[PATCH net-next v3 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.

Actually, it would be a very unusual situation that many different
addresses are used, normally only a small set of predefined
addresses are tried. Anyway, some cleanup is necessary because
maintaining old filters forever makes very little sense.

Reported-by: Yalin Li <yalli@redhat.com>
Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>
---
 drivers/net/ethernet/sfc/ptp.c | 83 ++++++++++++++++++++++++----------
 1 file changed, 60 insertions(+), 23 deletions(-)

diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index 5b6ee3d23a64..b93e7220e207 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;
 };
 
@@ -1318,8 +1323,8 @@ 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 *ptp_list,
-				  struct efx_filter_spec *spec)
+static struct efx_ptp_rxfilter *
+efx_ptp_find_filter(struct list_head *ptp_list, struct efx_filter_spec *spec)
 {
 	struct efx_ptp_rxfilter *rxfilter;
 
@@ -1327,10 +1332,19 @@ static bool efx_ptp_filter_exists(struct list_head *ptp_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,
@@ -1339,10 +1353,7 @@ static void efx_ptp_remove_filters(struct efx_nic *efx,
 	struct efx_ptp_rxfilter *rxfilter, *tmp;
 
 	list_for_each_entry_safe(rxfilter, tmp, ptp_list, list) {
-		efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
-					  rxfilter->handle);
-		list_del(&rxfilter->list);
-		kfree(rxfilter);
+		efx_ptp_remove_one_filter(efx, rxfilter);
 	}
 }
 
@@ -1358,13 +1369,17 @@ static void efx_ptp_init_filter(struct efx_nic *efx,
 
 static int efx_ptp_insert_filter(struct efx_nic *efx,
 				 struct list_head *ptp_list,
-				 struct efx_filter_spec *spec)
+				 struct efx_filter_spec *spec,
+				 unsigned long expiry)
 {
 	struct efx_ptp_rxfilter *rxfilter;
 	int rc;
 
-	if (efx_ptp_filter_exists(ptp_list, spec))
+	rxfilter = efx_ptp_find_filter(ptp_list, spec);
+	if (rxfilter) {
+		rxfilter->expiry = expiry;
 		return 0;
+	}
 
 	rc = efx_filter_insert_filter(efx, spec, true);
 	if (rc < 0)
@@ -1378,6 +1393,7 @@ 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, ptp_list);
 
 	return 0;
@@ -1385,28 +1401,31 @@ static int efx_ptp_insert_filter(struct efx_nic *efx,
 
 static int efx_ptp_insert_ipv4_filter(struct efx_nic *efx,
 				      struct list_head *ptp_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, ptp_list, &spec);
+	return efx_ptp_insert_filter(efx, ptp_list, &spec, expiry);
 }
 
 static int efx_ptp_insert_ipv6_filter(struct efx_nic *efx,
 				      struct list_head *ptp_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, ptp_list, &spec);
+	return efx_ptp_insert_filter(efx, ptp_list, &spec, expiry);
 }
 
 static int efx_ptp_insert_eth_multicast_filter(struct efx_nic *efx)
 {
+	struct efx_ptp_data *ptp = efx->ptp_data;
 	const u8 addr[ETH_ALEN] = PTP_ADDR_ETHER;
 	struct efx_filter_spec spec;
 
@@ -1414,7 +1433,7 @@ 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, &efx->ptp_data->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)
@@ -1429,12 +1448,14 @@ 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;
 
@@ -1445,12 +1466,12 @@ 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;
 
@@ -1486,21 +1507,24 @@ 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 fail;
 
 		rc = efx_ptp_insert_ipv4_filter(efx, &ptp->rxfilters_ucast,
-						addr, PTP_GENERAL_PORT);
+						addr, PTP_GENERAL_PORT, expiry);
 		if (rc < 0)
 			goto fail;
 	} else if (efx_ptp_use_mac_tx_timestamps(efx)) {
@@ -1508,12 +1532,12 @@ static int efx_ptp_insert_unicast_filter(struct efx_nic *efx,
 		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 fail;
 
 		rc = efx_ptp_insert_ipv6_filter(efx, &ptp->rxfilters_ucast,
-						addr, PTP_GENERAL_PORT);
+						addr, PTP_GENERAL_PORT, expiry);
 		if (rc < 0)
 			goto fail;
 	} else {
@@ -1527,6 +1551,17 @@ static int efx_ptp_insert_unicast_filter(struct efx_nic *efx,
 	return rc;
 }
 
+static void efx_ptp_drop_expired_unicast_filters(struct efx_nic *efx)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	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(efx, rxfilter);
+	}
+}
+
 static int efx_ptp_start(struct efx_nic *efx)
 {
 	struct efx_ptp_data *ptp = efx->ptp_data;
@@ -1627,6 +1662,8 @@ static void efx_ptp_worker(struct work_struct *work)
 
 	while ((skb = __skb_dequeue(&tempq)))
 		efx_ptp_process_rx(efx, skb);
+
+	efx_ptp_drop_expired_unicast_filters(efx);
 }
 
 static const struct ptp_clock_info efx_phc_clock_info = {
-- 
2.34.3