flow: Common address information for target side

Require the address and port information for the target (non
initiating) side to be populated when a flow enters TGT state.
Implement that for TCP and ICMP.  For now this leaves some information
redundantly recorded in both generic and type specific fields.  We'll
fix that in later patches.

For TCP we now use the information from the flow to construct the
destination socket address in both tcp_conn_from_tap() and
tcp_splice_connect().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 17 insertions, 28 deletions

diff --git a/tcp_splice.c b/tcp_splice.c
index ffddc85..608e7f2 100644
--- a/tcp_splice.c
+++ b/tcp_splice.c
@@ -340,31 +340,20 @@ static int tcp_splice_connect_finish(const struct ctx *c,
  * tcp_splice_connect() - Create and connect socket for new spliced connection
  * @c:		Execution context
  * @conn:	Connection pointer
- * @af:		Address family
- * @pif:	pif on which to create socket
- * @port:	Destination port, host order
  *
  * Return: 0 for connect() succeeded or in progress, negative value on error
  */
-static int tcp_splice_connect(const struct ctx *c, struct tcp_splice_conn *conn,
-			      sa_family_t af, uint8_t pif, in_port_t port)
+static int tcp_splice_connect(const struct ctx *c, struct tcp_splice_conn *conn)
 {
-	struct sockaddr_in6 addr6 = {
-		.sin6_family = AF_INET6,
-		.sin6_port = htons(port),
-		.sin6_addr = IN6ADDR_LOOPBACK_INIT,
-	};
-	struct sockaddr_in addr4 = {
-		.sin_family = AF_INET,
-		.sin_port = htons(port),
-		.sin_addr = IN4ADDR_LOOPBACK_INIT,
-	};
-	const struct sockaddr *sa;
+	const struct flowside *tgt = &conn->f.side[TGTSIDE];
+	sa_family_t af = inany_v4(&tgt->eaddr) ? AF_INET : AF_INET6;
+	uint8_t tgtpif = conn->f.pif[TGTSIDE];
+	union sockaddr_inany sa;
 	socklen_t sl;
 
-	if (pif == PIF_HOST)
+	if (tgtpif == PIF_HOST)
 		conn->s[1] = tcp_conn_sock(c, af);
-	else if (pif == PIF_SPLICE)
+	else if (tgtpif == PIF_SPLICE)
 		conn->s[1] = tcp_conn_sock_ns(c, af);
 	else
 		ASSERT(0);
@@ -378,15 +367,9 @@ static int tcp_splice_connect(const struct ctx *c, struct tcp_splice_conn *conn,
 			   conn->s[1]);
 	}
 
-	if (CONN_V6(conn)) {
-		sa = (struct sockaddr *)&addr6;
-		sl = sizeof(addr6);
-	} else {
-		sa = (struct sockaddr *)&addr4;
-		sl = sizeof(addr4);
-	}
+	pif_sockaddr(c, &sa, &sl, tgtpif, &tgt->eaddr, tgt->eport);
 
-	if (connect(conn->s[1], sa, sl)) {
+	if (connect(conn->s[1], &sa.sa, sl)) {
 		if (errno != EINPROGRESS) {
 			flow_trace(conn, "Couldn't connect socket for splice: %s",
 				   strerror(errno));
@@ -491,7 +474,13 @@ bool tcp_splice_conn_from_sock(const struct ctx *c,
 		return false;
 	}
 
-	flow_target(flow, tgtpif);
+	/* FIXME: Record outbound source address when known */
+	if (af == AF_INET)
+		flow_target_af(flow, tgtpif, AF_INET,
+			       NULL, 0, &in4addr_loopback, dstport);
+	else
+		flow_target_af(flow, tgtpif, AF_INET6,
+			       NULL, 0, &in6addr_loopback, dstport);
 	conn = FLOW_SET_TYPE(flow, FLOW_TCP_SPLICE, tcp_splice);
 
 	conn->flags = af == AF_INET ? 0 : SPLICE_V6;
@@ -503,7 +492,7 @@ bool tcp_splice_conn_from_sock(const struct ctx *c,
 	if (setsockopt(s0, SOL_TCP, TCP_QUICKACK, &((int){ 1 }), sizeof(int)))
 		flow_trace(conn, "failed to set TCP_QUICKACK on %i", s0);
 
-	if (tcp_splice_connect(c, conn, af, tgtpif, dstport))
+	if (tcp_splice_connect(c, conn))
 		conn_flag(c, conn, CLOSING);
 
 	FLOW_ACTIVATE(conn);