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
8struct {
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
15struct {
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
22extern int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx,
23					 __u64 *timestamp) __ksym;
24extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, __u32 *hash,
25				    enum xdp_rss_hash_type *rss_type) __ksym;
26extern int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
27					__be16 *vlan_proto,
28					__u16 *vlan_tci) __ksym;
29
30SEC("xdp")
31int rx(struct xdp_md *ctx)
32{
33	void *data, *data_meta, *data_end;
34	struct ipv6hdr *ip6h = NULL;
35	struct ethhdr *eth = NULL;
36	struct udphdr *udp = NULL;
37	struct iphdr *iph = NULL;
38	struct xdp_meta *meta;
39	u64 timestamp = -1;
40	int ret;
41
42	data = (void *)(long)ctx->data;
43	data_end = (void *)(long)ctx->data_end;
44	eth = data;
45	if (eth + 1 < data_end) {
46		if (eth->h_proto == bpf_htons(ETH_P_IP)) {
47			iph = (void *)(eth + 1);
48			if (iph + 1 < data_end && iph->protocol == IPPROTO_UDP)
49				udp = (void *)(iph + 1);
50		}
51		if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
52			ip6h = (void *)(eth + 1);
53			if (ip6h + 1 < data_end && ip6h->nexthdr == IPPROTO_UDP)
54				udp = (void *)(ip6h + 1);
55		}
56		if (udp && udp + 1 > data_end)
57			udp = NULL;
58	}
59
60	if (!udp)
61		return XDP_PASS;
62
63	/* Forwarding UDP:8080 to AF_XDP */
64	if (udp->dest != bpf_htons(8080))
65		return XDP_PASS;
66
67	/* Reserve enough for all custom metadata. */
68
69	ret = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
70	if (ret != 0)
71		return XDP_DROP;
72
73	data = (void *)(long)ctx->data;
74	data_meta = (void *)(long)ctx->data_meta;
75
76	if (data_meta + sizeof(struct xdp_meta) > data)
77		return XDP_DROP;
78
79	meta = data_meta;
80
81	/* Export metadata. */
82
83	/* We expect veth bpf_xdp_metadata_rx_timestamp to return 0 HW
84	 * timestamp, so put some non-zero value into AF_XDP frame for
85	 * the userspace.
86	 */
87	bpf_xdp_metadata_rx_timestamp(ctx, &timestamp);
88	if (timestamp == 0)
89		meta->rx_timestamp = 1;
90
91	bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash, &meta->rx_hash_type);
92	bpf_xdp_metadata_rx_vlan_tag(ctx, &meta->rx_vlan_proto,
93				     &meta->rx_vlan_tci);
94
95	return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
96}
97
98char _license[] SEC("license") = "GPL";
99