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 
24 SEC("xdp")
25 int rx(struct xdp_md *ctx)
26 {
27 	void *data, *data_meta, *data_end;
28 	struct ipv6hdr *ip6h = NULL;
29 	struct ethhdr *eth = NULL;
30 	struct udphdr *udp = NULL;
31 	struct iphdr *iph = NULL;
32 	struct xdp_meta *meta;
33 	int err;
34 
35 	data = (void *)(long)ctx->data;
36 	data_end = (void *)(long)ctx->data_end;
37 	eth = data;
38 	if (eth + 1 < data_end) {
39 		if (eth->h_proto == bpf_htons(ETH_P_IP)) {
40 			iph = (void *)(eth + 1);
41 			if (iph + 1 < data_end && iph->protocol == IPPROTO_UDP)
42 				udp = (void *)(iph + 1);
43 		}
44 		if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
45 			ip6h = (void *)(eth + 1);
46 			if (ip6h + 1 < data_end && ip6h->nexthdr == IPPROTO_UDP)
47 				udp = (void *)(ip6h + 1);
48 		}
49 		if (udp && udp + 1 > data_end)
50 			udp = NULL;
51 	}
52 
53 	if (!udp) {
54 		__sync_add_and_fetch(&pkts_skip, 1);
55 		return XDP_PASS;
56 	}
57 
58 	/* Forwarding UDP:9091 to AF_XDP */
59 	if (udp->dest != bpf_htons(9091)) {
60 		__sync_add_and_fetch(&pkts_skip, 1);
61 		return XDP_PASS;
62 	}
63 
64 	err = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
65 	if (err) {
66 		__sync_add_and_fetch(&pkts_fail, 1);
67 		return XDP_PASS;
68 	}
69 
70 	data = (void *)(long)ctx->data;
71 	data_meta = (void *)(long)ctx->data_meta;
72 	meta = data_meta;
73 
74 	if (meta + 1 > data) {
75 		__sync_add_and_fetch(&pkts_fail, 1);
76 		return XDP_PASS;
77 	}
78 
79 	err = bpf_xdp_metadata_rx_timestamp(ctx, &meta->rx_timestamp);
80 	if (!err)
81 		meta->xdp_timestamp = bpf_ktime_get_tai_ns();
82 	else
83 		meta->rx_timestamp = 0; /* Used by AF_XDP as not avail signal */
84 
85 	err = bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash, &meta->rx_hash_type);
86 	if (err < 0)
87 		meta->rx_hash_err = err; /* Used by AF_XDP as no hash signal */
88 
89 	__sync_add_and_fetch(&pkts_redir, 1);
90 	return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
91 }
92 
93 char _license[] SEC("license") = "GPL";
94