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// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2024 Meta
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_core_read.h>
#include <bpf/bpf_endian.h>
#include "bpf_tracing_net.h"
#include "bpf_kfuncs.h"
#define ATTR __always_inline
#include "test_jhash.h"
static bool ipv6_addr_loopback(const struct in6_addr *a)
{
return (a->s6_addr32[0] | a->s6_addr32[1] |
a->s6_addr32[2] | (a->s6_addr32[3] ^ bpf_htonl(1))) == 0;
}
static bool ipv4_addr_loopback(__be32 a)
{
return a == bpf_ntohl(0x7f000001);
}
volatile const unsigned int sf;
volatile const __u16 ports[2];
unsigned int bucket[2];
SEC("iter/tcp")
int iter_tcp_soreuse(struct bpf_iter__tcp *ctx)
{
struct sock *sk = (struct sock *)ctx->sk_common;
struct inet_hashinfo *hinfo;
unsigned int hash;
__u64 sock_cookie;
struct net *net;
int idx;
if (!sk)
return 0;
sock_cookie = bpf_get_socket_cookie(sk);
sk = bpf_core_cast(sk, struct sock);
if (sk->sk_family != sf ||
sk->sk_state != TCP_LISTEN ||
sk->sk_family == AF_INET6 ?
!ipv6_addr_loopback(&sk->sk_v6_rcv_saddr) :
!ipv4_addr_loopback(sk->sk_rcv_saddr))
return 0;
if (sk->sk_num == ports[0])
idx = 0;
else if (sk->sk_num == ports[1])
idx = 1;
else
return 0;
/* bucket selection as in inet_lhash2_bucket_sk() */
net = sk->sk_net.net;
hash = jhash2(sk->sk_v6_rcv_saddr.s6_addr32, 4, net->hash_mix);
hash ^= sk->sk_num;
hinfo = net->ipv4.tcp_death_row.hashinfo;
bucket[idx] = hash & hinfo->lhash2_mask;
bpf_seq_write(ctx->meta->seq, &idx, sizeof(idx));
bpf_seq_write(ctx->meta->seq, &sock_cookie, sizeof(sock_cookie));
return 0;
}
#define udp_sk(ptr) container_of(ptr, struct udp_sock, inet.sk)
SEC("iter/udp")
int iter_udp_soreuse(struct bpf_iter__udp *ctx)
{
struct sock *sk = (struct sock *)ctx->udp_sk;
struct udp_table *udptable;
__u64 sock_cookie;
int idx;
if (!sk)
return 0;
sock_cookie = bpf_get_socket_cookie(sk);
sk = bpf_core_cast(sk, struct sock);
if (sk->sk_family != sf ||
sk->sk_family == AF_INET6 ?
!ipv6_addr_loopback(&sk->sk_v6_rcv_saddr) :
!ipv4_addr_loopback(sk->sk_rcv_saddr))
return 0;
if (sk->sk_num == ports[0])
idx = 0;
else if (sk->sk_num == ports[1])
idx = 1;
else
return 0;
/* bucket selection as in udp_hashslot2() */
udptable = sk->sk_net.net->ipv4.udp_table;
bucket[idx] = udp_sk(sk)->udp_portaddr_hash & udptable->mask;
bpf_seq_write(ctx->meta->seq, &idx, sizeof(idx));
bpf_seq_write(ctx->meta->seq, &sock_cookie, sizeof(sock_cookie));
return 0;
}
char _license[] SEC("license") = "GPL";
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