diff mbox series

[v3,net-next,02/15] net: dsa: allow drivers to request promiscuous mode on master

Message ID 20200926193215.1405730-3-vladimir.oltean@nxp.com
State Accepted
Delegated to: David Miller
Headers show
Series Generic adjustment for flow dissector in DSA | expand

Commit Message

Vladimir Oltean Sept. 26, 2020, 7:32 p.m. UTC 
Currently DSA assumes that taggers don't mess with the destination MAC
address of the frames on RX. That is not always the case. Some DSA
headers are placed before the Ethernet header (ocelot), and others
simply mangle random bytes from the destination MAC address (sja1105
with its incl_srcpt option).

Currently the DSA master goes to promiscuous mode automatically when the
slave devices go too (such as when enslaved to a bridge), but in
standalone mode this is a problem that needs to be dealt with.

So give drivers the possibility to signal that their tagging protocol
will get randomly dropped otherwise, and let DSA deal with fixing that.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
Changes in v3:
Make "promisc_on_master" a tagger property.

 include/net/dsa.h |  6 ++++++
 net/dsa/master.c  | 20 +++++++++++++++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

Comments

Andrew Lunn Sept. 26, 2020, 8:22 p.m. UTC | #1 
On Sat, Sep 26, 2020 at 10:32:02PM +0300, Vladimir Oltean wrote:
> Currently DSA assumes that taggers don't mess with the destination MAC
> address of the frames on RX. That is not always the case. Some DSA
> headers are placed before the Ethernet header (ocelot), and others
> simply mangle random bytes from the destination MAC address (sja1105
> with its incl_srcpt option).
> 
> Currently the DSA master goes to promiscuous mode automatically when the
> slave devices go too (such as when enslaved to a bridge), but in
> standalone mode this is a problem that needs to be dealt with.
> 
> So give drivers the possibility to signal that their tagging protocol
> will get randomly dropped otherwise, and let DSA deal with fixing that.
> 
> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew
diff mbox series

Patch

diff --git a/include/net/dsa.h b/include/net/dsa.h
index d16057c5987a..46019edc32cb 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -84,6 +84,12 @@  struct dsa_device_ops {
 	unsigned int overhead;
 	const char *name;
 	enum dsa_tag_protocol proto;
+	/* Some tagging protocols either mangle or shift the destination MAC
+	 * address, in which case the DSA master would drop packets on ingress
+	 * if what it understands out of the destination MAC address is not in
+	 * its RX filter.
+	 */
+	bool promisc_on_master;
 };
 
 /* This structure defines the control interfaces that are overlayed by the
diff --git a/net/dsa/master.c b/net/dsa/master.c
index 61615ebc70e9..c91de041a91d 100644
--- a/net/dsa/master.c
+++ b/net/dsa/master.c
@@ -259,6 +259,18 @@  static void dsa_netdev_ops_set(struct net_device *dev,
 	dev->dsa_ptr->netdev_ops = ops;
 }
 
+static void dsa_master_set_promiscuity(struct net_device *dev, int inc)
+{
+	const struct dsa_device_ops *ops = dev->dsa_ptr->tag_ops;
+
+	if (!ops->promisc_on_master)
+		return;
+
+	rtnl_lock();
+	dev_set_promiscuity(dev, inc);
+	rtnl_unlock();
+}
+
 static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
 			    char *buf)
 {
@@ -314,9 +326,12 @@  int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
 	dev->dsa_ptr = cpu_dp;
 	lockdep_set_class(&dev->addr_list_lock,
 			  &dsa_master_addr_list_lock_key);
+
+	dsa_master_set_promiscuity(dev, 1);
+
 	ret = dsa_master_ethtool_setup(dev);
 	if (ret)
-		return ret;
+		goto out_err_reset_promisc;
 
 	dsa_netdev_ops_set(dev, &dsa_netdev_ops);
 
@@ -329,6 +344,8 @@  int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
 out_err_ndo_teardown:
 	dsa_netdev_ops_set(dev, NULL);
 	dsa_master_ethtool_teardown(dev);
+out_err_reset_promisc:
+	dsa_master_set_promiscuity(dev, -1);
 	return ret;
 }
 
@@ -338,6 +355,7 @@  void dsa_master_teardown(struct net_device *dev)
 	dsa_netdev_ops_set(dev, NULL);
 	dsa_master_ethtool_teardown(dev);
 	dsa_master_reset_mtu(dev);
+	dsa_master_set_promiscuity(dev, -1);
 
 	dev->dsa_ptr = NULL;