[PATCH net-next v2 0/2] net: flower: add cfm support

[PATCH net-next v2 0/2] net: flower: add cfm support

[Zahari Doychev]

From: Zahari Doychev <zdoychev@maxlinear.com>

The first patch adds cfm support to the flower classifier. 
The second adds a selftest for the flower cfm functionality.

iproute2 changes will come in follow up patches.

---

v1->v2:
 - add missing comments
 - improve cfm packet dissection
 - move defines to header file
 - fix code formatting
 - remove unneeded attribute defines

rfc->v1:
 - add selftest to the makefile TEST_PROGS.


Zahari Doychev (2):
  net: flower: add support for matching cfm fields
  selftests: net: add tc flower cfm test

 include/net/flow_dissector.h                  |  21 +++
 include/uapi/linux/pkt_cls.h                  |   9 +
 net/core/flow_dissector.c                     |  29 +++
 net/sched/cls_flower.c                        | 108 ++++++++++-
 .../testing/selftests/net/forwarding/Makefile |   1 +
 .../selftests/net/forwarding/tc_flower_cfm.sh | 175 ++++++++++++++++++
 6 files changed, 342 insertions(+), 1 deletion(-)
 create mode 100755 tools/testing/selftests/net/forwarding/tc_flower_cfm.sh

-- 
2.40.0

[PATCH net-next v2 1/2] net: flower: add support for matching cfm fields

[Zahari Doychev]

From: Zahari Doychev <zdoychev@maxlinear.com>

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>
---
 include/net/flow_dissector.h |  21 +++++++
 include/uapi/linux/pkt_cls.h |   9 +++
 net/core/flow_dissector.c    |  29 ++++++++++
 net/sched/cls_flower.c       | 108 ++++++++++++++++++++++++++++++++++-
 4 files changed, 166 insertions(+), 1 deletion(-)

diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index 5ccf52ef8809..e1e7e51db88f 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -297,6 +297,26 @@ struct flow_dissector_key_l2tpv3 {
 	__be32 session_id;
 };
 
+/**
+ * struct flow_dissector_key_cfm
+ * @mdl_ver: maintenance domain level(mdl) and cfm protocol version
+ * @opcode: code specifying a type of cfm protocol packet
+ *
+ * See 802.1ag, ITU-T G.8013/Y.1731
+ *         1               2
+ * |7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | mdl | version |     opcode    |
+ * +-----+---------+-+-+-+-+-+-+-+-+
+ */
+struct flow_dissector_key_cfm {
+	u8	mdl_ver;
+	u8	opcode;
+};
+
+#define FLOW_DIS_CFM_MDL_MASK	 7
+#define FLOW_DIS_CFM_MDL_SHIFT	 5
+
 enum flow_dissector_key_id {
 	FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
 	FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
@@ -329,6 +349,7 @@ enum flow_dissector_key_id {
 	FLOW_DISSECTOR_KEY_NUM_OF_VLANS, /* struct flow_dissector_key_num_of_vlans */
 	FLOW_DISSECTOR_KEY_PPPOE, /* struct flow_dissector_key_pppoe */
 	FLOW_DISSECTOR_KEY_L2TPV3, /* struct flow_dissector_key_l2tpv3 */
+	FLOW_DISSECTOR_KEY_CFM, /* struct flow_dissector_key_cfm */
 
 	FLOW_DISSECTOR_KEY_MAX,
 };
diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
index 648a82f32666..8e3f809c9a03 100644
--- a/include/uapi/linux/pkt_cls.h
+++ b/include/uapi/linux/pkt_cls.h
@@ -594,6 +594,8 @@ enum {
 
 	TCA_FLOWER_KEY_L2TPV3_SID,	/* be32 */
 
+	TCA_FLOWER_KEY_CFM,	/* nested */
+
 	__TCA_FLOWER_MAX,
 };
 
@@ -702,6 +704,13 @@ 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 */
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 25fb0bbc310f..7c694e7b9917 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -547,6 +547,29 @@ __skb_flow_dissect_arp(const struct sk_buff *skb,
 	return FLOW_DISSECT_RET_OUT_GOOD;
 }
 
+static enum flow_dissect_ret
+__skb_flow_dissect_cfm(const struct sk_buff *skb,
+		       struct flow_dissector *flow_dissector,
+		       void *target_container, const void *data,
+		       int nhoff, int hlen)
+{
+	struct flow_dissector_key_cfm *key, *hdr, _hdr;
+
+	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CFM))
+		return FLOW_DISSECT_RET_OUT_GOOD;
+
+	hdr = __skb_header_pointer(skb, nhoff, sizeof(*key), data, hlen, &_hdr);
+	if (!hdr)
+		return FLOW_DISSECT_RET_OUT_BAD;
+
+	key = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_CFM,
+					target_container);
+
+	*key = *hdr;
+
+	return  FLOW_DISSECT_RET_OUT_GOOD;
+}
+
 static enum flow_dissect_ret
 __skb_flow_dissect_gre(const struct sk_buff *skb,
 		       struct flow_dissector_key_control *key_control,
@@ -1390,6 +1413,12 @@ bool __skb_flow_dissect(const struct net *net,
 		break;
 	}
 
+	case htons(ETH_P_CFM): {
+		fdret = __skb_flow_dissect_cfm(skb, flow_dissector,
+					       target_container, data,
+					       nhoff, hlen);
+		break;
+	}
 	default:
 		fdret = FLOW_DISSECT_RET_OUT_BAD;
 		break;
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 885c95191ccf..75f3a64f0daa 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -71,6 +71,7 @@ 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 {
@@ -711,7 +712,7 @@ static const struct nla_policy fl_policy[TCA_FLOWER_MAX + 1] = {
 	[TCA_FLOWER_KEY_PPPOE_SID]	= { .type = NLA_U16 },
 	[TCA_FLOWER_KEY_PPP_PROTO]	= { .type = NLA_U16 },
 	[TCA_FLOWER_KEY_L2TPV3_SID]	= { .type = NLA_U32 },
-
+	[TCA_FLOWER_KEY_CFM]		= { .type = NLA_NESTED },
 };
 
 static const struct nla_policy
@@ -760,6 +761,11 @@ 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]		= { .type = NLA_U8 },
+	[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)
@@ -1644,6 +1650,60 @@ static bool is_vlan_key(struct nlattr *tb, __be16 *ethertype,
 	return false;
 }
 
+static int 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 0;
+
+	level = nla_get_u8(tb[TCA_FLOWER_KEY_CFM_MD_LEVEL]);
+	if (level & ~FLOW_DIS_CFM_MDL_MASK) {
+		NL_SET_ERR_MSG_ATTR(extack, tb[TCA_FLOWER_KEY_CFM_MD_LEVEL],
+				    "cfm md level must be 0-7");
+		return -EINVAL;
+	}
+
+	key->cfm.mdl_ver = level << FLOW_DIS_CFM_MDL_SHIFT;
+	mask->cfm.mdl_ver = FLOW_DIS_CFM_MDL_MASK << FLOW_DIS_CFM_MDL_SHIFT;
+
+	return 0;
+}
+
+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);
+
+	return fl_set_key_cfm_md_level(nla_cfm_opt, key, mask, extack);
+}
+
 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)
@@ -1794,6 +1854,10 @@ 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 ||
@@ -1976,6 +2040,8 @@ 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);
 }
@@ -2984,6 +3050,43 @@ static int fl_dump_key_ct(struct sk_buff *skb,
 	return -EMSGSIZE;
 }
 
+static int fl_dump_key_cfm(struct sk_buff *skb,
+			   struct fl_flow_key *key,
+			   struct fl_flow_key *mask)
+{
+	struct nlattr *opts;
+	int err;
+
+	if (!memchr_inv(&mask->cfm, 0, sizeof(mask->cfm)))
+		return 0;
+
+	opts = nla_nest_start(skb, TCA_FLOWER_KEY_CFM);
+	if (!opts)
+		return -EMSGSIZE;
+
+	if (mask->cfm.mdl_ver) {
+		err = nla_put_u8(skb, TCA_FLOWER_KEY_CFM_MD_LEVEL,
+				 key->cfm.mdl_ver >> FLOW_DIS_CFM_MDL_SHIFT);
+		if (err)
+			goto err_cfm_opts;
+	}
+
+	if (mask->cfm.opcode) {
+		err = nla_put_u8(skb, TCA_FLOWER_KEY_CFM_OPCODE,
+				 key->cfm.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)
 {
@@ -3266,6 +3369,9 @@ 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, mask))
+		goto nla_put_failure;
+
 	return 0;
 
 nla_put_failure:
-- 
2.40.0

[PATCH net-next v2 2/2] selftests: net: add tc flower cfm test

[Zahari Doychev]

From: Zahari Doychev <zdoychev@maxlinear.com>

New cfm flower test case is added to the net forwarding selfttests.

Signed-off-by: Zahari Doychev <zdoychev@maxlinear.com>
---
 .../testing/selftests/net/forwarding/Makefile |   1 +
 .../selftests/net/forwarding/tc_flower_cfm.sh | 175 ++++++++++++++++++
 2 files changed, 176 insertions(+)
 create mode 100755 tools/testing/selftests/net/forwarding/tc_flower_cfm.sh

diff --git a/tools/testing/selftests/net/forwarding/Makefile b/tools/testing/selftests/net/forwarding/Makefile
index 91201ab3c4fc..72ed9b18ba28 100644
--- a/tools/testing/selftests/net/forwarding/Makefile
+++ b/tools/testing/selftests/net/forwarding/Makefile
@@ -82,6 +82,7 @@ TEST_PROGS = bridge_igmp.sh \
 	tc_chains.sh \
 	tc_flower_router.sh \
 	tc_flower.sh \
+	tc_flower_cfm.sh \
 	tc_mpls_l2vpn.sh \
 	tc_police.sh \
 	tc_shblocks.sh \
diff --git a/tools/testing/selftests/net/forwarding/tc_flower_cfm.sh b/tools/testing/selftests/net/forwarding/tc_flower_cfm.sh
new file mode 100755
index 000000000000..c93cab2d7876
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/tc_flower_cfm.sh
@@ -0,0 +1,175 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+ALL_TESTS="match_cfm_opcode match_cfm_level match_cfm_level_and_opcode"
+NUM_NETIFS=2
+source tc_common.sh
+source lib.sh
+
+tcflags="skip_hw"
+
+h1_create()
+{
+	simple_if_init $h1 192.0.2.1/24 198.51.100.1/24
+}
+
+h1_destroy()
+{
+	simple_if_fini $h1 192.0.2.1/24 198.51.100.1/24
+}
+
+h2_create()
+{
+	simple_if_init $h2 192.0.2.2/24 198.51.100.2/24
+	tc qdisc add dev $h2 clsact
+}
+
+h2_destroy()
+{
+	tc qdisc del dev $h2 clsact
+	simple_if_fini $h2 192.0.2.2/24 198.51.100.2/24
+}
+
+cfm_mdl_opcode()
+{
+	local mdl=$1
+	local op=$2
+	local flags=$3
+	local tlv_offset=$4
+
+	printf "%02x %02x %02x %02x"    \
+		   $((mdl << 5))             \
+		   $((op & 0xff))             \
+		   $((flags & 0xff)) \
+		   $tlv_offset
+}
+
+match_cfm_opcode()
+{
+	local ethtype="89 02"; readonly ethtype
+	RET=0
+
+	tc filter add dev $h2 ingress protocol cfm pref 1 handle 101 \
+	   flower cfm op 47 action drop
+	tc filter add dev $h2 ingress protocol cfm pref 2 handle 102 \
+	   flower cfm op 43 action drop
+
+	pkt="$ethtype $(cfm_mdl_opcode 7 47 0 4)"
+	$MZ $h1 -c 1 -p 64 -a $h1mac -b $h2mac "$pkt" -q
+	pkt="$ethtype $(cfm_mdl_opcode 6 5 0 4)"
+	$MZ $h1 -c 1 -p 64 -a $h1mac -b $h2mac "$pkt" -q
+
+	tc_check_packets "dev $h2 ingress" 101 1
+	check_err $? "Did not match on correct opcode"
+
+	tc_check_packets "dev $h2 ingress" 102 0
+	check_err $? "Matched on the wrong opcode"
+
+	tc filter del dev $h2 ingress protocol cfm pref 1 handle 101 flower
+	tc filter del dev $h2 ingress protocol cfm pref 2 handle 102 flower
+
+	log_test "CFM opcode match test"
+}
+
+match_cfm_level()
+{
+	local ethtype="89 02"; readonly ethtype
+	RET=0
+
+	tc filter add dev $h2 ingress protocol cfm pref 1 handle 101 \
+	   flower cfm mdl 5 action drop
+	tc filter add dev $h2 ingress protocol cfm pref 2 handle 102 \
+	   flower cfm mdl 3 action drop
+	tc filter add dev $h2 ingress protocol cfm pref 3 handle 103 \
+	   flower cfm mdl 0 action drop
+
+	pkt="$ethtype $(cfm_mdl_opcode 5 42 0 4)"
+	$MZ $h1 -c 1 -p 64 -a $h1mac -b $h2mac "$pkt" -q
+	pkt="$ethtype $(cfm_mdl_opcode 6 1 0 4)"
+	$MZ $h1 -c 1 -p 64 -a $h1mac -b $h2mac "$pkt" -q
+	pkt="$ethtype $(cfm_mdl_opcode 0 1 0 4)"
+	$MZ $h1 -c 1 -p 64 -a $h1mac -b $h2mac "$pkt" -q
+
+	tc_check_packets "dev $h2 ingress" 101 1
+	check_err $? "Did not match on correct level"
+
+	tc_check_packets "dev $h2 ingress" 102 0
+	check_err $? "Matched on the wrong level"
+
+	tc_check_packets "dev $h2 ingress" 103 1
+	check_err $? "Did not match on corret level"
+
+	tc filter del dev $h2 ingress protocol cfm pref 1 handle 101 flower
+	tc filter del dev $h2 ingress protocol cfm pref 2 handle 102 flower
+	tc filter del dev $h2 ingress protocol cfm pref 3 handle 103 flower
+
+	log_test "CFM level match test"
+}
+
+match_cfm_level_and_opcode()
+{
+	local ethtype="89 02"; readonly ethtype
+	RET=0
+
+	tc filter add dev $h2 ingress protocol cfm pref 1 handle 101 \
+	   flower cfm mdl 5 op 41 action drop
+	tc filter add dev $h2 ingress protocol cfm pref 2 handle 102 \
+	   flower cfm mdl 7 op 42 action drop
+
+	pkt="$ethtype $(cfm_mdl_opcode 5 41 0 4)"
+	$MZ $h1 -c 1 -p 64 -a $h1mac -b $h2mac "$pkt" -q
+	pkt="$ethtype $(cfm_mdl_opcode 7 3 0 4)"
+	$MZ $h1 -c 1 -p 64 -a $h1mac -b $h2mac "$pkt" -q
+	pkt="$ethtype $(cfm_mdl_opcode 3 42 0 4)"
+	$MZ $h1 -c 1 -p 64 -a $h1mac -b $h2mac "$pkt" -q
+
+	tc_check_packets "dev $h2 ingress" 101 1
+	check_err $? "Did not match on correct level and opcode"
+	tc_check_packets "dev $h2 ingress" 102 0
+	check_err $? "Matched on the wrong level and opcode"
+
+	tc filter del dev $h2 ingress protocol cfm pref 1 handle 101 flower
+	tc filter del dev $h2 ingress protocol cfm pref 2 handle 102 flower
+
+	log_test "CFM opcode and level match test"
+}
+
+setup_prepare()
+{
+	h1=${NETIFS[p1]}
+	h2=${NETIFS[p2]}
+	h1mac=$(mac_get $h1)
+	h2mac=$(mac_get $h2)
+
+	vrf_prepare
+
+	h1_create
+	h2_create
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	h2_destroy
+	h1_destroy
+
+	vrf_cleanup
+}
+
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+tests_run
+
+tc_offload_check
+if [[ $? -ne 0 ]]; then
+	log_info "Could not test offloaded functionality"
+else
+	tcflags="skip_sw"
+	tests_run
+fi
+
+exit $EXIT_STATUS
-- 
2.40.0

Re: [PATCH net-next v2 2/2] selftests: net: add tc flower cfm test

[Simon Horman]

On Sun, Apr 02, 2023 at 05:10:31PM +0200, Zahari Doychev wrote:
> From: Zahari Doychev <zdoychev@maxlinear.com>
> 
> New cfm flower test case is added to the net forwarding selfttests.
> 
> Signed-off-by: Zahari Doychev <zdoychev@maxlinear.com>

...

> +	tc_check_packets "dev $h2 ingress" 103 1
> +	check_err $? "Did not match on corret level"

Hi Zahari,

if you need to repost for some reason you may consider
correcting the spelling of 'corret'.

...

Re: [PATCH net-next v2 1/2] net: flower: add support for matching cfm fields

[Simon Horman]

On Sun, Apr 02, 2023 at 05:10:30PM +0200, Zahari Doychev wrote:
> From: Zahari Doychev <zdoychev@maxlinear.com>
> 
> 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>

Hi Zahari,

thanks for your patch.
Some initial feedback from my side follows.

> ---
>  include/net/flow_dissector.h |  21 +++++++
>  include/uapi/linux/pkt_cls.h |   9 +++
>  net/core/flow_dissector.c    |  29 ++++++++++
>  net/sched/cls_flower.c       | 108 ++++++++++++++++++++++++++++++++++-
>  4 files changed, 166 insertions(+), 1 deletion(-)

FWIIW I would have split the flow dissector and cls flower
changes into separate patches.

> 
> diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
> index 5ccf52ef8809..e1e7e51db88f 100644
> --- a/include/net/flow_dissector.h
> +++ b/include/net/flow_dissector.h
> @@ -297,6 +297,26 @@ struct flow_dissector_key_l2tpv3 {
>  	__be32 session_id;
>  };
>  
> +/**
> + * struct flow_dissector_key_cfm
> + * @mdl_ver: maintenance domain level(mdl) and cfm protocol version
> + * @opcode: code specifying a type of cfm protocol packet
> + *
> + * See 802.1ag, ITU-T G.8013/Y.1731
> + *         1               2
> + * |7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|
> + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> + * | mdl | version |     opcode    |
> + * +-----+---------+-+-+-+-+-+-+-+-+
> + */
> +struct flow_dissector_key_cfm {
> +	u8	mdl_ver;
> +	u8	opcode;
> +};
> +
> +#define FLOW_DIS_CFM_MDL_MASK	 7
> +#define FLOW_DIS_CFM_MDL_SHIFT	 5

I think that if you used GENMASK to create the mask,
and then FIELD_PREP/FIELD_GET to use the mask you
could avoid _SHIFT entirely. Which might be cleaner.

...

> diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
> index 25fb0bbc310f..7c694e7b9917 100644
> --- a/net/core/flow_dissector.c
> +++ b/net/core/flow_dissector.c
> @@ -547,6 +547,29 @@ __skb_flow_dissect_arp(const struct sk_buff *skb,
>  	return FLOW_DISSECT_RET_OUT_GOOD;
>  }
>  
> +static enum flow_dissect_ret
> +__skb_flow_dissect_cfm(const struct sk_buff *skb,
> +		       struct flow_dissector *flow_dissector,
> +		       void *target_container, const void *data,
> +		       int nhoff, int hlen)
> +{
> +	struct flow_dissector_key_cfm *key, *hdr, _hdr;
> +
> +	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CFM))
> +		return FLOW_DISSECT_RET_OUT_GOOD;
> +
> +	hdr = __skb_header_pointer(skb, nhoff, sizeof(*key), data, hlen, &_hdr);
> +	if (!hdr)
> +		return FLOW_DISSECT_RET_OUT_BAD;
> +
> +	key = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_CFM,
> +					target_container);
> +
> +	*key = *hdr;

It is unusual to just copy the header directly to the key.
But as both are two u8 values I guess it is fine.

> +
> +	return  FLOW_DISSECT_RET_OUT_GOOD;
> +}
> +
>  static enum flow_dissect_ret
>  __skb_flow_dissect_gre(const struct sk_buff *skb,
>  		       struct flow_dissector_key_control *key_control,
> @@ -1390,6 +1413,12 @@ bool __skb_flow_dissect(const struct net *net,
>  		break;
>  	}
>  
> +	case htons(ETH_P_CFM): {
> +		fdret = __skb_flow_dissect_cfm(skb, flow_dissector,
> +					       target_container, data,
> +					       nhoff, hlen);

I do like that you moved the handling into it's own function.
But I do also note that this style differs from adjacent code in this
file.

> +		break;
> +	}
>  	default:
>  		fdret = FLOW_DISSECT_RET_OUT_BAD;
>  		break;

...

Re: [PATCH net-next v2 1/2] net: flower: add support for matching cfm fields

[Zahari Doychev]

On Mon, Apr 03, 2023 at 04:54:12PM +0200, Simon Horman wrote:
> On Sun, Apr 02, 2023 at 05:10:30PM +0200, Zahari Doychev wrote:
> > From: Zahari Doychev <zdoychev@maxlinear.com>
> > 
> > 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>
> 
> Hi Zahari,
> 
> thanks for your patch.
> Some initial feedback from my side follows.
> 
> > ---
> >  include/net/flow_dissector.h |  21 +++++++
> >  include/uapi/linux/pkt_cls.h |   9 +++
> >  net/core/flow_dissector.c    |  29 ++++++++++
> >  net/sched/cls_flower.c       | 108 ++++++++++++++++++++++++++++++++++-
> >  4 files changed, 166 insertions(+), 1 deletion(-)
> 
> FWIIW I would have split the flow dissector and cls flower
> changes into separate patches.

I think it makes sense so I would do it.

> 
> > 
> > diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
> > index 5ccf52ef8809..e1e7e51db88f 100644
> > --- a/include/net/flow_dissector.h
> > +++ b/include/net/flow_dissector.h
> > @@ -297,6 +297,26 @@ struct flow_dissector_key_l2tpv3 {
> >  	__be32 session_id;
> >  };
> >  
> > +/**
> > + * struct flow_dissector_key_cfm
> > + * @mdl_ver: maintenance domain level(mdl) and cfm protocol version
> > + * @opcode: code specifying a type of cfm protocol packet
> > + *
> > + * See 802.1ag, ITU-T G.8013/Y.1731
> > + *         1               2
> > + * |7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|
> > + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
> > + * | mdl | version |     opcode    |
> > + * +-----+---------+-+-+-+-+-+-+-+-+
> > + */
> > +struct flow_dissector_key_cfm {
> > +	u8	mdl_ver;
> > +	u8	opcode;
> > +};
> > +
> > +#define FLOW_DIS_CFM_MDL_MASK	 7
> > +#define FLOW_DIS_CFM_MDL_SHIFT	 5
> 
> I think that if you used GENMASK to create the mask,
> and then FIELD_PREP/FIELD_GET to use the mask you
> could avoid _SHIFT entirely. Which might be cleaner.

It was proposed in the previous version for different part but it applies here
as well so I would change it.

> 
> ...
> 
> > diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
> > index 25fb0bbc310f..7c694e7b9917 100644
> > --- a/net/core/flow_dissector.c
> > +++ b/net/core/flow_dissector.c
> > @@ -547,6 +547,29 @@ __skb_flow_dissect_arp(const struct sk_buff *skb,
> >  	return FLOW_DISSECT_RET_OUT_GOOD;
> >  }
> >  
> > +static enum flow_dissect_ret
> > +__skb_flow_dissect_cfm(const struct sk_buff *skb,
> > +		       struct flow_dissector *flow_dissector,
> > +		       void *target_container, const void *data,
> > +		       int nhoff, int hlen)
> > +{
> > +	struct flow_dissector_key_cfm *key, *hdr, _hdr;
> > +
> > +	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CFM))
> > +		return FLOW_DISSECT_RET_OUT_GOOD;
> > +
> > +	hdr = __skb_header_pointer(skb, nhoff, sizeof(*key), data, hlen, &_hdr);
> > +	if (!hdr)
> > +		return FLOW_DISSECT_RET_OUT_BAD;
> > +
> > +	key = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_CFM,
> > +					target_container);
> > +
> > +	*key = *hdr;
> 
> It is unusual to just copy the header directly to the key.
> But as both are two u8 values I guess it is fine.

I was wondering about this so I would use the fields here.

> 
> > +
> > +	return  FLOW_DISSECT_RET_OUT_GOOD;
> > +}
> > +
> >  static enum flow_dissect_ret
> >  __skb_flow_dissect_gre(const struct sk_buff *skb,
> >  		       struct flow_dissector_key_control *key_control,
> > @@ -1390,6 +1413,12 @@ bool __skb_flow_dissect(const struct net *net,
> >  		break;
> >  	}
> >  
> > +	case htons(ETH_P_CFM): {
> > +		fdret = __skb_flow_dissect_cfm(skb, flow_dissector,
> > +					       target_container, data,
> > +					       nhoff, hlen);
> 
> I do like that you moved the handling into it's own function.
> But I do also note that this style differs from adjacent code in this
> file.

I would prefer to have an own function here as I find __skb_flow_dissect
long enough already. But if you insist I am okay to change it.

Thanks
Zahari

> 
> > +		break;
> > +	}
> >  	default:
> >  		fdret = FLOW_DISSECT_RET_OUT_BAD;
> >  		break;
> 
> ...

Re: [PATCH net-next v2 2/2] selftests: net: add tc flower cfm test

[Zahari Doychev]

On Mon, Apr 03, 2023 at 03:31:55PM +0200, Simon Horman wrote:
> On Sun, Apr 02, 2023 at 05:10:31PM +0200, Zahari Doychev wrote:
> > From: Zahari Doychev <zdoychev@maxlinear.com>
> > 
> > New cfm flower test case is added to the net forwarding selfttests.
> > 
> > Signed-off-by: Zahari Doychev <zdoychev@maxlinear.com>
> 
> ...
> 
> > +	tc_check_packets "dev $h2 ingress" 103 1
> > +	check_err $? "Did not match on corret level"
> 
> Hi Zahari,
> 
> if you need to repost for some reason you may consider
> correcting the spelling of 'corret'.

thanks, I will correct it.

> 
> ...

Re: [PATCH net-next v2 1/2] net: flower: add support for matching cfm fields

[Simon Horman]

On Mon, Apr 03, 2023 at 05:36:22PM +0200, Zahari Doychev wrote:
> On Mon, Apr 03, 2023 at 04:54:12PM +0200, Simon Horman wrote:
> > On Sun, Apr 02, 2023 at 05:10:30PM +0200, Zahari Doychev wrote:
> > > From: Zahari Doychev <zdoychev@maxlinear.com>

...

> > > @@ -1390,6 +1413,12 @@ bool __skb_flow_dissect(const struct net *net,
> > >  		break;
> > >  	}
> > >  
> > > +	case htons(ETH_P_CFM): {
> > > +		fdret = __skb_flow_dissect_cfm(skb, flow_dissector,
> > > +					       target_container, data,
> > > +					       nhoff, hlen);
> > 
> > I do like that you moved the handling into it's own function.
> > But I do also note that this style differs from adjacent code in this
> > file.
> 
> I would prefer to have an own function here as I find __skb_flow_dissect
> long enough already. But if you insist I am okay to change it.

I don't insist.
I like it the way it is.