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 struct {
23 __uint(type, BPF_MAP_TYPE_DEVMAP);
24 __uint(key_size, sizeof(__u32));
25 __uint(value_size, sizeof(struct bpf_devmap_val));
26 __uint(max_entries, 1);
27 } dev_map SEC(".maps");
28
29 extern int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx,
30 __u64 *timestamp) __ksym;
31 extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, __u32 *hash,
32 enum xdp_rss_hash_type *rss_type) __ksym;
33 extern int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
34 __be16 *vlan_proto,
35 __u16 *vlan_tci) __ksym;
36
37 SEC("xdp")
rx(struct xdp_md * ctx)38 int rx(struct xdp_md *ctx)
39 {
40 void *data, *data_meta, *data_end;
41 struct ipv6hdr *ip6h = NULL;
42 struct ethhdr *eth = NULL;
43 struct udphdr *udp = NULL;
44 struct iphdr *iph = NULL;
45 struct xdp_meta *meta;
46 u64 timestamp = -1;
47 int ret;
48
49 data = (void *)(long)ctx->data;
50 data_end = (void *)(long)ctx->data_end;
51 eth = data;
52 if (eth + 1 < data_end) {
53 if (eth->h_proto == bpf_htons(ETH_P_IP)) {
54 iph = (void *)(eth + 1);
55 if (iph + 1 < data_end && iph->protocol == IPPROTO_UDP)
56 udp = (void *)(iph + 1);
57 }
58 if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
59 ip6h = (void *)(eth + 1);
60 if (ip6h + 1 < data_end && ip6h->nexthdr == IPPROTO_UDP)
61 udp = (void *)(ip6h + 1);
62 }
63 if (udp && udp + 1 > data_end)
64 udp = NULL;
65 }
66
67 if (!udp)
68 return XDP_PASS;
69
70 /* Forwarding UDP:8080 to AF_XDP */
71 if (udp->dest != bpf_htons(8080))
72 return XDP_PASS;
73
74 /* Reserve enough for all custom metadata. */
75
76 ret = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
77 if (ret != 0)
78 return XDP_DROP;
79
80 data = (void *)(long)ctx->data;
81 data_meta = (void *)(long)ctx->data_meta;
82
83 if (data_meta + sizeof(struct xdp_meta) > data)
84 return XDP_DROP;
85
86 meta = data_meta;
87
88 /* Export metadata. */
89
90 /* We expect veth bpf_xdp_metadata_rx_timestamp to return 0 HW
91 * timestamp, so put some non-zero value into AF_XDP frame for
92 * the userspace.
93 */
94 bpf_xdp_metadata_rx_timestamp(ctx, ×tamp);
95 if (timestamp == 0)
96 meta->rx_timestamp = 1;
97
98 bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash, &meta->rx_hash_type);
99 bpf_xdp_metadata_rx_vlan_tag(ctx, &meta->rx_vlan_proto,
100 &meta->rx_vlan_tci);
101
102 return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
103 }
104
105 SEC("xdp")
redirect(struct xdp_md * ctx)106 int redirect(struct xdp_md *ctx)
107 {
108 return bpf_redirect_map(&dev_map, ctx->rx_queue_index, XDP_PASS);
109 }
110
111 char _license[] SEC("license") = "GPL";
112