xref: /linux/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c (revision 2d7f3d1a5866705be2393150e1ffdf67030ab88d)
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, 256);
11 	__type(key, __u32);
12 	__type(value, __u32);
13 } xsk SEC(".maps");
14 
15 __u64 pkts_skip = 0;
16 __u64 pkts_fail = 0;
17 __u64 pkts_redir = 0;
18 
19 extern int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx,
20 					 __u64 *timestamp) __ksym;
21 extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, __u32 *hash,
22 				    enum xdp_rss_hash_type *rss_type) __ksym;
23 extern int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
24 					__be16 *vlan_proto,
25 					__u16 *vlan_tci) __ksym;
26 
27 SEC("xdp.frags")
28 int rx(struct xdp_md *ctx)
29 {
30 	void *data, *data_meta, *data_end;
31 	struct ipv6hdr *ip6h = NULL;
32 	struct udphdr *udp = NULL;
33 	struct iphdr *iph = NULL;
34 	struct xdp_meta *meta;
35 	struct ethhdr *eth;
36 	int err;
37 
38 	data = (void *)(long)ctx->data;
39 	data_end = (void *)(long)ctx->data_end;
40 	eth = data;
41 
42 	if (eth + 1 < data_end && (eth->h_proto == bpf_htons(ETH_P_8021AD) ||
43 				   eth->h_proto == bpf_htons(ETH_P_8021Q)))
44 		eth = (void *)eth + sizeof(struct vlan_hdr);
45 
46 	if (eth + 1 < data_end && eth->h_proto == bpf_htons(ETH_P_8021Q))
47 		eth = (void *)eth + sizeof(struct vlan_hdr);
48 
49 	if (eth + 1 < data_end) {
50 		if (eth->h_proto == bpf_htons(ETH_P_IP)) {
51 			iph = (void *)(eth + 1);
52 			if (iph + 1 < data_end && iph->protocol == IPPROTO_UDP)
53 				udp = (void *)(iph + 1);
54 		}
55 		if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
56 			ip6h = (void *)(eth + 1);
57 			if (ip6h + 1 < data_end && ip6h->nexthdr == IPPROTO_UDP)
58 				udp = (void *)(ip6h + 1);
59 		}
60 		if (udp && udp + 1 > data_end)
61 			udp = NULL;
62 	}
63 
64 	if (!udp) {
65 		__sync_add_and_fetch(&pkts_skip, 1);
66 		return XDP_PASS;
67 	}
68 
69 	/* Forwarding UDP:9091 to AF_XDP */
70 	if (udp->dest != bpf_htons(9091)) {
71 		__sync_add_and_fetch(&pkts_skip, 1);
72 		return XDP_PASS;
73 	}
74 
75 	err = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
76 	if (err) {
77 		__sync_add_and_fetch(&pkts_fail, 1);
78 		return XDP_PASS;
79 	}
80 
81 	data = (void *)(long)ctx->data;
82 	data_meta = (void *)(long)ctx->data_meta;
83 	meta = data_meta;
84 
85 	if (meta + 1 > data) {
86 		__sync_add_and_fetch(&pkts_fail, 1);
87 		return XDP_PASS;
88 	}
89 
90 	meta->hint_valid = 0;
91 
92 	meta->xdp_timestamp = bpf_ktime_get_tai_ns();
93 	err = bpf_xdp_metadata_rx_timestamp(ctx, &meta->rx_timestamp);
94 	if (err)
95 		meta->rx_timestamp_err = err;
96 	else
97 		meta->hint_valid |= XDP_META_FIELD_TS;
98 
99 	err = bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash,
100 				       &meta->rx_hash_type);
101 	if (err)
102 		meta->rx_hash_err = err;
103 	else
104 		meta->hint_valid |= XDP_META_FIELD_RSS;
105 
106 	err = bpf_xdp_metadata_rx_vlan_tag(ctx, &meta->rx_vlan_proto,
107 					   &meta->rx_vlan_tci);
108 	if (err)
109 		meta->rx_vlan_tag_err = err;
110 	else
111 		meta->hint_valid |= XDP_META_FIELD_VLAN_TAG;
112 
113 	__sync_add_and_fetch(&pkts_redir, 1);
114 	return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
115 }
116 
117 char _license[] SEC("license") = "GPL";
118