1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Cloudflare Ltd https://cloudflare.com */
4 #include <linux/skmsg.h>
7 #include <net/inet_common.h>
11 static struct proto *udpv6_prot_saved __read_mostly;
13 static int sk_udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
14 int noblock, int flags, int *addr_len)
16 #if IS_ENABLED(CONFIG_IPV6)
17 if (sk->sk_family == AF_INET6)
18 return udpv6_prot_saved->recvmsg(sk, msg, len, noblock, flags,
21 return udp_prot.recvmsg(sk, msg, len, noblock, flags, addr_len);
24 static int udp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
25 int nonblock, int flags, int *addr_len)
27 struct sk_psock *psock;
30 if (unlikely(flags & MSG_ERRQUEUE))
31 return inet_recv_error(sk, msg, len, addr_len);
33 psock = sk_psock_get(sk);
35 return sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
38 if (sk_psock_queue_empty(psock)) {
39 ret = sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
44 copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
49 timeo = sock_rcvtimeo(sk, nonblock);
50 data = sk_msg_wait_data(sk, psock, timeo);
52 if (!sk_psock_queue_empty(psock))
54 ret = sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
62 sk_psock_put(sk, psock);
72 static DEFINE_SPINLOCK(udpv6_prot_lock);
73 static struct proto udp_bpf_prots[UDP_BPF_NUM_PROTS];
75 static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
78 prot->unhash = sock_map_unhash;
79 prot->close = sock_map_close;
80 prot->recvmsg = udp_bpf_recvmsg;
83 static void udp_bpf_check_v6_needs_rebuild(struct proto *ops)
85 if (unlikely(ops != smp_load_acquire(&udpv6_prot_saved))) {
86 spin_lock_bh(&udpv6_prot_lock);
87 if (likely(ops != udpv6_prot_saved)) {
88 udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV6], ops);
89 smp_store_release(&udpv6_prot_saved, ops);
91 spin_unlock_bh(&udpv6_prot_lock);
95 static int __init udp_bpf_v4_build_proto(void)
97 udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV4], &udp_prot);
100 core_initcall(udp_bpf_v4_build_proto);
102 int udp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
104 int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
107 sk->sk_write_space = psock->saved_write_space;
108 WRITE_ONCE(sk->sk_prot, psock->sk_proto);
112 if (sk->sk_family == AF_INET6)
113 udp_bpf_check_v6_needs_rebuild(psock->sk_proto);
115 WRITE_ONCE(sk->sk_prot, &udp_bpf_prots[family]);
118 EXPORT_SYMBOL_GPL(udp_bpf_update_proto);