90 lines
1.6 KiB
C
90 lines
1.6 KiB
C
// 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";
|