From b5c80d310527223b93e4133ac2f4c8c063c70a98 Mon Sep 17 00:00:00 2001
From: Christian Poessinger <christian@poessinger.com>
Date: Fri, 18 Dec 2020 17:13:13 +0100
Subject: xdp: T2666: switch to example code provided by xdp-tutorial

---
 src/xdp/common/xdp_stats_kern.h | 44 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 src/xdp/common/xdp_stats_kern.h

(limited to 'src/xdp/common/xdp_stats_kern.h')

diff --git a/src/xdp/common/xdp_stats_kern.h b/src/xdp/common/xdp_stats_kern.h
new file mode 100644
index 000000000..4e08551a0
--- /dev/null
+++ b/src/xdp/common/xdp_stats_kern.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Used *ONLY* by BPF-prog running kernel side. */
+#ifndef __XDP_STATS_KERN_H
+#define __XDP_STATS_KERN_H
+
+/* Data record type 'struct datarec' is defined in common/xdp_stats_kern_user.h,
+ * programs using this header must first include that file.
+ */
+#ifndef __XDP_STATS_KERN_USER_H
+#warning "You forgot to #include <../common/xdp_stats_kern_user.h>"
+#include <../common/xdp_stats_kern_user.h>
+#endif
+
+/* Keeps stats per (enum) xdp_action */
+struct bpf_map_def SEC("maps") xdp_stats_map = {
+	.type        = BPF_MAP_TYPE_PERCPU_ARRAY,
+	.key_size    = sizeof(__u32),
+	.value_size  = sizeof(struct datarec),
+	.max_entries = XDP_ACTION_MAX,
+};
+
+static __always_inline
+__u32 xdp_stats_record_action(struct xdp_md *ctx, __u32 action)
+{
+	if (action >= XDP_ACTION_MAX)
+		return XDP_ABORTED;
+
+	/* Lookup in kernel BPF-side return pointer to actual data record */
+	struct datarec *rec = bpf_map_lookup_elem(&xdp_stats_map, &action);
+	if (!rec)
+		return XDP_ABORTED;
+
+	/* BPF_MAP_TYPE_PERCPU_ARRAY returns a data record specific to current
+	 * CPU and XDP hooks runs under Softirq, which makes it safe to update
+	 * without atomic operations.
+	 */
+	rec->rx_packets++;
+	rec->rx_bytes += (ctx->data_end - ctx->data);
+
+	return action;
+}
+
+#endif /* __XDP_STATS_KERN_H */
-- 
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