_CONN_MAXIDLE(tp));
+					    TCP_CONN_MAXIDLE(tp));
 					tcp_check_timer_state(tp);
 				}
 			}
@@ -2083,62 +2283,75 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 
 		case TCP_KEEPCNT:
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
-				sizeof(optval));
-			if (error)
+			    sizeof(optval));
+			if (error) {
 				break;
+			}
 			if (optval < 0 || optval > INT32_MAX) {
 				error = EINVAL;
 			} else {
 				tp->t_keepcnt = optval;
 				if (tp->t_state == TCPS_FIN_WAIT_2 &&
-					TCP_CONN_MAXIDLE(tp) > 0) {
+				    TCP_CONN_MAXIDLE(tp) > 0) {
 					tp->t_timer[TCPT_2MSL] = OFFSET_FROM_START(tp,
-						TCP_CONN_MAXIDLE(tp));
+					    TCP_CONN_MAXIDLE(tp));
 					tcp_check_timer_state(tp);
 				}
 			}
 			break;
 
 		case TCP_KEEPALIVE_OFFLOAD:
+			if ((error = priv_check_cred(kauth_cred_get(),
+			    PRIV_NETINET_TCP_KA_OFFLOAD, 0)) != 0) {
+				break;
+			}
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
-				sizeof(optval));
-			if (error)
+			    sizeof(optval));
+			if (error) {
 				break;
+			}
 			if (optval < 0 || optval > INT32_MAX) {
 				error = EINVAL;
 				break;
 			}
-			if (optval != 0)
-				inp->inp_flags2 |= INP2_KEEPALIVE_OFFLOAD;
-			else
-				inp->inp_flags2 &= ~INP2_KEEPALIVE_OFFLOAD;
+			if (optval != 0) {
+				error = tcp_set_keep_alive_offload(so,
+				    sopt->sopt_p);
+			} else {
+				tcp_clear_keep_alive_offload(so);
+			}
 			break;
 
 		case PERSIST_TIMEOUT:
 			error = sooptcopyin(sopt, &optval, sizeof optval,
-						sizeof optval);
-			if (error)
+			    sizeof optval);
+			if (error) {
 				break;
-			if (optval < 0)
+			}
+			if (optval < 0) {
 				error = EINVAL;
-			else
+			} else {
 				tp->t_persist_timeout = optval * TCP_RETRANSHZ;
+			}
 			break;
 		case TCP_RXT_CONNDROPTIME:
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
-					sizeof(optval));
-			if (error)
+			    sizeof(optval));
+			if (error) {
 				break;
-			if (optval < 0)
+			}
+			if (optval < 0) {
 				error = EINVAL;
-			else
+			} else {
 				tp->t_rxt_conndroptime = optval * TCP_RETRANSHZ;
+			}
 			break;
 		case TCP_NOTSENT_LOWAT:
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
-				sizeof(optval));
-			if (error)
+			    sizeof(optval));
+			if (error) {
 				break;
+			}
 			if (optval < 0) {
 				error = EINVAL;
 				break;
@@ -2153,10 +2366,11 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			}
 			break;
 		case TCP_ADAPTIVE_READ_TIMEOUT:
-			error = sooptcopyin(sopt, &optval, sizeof (optval),
+			error = sooptcopyin(sopt, &optval, sizeof(optval),
 			    sizeof(optval));
-			if (error)
+			if (error) {
 				break;
+			}
 			if (optval < 0 ||
 			    optval > TCP_ADAPTIVE_TIMEOUT_MAX) {
 				error = EINVAL;
@@ -2165,17 +2379,19 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 				tp->t_adaptive_rtimo = 0;
 				tcp_keepalive_reset(tp);
 
-				if (tp->t_mpsub)
+				if (tp->t_mpsub) {
 					mptcp_reset_keepalive(tp);
+				}
 			} else {
 				tp->t_adaptive_rtimo = optval;
 			}
 			break;
 		case TCP_ADAPTIVE_WRITE_TIMEOUT:
-			error = sooptcopyin(sopt, &optval, sizeof (optval),
-			    sizeof (optval));
-			if (error)
+			error = sooptcopyin(sopt, &optval, sizeof(optval),
+			    sizeof(optval));
+			if (error) {
 				break;
+			}
 			if (optval < 0 ||
 			    optval > TCP_ADAPTIVE_TIMEOUT_MAX) {
 				error = EINVAL;
@@ -2186,9 +2402,10 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			break;
 		case TCP_ENABLE_MSGS:
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
-				sizeof(optval));
-			if (error)
+			    sizeof(optval));
+			if (error) {
 				break;
+			}
 			if (optval < 0 || optval > 1) {
 				error = EINVAL;
 			} else if (optval == 1) {
@@ -2207,9 +2424,9 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 				 */
 				VERIFY(so->so_msg_state == NULL);
 				MALLOC(so->so_msg_state,
-					struct msg_state *,
-					sizeof(struct msg_state),
-					M_TEMP, M_WAITOK | M_ZERO);
+				    struct msg_state *,
+				    sizeof(struct msg_state),
+				    M_TEMP, M_WAITOK | M_ZERO);
 				if (so->so_msg_state == NULL) {
 					error = ENOMEM;
 					break;
@@ -2228,9 +2445,10 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			break;
 		case TCP_SENDMOREACKS:
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
-				sizeof(optval));
-			if (error)
+			    sizeof(optval));
+			if (error) {
 				break;
+			}
 			if (optval < 0 || optval > 1) {
 				error = EINVAL;
 			} else if (optval == 0) {
@@ -2241,9 +2459,10 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			break;
 		case TCP_DISABLE_BLACKHOLE_DETECTION:
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
-				sizeof(optval));
-			if (error)
+			    sizeof(optval));
+			if (error) {
 				break;
+			}
 			if (optval < 0 || optval > 1) {
 				error = EINVAL;
 			} else if (optval == 0) {
@@ -2251,8 +2470,9 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			} else {
 				tp->t_flagsext |= TF_NOBLACKHOLE_DETECTION;
 				if ((tp->t_flags & TF_BLACKHOLE) &&
-				    tp->t_pmtud_saved_maxopd > 0)
+				    tp->t_pmtud_saved_maxopd > 0) {
 					tcp_pmtud_revert_segment_size(tp);
+				}
 			}
 			break;
 		case TCP_FASTOPEN:
@@ -2262,9 +2482,10 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			}
 
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
-				sizeof(optval));
-			if (error)
+			    sizeof(optval));
+			if (error) {
 				break;
+			}
 			if (optval < 0 || optval > 1) {
 				error = EINVAL;
 				break;
@@ -2273,17 +2494,22 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 				error =  EINVAL;
 				break;
 			}
-			if (optval)
+			if (optval) {
 				tp->t_flagsext |= TF_FASTOPEN;
-			else
+			} else {
 				tcp_disable_tfo(tp);
+			}
 			break;
 		case TCP_FASTOPEN_FORCE_HEURISTICS:
+
+			break;
+		case TCP_FASTOPEN_FORCE_ENABLE:
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
-				sizeof(optval));
+			    sizeof(optval));
 
-			if (error)
+			if (error) {
 				break;
+			}
 			if (optval < 0 || optval > 1) {
 				error = EINVAL;
 				break;
@@ -2293,17 +2519,19 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 				error =  EINVAL;
 				break;
 			}
-			if (optval)
-				tp->t_flagsext |= TF_FASTOPEN_HEUR;
-			else
-				tp->t_flagsext &= ~TF_FASTOPEN_HEUR;
+			if (optval) {
+				tp->t_flagsext |= TF_FASTOPEN_FORCE_ENABLE;
+			} else {
+				tp->t_flagsext &= ~TF_FASTOPEN_FORCE_ENABLE;
+			}
 
 			break;
 		case TCP_ENABLE_ECN:
 			error = sooptcopyin(sopt, &optval, sizeof optval,
-					    sizeof optval);
-			if (error)
+			    sizeof optval);
+			if (error) {
 				break;
+			}
 			if (optval) {
 				tp->ecn_flags |= TE_ECN_MODE_ENABLE;
 				tp->ecn_flags &= ~TE_ECN_MODE_DISABLE;
@@ -2314,9 +2542,10 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			break;
 		case TCP_ECN_MODE:
 			error = sooptcopyin(sopt, &optval, sizeof optval,
-					    sizeof optval);
-			if (error)
+			    sizeof optval);
+			if (error) {
 				break;
+			}
 			if (optval == ECN_MODE_DEFAULT) {
 				tp->ecn_flags &= ~TE_ECN_MODE_ENABLE;
 				tp->ecn_flags &= ~TE_ECN_MODE_DISABLE;
@@ -2333,8 +2562,9 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 		case TCP_NOTIFY_ACKNOWLEDGEMENT:
 			error = sooptcopyin(sopt, &optval,
 			    sizeof(optval), sizeof(optval));
-			if (error)
+			if (error) {
 				break;
+			}
 			if (optval <= 0) {
 				error = EINVAL;
 				break;
@@ -2355,17 +2585,19 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			error = tcp_add_notify_ack_marker(tp, optval);
 			break;
 		case SO_FLUSH:
-			if ((error = sooptcopyin(sopt, &optval, sizeof (optval),
-			    sizeof (optval))) != 0)
+			if ((error = sooptcopyin(sopt, &optval, sizeof(optval),
+			    sizeof(optval))) != 0) {
 				break;
+			}
 
 			error = inp_flush(inp, optval);
 			break;
 
 		case SO_TRAFFIC_MGT_BACKGROUND:
-			if ((error = sooptcopyin(sopt, &optval, sizeof (optval),
-			    sizeof (optval))) != 0)
+			if ((error = sooptcopyin(sopt, &optval, sizeof(optval),
+			    sizeof(optval))) != 0) {
 				break;
+			}
 
 			if (optval) {
 				socket_set_traffic_mgt_flags_locked(so,
@@ -2378,8 +2610,9 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 		case TCP_RXT_MINIMUM_TIMEOUT:
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
 			    sizeof(optval));
-			if (error)
+			if (error) {
 				break;
+			}
 			if (optval < 0) {
 				error = EINVAL;
 				break;
@@ -2408,22 +2641,25 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			optval = tp->t_maxseg;
 			break;
 		case TCP_KEEPALIVE:
-			if (tp->t_keepidle > 0)
+			if (tp->t_keepidle > 0) {
 				optval = tp->t_keepidle / TCP_RETRANSHZ;
-			else
+			} else {
 				optval = tcp_keepidle  / TCP_RETRANSHZ;
+			}
 			break;
 		case TCP_KEEPINTVL:
-			if (tp->t_keepintvl > 0)
+			if (tp->t_keepintvl > 0) {
 				optval = tp->t_keepintvl / TCP_RETRANSHZ;
-			else
+			} else {
 				optval = tcp_keepintvl / TCP_RETRANSHZ;
+			}
 			break;
 		case TCP_KEEPCNT:
-			if (tp->t_keepcnt > 0)
+			if (tp->t_keepcnt > 0) {
 				optval = tp->t_keepcnt;
-			else
+			} else {
 				optval = tcp_keepcnt;
+			}
 			break;
 		case TCP_KEEPALIVE_OFFLOAD:
 			optval = !!(inp->inp_flags2 & INP2_KEEPALIVE_OFFLOAD);
@@ -2438,12 +2674,13 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			optval = (tp->ecn_flags & TE_ECN_MODE_ENABLE) ? 1 : 0;
 			break;
 		case TCP_ECN_MODE:
-			if (tp->ecn_flags & TE_ECN_MODE_ENABLE)
+			if (tp->ecn_flags & TE_ECN_MODE_ENABLE) {
 				optval = ECN_MODE_ENABLE;
-			else if (tp->ecn_flags & TE_ECN_MODE_DISABLE)
+			} else if (tp->ecn_flags & TE_ECN_MODE_DISABLE) {
 				optval = ECN_MODE_DISABLE;
-			else
+			} else {
 				optval = ECN_MODE_DEFAULT;
+			}
 			break;
 		case TCP_CONNECTIONTIMEOUT:
 			optval = tp->t_keepinit / TCP_RETRANSHZ;
@@ -2469,7 +2706,10 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			optval = tfo_enabled(tp);
 			break;
 		case TCP_FASTOPEN_FORCE_HEURISTICS:
-			optval = (tp->t_flagsext & TF_FASTOPEN_HEUR) ? 1 : 0;
+			optval = 0;
+			break;
+		case TCP_FASTOPEN_FORCE_ENABLE:
+			optval = (tp->t_flagsext & TF_FASTOPEN_FORCE_ENABLE) ? 1 : 0;
 			break;
 		case TCP_MEASURE_SND_BW:
 			optval = tp->t_flagsext & TF_MEASURESNDBW;
@@ -2490,9 +2730,9 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			goto done;
 		}
 		case TCP_MEASURE_BW_BURST: {
-			struct tcp_measure_bw_burst out;
+			struct tcp_measure_bw_burst out = {};
 			if ((tp->t_flagsext & TF_MEASURESNDBW) == 0 ||
-				tp->t_bwmeas == NULL) {
+			    tp->t_bwmeas == NULL) {
 				error = EINVAL;
 				break;
 			}
@@ -2517,22 +2757,25 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			}
 			break;
 		case TCP_SENDMOREACKS:
-			if (tp->t_flagsext & TF_NOSTRETCHACK)
+			if (tp->t_flagsext & TF_NOSTRETCHACK) {
 				optval = 1;
-			else
+			} else {
 				optval = 0;
+			}
 			break;
 		case TCP_DISABLE_BLACKHOLE_DETECTION:
-			if (tp->t_flagsext & TF_NOBLACKHOLE_DETECTION)
+			if (tp->t_flagsext & TF_NOBLACKHOLE_DETECTION) {
 				optval = 1;
-			else
+			} else {
 				optval = 0;
+			}
 			break;
 		case TCP_PEER_PID: {
-			pid_t	pid;
+			pid_t   pid;
 			error = tcp_lookup_peer_pid_locked(so, &pid);
-			if (error == 0)
+			if (error == 0) {
 				error = sooptcopyout(sopt, &pid, sizeof(pid));
+			}
 			goto done;
 		}
 		case TCP_ADAPTIVE_READ_TIMEOUT:
@@ -2548,16 +2791,17 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 		case TCP_NOTIFY_ACKNOWLEDGEMENT: {
 			struct tcp_notify_ack_complete retid;
 
-			if (sopt->sopt_valsize != sizeof (retid)) {
+			if (sopt->sopt_valsize != sizeof(retid)) {
 				error = EINVAL;
 				break;
 			}
-			bzero(&retid, sizeof (retid));
+			bzero(&retid, sizeof(retid));
 			tcp_get_notify_ack_count(tp, &retid);
-			if (retid.notify_complete_count > 0)
+			if (retid.notify_complete_count > 0) {
 				tcp_get_notify_ack_ids(tp, &retid);
+			}
 
-			error = sooptcopyout(sopt, &retid, sizeof (retid));
+			error = sooptcopyout(sopt, &retid, sizeof(retid));
 			goto done;
 		}
 		case TCP_RXT_MINIMUM_TIMEOUT:
@@ -2567,12 +2811,13 @@ tcp_ctloutput(struct socket *so, struct sockopt *sopt)
 			error = ENOPROTOOPT;
 			break;
 		}
-		if (error == 0)
+		if (error == 0) {
 			error = sooptcopyout(sopt, &optval, sizeof optval);
+		}
 		break;
 	}
 done:
-	return (error);
+	return error;
 }
 
 /*
@@ -2580,8 +2825,8 @@ done:
  * sizes, respectively.  These are obsolescent (this information should
  * be set by the route).
  */
-u_int32_t	tcp_sendspace = 1448*256;
-u_int32_t	tcp_recvspace = 1448*384;
+u_int32_t       tcp_sendspace = 1448 * 256;
+u_int32_t       tcp_recvspace = 1448 * 384;
 
 /* During attach, the size of socket buffer allocated is limited to
  * sb_max in sbreserve. Disallow setting the tcp send and recv space
@@ -2590,25 +2835,25 @@ u_int32_t	tcp_recvspace = 1448*384;
  */
 static int
 sysctl_tcp_sospace(struct sysctl_oid *oidp, __unused void *arg1,
-	int arg2, struct sysctl_req *req)
+    int arg2, struct sysctl_req *req)
 {
 #pragma unused(arg2)
 	u_int32_t new_value = 0, *space_p = NULL;
 	int changed = 0, error = 0;
-	u_quad_t sb_effective_max = (sb_max / (MSIZE+MCLBYTES)) * MCLBYTES;
+	u_quad_t sb_effective_max = (sb_max / (MSIZE + MCLBYTES)) * MCLBYTES;
 
 	switch (oidp->oid_number) {
-		case TCPCTL_SENDSPACE:
-			space_p = &tcp_sendspace;
-			break;
-		case TCPCTL_RECVSPACE:
-			space_p = &tcp_recvspace;
-			break;
-		default:
-			return EINVAL;
+	case TCPCTL_SENDSPACE:
+		space_p = &tcp_sendspace;
+		break;
+	case TCPCTL_RECVSPACE:
+		space_p = &tcp_recvspace;
+		break;
+	default:
+		return EINVAL;
 	}
 	error = sysctl_io_number(req, *space_p, sizeof(u_int32_t),
-		&new_value, &changed);
+	    &new_value, &changed);
 	if (changed) {
 		if (new_value > 0 && new_value <= sb_effective_max) {
 			*space_p = new_value;
@@ -2622,18 +2867,18 @@ sysctl_tcp_sospace(struct sysctl_oid *oidp, __unused void *arg1,
 
 #if SYSCTL_SKMEM
 SYSCTL_PROC(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace,
-			CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_sendspace,
-			offsetof(skmem_sysctl, tcp.sendspace), sysctl_tcp_sospace,
-			"IU", "Maximum outgoing TCP datagram size");
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_sendspace,
+    offsetof(skmem_sysctl, tcp.sendspace), sysctl_tcp_sospace,
+    "IU", "Maximum outgoing TCP datagram size");
 SYSCTL_PROC(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace,
-			CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_recvspace,
-			offsetof(skmem_sysctl, tcp.recvspace), sysctl_tcp_sospace,
-			"IU", "Maximum incoming TCP datagram size");
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_recvspace,
+    offsetof(skmem_sysctl, tcp.recvspace), sysctl_tcp_sospace,
+    "IU", "Maximum incoming TCP datagram size");
 #else /* SYSCTL_SKMEM */
 SYSCTL_PROC(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
-    &tcp_sendspace , 0, &sysctl_tcp_sospace, "IU", "Maximum outgoing TCP datagram size");
+    &tcp_sendspace, 0, &sysctl_tcp_sospace, "IU", "Maximum outgoing TCP datagram size");
 SYSCTL_PROC(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
-    &tcp_recvspace , 0, &sysctl_tcp_sospace, "IU", "Maximum incoming TCP datagram size");
+    &tcp_recvspace, 0, &sysctl_tcp_sospace, "IU", "Maximum incoming TCP datagram size");
 #endif /* SYSCTL_SKMEM */
 
 /*
@@ -2658,52 +2903,56 @@ tcp_attach(struct socket *so, struct proc *p)
 #endif
 
 	error = in_pcballoc(so, &tcbinfo, p);
-	if (error)
-		return (error);
+	if (error) {
+		return error;
+	}
 
 	inp = sotoinpcb(so);
 
 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 		error = soreserve(so, tcp_sendspace, tcp_recvspace);
-		if (error)
-			return (error);
+		if (error) {
+			return error;
+		}
 	}
 
 	if (so->so_snd.sb_preconn_hiwat == 0) {
 		soreserve_preconnect(so, 2048);
 	}
 
-	if ((so->so_rcv.sb_flags & SB_USRSIZE) == 0)
+	if ((so->so_rcv.sb_flags & SB_USRSIZE) == 0) {
 		so->so_rcv.sb_flags |= SB_AUTOSIZE;
-	if ((so->so_snd.sb_flags & SB_USRSIZE) == 0)
+	}
+	if ((so->so_snd.sb_flags & SB_USRSIZE) == 0) {
 		so->so_snd.sb_flags |= SB_AUTOSIZE;
+	}
 
 #if INET6
 	if (isipv6) {
 		inp->inp_vflag |= INP_IPV6;
-		inp->in6p_hops = -1;	/* use kernel default */
-	}
-	else
+		inp->in6p_hops = -1;    /* use kernel default */
+	} else
 #endif /* INET6 */
 	inp->inp_vflag |= INP_IPV4;
 	tp = tcp_newtcpcb(inp);
 	if (tp == NULL) {
-		int nofd = so->so_state & SS_NOFDREF;	/* XXX */
+		int nofd = so->so_state & SS_NOFDREF;   /* XXX */
 
-		so->so_state &= ~SS_NOFDREF;	/* don't free the socket yet */
+		so->so_state &= ~SS_NOFDREF;    /* don't free the socket yet */
 #if INET6
-		if (isipv6)
+		if (isipv6) {
 			in6_pcbdetach(inp);
-		else
+		} else
 #endif /* INET6 */
 		in_pcbdetach(inp);
 		so->so_state |= nofd;
-		return (ENOBUFS);
+		return ENOBUFS;
 	}
-	if (nstat_collect)
+	if (nstat_collect) {
 		nstat_tcp_new_pcb(inp);
+	}
 	tp->t_state = TCPS_CLOSED;
-	return (0);
+	return 0;
 }
 
 /*
@@ -2719,24 +2968,30 @@ tcp_disconnect(struct tcpcb *tp)
 {
 	struct socket *so = tp->t_inpcb->inp_socket;
 
-	if (tp->t_state < TCPS_ESTABLISHED)
+	if (so->so_rcv.sb_cc != 0 || tp->t_reassqlen != 0) {
+		return tcp_drop(tp, 0);
+	}
+
+	if (tp->t_state < TCPS_ESTABLISHED) {
 		tp = tcp_close(tp);
-	else if ((so->so_options & SO_LINGER) && so->so_linger == 0)
+	} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
 		tp = tcp_drop(tp, 0);
-	else {
+	} else {
 		soisdisconnecting(so);
 		sbflush(&so->so_rcv);
 		tp = tcp_usrclosed(tp);
 #if MPTCP
 		/* A reset has been sent but socket exists, do not send FIN */
 		if ((so->so_flags & SOF_MP_SUBFLOW) &&
-		    (tp) && (tp->t_mpflags & TMPF_RESET))
-			return (tp);
+		    (tp) && (tp->t_mpflags & TMPF_RESET)) {
+			return tp;
+		}
 #endif
-		if (tp)
+		if (tp) {
 			(void) tcp_output(tp);
+		}
 	}
-	return (tp);
+	return tp;
 }
 
 /*
@@ -2753,41 +3008,43 @@ static struct tcpcb *
 tcp_usrclosed(struct tcpcb *tp)
 {
 	switch (tp->t_state) {
-
 	case TCPS_CLOSED:
 	case TCPS_LISTEN:
+	case TCPS_SYN_SENT:
 		tp = tcp_close(tp);
 		break;
 
-	case TCPS_SYN_SENT:
 	case TCPS_SYN_RECEIVED:
 		tp->t_flags |= TF_NEEDFIN;
 		break;
 
 	case TCPS_ESTABLISHED:
 		DTRACE_TCP4(state__change, void, NULL,
-			struct inpcb *, tp->t_inpcb,
-			struct tcpcb *, tp,
-			int32_t, TCPS_FIN_WAIT_1);
+		    struct inpcb *, tp->t_inpcb,
+		    struct tcpcb *, tp,
+		    int32_t, TCPS_FIN_WAIT_1);
 		tp->t_state = TCPS_FIN_WAIT_1;
+		TCP_LOG_CONNECTION_SUMMARY(tp);
 		break;
 
 	case TCPS_CLOSE_WAIT:
 		DTRACE_TCP4(state__change, void, NULL,
-			struct inpcb *, tp->t_inpcb,
-			struct tcpcb *, tp,
-			int32_t, TCPS_LAST_ACK);
+		    struct inpcb *, tp->t_inpcb,
+		    struct tcpcb *, tp,
+		    int32_t, TCPS_LAST_ACK);
 		tp->t_state = TCPS_LAST_ACK;
+		TCP_LOG_CONNECTION_SUMMARY(tp);
 		break;
 	}
 	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
 		soisdisconnected(tp->t_inpcb->inp_socket);
 		/* To prevent the connection hanging in FIN_WAIT_2 forever. */
-		if (tp->t_state == TCPS_FIN_WAIT_2)
+		if (tp->t_state == TCPS_FIN_WAIT_2) {
 			tp->t_timer[TCPT_2MSL] = OFFSET_FROM_START(tp,
-				TCP_CONN_MAXIDLE(tp));
+			    TCP_CONN_MAXIDLE(tp));
+		}
 	}
-	return (tp);
+	return tp;
 }
 
 void
@@ -2818,6 +3075,7 @@ tcp_out6_cksum_stats(u_int32_t len)
 	tcpstat.tcps_snd6_swcsum++;
 	tcpstat.tcps_snd6_swcsum_bytes += len;
 }
+#endif /* INET6 */
 
 /*
  * When messages are enabled on a TCP socket, the message priority
@@ -2827,23 +3085,55 @@ int
 tcp_get_msg_priority(struct mbuf *control, uint32_t *msgpri)
 {
 	struct cmsghdr *cm;
-	if (control == NULL)
-		return(EINVAL);
 
-	for (cm = M_FIRST_CMSGHDR(control); cm;
-		cm = M_NXT_CMSGHDR(control, cm)) {
-		if (cm->cmsg_len < sizeof(struct cmsghdr) ||
-			cm->cmsg_len > control->m_len) {
-			return (EINVAL);
-		}
+	if (control == NULL) {
+		return EINVAL;
+	}
+
+	for (cm = M_FIRST_CMSGHDR(control);
+	    is_cmsg_valid(control, cm);
+	    cm = M_NXT_CMSGHDR(control, cm)) {
 		if (cm->cmsg_level == SOL_SOCKET &&
-			cm->cmsg_type == SCM_MSG_PRIORITY) {
-			*msgpri = *(unsigned int *)(void *)CMSG_DATA(cm);
+		    cm->cmsg_type == SCM_MSG_PRIORITY) {
+			if (cm->cmsg_len != CMSG_LEN(sizeof(uint32_t))) {
+				return EINVAL;
+			}
+			*msgpri = *(uint32_t *)(void *)CMSG_DATA(cm);
+			if (*msgpri < MSG_PRI_MIN || *msgpri > MSG_PRI_MAX) {
+				return EINVAL;
+			}
 			break;
 		}
 	}
+	return 0;
+}
+
+int
+tcp_get_mpkl_send_info(struct mbuf *control,
+    struct so_mpkl_send_info *mpkl_send_info)
+{
+	struct cmsghdr *cm;
 
-	VERIFY(*msgpri >= MSG_PRI_MIN && *msgpri <= MSG_PRI_MAX);
-	return (0);
+	if (control == NULL || mpkl_send_info == NULL) {
+		return EINVAL;
+	}
+
+	for (cm = M_FIRST_CMSGHDR(control); cm;
+	    cm = M_NXT_CMSGHDR(control, cm)) {
+		if (cm->cmsg_len < sizeof(struct cmsghdr) ||
+		    cm->cmsg_len > control->m_len) {
+			return EINVAL;
+		}
+		if (cm->cmsg_level != SOL_SOCKET ||
+		    cm->cmsg_type != SCM_MPKL_SEND_INFO) {
+			continue;
+		}
+		if (cm->cmsg_len != CMSG_LEN(sizeof(struct so_mpkl_send_info))) {
+			return EINVAL;
+		}
+		memcpy(mpkl_send_info, CMSG_DATA(cm),
+		    sizeof(struct so_mpkl_send_info));
+		return 0;
+	}
+	return ENOMSG;
 }
-#endif /* INET6 */