Le 13/03/2016 02:56, Roopa Prabhu a écrit :
From: Roopa Prabhu <ro...@cumulusnetworks.com>
This patch adds a new RTM_GETSTATS message to query link stats via netlink
from the kernel. RTM_NEWLINK also dumps stats today, but RTM_NEWLINK
returns a lot more than just stats and is expensive in some cases when
frequent polling for stats from userspace is a common operation.
RTM_GETSTATS is an attempt to provide a light weight netlink message
to explicity query only link stats from the kernel on an interface.
The idea is to also keep it extensible so that new kinds of stats can be
added to it in the future.
This patch adds the following attribute for NETDEV stats:
struct nla_policy ifla_stats_policy[IFLA_STATS_MAX + 1] = {
[IFLA_STATS_LINK64] = { .len = sizeof(struct rtnl_link_stats64) },
};
This patch also allows for af family stats (an example af stats for IPV6
is available with the second patch in the series).
Like any other rtnetlink message, RTM_GETSTATS can be used to get stats of
a single interface or all interfaces with NLM_F_DUMP.
Future possible new types of stat attributes:
- IFLA_MPLS_STATS (nested. for mpls/mdev stats)
- IFLA_EXTENDED_STATS (nested. extended software netdev stats like bridge,
vlan, vxlan etc)
- IFLA_EXTENDED_HW_STATS (nested. extended hardware stats which are
available via ethtool today)
This patch also declares a filter mask for all stat attributes.
User has to provide a mask of stats attributes to query. This will be
specified in a new hdr 'struct if_stats_msg' for stats messages.
Without any attributes in the filter_mask, no stats will be returned.
This patch has been tested with modified iproute2 ifstat.
Suggested-by: Jamal Hadi Salim <j...@mojatatu.com>
Signed-off-by: Roopa Prabhu <ro...@cumulusnetworks.com>
[snip]
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 249eef9..0840f3e 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
[snip]
+enum {
+ IFLA_STATS_UNSPEC,
+ IFLA_STATS_LINK64,
+ IFLA_STATS_INET6,
IFLA_STATS_INET6 is part on patch #2, it's not used in this patch.
+ __IFLA_STATS_MAX,
+};
+
+#define IFLA_STATS_MAX (__IFLA_STATS_MAX - 1)
+
+#define IFLA_STATS_FILTER_BIT(ATTR) (1 << (ATTR))
+
#endif /* _UAPI_LINUX_IF_LINK_H */
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index ca764b5..2bbb300 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -139,6 +139,13 @@ enum {
RTM_GETNSID = 90,
#define RTM_GETNSID RTM_GETNSID
+ RTM_NEWSTATS = 92,
+#define RTM_NEWSTATS RTM_NEWSTATS
+ RTM_DELSTATS = 93,
+#define RTM_DELSTATS RTM_DELSTATS
RTM_DELSTATS is never used.
+ RTM_GETSTATS = 94,
+#define RTM_GETSTATS RTM_GETSTATS
+
__RTM_MAX,
#define RTM_MAX (((__RTM_MAX + 3) & ~3) - 1)
};
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index d2d9e5e..d1e3d17 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
[snip]
+static noinline size_t if_nlmsg_stats_size(const struct net_device *dev,
+ u32 filter_mask)
Why are you using the 'noinline' attribute?
+{
+ size_t size = 0;
+
+ if (filter_mask & IFLA_STATS_FILTER_BIT(IFLA_STATS_LINK64))
+ size += nla_total_size(sizeof(struct rtnl_link_stats64));
+
+ size += rtnl_link_get_af_stats_size(dev, filter_mask);
+
+ return size;
+}
