net: flower: add support for matching cfm fields

Add support to the tc flower classifier to match based on fields in CFM
information elements like level and opcode.

tc filter add dev ens6 ingress protocol 802.1q \
	flower vlan_id 698 vlan_ethtype 0x8902 cfm mdl 5 op 46 \
	action drop
Signed-off-by: Zahari Doychev <zdoychev@maxlinear.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/uapi/linux/pkt_cls.h

@@ -596,6 +596,8 @@ enum {
 
 	TCA_FLOWER_L2_MISS,		/* u8 */
 
+	TCA_FLOWER_KEY_CFM,		/* nested */
+
 	__TCA_FLOWER_MAX,
 };
 
@@ -704,6 +706,13 @@ enum {
 	TCA_FLOWER_KEY_FLAGS_FRAG_IS_FIRST = (1 << 1),
 };
 
+enum {
+	TCA_FLOWER_KEY_CFM_OPT_UNSPEC,
+	TCA_FLOWER_KEY_CFM_MD_LEVEL,
+	TCA_FLOWER_KEY_CFM_OPCODE,
+	TCA_FLOWER_KEY_CFM_OPT_MAX,
+};
+
 #define TCA_FLOWER_MASK_FLAGS_RANGE	(1 << 0) /* Range-based match */
 
 /* Match-all classifier */

net/sched/cls_flower.c

@@ -11,6 +11,7 @@
 #include <linux/rhashtable.h>
 #include <linux/workqueue.h>
 #include <linux/refcount.h>
+#include <linux/bitfield.h>
 
 #include <linux/if_ether.h>
 #include <linux/in6.h>
@@ -71,6 +72,7 @@ struct fl_flow_key {
 	struct flow_dissector_key_num_of_vlans num_of_vlans;
 	struct flow_dissector_key_pppoe pppoe;
 	struct flow_dissector_key_l2tpv3 l2tpv3;
+	struct flow_dissector_key_cfm cfm;
 } __aligned(BITS_PER_LONG / 8); /* Ensure that we can do comparisons as longs. */
 
 struct fl_flow_mask_range {
@@ -725,6 +727,7 @@ static const struct nla_policy fl_policy[TCA_FLOWER_MAX + 1] = {
 	[TCA_FLOWER_KEY_PPP_PROTO]	= { .type = NLA_U16 },
 	[TCA_FLOWER_KEY_L2TPV3_SID]	= { .type = NLA_U32 },
 	[TCA_FLOWER_L2_MISS]		= NLA_POLICY_MAX(NLA_U8, 1),
+	[TCA_FLOWER_KEY_CFM]		= { .type = NLA_NESTED },
 };
 
 static const struct nla_policy
@@ -773,6 +776,12 @@ mpls_stack_entry_policy[TCA_FLOWER_KEY_MPLS_OPT_LSE_MAX + 1] = {
 	[TCA_FLOWER_KEY_MPLS_OPT_LSE_LABEL]    = { .type = NLA_U32 },
 };
 
+static const struct nla_policy cfm_opt_policy[TCA_FLOWER_KEY_CFM_OPT_MAX] = {
+	[TCA_FLOWER_KEY_CFM_MD_LEVEL]	= NLA_POLICY_MAX(NLA_U8,
+						FLOW_DIS_CFM_MDL_MAX),
+	[TCA_FLOWER_KEY_CFM_OPCODE]	= { .type = NLA_U8 },
+};
+
 static void fl_set_key_val(struct nlattr **tb,
 			   void *val, int val_type,
 			   void *mask, int mask_type, int len)
@@ -1660,6 +1669,53 @@ static bool is_vlan_key(struct nlattr *tb, __be16 *ethertype,
 	return false;
 }
 
+static void fl_set_key_cfm_md_level(struct nlattr **tb,
+				    struct fl_flow_key *key,
+				    struct fl_flow_key *mask,
+				    struct netlink_ext_ack *extack)
+{
+	u8 level;
+
+	if (!tb[TCA_FLOWER_KEY_CFM_MD_LEVEL])
+		return;
+
+	level = nla_get_u8(tb[TCA_FLOWER_KEY_CFM_MD_LEVEL]);
+	key->cfm.mdl_ver = FIELD_PREP(FLOW_DIS_CFM_MDL_MASK, level);
+	mask->cfm.mdl_ver = FLOW_DIS_CFM_MDL_MASK;
+}
+
+static void fl_set_key_cfm_opcode(struct nlattr **tb,
+				  struct fl_flow_key *key,
+				  struct fl_flow_key *mask,
+				  struct netlink_ext_ack *extack)
+{
+	fl_set_key_val(tb, &key->cfm.opcode, TCA_FLOWER_KEY_CFM_OPCODE,
+		       &mask->cfm.opcode, TCA_FLOWER_UNSPEC,
+		       sizeof(key->cfm.opcode));
+}
+
+static int fl_set_key_cfm(struct nlattr **tb,
+			  struct fl_flow_key *key,
+			  struct fl_flow_key *mask,
+			  struct netlink_ext_ack *extack)
+{
+	struct nlattr *nla_cfm_opt[TCA_FLOWER_KEY_CFM_OPT_MAX];
+	int err;
+
+	if (!tb[TCA_FLOWER_KEY_CFM])
+		return 0;
+
+	err = nla_parse_nested(nla_cfm_opt, TCA_FLOWER_KEY_CFM_OPT_MAX,
+			       tb[TCA_FLOWER_KEY_CFM], cfm_opt_policy, extack);
+	if (err < 0)
+		return err;
+
+	fl_set_key_cfm_opcode(nla_cfm_opt, key, mask, extack);
+	fl_set_key_cfm_md_level(nla_cfm_opt, key, mask, extack);
+
+	return 0;
+}
+
 static int fl_set_key(struct net *net, struct nlattr **tb,
 		      struct fl_flow_key *key, struct fl_flow_key *mask,
 		      struct netlink_ext_ack *extack)
@@ -1814,6 +1870,10 @@ static int fl_set_key(struct net *net, struct nlattr **tb,
 			       TCA_FLOWER_KEY_L2TPV3_SID,
 			       &mask->l2tpv3.session_id, TCA_FLOWER_UNSPEC,
 			       sizeof(key->l2tpv3.session_id));
+	} else if (key->basic.n_proto  == htons(ETH_P_CFM)) {
+		ret = fl_set_key_cfm(tb, key, mask, extack);
+		if (ret)
+			return ret;
 	}
 
 	if (key->basic.ip_proto == IPPROTO_TCP ||
@@ -1996,6 +2056,8 @@ static void fl_init_dissector(struct flow_dissector *dissector,
 			     FLOW_DISSECTOR_KEY_PPPOE, pppoe);
 	FL_KEY_SET_IF_MASKED(mask, keys, cnt,
 			     FLOW_DISSECTOR_KEY_L2TPV3, l2tpv3);
+	FL_KEY_SET_IF_MASKED(mask, keys, cnt,
+			     FLOW_DISSECTOR_KEY_CFM, cfm);
 
 	skb_flow_dissector_init(dissector, keys, cnt);
 }
@@ -3029,6 +3091,43 @@ static int fl_dump_key_ct(struct sk_buff *skb,
 	return -EMSGSIZE;
 }
 
+static int fl_dump_key_cfm(struct sk_buff *skb,
+			   struct flow_dissector_key_cfm *key,
+			   struct flow_dissector_key_cfm *mask)
+{
+	struct nlattr *opts;
+	int err;
+	u8 mdl;
+
+	if (!memchr_inv(mask, 0, sizeof(*mask)))
+		return 0;
+
+	opts = nla_nest_start(skb, TCA_FLOWER_KEY_CFM);
+	if (!opts)
+		return -EMSGSIZE;
+
+	if (FIELD_GET(FLOW_DIS_CFM_MDL_MASK, mask->mdl_ver)) {
+		mdl = FIELD_GET(FLOW_DIS_CFM_MDL_MASK, key->mdl_ver);
+		err = nla_put_u8(skb, TCA_FLOWER_KEY_CFM_MD_LEVEL, mdl);
+		if (err)
+			goto err_cfm_opts;
+	}
+
+	if (mask->opcode) {
+		err = nla_put_u8(skb, TCA_FLOWER_KEY_CFM_OPCODE, key->opcode);
+		if (err)
+			goto err_cfm_opts;
+	}
+
+	nla_nest_end(skb, opts);
+
+	return 0;
+
+err_cfm_opts:
+	nla_nest_cancel(skb, opts);
+	return err;
+}
+
 static int fl_dump_key_options(struct sk_buff *skb, int enc_opt_type,
 			       struct flow_dissector_key_enc_opts *enc_opts)
 {
@@ -3316,6 +3415,9 @@ static int fl_dump_key(struct sk_buff *skb, struct net *net,
 			     sizeof(key->hash.hash)))
 		goto nla_put_failure;
 
+	if (fl_dump_key_cfm(skb, &key->cfm, &mask->cfm))
+		goto nla_put_failure;
+
 	return 0;
 
 nla_put_failure: