// SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2020 Cloudflare Ltd https://cloudflare.com */ #include <linux/skmsg.h> #include <net/sock.h> #include <net/udp.h> enum { UDP_BPF_IPV4, UDP_BPF_IPV6, UDP_BPF_NUM_PROTS, }; static struct proto *udpv6_prot_saved __read_mostly; static DEFINE_SPINLOCK(udpv6_prot_lock); static struct proto udp_bpf_prots[UDP_BPF_NUM_PROTS]; static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base) { *prot = *base; prot->unhash = sock_map_unhash; prot->close = sock_map_close; } static void udp_bpf_check_v6_needs_rebuild(struct proto *ops) { if (unlikely(ops != smp_load_acquire(&udpv6_prot_saved))) { spin_lock_bh(&udpv6_prot_lock); if (likely(ops != udpv6_prot_saved)) { udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV6], ops); smp_store_release(&udpv6_prot_saved, ops); } spin_unlock_bh(&udpv6_prot_lock); } } static int __init udp_bpf_v4_build_proto(void) { udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV4], &udp_prot); return 0; } core_initcall(udp_bpf_v4_build_proto); struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock) { int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6; if (sk->sk_family == AF_INET6) udp_bpf_check_v6_needs_rebuild(psock->sk_proto); return &udp_bpf_prots[family]; }