Subject: [PATCH net-next 1/3] net: mscc: ocelot: support matching on EtherType

From: Vladimir Oltean <[email-masked]>
Date: Mon, 20 Apr 2020 19:27:41 +0300

From: Vladimir Oltean <[email-masked]>

Currently, the filter's protocol is ignored except for a few special
cases (IPv4 and IPv6).

The EtherType can be matched inside VCAP IS2 by using a MAC_ETYPE key.
So there are 2 cases in which EtherType matches are supported:

  - As part of a larger MAC_ETYPE rule, such as:

    tc filter add dev swp0 ingress protocol ip \
            flower skip_sw src_mac 42:be:24:9b:76:20 action drop

  - Standalone (matching on protocol only):

    tc filter add dev swp0 ingress protocol arp \
            flower skip_sw action drop

As before, if the protocol is not specified, is it implicitly "all" and
the EtherType mask in the MAC_ETYPE half key is set to zero.

Signed-off-by: Vladimir Oltean <[email-masked]>
---
 drivers/net/ethernet/mscc/ocelot_flower.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mscc/ocelot_flower.c b/drivers/net/ethernet/mscc/ocelot_flower.c
index 954cb67eeaa2..67f0f5455ff0 100644
--- a/drivers/net/ethernet/mscc/ocelot_flower.c
+++ b/drivers/net/ethernet/mscc/ocelot_flower.c
@@ -51,6 +51,8 @@ static int ocelot_flower_parse(struct flow_cls_offload *f,
 {
 	struct flow_rule *rule = flow_cls_offload_flow_rule(f);
 	struct flow_dissector *dissector = rule->match.dissector;
+	u16 proto = ntohs(f->common.protocol);
+	bool match_protocol = true;
 
 	if (dissector->used_keys &
 	    ~(BIT(FLOW_DISSECTOR_KEY_CONTROL) |
@@ -71,7 +73,6 @@ static int ocelot_flower_parse(struct flow_cls_offload *f,
 
 	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 		struct flow_match_eth_addrs match;
-		u16 proto = ntohs(f->common.protocol);
 
 		/* The hw support mac matches only for MAC_ETYPE key,
 		 * therefore if other matches(port, tcp flags, etc) are added
@@ -114,6 +115,7 @@ static int ocelot_flower_parse(struct flow_cls_offload *f,
 				match.key->ip_proto;
 			ace->frame.ipv4.proto.mask[0] =
 				match.mask->ip_proto;
+			match_protocol = false;
 		}
 		if (ntohs(match.key->n_proto) == ETH_P_IPV6) {
 			ace->type = OCELOT_ACE_TYPE_IPV6;
@@ -121,11 +123,12 @@ static int ocelot_flower_parse(struct flow_cls_offload *f,
 				match.key->ip_proto;
 			ace->frame.ipv6.proto.mask[0] =
 				match.mask->ip_proto;
+			match_protocol = false;
 		}
 	}
 
 	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_IPV4_ADDRS) &&
-	    ntohs(f->common.protocol) == ETH_P_IP) {
+	    proto == ETH_P_IP) {
 		struct flow_match_ipv4_addrs match;
 		u8 *tmp;
 
@@ -141,10 +144,11 @@ static int ocelot_flower_parse(struct flow_cls_offload *f,
 
 		tmp = &ace->frame.ipv4.dip.mask.addr[0];
 		memcpy(tmp, &match.mask->dst, 4);
+		match_protocol = false;
 	}
 
 	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_IPV6_ADDRS) &&
-	    ntohs(f->common.protocol) == ETH_P_IPV6) {
+	    proto == ETH_P_IPV6) {
 		return -EOPNOTSUPP;
 	}
 
@@ -156,6 +160,7 @@ static int ocelot_flower_parse(struct flow_cls_offload *f,
 		ace->frame.ipv4.sport.mask = ntohs(match.mask->src);
 		ace->frame.ipv4.dport.value = ntohs(match.key->dst);
 		ace->frame.ipv4.dport.mask = ntohs(match.mask->dst);
+		match_protocol = false;
 	}
 
 	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_VLAN)) {
@@ -167,9 +172,20 @@ static int ocelot_flower_parse(struct flow_cls_offload *f,
 		ace->vlan.vid.mask = match.mask->vlan_id;
 		ace->vlan.pcp.value[0] = match.key->vlan_priority;
 		ace->vlan.pcp.mask[0] = match.mask->vlan_priority;
+		match_protocol = false;
 	}
 
 finished_key_parsing:
+	if (match_protocol && proto != ETH_P_ALL) {
+		/* TODO: support SNAP, LLC etc */
+		if (proto < ETH_P_802_3_MIN)
+			return -EOPNOTSUPP;
+		ace->type = OCELOT_ACE_TYPE_ETYPE;
+		*(u16 *)ace->frame.etype.etype.value = htons(proto);
+		*(u16 *)ace->frame.etype.etype.mask = 0xffff;
+	}
+	/* else, a rule of type OCELOT_ACE_TYPE_ANY is implicitly added */
+
 	ace->prio = f->common.prio;
 	ace->id = f->cookie;
 	return ocelot_flower_parse_action(f, ace);
-- 
2.17.1