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// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include "xdp_metadata.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
struct {
__uint(type, BPF_MAP_TYPE_XSKMAP);
__uint(max_entries, 256);
__type(key, __u32);
__type(value, __u32);
} xsk SEC(".maps");
extern int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx,
__u64 *timestamp) __ksym;
extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx,
__u32 *hash) __ksym;
SEC("xdp")
int rx(struct xdp_md *ctx)
{
void *data, *data_meta, *data_end;
struct ipv6hdr *ip6h = NULL;
struct ethhdr *eth = NULL;
struct udphdr *udp = NULL;
struct iphdr *iph = NULL;
struct xdp_meta *meta;
int ret;
data = (void *)(long)ctx->data;
data_end = (void *)(long)ctx->data_end;
eth = data;
if (eth + 1 < data_end) {
if (eth->h_proto == bpf_htons(ETH_P_IP)) {
iph = (void *)(eth + 1);
if (iph + 1 < data_end && iph->protocol == IPPROTO_UDP)
udp = (void *)(iph + 1);
}
if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
ip6h = (void *)(eth + 1);
if (ip6h + 1 < data_end && ip6h->nexthdr == IPPROTO_UDP)
udp = (void *)(ip6h + 1);
}
if (udp && udp + 1 > data_end)
udp = NULL;
}
if (!udp)
return XDP_PASS;
if (udp->dest != bpf_htons(9091))
return XDP_PASS;
bpf_printk("forwarding UDP:9091 to AF_XDP");
ret = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
if (ret != 0) {
bpf_printk("bpf_xdp_adjust_meta returned %d", ret);
return XDP_PASS;
}
data = (void *)(long)ctx->data;
data_meta = (void *)(long)ctx->data_meta;
meta = data_meta;
if (meta + 1 > data) {
bpf_printk("bpf_xdp_adjust_meta doesn't appear to work");
return XDP_PASS;
}
if (!bpf_xdp_metadata_rx_timestamp(ctx, &meta->rx_timestamp))
bpf_printk("populated rx_timestamp with %llu", meta->rx_timestamp);
else
meta->rx_timestamp = 0; /* Used by AF_XDP as not avail signal */
if (!bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash))
bpf_printk("populated rx_hash with %u", meta->rx_hash);
else
meta->rx_hash = 0; /* Used by AF_XDP as not avail signal */
return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
}
char _license[] SEC("license") = "GPL";
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