port: Add configurable option to set asCapable.

If set to 'true', this unconditionally sets the asCapable variable. The
usual checks will be applied to asCapable if it is set to 'auto'. The
default value is 'auto'.

This config option is needed by the Automotive Profile. The master will
be able to send out Sync Message as soon as the daemon is started.

Signed-off-by: Vedang Patel <vedang.patel@intel.com>

as_capable.h

@@ -0,0 +1,45 @@
+/**
+ * @file as_capable.h
+ * @brief Enumerates the states for asCapable.
+ * @note Copyright (C) 2018 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#ifndef HAVE_AS_CAPABLE_H
+#define HAVE_AS_CAPABLE_H
+
+/* Enum used by the asCapable config option. */
+enum as_capable_option {
+	AS_CAPABLE_TRUE,
+	AS_CAPABLE_AUTO,
+};
+
+/*
+ * Defines whether the device can interoperate with the device on other end via
+ * IEEE 802.1AS protocol.
+ *
+ * More information about this in Section 10.2.4.1 of IEEE 802.1AS standard.
+ */
+enum as_capable {
+	NOT_CAPABLE,
+	AS_CAPABLE,
+	/*
+	 * Non-standard extension to support Automotive Profile. asCapable
+	 * always set to true without checking the system at other end.
+	 */
+	ALWAYS_CAPABLE,
+};
+
+#endif

config.c

@@ -23,6 +23,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "as_capable.h"
 #include "bmc.h"
 #include "clock.h"
 #include "config.h"
@@ -195,8 +196,15 @@ static struct config_enum tsproc_enu[] = {
 	{ NULL, 0 },
 };
 
+static struct config_enum as_capable_enu[] = {
+	{ "true", AS_CAPABLE_TRUE },
+	{ "auto", AS_CAPABLE_AUTO },
+	{ NULL, 0 },
+};
+
 struct config_item config_tab[] = {
 	PORT_ITEM_INT("announceReceiptTimeout", 3, 2, UINT8_MAX),
+	PORT_ITEM_ENU("asCapable", AS_CAPABLE_AUTO, as_capable_enu),
 	GLOB_ITEM_INT("assume_two_step", 0, 0, 1),
 	PORT_ITEM_INT("boundary_clock_jbod", 0, 0, 1),
 	GLOB_ITEM_INT("check_fup_sync", 0, 0, 1),

configs/default.cfg

@@ -32,6 +32,7 @@ fault_reset_interval	4
 neighborPropDelayThresh	20000000
 masterOnly		0
 G.8275.portDS.localPriority	128
+asCapable               auto
 #
 # Run time options
 #

port.c

@@ -644,15 +644,16 @@ static int port_capable(struct port *p)
 	}
 
 capable:
-	if (!p->asCapable)
+	if (p->asCapable == NOT_CAPABLE) {
 		pr_debug("port %hu: setting asCapable", portnum(p));
-	p->asCapable = 1;
+		p->asCapable = AS_CAPABLE;
+	}
 	return 1;
 
 not_capable:
 	if (p->asCapable)
 		port_nrate_initialize(p);
-	p->asCapable = 0;
+	p->asCapable = NOT_CAPABLE;
 	return 0;
 }
 
@@ -742,6 +743,9 @@ static int port_sync_incapable(struct port *p)
 
 static int port_is_ieee8021as(struct port *p)
 {
+	if (p->asCapable == ALWAYS_CAPABLE) {
+		return 0;
+	}
 	return p->follow_up_info ? 1 : 0;
 }
 
@@ -1021,7 +1025,6 @@ static void port_nrate_initialize(struct port *p)
 
 	/* We start in the 'incapable' state. */
 	p->pdr_missing = ALLOWED_LOST_RESPONSES + 1;
-	p->asCapable = 0;
 
 	p->peer_portid_valid = 0;
 
@@ -1600,6 +1603,12 @@ int port_initialize(struct port *p)
 	p->neighborPropDelayThresh = config_get_int(cfg, p->name, "neighborPropDelayThresh");
 	p->min_neighbor_prop_delay = config_get_int(cfg, p->name, "min_neighbor_prop_delay");
 
+	if (config_get_int(cfg, p->name, "asCapable") == AS_CAPABLE_TRUE) {
+		p->asCapable = ALWAYS_CAPABLE;
+	} else {
+		p->asCapable = NOT_CAPABLE;
+	}
+
 	for (i = 0; i < N_TIMER_FDS; i++) {
 		fd[i] = -1;
 	}

port_private.h

@@ -21,6 +21,7 @@
 
 #include <sys/queue.h>
 
+#include "as_capable.h"
 #include "clock.h"
 #include "fsm.h"
 #include "msg.h"
@@ -100,7 +101,7 @@ struct port {
 	struct PortIdentity portIdentity;
 	enum port_state     state; /*portState*/
 	Integer64           asymmetry;
-	int                 asCapable;
+	enum as_capable     asCapable;
 	Integer8            logMinDelayReqInterval;
 	TimeInterval        peerMeanPathDelay;
 	Integer8            logAnnounceInterval;

ptp4l.8

@@ -686,6 +686,12 @@ Check mode only check but do not set.
 Full mode set the receive filter to mark all packets with hardware time stamp,
  so all applications can get them.
 The default is normal.
+.TP
+.B asCapable
+If set to 'true', all the checks which can unset asCapable variable (as
+described in Section 10.2.4.1 of 802.1AS) are skipped. If set to 'auto',
+asCapable is initialized to 'false' and will be set to 'true' after the
+relevant checks have passed. The default value is 'auto'.
 
 .SH UNICAST DISCOVERY OPTIONS