// 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; } 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; struct net *net; int idx; if (!sk) return 0; sk = bpf_core_cast(sk, struct sock); if (sk->sk_family != AF_INET6 || sk->sk_state != TCP_LISTEN || !ipv6_addr_loopback(&sk->sk_v6_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)); 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; int idx; if (!sk) return 0; sk = bpf_core_cast(sk, struct sock); if (sk->sk_family != AF_INET6 || !ipv6_addr_loopback(&sk->sk_v6_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)); return 0; } char _license[] SEC("license") = "GPL";