[net-next PATCH 0/3] Broadcast/Multicast rate limit via Ethtool Coalesce

[net-next PATCH 0/3] Broadcast/Multicast rate limit via Ethtool Coalesce

[Mugunthan V N]

A system/cpu can be loaded by a hacker with flooding of broadcast or
multicast packets, to prevent this some Ethernet controllers like CPSW
provide a mechanism to limit the broadcast/multicast packet rate via
hardware limiters. This patch series enables this feature via
Ethtool Coalesce.

Mugunthan V N (3):
  net: ethtool: Add Multicast and broadcast rate limit coalescing
    feature
  drivers: net: cpsw: remove redundancy check
  drivers: net: cpsw: Add support for multicast/boradcast rate limit

 drivers/net/ethernet/ti/cpsw.c | 83 +++++++++++++++++++++++++++++++++++++++---
 include/uapi/linux/ethtool.h   |  4 ++
 2 files changed, 82 insertions(+), 5 deletions(-)

-- 
2.0.0.390.gcb682f8

[net-next PATCH 1/3] net: ethtool: Add Multicast and broadcast rate limit coalescing feature

[Mugunthan V N]

Add ability to limit the broadcast or multicast packets to prevent
the loading of the CPU by a hacker with a broadcast or multicast
packet flood.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
---
 include/uapi/linux/ethtool.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index e3c7a71..96ade34 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -350,6 +350,8 @@ struct ethtool_modinfo {
  *	a TX interrupt, when the packet rate is above @pkt_rate_high.
  * @rate_sample_interval: How often to do adaptive coalescing packet rate
  *	sampling, measured in seconds.  Must not be zero.
+ * @rx_max_mcast: Threshold for high multicast packet rate (packets per second)
+ * @rx_max_bcast: Threshold for high broadcast packet rate (packets per second)
  *
  * Each pair of (usecs, max_frames) fields specifies that interrupts
  * should be coalesced until
@@ -400,6 +402,8 @@ struct ethtool_coalesce {
 	__u32	tx_coalesce_usecs_high;
 	__u32	tx_max_coalesced_frames_high;
 	__u32	rate_sample_interval;
+	__u32	rx_max_mcast;
+	__u32	rx_max_bcast;
 };
 
 /**
-- 
2.0.0.390.gcb682f8

[net-next PATCH 2/3] drivers: net: cpsw: remove redundancy check

[Mugunthan V N]

In cpsw_set_coalesce, rx_coalesce_usecs is already checked before
calling this function, so removing redundancy check.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
---
 drivers/net/ethernet/ti/cpsw.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index b988d16..a6117e6 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -884,9 +884,6 @@ static int cpsw_set_coalesce(struct net_device *ndev,
 	u32 addnl_dvdr = 1;
 	u32 coal_intvl = 0;
 
-	if (!coal->rx_coalesce_usecs)
-		return -EINVAL;
-
 	coal_intvl = coal->rx_coalesce_usecs;
 
 	int_ctrl =  readl(&priv->wr_regs->int_control);
-- 
2.0.0.390.gcb682f8

[net-next PATCH 3/3] drivers: net: cpsw: Add support for multicast/boradcast rate limit

[Mugunthan V N]

Add support for multicast/boradcast rate limit feature via ethtool coalesce.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
---
 drivers/net/ethernet/ti/cpsw.c | 80 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 78 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index a6117e6..2a984e6 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -403,6 +403,8 @@ struct cpsw_priv {
 	bool irq_enabled;
 	struct cpts *cpts;
 	u32 emac_port;
+	u32 rx_max_mcast;
+	u32 rx_max_bcast;
 };
 
 struct cpsw_stats {
@@ -871,11 +873,13 @@ static int cpsw_get_coalesce(struct net_device *ndev,
 	struct cpsw_priv *priv = netdev_priv(ndev);
 
 	coal->rx_coalesce_usecs = priv->coal_intvl;
+	coal->rx_max_mcast = priv->rx_max_mcast;
+	coal->rx_max_bcast = priv->rx_max_bcast;
 	return 0;
 }
 
-static int cpsw_set_coalesce(struct net_device *ndev,
-				struct ethtool_coalesce *coal)
+static int cpsw_set_coalesce_usecs(struct net_device *ndev,
+				   struct ethtool_coalesce *coal)
 {
 	struct cpsw_priv *priv = netdev_priv(ndev);
 	u32 int_ctrl;
@@ -933,6 +937,74 @@ static int cpsw_set_coalesce(struct net_device *ndev,
 	return 0;
 }
 
+static int cpsw_set_coalesce_mcast(struct net_device *ndev,
+				   struct ethtool_coalesce *coal)
+{
+	struct cpsw_priv *priv = netdev_priv(ndev);
+	int port;
+
+	priv->rx_max_mcast = coal->rx_max_mcast;
+
+	if (priv->data.dual_emac)
+		port = priv->emac_port;
+	else
+		port = priv->data.active_slave;
+
+	cpsw_ale_control_set(priv->ale, port, ALE_PORT_MCAST_LIMIT,
+			     coal->rx_max_mcast);
+
+	dev_dbg(priv->dev, "rx_max_mcast set to %d\n", priv->rx_max_mcast);
+	return 0;
+}
+
+static int cpsw_set_coalesce_bcast(struct net_device *ndev,
+				   struct ethtool_coalesce *coal)
+{
+	struct cpsw_priv *priv = netdev_priv(ndev);
+	int port;
+
+	priv->rx_max_bcast = coal->rx_max_bcast;
+
+	if (priv->data.dual_emac)
+		port = priv->emac_port + 1;
+	else
+		port = priv->data.active_slave + 1;
+
+	cpsw_ale_control_set(priv->ale, port, ALE_PORT_BCAST_LIMIT,
+			     coal->rx_max_bcast);
+
+	dev_dbg(priv->dev, "rx_max_mcast set to %d\n", priv->rx_max_bcast);
+	return 0;
+}
+
+static int cpsw_set_coalesce(struct net_device *ndev,
+			     struct ethtool_coalesce *coal)
+{
+	int ret = -EINVAL;
+
+	if (coal->rx_coalesce_usecs) {
+		ret = cpsw_set_coalesce_usecs(ndev, coal);
+		if (ret) {
+			dev_err(&ndev->dev, "set rx-usecs failed\n");
+			return ret;
+		}
+	}
+
+	ret = cpsw_set_coalesce_mcast(ndev, coal);
+	if (ret) {
+		dev_err(&ndev->dev, "set coalesce rx-max-mcast failed\n");
+		return ret;
+	}
+
+	ret = cpsw_set_coalesce_bcast(ndev, coal);
+	if (ret) {
+		dev_err(&ndev->dev, "set coalesce rx-max-bcast failed\n");
+		return ret;
+	}
+
+	return ret;
+}
+
 static int cpsw_get_sset_count(struct net_device *ndev, int sset)
 {
 	switch (sset) {
@@ -1227,6 +1299,10 @@ static int cpsw_ndo_open(struct net_device *ndev)
 		/* enable statistics collection only on all ports */
 		__raw_writel(0x7, &priv->regs->stat_port_en);
 
+		/* Enable rate limit feature in the switch for rx only */
+		cpsw_ale_control_set(priv->ale, 0, ALE_RATE_LIMIT, 1);
+		cpsw_ale_control_set(priv->ale, 0, ALE_RATE_LIMIT_TX, 0);
+
 		if (WARN_ON(!priv->data.rx_descs))
 			priv->data.rx_descs = 128;
 
-- 
2.0.0.390.gcb682f8

Re: [net-next PATCH 3/3] drivers: net: cpsw: Add support for multicast/boradcast rate limit

[Mugunthan V N]

On Tuesday 08 July 2014 02:27 PM, Mugunthan V N wrote:
> Add support for multicast/boradcast rate limit feature via ethtool coalesce.
>
> Signed-off-by: Mugunthan V N <mugunthanvnm-l0cyMroinI0@public.gmane.org>

s/boradcast/broadcast

Will fix this in next patch set.

Regards
Mugunthan V N