Index: sys/mbuf.h
===================================================================
RCS file: /cvs/src/sys/sys/mbuf.h,v
retrieving revision 1.196
diff -u -p -r1.196 mbuf.h
--- sys/mbuf.h	14 Aug 2015 05:25:29 -0000	1.196
+++ sys/mbuf.h	18 Sep 2015 05:47:30 -0000
@@ -125,7 +125,7 @@ struct	pkthdr {
 	SLIST_HEAD(packet_tags, m_tag) tags;	/* list of packet tags */
 	int			 len;		/* total packet length */
 	u_int16_t		 tagsset;	/* mtags attached */
-	u_int16_t		 pad;
+	u_int16_t		 flowid;	/* pseudo unique flow id */
 	u_int16_t		 csum_flags;	/* checksum flags */
 	u_int16_t		 ether_vtag;	/* Ethernet 802.1p+Q vlan tag */
 	u_int			 ph_rtableid;	/* routing table id */
@@ -236,6 +236,10 @@ struct mbuf {
 #define	MT_FTABLE	5	/* fragment reassembly header */
 #define	MT_CONTROL	6	/* extra-data protocol message */
 #define	MT_OOBDATA	7	/* expedited data  */
+
+/* flowid field */
+#define M_FLOWID_VALID	0x8000	/* is the flowid set */
+#define M_FLOWID_MASK	0x7fff	/* flow id to map to path */
 
 /* flags to m_get/MGET */
 #define	M_DONTWAIT	M_NOWAIT
Index: net/pf.c
===================================================================
RCS file: /cvs/src/sys/net/pf.c,v
retrieving revision 1.944
diff -u -p -r1.944 pf.c
--- net/pf.c	13 Sep 2015 17:53:44 -0000	1.944
+++ net/pf.c	18 Sep 2015 05:47:30 -0000
@@ -6531,11 +6531,15 @@ done:
 		pd.m->m_pkthdr.pf.qid = qid;
 	if (pd.dir == PF_IN && s && s->key[PF_SK_STACK])
 		pd.m->m_pkthdr.pf.statekey = s->key[PF_SK_STACK];
-	if (pd.dir == PF_OUT &&
-	    pd.m->m_pkthdr.pf.inp && !pd.m->m_pkthdr.pf.inp->inp_pf_sk &&
-	    s && s->key[PF_SK_STACK] && !s->key[PF_SK_STACK]->inp) {
-		pd.m->m_pkthdr.pf.inp->inp_pf_sk = s->key[PF_SK_STACK];
-		s->key[PF_SK_STACK]->inp = pd.m->m_pkthdr.pf.inp;
+	if (pd.dir == PF_OUT && s) {
+		if (pd.m->m_pkthdr.pf.inp &&
+		    !pd.m->m_pkthdr.pf.inp->inp_pf_sk &&
+		    s->key[PF_SK_STACK] && !s->key[PF_SK_STACK]->inp) {
+			pd.m->m_pkthdr.pf.inp->inp_pf_sk = s->key[PF_SK_STACK];
+			s->key[PF_SK_STACK]->inp = pd.m->m_pkthdr.pf.inp;
+		}
+		pd.m->m_pkthdr.flowid = M_FLOWID_VALID |
+		    (M_FLOWID_MASK & bemtoh64(&s->id));
 	}
 
 	/*
Index: net/if_trunk.c
===================================================================
RCS file: /cvs/src/sys/net/if_trunk.c,v
retrieving revision 1.111
diff -u -p -r1.111 if_trunk.c
--- net/if_trunk.c	10 Sep 2015 16:41:30 -0000	1.111
+++ net/if_trunk.c	18 Sep 2015 05:47:30 -0000
@@ -985,6 +990,9 @@ trunk_hashmbuf(struct mbuf *m, SIPHASH_K
 #endif
 	SIPHASH_CTX ctx;
 
+	if (m->m_pkthdr.flowid & M_FLOWID_VALID)
+		return (m->m_pkthdr.flowid & M_FLOWID_MASK);
+
 	SipHash24_Init(&ctx, key);
 	off = sizeof(*eh);
 	if (m->m_len < off)