diff --git a/passt.h b/passt.h
index 53defa4..cac720a 100644
--- a/passt.h
+++ b/passt.h
@@ -35,6 +35,7 @@ union epoll_ref;
 #include <assert.h>
 #include <sys/epoll.h>
 
+#include "pif.h"
 #include "packet.h"
 #include "icmp.h"
 #include "port_fwd.h"
diff --git a/tcp.c b/tcp.c
index c13b7de..bad8c38 100644
--- a/tcp.c
+++ b/tcp.c
@@ -2964,6 +2964,7 @@ static int tcp_sock_init_af(const struct ctx *c, int af, in_port_t port,
 {
 	union tcp_listen_epoll_ref tref = {
 		.port = port + c->tcp.fwd_in.delta[port],
+		.pif = PIF_HOST,
 	};
 	int s;
 
@@ -3025,7 +3026,7 @@ static void tcp_ns_sock_init4(const struct ctx *c, in_port_t port)
 {
 	union tcp_listen_epoll_ref tref = {
 		.port = port + c->tcp.fwd_out.delta[port],
-		.ns = true,
+		.pif = PIF_SPLICE,
 	};
 	struct in_addr loopback = { htonl(INADDR_LOOPBACK) };
 	int s;
@@ -3051,7 +3052,7 @@ static void tcp_ns_sock_init6(const struct ctx *c, in_port_t port)
 {
 	union tcp_listen_epoll_ref tref = {
 		.port = port + c->tcp.fwd_out.delta[port],
-		.ns = true,
+		.pif = PIF_SPLICE,
 	};
 	int s;
 
diff --git a/tcp.h b/tcp.h
index 6444d6a..5a321db 100644
--- a/tcp.h
+++ b/tcp.h
@@ -41,13 +41,13 @@ union tcp_epoll_ref {
 /**
  * union tcp_listen_epoll_ref - epoll reference portion for TCP listening
  * @port:	Port number we're forwarding *to* (listening port plus delta)
- * @ns:		True if listening within the pasta namespace
+ * @pif:	pif in which the socket is listening
  * @u32:	Opaque u32 value of reference
  */
 union tcp_listen_epoll_ref {
 	struct {
 		in_port_t	port;
-		bool		ns;
+		uint8_t		pif;
 	};
 	uint32_t u32;
 };
diff --git a/tcp_splice.c b/tcp_splice.c
index 54fc317..133e825 100644
--- a/tcp_splice.c
+++ b/tcp_splice.c
@@ -411,12 +411,12 @@ static int tcp_splice_connect(const struct ctx *c, struct tcp_splice_conn *conn,
  * @c:		Execution context
  * @conn:	Connection pointer
  * @port:	Destination port, host order
- * @outbound:	Connection request coming from namespace
+ * @pif:	Originating pif of the splice
  *
  * Return: return code from connect()
  */
 static int tcp_splice_new(const struct ctx *c, struct tcp_splice_conn *conn,
-			  in_port_t port, int outbound)
+			  in_port_t port, uint8_t pif)
 {
 	int s = -1;
 
@@ -427,7 +427,7 @@ static int tcp_splice_new(const struct ctx *c, struct tcp_splice_conn *conn,
 	 * entering the ns anyway, so we might as well refill the
 	 * pool.
 	 */
-	if (outbound) {
+	if (pif == PIF_SPLICE) {
 		int *p = CONN_V6(conn) ? init_sock_pool6 : init_sock_pool4;
 		int af = CONN_V6(conn) ? AF_INET6 : AF_INET;
 
@@ -437,6 +437,8 @@ static int tcp_splice_new(const struct ctx *c, struct tcp_splice_conn *conn,
 	} else {
 		int *p = CONN_V6(conn) ? ns_sock_pool6 : ns_sock_pool4;
 
+		ASSERT(pif == PIF_HOST);
+
 		/* If pool is empty, refill it first */
 		if (p[TCP_SOCK_POOL_SIZE-1] < 0)
 			NS_CALL(tcp_sock_refill_ns, c);
@@ -516,7 +518,7 @@ bool tcp_splice_conn_from_sock(const struct ctx *c,
 	conn->c.spliced = true;
 	conn->a = s;
 
-	if (tcp_splice_new(c, conn, ref.port, ref.ns))
+	if (tcp_splice_new(c, conn, ref.port, ref.pif))
 		conn_flag(c, conn, CLOSING);
 
 	return true;
diff --git a/udp.c b/udp.c
index db35859..ccfe2fa 100644
--- a/udp.c
+++ b/udp.c
@@ -365,7 +365,7 @@ static void udp_sock6_iov_init(const struct ctx *c)
  * @c:		Execution context
  * @v6:		Set for IPv6 sockets
  * @src:	Source port of original connection, host order
- * @splice:	UDP_BACK_TO_INIT from init, UDP_BACK_TO_NS from namespace
+ * @ns:		Does the splice originate in the ns or not
  *
  * Return: prepared socket, negative error code on failure
  *
@@ -375,16 +375,17 @@ int udp_splice_new(const struct ctx *c, int v6, in_port_t src, bool ns)
 {
 	struct epoll_event ev = { .events = EPOLLIN | EPOLLRDHUP | EPOLLHUP };
 	union epoll_ref ref = { .type = EPOLL_TYPE_UDP,
-				.udp = { .splice = true, .ns = ns,
-					 .v6 = v6, .port = src }
+				.udp = { .splice = true, .v6 = v6, .port = src }
 			      };
 	struct udp_splice_port *sp;
 	int act, s;
 
 	if (ns) {
+		ref.udp.pif = PIF_SPLICE;
 		sp = &udp_splice_ns[v6 ? V6 : V4][src];
 		act = UDP_ACT_SPLICE_NS;
 	} else {
+		ref.udp.pif = PIF_HOST;
 		sp = &udp_splice_init[v6 ? V6 : V4][src];
 		act = UDP_ACT_SPLICE_INIT;
 	}
@@ -495,15 +496,15 @@ static int udp_mmh_splice_port(bool v6, const struct mmsghdr *mmh)
  * @n:		Number of datagrams to send
  * @src:	Datagrams will be sent from this port (on origin side)
  * @dst:	Datagrams will be send to this port (on destination side)
+ * @from_pif:	pif from which the packet originated
  * @v6:		Send as IPv6?
- * @from_ns:	If true send from pasta ns to init, otherwise reverse
  * @allow_new:	If true create sending socket if needed, if false discard
  *              if no sending socket is available
  * @now:	Timestamp
  */
 static void udp_splice_sendfrom(const struct ctx *c, unsigned start, unsigned n,
-				in_port_t src, in_port_t dst,
-				bool v6, bool from_ns, bool allow_new,
+				in_port_t src, in_port_t dst, uint8_t from_pif,
+				bool v6, bool allow_new,
 				const struct timespec *now)
 {
 	struct mmsghdr *mmh_recv, *mmh_send;
@@ -518,7 +519,7 @@ static void udp_splice_sendfrom(const struct ctx *c, unsigned start, unsigned n,
 		mmh_send = udp4_mh_splice;
 	}
 
-	if (from_ns) {
+	if (from_pif == PIF_SPLICE) {
 		src += c->udp.fwd_in.rdelta[src];
 		s = udp_splice_init[v6][src].sock;
 		if (!s && allow_new)
@@ -530,6 +531,7 @@ static void udp_splice_sendfrom(const struct ctx *c, unsigned start, unsigned n,
 		udp_splice_ns[v6][dst].ts = now->tv_sec;
 		udp_splice_init[v6][src].ts = now->tv_sec;
 	} else {
+		ASSERT(from_pif == PIF_HOST);
 		src += c->udp.fwd_out.rdelta[src];
 		s = udp_splice_ns[v6][src].sock;
 		if (!s && allow_new) {
@@ -776,7 +778,7 @@ void udp_sock_handler(const struct ctx *c, union epoll_ref ref, uint32_t events,
 
 		if (splicefrom >= 0)
 			udp_splice_sendfrom(c, i, m, splicefrom, dstport,
-					    v6, ref.udp.ns, ref.udp.orig, now);
+					    ref.udp.pif, v6, ref.udp.orig, now);
 		else
 			udp_tap_send(c, i, m, dstport, v6, now);
 	}
@@ -974,8 +976,10 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 	int s, r4 = FD_REF_MAX + 1, r6 = FD_REF_MAX + 1;
 
 	if (ns) {
+		uref.pif = PIF_SPLICE;
 		uref.port = (in_port_t)(port + c->udp.fwd_out.f.delta[port]);
 	} else {
+		uref.pif = PIF_HOST;
 		uref.port = (in_port_t)(port + c->udp.fwd_in.f.delta[port]);
 	}
 
@@ -990,7 +994,6 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 			udp_splice_init[V4][port].sock = s < 0 ? -1 : s;
 		} else {
 			struct in_addr loopback = { htonl(INADDR_LOOPBACK) };
-			uref.ns = true;
 
 			r4 = s = sock_l4(c, AF_INET, IPPROTO_UDP, &loopback,
 					 ifname, port, uref.u32);
@@ -1008,8 +1011,6 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 			udp_tap_map[V6][uref.port].sock = s < 0 ? -1 : s;
 			udp_splice_init[V6][port].sock = s < 0 ? -1 : s;
 		} else {
-			uref.ns = true;
-
 			r6 = s = sock_l4(c, AF_INET6, IPPROTO_UDP,
 					 &in6addr_loopback,
 					 ifname, port, uref.u32);
diff --git a/udp.h b/udp.h
index 7837134..dbaa018 100644
--- a/udp.h
+++ b/udp.h
@@ -20,21 +20,21 @@ void udp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s);
 
 /**
  * union udp_epoll_ref - epoll reference portion for TCP connections
+ * @port:		Source port for connected sockets, bound port otherwise
+ * @pif:		pif for this socket
  * @bound:		Set if this file descriptor is a bound socket
  * @splice:		Set if descriptor packets to be "spliced"
  * @orig:		Set if a spliced socket which can originate "connections"
- * @ns:			Set if this is a socket in the pasta network namespace
  * @v6:			Set for IPv6 sockets or connections
- * @port:		Source port for connected sockets, bound port otherwise
  * @u32:		Opaque u32 value of reference
  */
 union udp_epoll_ref {
 	struct {
+		in_port_t	port;
+		uint8_t		pif;
 		bool		splice:1,
 				orig:1,
-				ns:1,
 				v6:1;
-		uint32_t	port:16;
 	};
 	uint32_t u32;
 };