[Linuxptp-devel] [RFC PATCH v1 1/8] Add new TLV for CommonMeanLinkDelayInformation

[Kishen M. <kis...@in...>]

This change introduces a new TLV to convey link delay
measurements by the Common Mean Link Delay Service (CMLDS)
(as specified in IEEE 1588/16.6.3) over the management
interface. Also updated 'pmc' to support the new MID,
MID_CMLDS_INFO_NP.

Co-authored-by: Andrew Zaborowski <and...@in...>
Signed-off-by: Kishen Maloor <kis...@in...>
---
 clock.c      |  1 -
 msg.h        |  2 ++
 pmc.c        | 10 ++++++++++
 pmc_common.c |  1 +
 port.c       | 12 ++++++++++++
 tlv.c        | 14 ++++++++++++++
 tlv.h        |  9 +++++++++
 7 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/clock.c b/clock.c
index 75d7c4008977..85f2a04867e5 100644
--- a/clock.c
+++ b/clock.c
@@ -47,7 +47,6 @@
 #include "util.h"
 
 #define N_CLOCK_PFD (N_POLLFD + 1) /* one extra per port, for the fault timer */
-#define POW2_41 ((double)(1ULL << 41))
 
 struct interface {
 	STAILQ_ENTRY(interface) list;
diff --git a/msg.h b/msg.h
index b7423eec8778..0feb6c4b18fa 100644
--- a/msg.h
+++ b/msg.h
@@ -69,6 +69,8 @@
 #define SIGNAL_NO_CHANGE   -128
 #define SIGNAL_SET_INITIAL 126
 
+#define POW2_41 ((double)(1ULL << 41))
+
 enum timestamp_type {
 	TS_SOFTWARE,
 	TS_HARDWARE,
diff --git a/pmc.c b/pmc.c
index 00e691f0c244..fbf312cb6c53 100644
--- a/pmc.c
+++ b/pmc.c
@@ -169,6 +169,7 @@ static void pmc_show(struct ptp_message *msg, FILE *fp)
 	struct subscribe_events_np *sen;
 	struct port_properties_np *ppn;
 	struct port_hwclock_np *phn;
+	struct cmlds_info_np *cmlds;
 	struct timePropertiesDS *tp;
 	struct management_tlv *mgt;
 	struct time_status_np *tsn;
@@ -651,6 +652,15 @@ static void pmc_show(struct ptp_message *msg, FILE *fp)
 		fprintf(fp, "LOG_MIN_PDELAY_REQ_INTERVAL "
 			IFMT "logMinPdelayReqInterval %hhd", mtd->val);
 		break;
+	case MID_CMLDS_INFO_NP:
+		cmlds = (struct cmlds_info_np *) mgt->data;
+		fprintf(fp, "CMLDS INFO "
+			IFMT "serviceMeasurementValid %i"
+			IFMT "meanLinkDelay %" PRId64
+			IFMT "scaledNeighborRateRatio %" PRId32,
+			cmlds->serviceMeasurementValid, cmlds->meanLinkDelay,
+			cmlds->scaledNeighborRateRatio);
+		break;
 	}
 out:
 	fprintf(fp, "\n");
diff --git a/pmc_common.c b/pmc_common.c
index a03f191e8dc6..50d9db46aa92 100644
--- a/pmc_common.c
+++ b/pmc_common.c
@@ -156,6 +156,7 @@ struct management_id idtab[] = {
 	{ "UNICAST_MASTER_TABLE_NP", MID_UNICAST_MASTER_TABLE_NP, do_get_action },
 	{ "PORT_HWCLOCK_NP", MID_PORT_HWCLOCK_NP, do_get_action },
 	{ "POWER_PROFILE_SETTINGS_NP", MID_POWER_PROFILE_SETTINGS_NP, do_set_action },
+	{ "CMLDS_INFO_NP", MID_CMLDS_INFO_NP, do_get_action },
 };
 
 static void do_get_action(struct pmc *pmc, int action, int index, char *str)
diff --git a/port.c b/port.c
index 3453716f6020..d61e9b67e422 100644
--- a/port.c
+++ b/port.c
@@ -887,6 +887,7 @@ static int port_management_fill_response(struct port *target,
 	struct clock_description *desc;
 	struct port_properties_np *ppn;
 	struct port_hwclock_np *phn;
+	struct cmlds_info_np *cmlds;
 	struct management_tlv *tlv;
 	struct port_stats_np *psn;
 	struct foreign_clock *fc;
@@ -1129,6 +1130,17 @@ static int port_management_fill_response(struct port *target,
 		memcpy(pwr, &target->pwr, sizeof(*pwr));
 		datalen = sizeof(*pwr);
 		break;
+	case MID_CMLDS_INFO_NP:
+		cmlds = (struct cmlds_info_np *)tlv->data;
+		cmlds->serviceMeasurementValid =
+			/* IEEE1588-2019 16.6.3.2 h) 1) */
+			target->peer_portid_valid && !target->pdr_missing &&
+			!target->multiple_pdr_detected;
+		cmlds->meanLinkDelay = target->peerMeanPathDelay;
+		cmlds->scaledNeighborRateRatio =
+			(Integer32) (target->nrate.ratio * POW2_41 - POW2_41);
+		datalen = sizeof(*cmlds);
+		break;
 	default:
 		/* The caller should *not* respond to this message. */
 		tlv_extra_recycle(extra);
diff --git a/tlv.c b/tlv.c
index 79400126cbc4..aefbcb9f744e 100644
--- a/tlv.c
+++ b/tlv.c
@@ -176,6 +176,7 @@ static int mgt_post_recv(struct management_tlv *m, uint16_t data_len,
 	struct port_properties_np *ppn;
 	struct port_hwclock_np *phn;
 	struct timePropertiesDS *tp;
+	struct cmlds_info_np *cmlds;
 	struct time_status_np *tsn;
 	struct port_stats_np *psn;
 	int extra_len = 0, i, len;
@@ -490,6 +491,13 @@ static int mgt_post_recv(struct management_tlv *m, uint16_t data_len,
 		if (data_len != 0)
 			goto bad_length;
 		break;
+	case MID_CMLDS_INFO_NP:
+		if (data_len < sizeof(struct cmlds_info_np))
+			goto bad_length;
+		cmlds = (struct cmlds_info_np *)m->data;
+		net2host64_unaligned(&cmlds->meanLinkDelay);
+		NTOHL(cmlds->scaledNeighborRateRatio);
+		break;
 	}
 	if (extra_len) {
 		if (extra_len % 2)
@@ -514,6 +522,7 @@ static void mgt_pre_send(struct management_tlv *m, struct tlv_extra *extra)
 	struct subscribe_events_np *sen;
 	struct port_properties_np *ppn;
 	struct port_hwclock_np *phn;
+	struct cmlds_info_np *cmlds;
 	struct timePropertiesDS *tp;
 	struct time_status_np *tsn;
 	struct port_stats_np *psn;
@@ -672,6 +681,11 @@ static void mgt_pre_send(struct management_tlv *m, struct tlv_extra *extra)
 		HTONL(pwr->networkTimeInaccuracy);
 		HTONL(pwr->totalTimeInaccuracy);
 		break;
+	case MID_CMLDS_INFO_NP:
+		cmlds = (struct cmlds_info_np *)m->data;
+		host2net64_unaligned(&cmlds->meanLinkDelay);
+		HTONL(cmlds->scaledNeighborRateRatio);
+		break;
 	}
 }
 
diff --git a/tlv.h b/tlv.h
index 8b51ffd88816..73b6078e2efd 100644
--- a/tlv.h
+++ b/tlv.h
@@ -130,6 +130,9 @@ enum management_action {
 #define MID_PORT_HWCLOCK_NP				0xC009
 #define MID_POWER_PROFILE_SETTINGS_NP			0xC00A
 
+/* CMLDS management ID values */
+#define MID_CMLDS_INFO_NP				0xC00B
+
 /* Management error ID values */
 #define MID_RESPONSE_TOO_BIG				0x0001
 #define MID_NO_SUCH_ID					0x0002
@@ -473,6 +476,12 @@ struct msg_interface_rate_tlv {
        UInteger16    numberOfBitsAfterTimestamp;
 } PACKED;
 
+struct cmlds_info_np {
+	Integer8     serviceMeasurementValid;
+	TimeInterval meanLinkDelay;
+	Integer32    scaledNeighborRateRatio;
+} PACKED;
+
 /**
  * Allocates a new tlv_extra structure.
  * @return  Pointer to a new structure on success or NULL otherwise.
-- 
2.31.1