In certain scenarios it is useful to know whether a remote port is
synchronized, for example when the local system is the PTP master and we
are trying to send time-synchronized data to a slave.
Introduce a new option in ptp4l, which defaults to false, and which
allows the following:
- a remote PMC agent to subscribe to a given data set
- the clock API to push notifications towards a non-local subscriber
The only SET that is supported is adding a subscription, no clock state
can be modified remotely. Nonetheless, there is no authentication
implemented, so the option should be used with care.
Signed-off-by: Vladimir Oltean <olte...@gmail.com>
---
clock.c | 22 +++++++++++++++-------
config.c | 1 +
2 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/clock.c b/clock.c
index d1c85ec5a7b1..0689360db410 100644
--- a/clock.c
+++ b/clock.c
@@ -76,6 +76,7 @@ struct clock_subscriber {
struct address addr;
UInteger16 sequenceId;
time_t expiration;
+ struct port *port;
};
struct clock {
@@ -152,8 +153,9 @@ static void remove_subscriber(struct clock_subscriber *s)
free(s);
}
-static void clock_update_subscription(struct clock *c, struct ptp_message *req,
- uint8_t *bitmask, uint16_t duration)
+static void clock_update_subscription(struct clock *c, struct port *p,
+ struct ptp_message *req, uint8_t *bitmask,
+ uint16_t duration)
{
struct clock_subscriber *s, *tmp;
struct timespec now;
@@ -175,6 +177,7 @@ static void clock_update_subscription(struct clock *c,
struct ptp_message *req,
memcpy(s->events, bitmask, EVENT_BITMASK_CNT);
clock_gettime(CLOCK_MONOTONIC, &now);
s->expiration = now.tv_sec + duration;
+ s->port = p;
} else {
remove_subscriber(s);
}
@@ -195,6 +198,7 @@ static void clock_update_subscription(struct clock *c,
struct ptp_message *req,
clock_gettime(CLOCK_MONOTONIC, &now);
s->expiration = now.tv_sec + duration;
s->sequenceId = 0;
+ s->port = p;
LIST_INSERT_HEAD(&c->subscribers, s, list);
}
@@ -248,10 +252,11 @@ static void clock_prune_subscriptions(struct clock *c)
void clock_send_notification(struct clock *c, struct ptp_message *msg,
enum notification event)
{
- struct port *uds = c->uds_rw_port;
struct clock_subscriber *s;
LIST_FOREACH(s, &c->subscribers, list) {
+ struct port *port = s->port ? s->port : c->uds_rw_port;
+
if (!event_bitmask_get(s->events, event))
continue;
/* send event */
@@ -262,7 +267,7 @@ void clock_send_notification(struct clock *c, struct
ptp_message *msg,
msg->management.targetPortIdentity.portNumber =
htons(s->targetPortIdentity.portNumber);
msg->address = s->addr;
- port_forward_to(uds, msg);
+ port_forward_to(port, msg);
}
}
@@ -532,7 +537,7 @@ static int clock_management_set(struct clock *c, struct
port *p,
break;
case MID_SUBSCRIBE_EVENTS_NP:
sen = (struct subscribe_events_np *)tlv->data;
- clock_update_subscription(c, req, sen->bitmask, sen->duration);
+ clock_update_subscription(c, p, req, sen->bitmask,
sen->duration);
respond = 1;
break;
case MID_SYNCHRONIZATION_UNCERTAIN_NP:
@@ -1436,6 +1441,7 @@ tmv_t clock_ingress_time(struct clock *c)
int clock_manage(struct clock *c, struct port *p, struct ptp_message *msg)
{
+ bool allow_remote_subscriptions = config_get_int(c->config, NULL,
"allow_remote_subscriptions");
int changed = 0, res, answers;
struct port *piter;
struct management_tlv *mgt;
@@ -1472,7 +1478,9 @@ int clock_manage(struct clock *c, struct port *p, struct
ptp_message *msg)
clock_management_send_error(p, msg, MID_WRONG_LENGTH);
return changed;
}
- if (p != c->uds_rw_port) {
+ if (p != c->uds_rw_port &&
+ (!allow_remote_subscriptions ||
+ mgt->id != MID_SUBSCRIBE_EVENTS_NP)) {
/* Sorry, only allowed on the UDS-RW port. */
clock_management_send_error(p, msg, MID_NOT_SUPPORTED);
return changed;
@@ -1493,7 +1501,7 @@ int clock_manage(struct clock *c, struct port *p, struct
ptp_message *msg)
switch (mgt->id) {
case MID_PORT_PROPERTIES_NP:
- if (p != c->uds_rw_port) {
+ if (p != c->uds_rw_port && !allow_remote_subscriptions) {
/* Only the UDS-RW port allowed. */
clock_management_send_error(p, msg, MID_NOT_SUPPORTED);
return 0;
diff --git a/config.c b/config.c
index 760d0e12b0b6..6ee46b448adc 100644
--- a/config.c
+++ b/config.c
@@ -221,6 +221,7 @@ static struct config_enum bmca_enu[] = {
};
struct config_item config_tab[] = {
+ PORT_ITEM_INT("allow_remote_subscriptions", 0, 0, 1),
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),
--
2.25.1
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