[patch net-next v3 2/4] rtnetlink: add HW/SW stats distinction in rtnl_fill_stats

[Jiri Pirko]

From: Nogah Frankel <nog...@mellanox.com>

Since hardware stats are now returned by default, add a way to
query only software stats.
They are saved in IFLA_SW_STATS64.
(This option is valid only if the driver return HW stats in the
default ndo stats)

Signed-off-by: Nogah Frankel <nog...@mellanox.com>
Signed-off-by: Jiri Pirko <j...@mellanox.com>
---
v2->v3:
- avoided memcpy as requerted by DaveM
v1->v2:
- no change
---
 include/uapi/linux/if_link.h |  1 +
 net/core/rtnetlink.c         | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index bb36bd5..98175e7 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -156,6 +156,7 @@ enum {
        IFLA_GSO_MAX_SEGS,
        IFLA_GSO_MAX_SIZE,
        IFLA_PAD,
+       IFLA_SW_STATS64,
        __IFLA_MAX
 };
 
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index d69c464..b0ebac6 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1054,12 +1054,25 @@ static noinline_for_stack int rtnl_fill_stats(struct 
sk_buff *skb,
 
        attr = nla_reserve_64bit(skb, IFLA_STATS64,
                                 sizeof(struct rtnl_link_stats64), IFLA_PAD);
+
        if (!attr)
                return -EMSGSIZE;
 
        sp = nla_data(attr);
        dev_get_stats(dev, sp);
 
+       if (dev_have_sw_stats(dev)) {
+               attr = nla_reserve_64bit(skb, IFLA_SW_STATS64,
+                                        sizeof(struct rtnl_link_stats64),
+                                        IFLA_PAD);
+
+               if (!attr)
+                       return -EMSGSIZE;
+
+               sp = nla_data(attr);
+               dev_get_sw_stats(dev, sp);
+       }
+
        attr = nla_reserve(skb, IFLA_STATS,
                           sizeof(struct rtnl_link_stats));
        if (!attr)
-- 
2.5.5