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// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
#include <linux/ip.h>
#include <linux/in.h>
#include <linux/if_ether.h>
#include <linux/pkt_cls.h>
#include <stdbool.h>
int lookup_status;
bool test_xdp;
bool tcp_skc;
#define CUR_NS BPF_F_CURRENT_NETNS
static void socket_lookup(void *ctx, void *data_end, void *data)
{
struct ethhdr *eth = data;
struct bpf_sock_tuple *tp;
struct bpf_sock *sk;
struct iphdr *iph;
int tplen;
if (eth + 1 > data_end)
return;
if (eth->h_proto != bpf_htons(ETH_P_IP))
return;
iph = (struct iphdr *)(eth + 1);
if (iph + 1 > data_end)
return;
tp = (struct bpf_sock_tuple *)&iph->saddr;
tplen = sizeof(tp->ipv4);
if ((void *)tp + tplen > data_end)
return;
switch (iph->protocol) {
case IPPROTO_TCP:
if (tcp_skc)
sk = bpf_skc_lookup_tcp(ctx, tp, tplen, CUR_NS, 0);
else
sk = bpf_sk_lookup_tcp(ctx, tp, tplen, CUR_NS, 0);
break;
case IPPROTO_UDP:
sk = bpf_sk_lookup_udp(ctx, tp, tplen, CUR_NS, 0);
break;
default:
return;
}
lookup_status = 0;
if (sk) {
bpf_sk_release(sk);
lookup_status = 1;
}
}
SEC("tc")
int tc_socket_lookup(struct __sk_buff *skb)
{
void *data_end = (void *)(long)skb->data_end;
void *data = (void *)(long)skb->data;
if (test_xdp)
return TC_ACT_UNSPEC;
socket_lookup(skb, data_end, data);
return TC_ACT_UNSPEC;
}
SEC("xdp")
int xdp_socket_lookup(struct xdp_md *xdp)
{
void *data_end = (void *)(long)xdp->data_end;
void *data = (void *)(long)xdp->data;
if (!test_xdp)
return XDP_PASS;
socket_lookup(xdp, data_end, data);
return XDP_PASS;
}
char _license[] SEC("license") = "GPL";
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