Index: head/cddl/lib/libdtrace/tcp.d
===================================================================
--- head/cddl/lib/libdtrace/tcp.d
+++ head/cddl/lib/libdtrace/tcp.d
@@ -241,3 +241,78 @@
 translator tcplsinfo_t < int s > {
 	tcps_state =	s;
 };
+
+/*
+ * Convert a SIFTR direction value to a string
+ */
+#pragma D binding "1.12.1" SIFTR_IN
+inline int SIFTR_IN =	1;
+#pragma D binding "1.12.1" SIFTR_OUT
+inline int SIFTR_OUT =	2;
+
+/* SIFTR direction strings. */
+#pragma D binding "1.12.1" siftr_dir_string
+inline string siftr_dir_string[uint8_t direction] =
+	direction == SIFTR_IN ?	"in" :
+	direction == SIFTR_OUT ? "out" :
+	"unknown" ;
+
+typedef struct siftrinfo {
+	struct timeval		tval;
+	uint8_t			direction;
+	uint8_t			ipver;
+	uint32_t		hash;
+	uint16_t		tcp_localport;
+	uint16_t		tcp_foreignport;
+	uint64_t		snd_cwnd;
+	u_long			snd_wnd;
+	u_long			rcv_wnd;
+	u_long			snd_bwnd;
+	u_long			snd_ssthresh;
+	int			conn_state;
+	u_int			max_seg_size;
+	int			smoothed_rtt;
+	u_char			sack_enabled;
+	u_char			snd_scale;
+	u_char			rcv_scale;
+	u_int			flags;
+	int			rxt_length;
+	u_int			snd_buf_hiwater;
+	u_int			snd_buf_cc;
+	u_int			rcv_buf_hiwater;
+	u_int			rcv_buf_cc;
+	u_int			sent_inflight_bytes;
+	int			t_segqlen;
+	u_int			flowid;
+	u_int			flowtype;
+} siftrinfo_t;
+
+#pragma D binding "1.12.1" translator
+translator siftrinfo_t < struct pkt_node *p > {
+	direction = 		p == NULL ? 0 : p->direction;
+	ipver =			p == NULL ? 0 : p->ipver;
+	hash = 			p == NULL ? 0 : p->hash;
+	tcp_localport =		p == NULL ? 0 : ntohs(p->tcp_localport);
+	tcp_foreignport =	p == NULL ? 0 : ntohs(p->tcp_foreignport);
+	snd_cwnd =		p == NULL ? 0 : p->snd_cwnd;
+	snd_wnd =		p == NULL ? 0 : p->snd_wnd;
+	rcv_wnd =		p == NULL ? 0 : p->rcv_wnd;
+	snd_bwnd =		p == NULL ? 0 : p->snd_bwnd;
+	snd_ssthresh =		p == NULL ? 0 : p->snd_ssthresh;
+	conn_state =		p == NULL ? 0 : p->conn_state;
+	max_seg_size = 		p == NULL ? 0 : p->max_seg_size;
+	smoothed_rtt =		p == NULL ? 0 : p->smoothed_rtt;
+	sack_enabled = 		p == NULL ? 0 : p->sack_enabled;
+	snd_scale =		p == NULL ? 0 : p->snd_scale;
+	rcv_scale =		p == NULL ? 0 : p->rcv_scale;
+	flags =			p == NULL ? 0 : p->flags;
+	rxt_length = 		p == NULL ? 0 : p->rxt_length;
+	snd_buf_hiwater =	p == NULL ? 0 : p->snd_buf_hiwater;
+	snd_buf_cc = 		p == NULL ? 0 : p->snd_buf_cc;
+	rcv_buf_hiwater = 	p == NULL ? 0 : p->rcv_buf_hiwater;
+	rcv_buf_cc = 		p == NULL ? 0 : p->rcv_buf_cc;
+	sent_inflight_bytes = 	p == NULL ? 0 : p->sent_inflight_bytes;
+	t_segqlen =		p == NULL ? 0 : p->t_segqlen;
+	flowid = 		p == NULL ? 0 : p->flowid;
+	flowtype = 		p == NULL ? 0 : p->flowtype;
+};
Index: head/sys/netinet/in_kdtrace.h
===================================================================
--- head/sys/netinet/in_kdtrace.h
+++ head/sys/netinet/in_kdtrace.h
@@ -32,6 +32,8 @@
 	SDT_PROBE6(ip, , , probe, arg0, arg1, arg2, arg3, arg4, arg5)
 #define	UDP_PROBE(probe, arg0, arg1, arg2, arg3, arg4)			\
 	SDT_PROBE5(udp, , , probe, arg0, arg1, arg2, arg3, arg4)
+#define	TCP_PROBE1(probe, arg0) \
+	SDT_PROBE1(tcp, , , probe, arg0)
 #define	TCP_PROBE5(probe, arg0, arg1, arg2, arg3, arg4)			\
 	SDT_PROBE5(tcp, , , probe, arg0, arg1, arg2, arg3, arg4)
 #define	TCP_PROBE6(probe, arg0, arg1, arg2, arg3, arg4, arg5)		\
@@ -51,6 +53,7 @@
 SDT_PROBE_DECLARE(tcp, , , connect__request);
 SDT_PROBE_DECLARE(tcp, , , receive);
 SDT_PROBE_DECLARE(tcp, , , send);
+SDT_PROBE_DECLARE(tcp, , , siftr);
 SDT_PROBE_DECLARE(tcp, , , state__change);
 
 SDT_PROBE_DECLARE(udp, , , receive);
Index: head/sys/netinet/in_kdtrace.c
===================================================================
--- head/sys/netinet/in_kdtrace.c
+++ head/sys/netinet/in_kdtrace.c
@@ -102,6 +102,9 @@
     "struct tcpcb *", "tcpsinfo_t *" ,
     "struct tcphdr *", "tcpinfo_t *");
 
+SDT_PROBE_DEFINE1_XLATE(tcp, , , siftr,
+    "struct pkt_node *", "siftrinfo_t *");
+
 SDT_PROBE_DEFINE6_XLATE(tcp, , , state__change,
     "void *", "void *",
     "struct tcpcb *", "csinfo_t *",
Index: head/sys/netinet/siftr.c
===================================================================
--- head/sys/netinet/siftr.c
+++ head/sys/netinet/siftr.c
@@ -75,6 +75,7 @@
 #include <sys/pcpu.h>
 #include <sys/proc.h>
 #include <sys/sbuf.h>
+#include <sys/sdt.h>
 #include <sys/smp.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
@@ -86,6 +87,7 @@
 #include <net/pfil.h>
 
 #include <netinet/in.h>
+#include <netinet/in_kdtrace.h>
 #include <netinet/in_pcb.h>
 #include <netinet/in_systm.h>
 #include <netinet/in_var.h>
@@ -547,6 +549,7 @@
 	}
 #endif
 
+	TCP_PROBE1(siftr, pkt_node);
 	alq_post_flags(siftr_alq, log_buf, 0);
 }