[PATCH v5 net-next 4/4] sfc: remove expired unicast PTP filters

["Íñigo Huguet" <ihuguet@redhat.com>]

Filters inserted to support unicast PTP mode might become unused after
some time, so we need to remove them to avoid accumulating many of them.

Refresh the expiration time of a filter each time it's used. Then check
periodically if any filter hasn't been used for a long time (30s) and
remove it.

Reported-by: Yalin Li <yalli@redhat.com>
Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>
---
 drivers/net/ethernet/sfc/ptp.c | 96 +++++++++++++++++++++++++---------
 1 file changed, 71 insertions(+), 25 deletions(-)

diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index b495f3d0616b..949299f61bdd 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -75,6 +75,9 @@
 /* How long an unmatched event or packet can be held */
 #define PKT_EVENT_LIFETIME_MS		10
 
+/* How long unused unicast filters can be held */
+#define UCAST_FILTER_EXPIRY_JIFFIES	msecs_to_jiffies(30000)
+
 /* Offsets into PTP packet for identification.  These offsets are from the
  * start of the IP header, not the MAC header.  Note that neither PTP V1 nor
  * PTP V2 permit the use of IPV4 options.
@@ -218,6 +221,7 @@ struct efx_ptp_timeset {
  * @ether_type: Network protocol of the filter (ETHER_P_IP / ETHER_P_IPV6)
  * @loc_port: UDP port of the filter (PTP_EVENT_PORT / PTP_GENERAL_PORT)
  * @loc_host: IPv4/v6 address of the filter
+ * @expiry: time when the filter expires, in jiffies
  * @handle: Handle ID for the MCDI filters table
  */
 struct efx_ptp_rxfilter {
@@ -225,6 +229,7 @@ struct efx_ptp_rxfilter {
 	__be16 ether_type;
 	__be16 loc_port;
 	__be32 loc_host[4];
+	unsigned long expiry;
 	int handle;
 };
 
@@ -313,6 +318,7 @@ struct efx_ptp_data {
 	struct efx_ptp_event_rx rx_evts[MAX_RECEIVE_EVENTS];
 	struct workqueue_struct *workwq;
 	struct work_struct work;
+	struct delayed_work cleanup_work;
 	bool reset_required;
 	struct list_head rxfilters_mcast;
 	struct list_head rxfilters_ucast;
@@ -1318,8 +1324,8 @@ static inline void efx_ptp_process_rx(struct efx_nic *efx, struct sk_buff *skb)
 	local_bh_enable();
 }
 
-static bool efx_ptp_filter_exists(struct list_head *filter_list,
-				  struct efx_filter_spec *spec)
+static struct efx_ptp_rxfilter *
+efx_ptp_find_filter(struct list_head *filter_list, struct efx_filter_spec *spec)
 {
 	struct efx_ptp_rxfilter *rxfilter;
 
@@ -1327,10 +1333,19 @@ static bool efx_ptp_filter_exists(struct list_head *filter_list,
 		if (rxfilter->ether_type == spec->ether_type &&
 		    rxfilter->loc_port == spec->loc_port &&
 		    !memcmp(rxfilter->loc_host, spec->loc_host, sizeof(spec->loc_host)))
-			return true;
+			return rxfilter;
 	}
 
-	return false;
+	return NULL;
+}
+
+static void efx_ptp_remove_one_filter(struct efx_nic *efx,
+				      struct efx_ptp_rxfilter *rxfilter)
+{
+	efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
+				  rxfilter->handle);
+	list_del(&rxfilter->list);
+	kfree(rxfilter);
 }
 
 static void efx_ptp_remove_filters(struct efx_nic *efx,
@@ -1338,12 +1353,8 @@ static void efx_ptp_remove_filters(struct efx_nic *efx,
 {
 	struct efx_ptp_rxfilter *rxfilter, *tmp;
 
-	list_for_each_entry_safe(rxfilter, tmp, filter_list, list) {
-		efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
-					  rxfilter->handle);
-		list_del(&rxfilter->list);
-		kfree(rxfilter);
-	}
+	list_for_each_entry_safe(rxfilter, tmp, filter_list, list)
+		efx_ptp_remove_one_filter(efx, rxfilter);
 }
 
 static void efx_ptp_init_filter(struct efx_nic *efx,
@@ -1358,13 +1369,18 @@ static void efx_ptp_init_filter(struct efx_nic *efx,
 
 static int efx_ptp_insert_filter(struct efx_nic *efx,
 				 struct list_head *filter_list,
-				 struct efx_filter_spec *spec)
+				 struct efx_filter_spec *spec,
+				 unsigned long expiry)
 {
+	struct efx_ptp_data *ptp = efx->ptp_data;
 	struct efx_ptp_rxfilter *rxfilter;
 	int rc;
 
-	if (efx_ptp_filter_exists(filter_list, spec))
+	rxfilter = efx_ptp_find_filter(filter_list, spec);
+	if (rxfilter) {
+		rxfilter->expiry = expiry;
 		return 0;
+	}
 
 	rxfilter = kzalloc(sizeof(*rxfilter), GFP_KERNEL);
 	if (!rxfilter)
@@ -1378,8 +1394,12 @@ static int efx_ptp_insert_filter(struct efx_nic *efx,
 	rxfilter->ether_type = spec->ether_type;
 	rxfilter->loc_port = spec->loc_port;
 	memcpy(rxfilter->loc_host, spec->loc_host, sizeof(spec->loc_host));
+	rxfilter->expiry = expiry;
 	list_add(&rxfilter->list, filter_list);
 
+	queue_delayed_work(ptp->workwq, &ptp->cleanup_work,
+			   UCAST_FILTER_EXPIRY_JIFFIES);
+
 	return 0;
 
 fail:
@@ -1389,24 +1409,26 @@ static int efx_ptp_insert_filter(struct efx_nic *efx,
 
 static int efx_ptp_insert_ipv4_filter(struct efx_nic *efx,
 				      struct list_head *filter_list,
-				      __be32 addr, u16 port)
+				      __be32 addr, u16 port,
+				      unsigned long expiry)
 {
 	struct efx_filter_spec spec;
 
 	efx_ptp_init_filter(efx, &spec);
 	efx_filter_set_ipv4_local(&spec, IPPROTO_UDP, addr, htons(port));
-	return efx_ptp_insert_filter(efx, filter_list, &spec);
+	return efx_ptp_insert_filter(efx, filter_list, &spec, expiry);
 }
 
 static int efx_ptp_insert_ipv6_filter(struct efx_nic *efx,
 				      struct list_head *filter_list,
-				      struct in6_addr *addr, u16 port)
+				      struct in6_addr *addr, u16 port,
+				      unsigned long expiry)
 {
 	struct efx_filter_spec spec;
 
 	efx_ptp_init_filter(efx, &spec);
 	efx_filter_set_ipv6_local(&spec, IPPROTO_UDP, addr, htons(port));
-	return efx_ptp_insert_filter(efx, filter_list, &spec);
+	return efx_ptp_insert_filter(efx, filter_list, &spec, expiry);
 }
 
 static int efx_ptp_insert_eth_multicast_filter(struct efx_nic *efx)
@@ -1419,7 +1441,7 @@ static int efx_ptp_insert_eth_multicast_filter(struct efx_nic *efx)
 	efx_filter_set_eth_local(&spec, EFX_FILTER_VID_UNSPEC, addr);
 	spec.match_flags |= EFX_FILTER_MATCH_ETHER_TYPE;
 	spec.ether_type = htons(ETH_P_1588);
-	return efx_ptp_insert_filter(efx, &ptp->rxfilters_mcast, &spec);
+	return efx_ptp_insert_filter(efx, &ptp->rxfilters_mcast, &spec, 0);
 }
 
 static int efx_ptp_insert_multicast_filters(struct efx_nic *efx)
@@ -1434,12 +1456,14 @@ static int efx_ptp_insert_multicast_filters(struct efx_nic *efx)
 	 * that there is no packet re-ordering.
 	 */
 	rc = efx_ptp_insert_ipv4_filter(efx, &ptp->rxfilters_mcast,
-					htonl(PTP_ADDR_IPV4), PTP_EVENT_PORT);
+					htonl(PTP_ADDR_IPV4), PTP_EVENT_PORT,
+					0);
 	if (rc < 0)
 		goto fail;
 
 	rc = efx_ptp_insert_ipv4_filter(efx, &ptp->rxfilters_mcast,
-					htonl(PTP_ADDR_IPV4), PTP_GENERAL_PORT);
+					htonl(PTP_ADDR_IPV4), PTP_GENERAL_PORT,
+					0);
 	if (rc < 0)
 		goto fail;
 
@@ -1450,12 +1474,12 @@ static int efx_ptp_insert_multicast_filters(struct efx_nic *efx)
 		struct in6_addr ipv6_addr = {{PTP_ADDR_IPV6}};
 
 		rc = efx_ptp_insert_ipv6_filter(efx, &ptp->rxfilters_mcast,
-						&ipv6_addr, PTP_EVENT_PORT);
+						&ipv6_addr, PTP_EVENT_PORT, 0);
 		if (rc < 0)
 			goto fail;
 
 		rc = efx_ptp_insert_ipv6_filter(efx, &ptp->rxfilters_mcast,
-						&ipv6_addr, PTP_GENERAL_PORT);
+						&ipv6_addr, PTP_GENERAL_PORT, 0);
 		if (rc < 0)
 			goto fail;
 
@@ -1491,32 +1515,35 @@ static int efx_ptp_insert_unicast_filter(struct efx_nic *efx,
 					 struct sk_buff *skb)
 {
 	struct efx_ptp_data *ptp = efx->ptp_data;
+	unsigned long expiry;
 	int rc;
 
 	if (!efx_ptp_valid_unicast_event_pkt(skb))
 		return -EINVAL;
 
+	expiry = jiffies + UCAST_FILTER_EXPIRY_JIFFIES;
+
 	if (skb->protocol == htons(ETH_P_IP)) {
 		__be32 addr = ip_hdr(skb)->saddr;
 
 		rc = efx_ptp_insert_ipv4_filter(efx, &ptp->rxfilters_ucast,
-						addr, PTP_EVENT_PORT);
+						addr, PTP_EVENT_PORT, expiry);
 		if (rc < 0)
 			goto out;
 
 		rc = efx_ptp_insert_ipv4_filter(efx, &ptp->rxfilters_ucast,
-						addr, PTP_GENERAL_PORT);
+						addr, PTP_GENERAL_PORT, expiry);
 	} else if (efx_ptp_use_mac_tx_timestamps(efx)) {
 		/* IPv6 PTP only supported by devices with MAC hw timestamp */
 		struct in6_addr *addr = &ipv6_hdr(skb)->saddr;
 
 		rc = efx_ptp_insert_ipv6_filter(efx, &ptp->rxfilters_ucast,
-						addr, PTP_EVENT_PORT);
+						addr, PTP_EVENT_PORT, expiry);
 		if (rc < 0)
 			goto out;
 
 		rc = efx_ptp_insert_ipv6_filter(efx, &ptp->rxfilters_ucast,
-						addr, PTP_GENERAL_PORT);
+						addr, PTP_GENERAL_PORT, expiry);
 	} else {
 		return -EOPNOTSUPP;
 	}
@@ -1627,6 +1654,23 @@ static void efx_ptp_worker(struct work_struct *work)
 		efx_ptp_process_rx(efx, skb);
 }
 
+static void efx_ptp_cleanup_worker(struct work_struct *work)
+{
+	struct efx_ptp_data *ptp =
+		container_of(work, struct efx_ptp_data, cleanup_work.work);
+	struct efx_ptp_rxfilter *rxfilter, *tmp;
+
+	list_for_each_entry_safe(rxfilter, tmp, &ptp->rxfilters_ucast, list) {
+		if (time_is_before_jiffies(rxfilter->expiry))
+			efx_ptp_remove_one_filter(ptp->efx, rxfilter);
+	}
+
+	if (!list_empty(&ptp->rxfilters_ucast)) {
+		queue_delayed_work(ptp->workwq, &ptp->cleanup_work,
+				   UCAST_FILTER_EXPIRY_JIFFIES + 1);
+	}
+}
+
 static const struct ptp_clock_info efx_phc_clock_info = {
 	.owner		= THIS_MODULE,
 	.name		= "sfc",
@@ -1685,6 +1729,7 @@ int efx_ptp_probe(struct efx_nic *efx, struct efx_channel *channel)
 	}
 
 	INIT_WORK(&ptp->work, efx_ptp_worker);
+	INIT_DELAYED_WORK(&ptp->cleanup_work, efx_ptp_cleanup_worker);
 	ptp->config.flags = 0;
 	ptp->config.tx_type = HWTSTAMP_TX_OFF;
 	ptp->config.rx_filter = HWTSTAMP_FILTER_NONE;
@@ -1776,6 +1821,7 @@ void efx_ptp_remove(struct efx_nic *efx)
 	(void)efx_ptp_disable(efx);
 
 	cancel_work_sync(&efx->ptp_data->work);
+	cancel_delayed_work_sync(&efx->ptp_data->cleanup_work);
 	if (efx->ptp_data->pps_workwq)
 		cancel_work_sync(&efx->ptp_data->pps_work);
 
-- 
2.39.2