net: mscc: ocelot: fix all IP traffic getting trapped to CPU with PTP over IP

The filters for the PTP trap keys are incorrectly configured, in the
sense that is2_entry_set() only looks at trap->key.ipv4.dport or
trap->key.ipv6.dport if trap->key.ipv4.proto or trap->key.ipv6.proto is
set to IPPROTO_TCP or IPPROTO_UDP.

But we don't do that, so is2_entry_set() goes through the "else" branch
of the IP protocol check, and ends up installing a rule for "Any IP
protocol match" (because msk is also 0). The UDP port is ignored.

This means that when we run "ptp4l -i swp0 -4", all IP traffic is
trapped to the CPU, which hinders bridging.

Fix this by specifying the IP protocol in the VCAP IS2 filters for PTP
over UDP.

Fixes: 96ca08c058 ("net: mscc: ocelot: set up traps for PTP packets")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mscc/ocelot.c

@@ -1432,6 +1432,8 @@ static void
 ocelot_populate_ipv4_ptp_event_trap_key(struct ocelot_vcap_filter *trap)
 {
 	trap->key_type = OCELOT_VCAP_KEY_IPV4;
+	trap->key.ipv4.proto.value[0] = IPPROTO_UDP;
+	trap->key.ipv4.proto.mask[0] = 0xff;
 	trap->key.ipv4.dport.value = PTP_EV_PORT;
 	trap->key.ipv4.dport.mask = 0xffff;
 }
@@ -1440,6 +1442,8 @@ static void
 ocelot_populate_ipv6_ptp_event_trap_key(struct ocelot_vcap_filter *trap)
 {
 	trap->key_type = OCELOT_VCAP_KEY_IPV6;
+	trap->key.ipv4.proto.value[0] = IPPROTO_UDP;
+	trap->key.ipv4.proto.mask[0] = 0xff;
 	trap->key.ipv6.dport.value = PTP_EV_PORT;
 	trap->key.ipv6.dport.mask = 0xffff;
 }
@@ -1448,6 +1452,8 @@ static void
 ocelot_populate_ipv4_ptp_general_trap_key(struct ocelot_vcap_filter *trap)
 {
 	trap->key_type = OCELOT_VCAP_KEY_IPV4;
+	trap->key.ipv4.proto.value[0] = IPPROTO_UDP;
+	trap->key.ipv4.proto.mask[0] = 0xff;
 	trap->key.ipv4.dport.value = PTP_GEN_PORT;
 	trap->key.ipv4.dport.mask = 0xffff;
 }
@@ -1456,6 +1462,8 @@ static void
 ocelot_populate_ipv6_ptp_general_trap_key(struct ocelot_vcap_filter *trap)
 {
 	trap->key_type = OCELOT_VCAP_KEY_IPV6;
+	trap->key.ipv4.proto.value[0] = IPPROTO_UDP;
+	trap->key.ipv4.proto.mask[0] = 0xff;
 	trap->key.ipv6.dport.value = PTP_GEN_PORT;
 	trap->key.ipv6.dport.mask = 0xffff;
 }