Consolidate port forwarding configuration into a common structure

The configuration for how to forward ports in and out of the guest/ns is
divided between several different variables.  For each connect direction
and protocol we have a mode in the udp/tcp context structure, a bitmap
of which ports to forward also in the context structure and an array of
deltas to apply if the outward facing and inward facing port numbers are
different.  This last is a separate global variable, rather than being in
the context structure, for no particular reason.  UDP also requires an
additional array which has the reverse mapping used for return packets.

Consolidate these into a re-used substructure in the context structure.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 13 insertions, 17 deletions

diff --git a/udp.c b/udp.c
index 0b4e134..38bb8d8 100644
--- a/udp.c
+++ b/udp.c
@@ -166,12 +166,6 @@ struct udp_splice_port {
 static struct udp_tap_port	udp_tap_map	[IP_VERSIONS][USHRT_MAX];
 static struct udp_splice_port	udp_splice_map	[IP_VERSIONS][USHRT_MAX];
 
-/* Port re-mappings as delta, indexed by original destination port */
-static in_port_t		udp_port_delta_to_tap	[USHRT_MAX];
-static in_port_t		udp_port_delta_from_tap	[USHRT_MAX];
-static in_port_t		udp_port_delta_to_init	[USHRT_MAX];
-static in_port_t		udp_port_delta_from_init[USHRT_MAX];
-
 enum udp_act_type {
 	UDP_ACT_TAP,
 	UDP_ACT_NS_CONN,
@@ -265,24 +259,26 @@ static struct mmsghdr	udp_mmh_sendto		[UDP_SPLICE_FRAMES];
 
 /**
  * udp_remap_to_tap() - Set delta for port translation to/from guest/tap
+ * @c:		Execution context
  * @port:	Original destination port, host order
  * @delta:	Delta to be added to original destination port
  */
-void udp_remap_to_tap(in_port_t port, in_port_t delta)
+void udp_remap_to_tap(struct ctx *c, in_port_t port, in_port_t delta)
 {
-	udp_port_delta_to_tap[port] = delta;
-	udp_port_delta_from_tap[port + delta] = USHRT_MAX - delta;
+	c->udp.fwd_in.f.delta[port] = delta;
+	c->udp.fwd_in.rdelta[port + delta] = USHRT_MAX - delta;
 }
 
 /**
  * udp_remap_to_init() - Set delta for port translation to/from init namespace
+ * @c:		Execution context
  * @port:	Original destination port, host order
  * @delta:	Delta to be added to original destination port
  */
-void udp_remap_to_init(in_port_t port, in_port_t delta)
+void udp_remap_to_init(struct ctx *c, in_port_t port, in_port_t delta)
 {
-	udp_port_delta_to_init[port] = delta;
-	udp_port_delta_from_init[port + delta] = USHRT_MAX - delta;
+	c->udp.fwd_out.f.delta[port] = delta;
+	c->udp.fwd_out.rdelta[port + delta] = USHRT_MAX - delta;
 }
 
 /**
@@ -583,7 +579,7 @@ static void udp_sock_handler_splice(const struct ctx *c, union epoll_ref ref,
 
 	switch (ref.r.p.udp.udp.splice) {
 	case UDP_TO_NS:
-		src += udp_port_delta_from_init[src];
+		src += c->udp.fwd_out.rdelta[src];
 
 		if (!(s = udp_splice_map[v6][src].ns_conn_sock)) {
 			struct udp_splice_connect_ns_arg arg = {
@@ -603,7 +599,7 @@ static void udp_sock_handler_splice(const struct ctx *c, union epoll_ref ref,
 		send_dst = udp_splice_map[v6][dst].init_dst_port;
 		break;
 	case UDP_TO_INIT:
-		src += udp_port_delta_from_tap[src];
+		src += c->udp.fwd_in.rdelta[src];
 
 		if (!(s = udp_splice_map[v6][src].init_conn_sock)) {
 			s = udp_splice_connect(c, v6, ref.r.s, src, dst,
@@ -1121,10 +1117,10 @@ void udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 
 	if (ns) {
 		uref.udp.port = (in_port_t)(port +
-					    udp_port_delta_to_init[port]);
+					    c->udp.fwd_out.f.delta[port]);
 	} else {
 		uref.udp.port = (in_port_t)(port +
-					    udp_port_delta_to_tap[port]);
+					    c->udp.fwd_in.f.delta[port]);
 	}
 
 	if (af == AF_INET || af == AF_UNSPEC) {
@@ -1209,7 +1205,7 @@ int udp_sock_init_ns(void *arg)
 		return 0;
 
 	for (dst = 0; dst < USHRT_MAX; dst++) {
-		if (!bitmap_isset(c->udp.port_to_init, dst))
+		if (!bitmap_isset(c->udp.fwd_out.f.map, dst))
 			continue;
 
 		udp_sock_init(c, 1, AF_UNSPEC, NULL, dst);