2014-07-08 08:57:52

by Mugunthan V N

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

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


2014-07-08 08:57:55

by Mugunthan V N

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

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 <[email protected]>
---
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

2014-07-08 08:58:00

by Mugunthan V N

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

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

Signed-off-by: Mugunthan V N <[email protected]>
---
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

2014-07-08 08:58:47

by Mugunthan V N

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

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

Signed-off-by: Mugunthan V N <[email protected]>
---
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

2014-07-08 09:19:01

by Mugunthan V N

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

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 <[email protected]>

s/boradcast/broadcast

Will fix this in next patch set.

Regards
Mugunthan V N