[Linuxptp-devel] [RFC v2 4/5] Add ignore_source_id config option.

[Vedang P. <ved...@in...>]

This config option will skip the source port identity verification in
the Sync and Follow_up messages. This option is needed when the announce
messages are disabled because the slave cannot know the identity of
master without announce messages.

This is required by AVnu Automotive Profile[1] as described in Section
6.3 pt #2 (lines 196 to 199).

[1] - http://avnu.org/wp-content/uploads/2014/05/
      Automotive-Ethernet-AVB-Func-Interop-Spec-v1.5-Public.pdf

Signed-off-by: Vedang Patel <ved...@in...>
Change-Id: Iae5e0c1d8946499e05c498792ece1bd40b33cee0
---
 config.c            |  1 +
 configs/default.cfg |  1 +
 port.c              | 24 ++++++++++++++++++------
 port_private.h      |  1 +
 ptp4l.8             |  6 ++++++
 5 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/config.c b/config.c
index 702ee1b4e52a..1e7734bc8607 100644
--- a/config.c
+++ b/config.c
@@ -223,6 +223,7 @@ struct config_item config_tab[] = {
 	PORT_ITEM_INT("G.8275.portDS.localPriority", 128, 1, UINT8_MAX),
 	GLOB_ITEM_INT("gmCapable", 1, 0, 1),
 	PORT_ITEM_INT("hybrid_e2e", 0, 0, 1),
+	PORT_ITEM_INT("ignore_source_id", 0, 0, 1),
 	PORT_ITEM_INT("ignore_transport_specific", 0, 0, 1),
 	PORT_ITEM_INT("ingressLatency", 0, INT_MIN, INT_MAX),
 	PORT_ITEM_INT("inhibit_announce", 0, 0, 1),
diff --git a/configs/default.cfg b/configs/default.cfg
index 56dfbe4aace1..3f18830f8d9f 100644
--- a/configs/default.cfg
+++ b/configs/default.cfg
@@ -33,6 +33,7 @@ masterOnly		0
 G.8275.portDS.localPriority	128
 BMCA                    ptp
 inhibit_announce        0
+ignore_source_id        0
 #
 # Run time options
 #
diff --git a/port.c b/port.c
index dacc8d383607..897da704aad4 100644
--- a/port.c
+++ b/port.c
@@ -1593,6 +1593,7 @@ int port_initialize(struct port *p)
 	p->peerMeanPathDelay       = 0;
 	p->logAnnounceInterval     = config_get_int(cfg, p->name, "logAnnounceInterval");
 	p->inhibit_announce        = config_get_int(cfg, p->name, "inhibit_announce");
+	p->ignore_source_id        = config_get_int(cfg, p->name, "ignore_source_id");
 	p->announceReceiptTimeout  = config_get_int(cfg, p->name, "announceReceiptTimeout");
 	p->syncReceiptTimeout      = config_get_int(cfg, p->name, "syncReceiptTimeout");
 	p->transportSpecific       = config_get_int(cfg, p->name, "transportSpecific");
@@ -1866,10 +1867,22 @@ void process_delay_resp(struct port *p, struct ptp_message *m)
 	port_set_delay_tmo(p);
 }
 
+static int check_source_identity(struct port *p, struct ptp_message *m)
+{
+	struct PortIdentity master;
+
+	if (!p->ignore_source_id) {
+		master = clock_parent_identity(p->clock);
+		if (!pid_eq(&master, &m->header.sourcePortIdentity)) {
+			return -1;
+		}
+	}
+	return 0;
+}
+
 void process_follow_up(struct port *p, struct ptp_message *m)
 {
 	enum syfu_event event;
-	struct PortIdentity master;
 	switch (p->state) {
 	case PS_INITIALIZING:
 	case PS_FAULTY:
@@ -1884,8 +1897,8 @@ void process_follow_up(struct port *p, struct ptp_message *m)
 	case PS_SLAVE:
 		break;
 	}
-	master = clock_parent_identity(p->clock);
-	if (!pid_eq(&master, &m->header.sourcePortIdentity)) {
+
+	if (check_source_identity(p, m)) {
 		return;
 	}
 
@@ -2174,7 +2187,6 @@ void process_pdelay_resp_fup(struct port *p, struct ptp_message *m)
 void process_sync(struct port *p, struct ptp_message *m)
 {
 	enum syfu_event event;
-	struct PortIdentity master;
 	switch (p->state) {
 	case PS_INITIALIZING:
 	case PS_FAULTY:
@@ -2189,8 +2201,8 @@ void process_sync(struct port *p, struct ptp_message *m)
 	case PS_SLAVE:
 		break;
 	}
-	master = clock_parent_identity(p->clock);
-	if (!pid_eq(&master, &m->header.sourcePortIdentity)) {
+
+	if (check_source_identity(p, m)) {
 		return;
 	}
 
diff --git a/port_private.h b/port_private.h
index b454901f208d..55ce791f8494 100644
--- a/port_private.h
+++ b/port_private.h
@@ -98,6 +98,7 @@ struct port {
 					 enum fsm_event event, int mdiff);
 	int bmca;
 	int inhibit_announce;
+	int ignore_source_id;
 	/* portDS */
 	struct PortIdentity portIdentity;
 	enum port_state     state; /*portState*/
diff --git a/ptp4l.8 b/ptp4l.8
index 24ba45342460..2adcbca1ac7d 100644
--- a/ptp4l.8
+++ b/ptp4l.8
@@ -678,6 +678,12 @@ by the AVnu Automotive profile as part of switching over to a static BMCA. if
 this option is enabled, ignore_source_id has to be enabled in the slave because
 it has no way to identify master identity in Sync and Follow_Up messages. The
 default is 0 (disabled).
+.TP
+.B ignore_source_port_id
+This will disable source port identity checking for Sync and Follow_Up
+messages. This is useful when the announce messages are disabled in the master
+and the slave does not have any way to know it's identity. The default is 0
+(disabled).
 
 .SH UNICAST DISCOVERY OPTIONS
 
-- 
2.7.3