On 09/29/2017 12:45 PM, Nikolay Aleksandrov wrote:

On 29/09/17 12:29, Nikolay Aleksandrov wrote:

quoted

On 28/09/17 20:34, Jiri Pirko wrote:

quoted

From: Yotam Gigi <redacted>

In order to allow the ipmr module to do partial multicast forwarding
according to the device parent ID, add the device parent ID field to the
VIF struct. This way, the forwarding path can use the parent ID field
without invoking switchdev calls, which requires the RTNL lock.

When a new VIF is added, set the device parent ID field in it by invoking
the switchdev_port_attr_get call.

Signed-off-by: Yotam Gigi <redacted>
Reviewed-by: Ido Schimmel <redacted>
Signed-off-by: Jiri Pirko <redacted>
---
 include/linux/mroute.h | 2 ++
 net/ipv4/ipmr.c        | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/include/linux/mroute.h b/include/linux/mroute.h
index b072a84..a46577f 100644
--- a/include/linux/mroute.h
+++ b/include/linux/mroute.h

@@ -57,6 +57,8 @@ static inline bool ipmr_rule_default(const struct fib_rule *rule)
 
 struct vif_device {
 	struct net_device 	*dev;			/* Device we are using */
+	struct netdev_phys_item_id dev_parent_id;	/* Device parent ID    */
+	bool		dev_parent_id_valid;
 	unsigned long	bytes_in,bytes_out;
 	unsigned long	pkt_in,pkt_out;		/* Statistics 			*/
 	unsigned long	rate_limit;		/* Traffic shaping (NI) 	*/

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 292a8e8..4566c54 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c

@@ -67,6 +67,7 @@
 #include <net/fib_rules.h>
 #include <linux/netconf.h>
 #include <net/nexthop.h>
+#include <net/switchdev.h>
 
 struct ipmr_rule {
 	struct fib_rule		common;

@@ -868,6 +869,9 @@ static int vif_add(struct net *net, struct mr_table *mrt,
 		   struct vifctl *vifc, int mrtsock)
 {
 	int vifi = vifc->vifc_vifi;
+	struct switchdev_attr attr = {
+		.id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID,
+	};
 	struct vif_device *v = &mrt->vif_table[vifi];
 	struct net_device *dev;
 	struct in_device *in_dev;

@@ -942,6 +946,11 @@ static int vif_add(struct net *net, struct mr_table *mrt,
 
 	/* Fill in the VIF structures */
 
+	attr.orig_dev = dev;
+	if (!switchdev_port_attr_get(dev, &attr)) {
+		v->dev_parent_id_valid = true;
+		memcpy(v->dev_parent_id.id, attr.u.ppid.id, attr.u.ppid.id_len);

Hmm, shouldn't you set dev_parent_id.id_len too ? It would seem netdev_phys_item_id_same()
uses it in the comparison and without the len it would always look like they're the same
because memcmp will simply return 0 with count = 0.

Also maybe we can use the non-zero id_len as a signal that it was set and drop the dev_parent_id_valid
field altogether, it would seem there's no valid reason to have id_len == 0 and yet expect a valid
parent_id.

Yes, I agree to both. I will remove the parent_id_valid field and use the len to
indicate whether it is valid.

Thanks for spotting the bug - since we have only been testing it with a pimreg
device, the problem was not found in our tests. Multi-ASIC setups are a bit
hard to find these days :)

quoted

quoted

+	}
 	v->rate_limit = vifc->vifc_rate_limit;
 	v->local = vifc->vifc_lcl_addr.s_addr;
 	v->remote = vifc->vifc_rmt_addr.s_addr;