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 bool udp_sk_has_data(struct sock *sk)
26 return !skb_queue_empty(&udp_sk(sk)->reader_queue) ||
27 !skb_queue_empty(&sk->sk_receive_queue);
30 static bool psock_has_data(struct sk_psock *psock)
32 return !skb_queue_empty(&psock->ingress_skb) ||
33 !sk_psock_queue_empty(psock);
36 #define udp_msg_has_data(__sk, __psock) \
37 ({ udp_sk_has_data(__sk) || psock_has_data(__psock); })
39 static int udp_msg_wait_data(struct sock *sk, struct sk_psock *psock, int flags,
42 DEFINE_WAIT_FUNC(wait, woken_wake_function);
45 if (sk->sk_shutdown & RCV_SHUTDOWN)
51 add_wait_queue(sk_sleep(sk), &wait);
52 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
53 ret = udp_msg_has_data(sk, psock);
55 wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
56 ret = udp_msg_has_data(sk, psock);
58 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
59 remove_wait_queue(sk_sleep(sk), &wait);
63 static int udp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
64 int nonblock, int flags, int *addr_len)
66 struct sk_psock *psock;
69 if (unlikely(flags & MSG_ERRQUEUE))
70 return inet_recv_error(sk, msg, len, addr_len);
72 psock = sk_psock_get(sk);
74 return sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
76 if (!psock_has_data(psock)) {
77 ret = sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
82 copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
87 timeo = sock_rcvtimeo(sk, nonblock);
88 data = udp_msg_wait_data(sk, psock, flags, timeo, &err);
90 if (psock_has_data(psock))
92 ret = sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
103 sk_psock_put(sk, psock);
113 static DEFINE_SPINLOCK(udpv6_prot_lock);
114 static struct proto udp_bpf_prots[UDP_BPF_NUM_PROTS];
116 static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
119 prot->unhash = sock_map_unhash;
120 prot->close = sock_map_close;
121 prot->recvmsg = udp_bpf_recvmsg;
124 static void udp_bpf_check_v6_needs_rebuild(struct proto *ops)
126 if (unlikely(ops != smp_load_acquire(&udpv6_prot_saved))) {
127 spin_lock_bh(&udpv6_prot_lock);
128 if (likely(ops != udpv6_prot_saved)) {
129 udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV6], ops);
130 smp_store_release(&udpv6_prot_saved, ops);
132 spin_unlock_bh(&udpv6_prot_lock);
136 static int __init udp_bpf_v4_build_proto(void)
138 udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV4], &udp_prot);
141 core_initcall(udp_bpf_v4_build_proto);
143 int udp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
145 int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
148 sk->sk_write_space = psock->saved_write_space;
149 WRITE_ONCE(sk->sk_prot, psock->sk_proto);
153 if (sk->sk_family == AF_INET6)
154 udp_bpf_check_v6_needs_rebuild(psock->sk_proto);
156 WRITE_ONCE(sk->sk_prot, &udp_bpf_prots[family]);
159 EXPORT_SYMBOL_GPL(udp_bpf_update_proto);