1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /* Copyright (c) 2020 Cloudflare Ltd https://cloudflare.com */
3*4882a593Smuzhiyun
4*4882a593Smuzhiyun #include <linux/skmsg.h>
5*4882a593Smuzhiyun #include <net/sock.h>
6*4882a593Smuzhiyun #include <net/udp.h>
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun enum {
9*4882a593Smuzhiyun UDP_BPF_IPV4,
10*4882a593Smuzhiyun UDP_BPF_IPV6,
11*4882a593Smuzhiyun UDP_BPF_NUM_PROTS,
12*4882a593Smuzhiyun };
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun static struct proto *udpv6_prot_saved __read_mostly;
15*4882a593Smuzhiyun static DEFINE_SPINLOCK(udpv6_prot_lock);
16*4882a593Smuzhiyun static struct proto udp_bpf_prots[UDP_BPF_NUM_PROTS];
17*4882a593Smuzhiyun
udp_bpf_rebuild_protos(struct proto * prot,const struct proto * base)18*4882a593Smuzhiyun static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun *prot = *base;
21*4882a593Smuzhiyun prot->unhash = sock_map_unhash;
22*4882a593Smuzhiyun prot->close = sock_map_close;
23*4882a593Smuzhiyun }
24*4882a593Smuzhiyun
udp_bpf_check_v6_needs_rebuild(struct proto * ops)25*4882a593Smuzhiyun static void udp_bpf_check_v6_needs_rebuild(struct proto *ops)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun if (unlikely(ops != smp_load_acquire(&udpv6_prot_saved))) {
28*4882a593Smuzhiyun spin_lock_bh(&udpv6_prot_lock);
29*4882a593Smuzhiyun if (likely(ops != udpv6_prot_saved)) {
30*4882a593Smuzhiyun udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV6], ops);
31*4882a593Smuzhiyun smp_store_release(&udpv6_prot_saved, ops);
32*4882a593Smuzhiyun }
33*4882a593Smuzhiyun spin_unlock_bh(&udpv6_prot_lock);
34*4882a593Smuzhiyun }
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun
udp_bpf_v4_build_proto(void)37*4882a593Smuzhiyun static int __init udp_bpf_v4_build_proto(void)
38*4882a593Smuzhiyun {
39*4882a593Smuzhiyun udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV4], &udp_prot);
40*4882a593Smuzhiyun return 0;
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun late_initcall(udp_bpf_v4_build_proto);
43*4882a593Smuzhiyun
udp_bpf_get_proto(struct sock * sk,struct sk_psock * psock)44*4882a593Smuzhiyun struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock)
45*4882a593Smuzhiyun {
46*4882a593Smuzhiyun int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun if (sk->sk_family == AF_INET6)
49*4882a593Smuzhiyun udp_bpf_check_v6_needs_rebuild(psock->sk_proto);
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun return &udp_bpf_prots[family];
52*4882a593Smuzhiyun }
53