1 files changed, 112 insertions, 0 deletions
diff --git a/samples/bpf/xdp_sample.bpf.c b/samples/bpf/xdp_sample.bpf.c
new file mode 100644
index 000000000000..e22f2a97a988
--- /dev/null
+++ b/samples/bpf/xdp_sample.bpf.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0
+/*  GPLv2, Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc. */
+#include "xdp_sample.bpf.h"
+
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+#include <bpf/bpf_helpers.h>
+
+array_map rx_cnt SEC(".maps");
+array_map redir_err_cnt SEC(".maps");
+
+const volatile int nr_cpus = 0;
+
+/* These can be set before loading so that redundant comparisons can be DCE'd by
+ * the verifier, and only actual matches are tried after loading tp_btf program.
+ * This allows sample to filter tracepoint stats based on net_device.
+ */
+const volatile int from_match[32] = {};
+const volatile int to_match[32] = {};
+
+/* Find if b is part of set a, but if a is empty set then evaluate to true */
+#define IN_SET(a, b)                                                 \
+	({                                                           \
+		bool __res = !(a)[0];                                \
+		for (int i = 0; i < ARRAY_SIZE(a) && (a)[i]; i++) { \
+			__res = (a)[i] == (b);                       \
+			if (__res)                                   \
+				break;                               \
+		}                                                    \
+		__res;                                               \
+	})
+
+static __always_inline __u32 xdp_get_err_key(int err)
+{
+	switch (err) {
+	case 0:
+		return 0;
+	case -EINVAL:
+		return 2;
+	case -ENETDOWN:
+		return 3;
+	case -EMSGSIZE:
+		return 4;
+	case -EOPNOTSUPP:
+		return 5;
+	case -ENOSPC:
+		return 6;
+	default:
+		return 1;
+	}
+}
+
+static __always_inline int xdp_redirect_collect_stat(int from, int err)
+{
+	u32 cpu = bpf_get_smp_processor_id();
+	u32 key = XDP_REDIRECT_ERROR;
+	struct datarec *rec;
+	u32 idx;
+
+	if (!IN_SET(from_match, from))
+		return 0;
+
+	key = xdp_get_err_key(err);
+
+	idx = key * nr_cpus + cpu;
+	rec = bpf_map_lookup_elem(&redir_err_cnt, &idx);
+	if (!rec)
+		return 0;
+	if (key)
+		NO_TEAR_INC(rec->dropped);
+	else
+		NO_TEAR_INC(rec->processed);
+	return 0; /* Indicate event was filtered (no further processing)*/
+	/*
+	 * Returning 1 here would allow e.g. a perf-record tracepoint
+	 * to see and record these events, but it doesn't work well
+	 * in-practice as stopping perf-record also unload this
+	 * bpf_prog.  Plus, there is additional overhead of doing so.
+	 */
+}
+
+SEC("tp_btf/xdp_redirect_err")
+int BPF_PROG(tp_xdp_redirect_err, const struct net_device *dev,
+	     const struct bpf_prog *xdp, const void *tgt, int err,
+	     const struct bpf_map *map, u32 index)
+{
+	return xdp_redirect_collect_stat(dev->ifindex, err);
+}
+
+SEC("tp_btf/xdp_redirect_map_err")
+int BPF_PROG(tp_xdp_redirect_map_err, const struct net_device *dev,
+	     const struct bpf_prog *xdp, const void *tgt, int err,
+	     const struct bpf_map *map, u32 index)
+{
+	return xdp_redirect_collect_stat(dev->ifindex, err);
+}
+
+SEC("tp_btf/xdp_redirect")
+int BPF_PROG(tp_xdp_redirect, const struct net_device *dev,
+	     const struct bpf_prog *xdp, const void *tgt, int err,
+	     const struct bpf_map *map, u32 index)
+{
+	return xdp_redirect_collect_stat(dev->ifindex, err);
+}
+
+SEC("tp_btf/xdp_redirect_map")
+int BPF_PROG(tp_xdp_redirect_map, const struct net_device *dev,
+	     const struct bpf_prog *xdp, const void *tgt, int err,
+	     const struct bpf_map *map, u32 index)
+{
+	return xdp_redirect_collect_stat(dev->ifindex, err);
+}