[NET]: Generic network statistics/estimator

Work done by Thomas Graf <tgraf@suug.ch> and
Jamal Hadi Salim <hadi@cyberus.ca>

The following patchset introduces generic network statistics for
netlink users. It uses nested TLV which prevents further compatibility
problems when introducing new statistics. Backward compatibility to
existing TLV types TCA_STATS and TCA_XSTATS is ensured but can be
easly removed once it is no longer needed. Therefore prior users of
struct tc_stats can be converted to this API and existing userspace
applications will not notice a difference while converted applications
can use the new extendable statistic interface.

Changes:
- Add generic network statistics API for netlink users.
- Introduces a generic rate estimator based on timers. Patch is based
  on Jamals patch and adapted to the new generic network statistics
  API.
- Add documentation of generic network statistics and estimator API.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 62 insertions, 0 deletions

diff --git a/include/linux/gen_stats.h b/include/linux/gen_stats.h
new file mode 100644
index 000000000000..ab631c3571ce
--- /dev/null
+++ b/include/linux/gen_stats.h
@@ -0,0 +1,62 @@
+#ifndef __LINUX_GEN_STATS_H
+#define __LINUX_GEN_STATS_H
+
+#include <linux/types.h>
+
+enum {
+	TCA_STATS_UNSPEC,
+	TCA_STATS_BASIC,
+	TCA_STATS_RATE_EST,
+	TCA_STATS_QUEUE,
+	TCA_STATS_APP,
+	__TCA_STATS_MAX,
+};
+#define TCA_STATS_MAX (__TCA_STATS_MAX - 1)
+
+/**
+ * @bytes: number of seen bytes
+ * @packets: number of seen packets
+ */
+struct gnet_stats_basic
+{
+	__u64	bytes;
+	__u32	packets;
+};
+
+/**
+ * @bps: current byte rate
+ * @pps: current packet rate
+ */
+struct gnet_stats_rate_est
+{
+	__u32	bps;
+	__u32	pps;
+};
+
+/**
+ * @qlen: queue length
+ * @backlog: backlog size of queue
+ * @drops: number of dropped packets
+ * @requeues: number of requeues
+ */
+struct gnet_stats_queue
+{
+	__u32	qlen;
+	__u32	backlog;
+	__u32	drops;
+	__u32	requeues;
+	__u32	overlimits;
+};
+
+/**
+ * @interval: sampling period
+ * @ewma_log: the log of measurement window weight
+ */
+struct gnet_estimator
+{
+	signed char	interval;
+	unsigned char	ewma_log;
+};
+
+
+#endif /* __LINUX_GEN_STATS_H */