samples: bpf: Convert xdp_redirect_kern.o to XDP samples helper

We moved swap_src_dst_mac to xdp_sample.bpf.h to be shared with other
potential users, so drop it while moving code to the new file.
Also, consistently use SEC("xdp") naming instead.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-16-memxor@gmail.com

1 files changed, 49 insertions, 0 deletions

diff --git a/samples/bpf/xdp_redirect.bpf.c b/samples/bpf/xdp_redirect.bpf.c
new file mode 100644
index 000000000000..7c02bacfe96b
--- /dev/null
+++ b/samples/bpf/xdp_redirect.bpf.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2016 John Fastabend <john.r.fastabend@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#include "vmlinux.h"
+#include "xdp_sample.bpf.h"
+#include "xdp_sample_shared.h"
+
+const volatile int ifindex_out;
+
+SEC("xdp")
+int xdp_redirect_prog(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	u32 key = bpf_get_smp_processor_id();
+	struct ethhdr *eth = data;
+	struct datarec *rec;
+	u64 nh_off;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return XDP_DROP;
+
+	rec = bpf_map_lookup_elem(&rx_cnt, &key);
+	if (!rec)
+		return XDP_PASS;
+	NO_TEAR_INC(rec->processed);
+
+	swap_src_dst_mac(data);
+	return bpf_redirect(ifindex_out, 0);
+}
+
+/* Redirect require an XDP bpf_prog loaded on the TX device */
+SEC("xdp")
+int xdp_redirect_dummy_prog(struct xdp_md *ctx)
+{
+	return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";