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
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