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1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020 Cloudflare Ltd https://cloudflare.com */
3
4#include <linux/skmsg.h>
5#include <net/sock.h>
6#include <net/udp.h>
7#include <net/inet_common.h>
8
9#include "udp_impl.h"
10
11static struct proto *udpv6_prot_saved __read_mostly;
12
13static int sk_udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
14 int flags, int *addr_len)
15{
16#if IS_ENABLED(CONFIG_IPV6)
17 if (sk->sk_family == AF_INET6)
18 return udpv6_prot_saved->recvmsg(sk, msg, len, flags, addr_len);
19#endif
20 return udp_prot.recvmsg(sk, msg, len, flags, addr_len);
21}
22
23static bool udp_sk_has_data(struct sock *sk)
24{
25 return !skb_queue_empty(&udp_sk(sk)->reader_queue) ||
26 !skb_queue_empty(&sk->sk_receive_queue);
27}
28
29static bool psock_has_data(struct sk_psock *psock)
30{
31 return !skb_queue_empty(&psock->ingress_skb) ||
32 !sk_psock_queue_empty(psock);
33}
34
35#define udp_msg_has_data(__sk, __psock) \
36 ({ udp_sk_has_data(__sk) || psock_has_data(__psock); })
37
38static int udp_msg_wait_data(struct sock *sk, struct sk_psock *psock,
39 long timeo)
40{
41 DEFINE_WAIT_FUNC(wait, woken_wake_function);
42 int ret = 0;
43
44 if (sk->sk_shutdown & RCV_SHUTDOWN)
45 return 1;
46
47 if (!timeo)
48 return ret;
49
50 add_wait_queue(sk_sleep(sk), &wait);
51 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
52 ret = udp_msg_has_data(sk, psock);
53 if (!ret) {
54 wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
55 ret = udp_msg_has_data(sk, psock);
56 }
57 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
58 remove_wait_queue(sk_sleep(sk), &wait);
59 return ret;
60}
61
62static int udp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
63 int flags, int *addr_len)
64{
65 struct sk_psock *psock;
66 int copied, ret;
67
68 if (unlikely(flags & MSG_ERRQUEUE))
69 return inet_recv_error(sk, msg, len, addr_len);
70
71 if (!len)
72 return 0;
73
74 psock = sk_psock_get(sk);
75 if (unlikely(!psock))
76 return sk_udp_recvmsg(sk, msg, len, flags, addr_len);
77
78 if (!psock_has_data(psock)) {
79 ret = sk_udp_recvmsg(sk, msg, len, flags, addr_len);
80 goto out;
81 }
82
83msg_bytes_ready:
84 copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
85 if (!copied) {
86 long timeo;
87 int data;
88
89 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
90 data = udp_msg_wait_data(sk, psock, timeo);
91 if (data) {
92 if (psock_has_data(psock))
93 goto msg_bytes_ready;
94 ret = sk_udp_recvmsg(sk, msg, len, flags, addr_len);
95 goto out;
96 }
97 copied = -EAGAIN;
98 }
99 ret = copied;
100out:
101 sk_psock_put(sk, psock);
102 return ret;
103}
104
105enum {
106 UDP_BPF_IPV4,
107 UDP_BPF_IPV6,
108 UDP_BPF_NUM_PROTS,
109};
110
111static DEFINE_SPINLOCK(udpv6_prot_lock);
112static struct proto udp_bpf_prots[UDP_BPF_NUM_PROTS];
113
114static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
115{
116 *prot = *base;
117 prot->close = sock_map_close;
118 prot->recvmsg = udp_bpf_recvmsg;
119 prot->sock_is_readable = sk_msg_is_readable;
120}
121
122static void udp_bpf_check_v6_needs_rebuild(struct proto *ops)
123{
124 if (unlikely(ops != smp_load_acquire(&udpv6_prot_saved))) {
125 spin_lock_bh(&udpv6_prot_lock);
126 if (likely(ops != udpv6_prot_saved)) {
127 udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV6], ops);
128 smp_store_release(&udpv6_prot_saved, ops);
129 }
130 spin_unlock_bh(&udpv6_prot_lock);
131 }
132}
133
134static int __init udp_bpf_v4_build_proto(void)
135{
136 udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV4], &udp_prot);
137 return 0;
138}
139late_initcall(udp_bpf_v4_build_proto);
140
141int udp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
142{
143 int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
144
145 if (restore) {
146 sk->sk_write_space = psock->saved_write_space;
147 sock_replace_proto(sk, psock->sk_proto);
148 return 0;
149 }
150
151 if (sk->sk_family == AF_INET6)
152 udp_bpf_check_v6_needs_rebuild(psock->sk_proto);
153
154 sock_replace_proto(sk, &udp_bpf_prots[family]);
155 return 0;
156}
157EXPORT_SYMBOL_GPL(udp_bpf_update_proto);
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020 Cloudflare Ltd https://cloudflare.com */
3
4#include <linux/skmsg.h>
5#include <net/sock.h>
6#include <net/udp.h>
7#include <net/inet_common.h>
8
9#include "udp_impl.h"
10
11static struct proto *udpv6_prot_saved __read_mostly;
12
13static int sk_udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
14 int flags, int *addr_len)
15{
16#if IS_ENABLED(CONFIG_IPV6)
17 if (sk->sk_family == AF_INET6)
18 return udpv6_prot_saved->recvmsg(sk, msg, len, flags, addr_len);
19#endif
20 return udp_prot.recvmsg(sk, msg, len, flags, addr_len);
21}
22
23static bool udp_sk_has_data(struct sock *sk)
24{
25 return !skb_queue_empty(&udp_sk(sk)->reader_queue) ||
26 !skb_queue_empty(&sk->sk_receive_queue);
27}
28
29static bool psock_has_data(struct sk_psock *psock)
30{
31 return !skb_queue_empty(&psock->ingress_skb) ||
32 !sk_psock_queue_empty(psock);
33}
34
35#define udp_msg_has_data(__sk, __psock) \
36 ({ udp_sk_has_data(__sk) || psock_has_data(__psock); })
37
38static int udp_msg_wait_data(struct sock *sk, struct sk_psock *psock,
39 long timeo)
40{
41 DEFINE_WAIT_FUNC(wait, woken_wake_function);
42 int ret = 0;
43
44 if (sk->sk_shutdown & RCV_SHUTDOWN)
45 return 1;
46
47 if (!timeo)
48 return ret;
49
50 add_wait_queue(sk_sleep(sk), &wait);
51 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
52 ret = udp_msg_has_data(sk, psock);
53 if (!ret) {
54 wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
55 ret = udp_msg_has_data(sk, psock);
56 }
57 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
58 remove_wait_queue(sk_sleep(sk), &wait);
59 return ret;
60}
61
62static int udp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
63 int flags, int *addr_len)
64{
65 struct sk_psock *psock;
66 int copied, ret;
67
68 if (unlikely(flags & MSG_ERRQUEUE))
69 return inet_recv_error(sk, msg, len, addr_len);
70
71 psock = sk_psock_get(sk);
72 if (unlikely(!psock))
73 return sk_udp_recvmsg(sk, msg, len, flags, addr_len);
74
75 if (!psock_has_data(psock)) {
76 ret = sk_udp_recvmsg(sk, msg, len, flags, addr_len);
77 goto out;
78 }
79
80msg_bytes_ready:
81 copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
82 if (!copied) {
83 long timeo;
84 int data;
85
86 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
87 data = udp_msg_wait_data(sk, psock, timeo);
88 if (data) {
89 if (psock_has_data(psock))
90 goto msg_bytes_ready;
91 ret = sk_udp_recvmsg(sk, msg, len, flags, addr_len);
92 goto out;
93 }
94 copied = -EAGAIN;
95 }
96 ret = copied;
97out:
98 sk_psock_put(sk, psock);
99 return ret;
100}
101
102enum {
103 UDP_BPF_IPV4,
104 UDP_BPF_IPV6,
105 UDP_BPF_NUM_PROTS,
106};
107
108static DEFINE_SPINLOCK(udpv6_prot_lock);
109static struct proto udp_bpf_prots[UDP_BPF_NUM_PROTS];
110
111static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
112{
113 *prot = *base;
114 prot->close = sock_map_close;
115 prot->recvmsg = udp_bpf_recvmsg;
116 prot->sock_is_readable = sk_msg_is_readable;
117}
118
119static void udp_bpf_check_v6_needs_rebuild(struct proto *ops)
120{
121 if (unlikely(ops != smp_load_acquire(&udpv6_prot_saved))) {
122 spin_lock_bh(&udpv6_prot_lock);
123 if (likely(ops != udpv6_prot_saved)) {
124 udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV6], ops);
125 smp_store_release(&udpv6_prot_saved, ops);
126 }
127 spin_unlock_bh(&udpv6_prot_lock);
128 }
129}
130
131static int __init udp_bpf_v4_build_proto(void)
132{
133 udp_bpf_rebuild_protos(&udp_bpf_prots[UDP_BPF_IPV4], &udp_prot);
134 return 0;
135}
136late_initcall(udp_bpf_v4_build_proto);
137
138int udp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
139{
140 int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
141
142 if (restore) {
143 sk->sk_write_space = psock->saved_write_space;
144 sock_replace_proto(sk, psock->sk_proto);
145 return 0;
146 }
147
148 if (sk->sk_family == AF_INET6)
149 udp_bpf_check_v6_needs_rebuild(psock->sk_proto);
150
151 sock_replace_proto(sk, &udp_bpf_prots[family]);
152 return 0;
153}
154EXPORT_SYMBOL_GPL(udp_bpf_update_proto);