1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <vmlinux.h>
4 #include "xdp_metadata.h"
5 #include <bpf/bpf_helpers.h>
6 #include <bpf/bpf_endian.h>
7 
8 struct {
9 	__uint(type, BPF_MAP_TYPE_XSKMAP);
10 	__uint(max_entries, 4);
11 	__type(key, __u32);
12 	__type(value, __u32);
13 } xsk SEC(".maps");
14 
15 struct {
16 	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
17 	__uint(max_entries, 1);
18 	__type(key, __u32);
19 	__type(value, __u32);
20 } prog_arr SEC(".maps");
21 
22 extern int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx,
23 					 __u64 *timestamp) __ksym;
24 extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, __u32 *hash,
25 				    enum xdp_rss_hash_type *rss_type) __ksym;
26 
27 SEC("xdp")
rx(struct xdp_md * ctx)28 int rx(struct xdp_md *ctx)
29 {
30 	void *data, *data_meta;
31 	struct xdp_meta *meta;
32 	u64 timestamp = -1;
33 	int ret;
34 
35 	/* Reserve enough for all custom metadata. */
36 
37 	ret = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
38 	if (ret != 0)
39 		return XDP_DROP;
40 
41 	data = (void *)(long)ctx->data;
42 	data_meta = (void *)(long)ctx->data_meta;
43 
44 	if (data_meta + sizeof(struct xdp_meta) > data)
45 		return XDP_DROP;
46 
47 	meta = data_meta;
48 
49 	/* Export metadata. */
50 
51 	/* We expect veth bpf_xdp_metadata_rx_timestamp to return 0 HW
52 	 * timestamp, so put some non-zero value into AF_XDP frame for
53 	 * the userspace.
54 	 */
55 	bpf_xdp_metadata_rx_timestamp(ctx, &timestamp);
56 	if (timestamp == 0)
57 		meta->rx_timestamp = 1;
58 
59 	bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash, &meta->rx_hash_type);
60 
61 	return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
62 }
63 
64 char _license[] SEC("license") = "GPL";
65