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 extern int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx,
23 __u64 *timestamp) __ksym;
24 extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, __u32 *hash,
25 enum xdp_rss_hash_type *rss_type) __ksym;
26 extern int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
27 __be16 *vlan_proto,
28 __u16 *vlan_tci) __ksym;
29
30 SEC("xdp")
31 int 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, ×tamp);
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
98 char _license[] SEC("license") = "GPL";
99
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.