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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Definitions for the UDP protocol.
8 *
9 * Version: @(#)udp.h 1.0.2 04/28/93
10 *
11 * Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 */
13#ifndef _LINUX_UDP_H
14#define _LINUX_UDP_H
15
16#include <net/inet_sock.h>
17#include <linux/skbuff.h>
18#include <net/netns/hash.h>
19#include <uapi/linux/udp.h>
20
21static inline struct udphdr *udp_hdr(const struct sk_buff *skb)
22{
23 return (struct udphdr *)skb_transport_header(skb);
24}
25
26#define UDP_HTABLE_SIZE_MIN_PERNET 128
27#define UDP_HTABLE_SIZE_MIN (CONFIG_BASE_SMALL ? 128 : 256)
28#define UDP_HTABLE_SIZE_MAX 65536
29
30static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask)
31{
32 return (num + net_hash_mix(net)) & mask;
33}
34
35struct udp_sock {
36 /* inet_sock has to be the first member */
37 struct inet_sock inet;
38#define udp_port_hash inet.sk.__sk_common.skc_u16hashes[0]
39#define udp_portaddr_hash inet.sk.__sk_common.skc_u16hashes[1]
40#define udp_portaddr_node inet.sk.__sk_common.skc_portaddr_node
41 int pending; /* Any pending frames ? */
42 unsigned int corkflag; /* Cork is required */
43 __u8 encap_type; /* Is this an Encapsulation socket? */
44 unsigned char no_check6_tx:1,/* Send zero UDP6 checksums on TX? */
45 no_check6_rx:1,/* Allow zero UDP6 checksums on RX? */
46 encap_enabled:1, /* This socket enabled encap
47 * processing; UDP tunnels and
48 * different encapsulation layer set
49 * this
50 */
51 gro_enabled:1, /* Request GRO aggregation */
52 accept_udp_l4:1,
53 accept_udp_fraglist:1;
54 /*
55 * Following member retains the information to create a UDP header
56 * when the socket is uncorked.
57 */
58 __u16 len; /* total length of pending frames */
59 __u16 gso_size;
60 /*
61 * Fields specific to UDP-Lite.
62 */
63 __u16 pcslen;
64 __u16 pcrlen;
65/* indicator bits used by pcflag: */
66#define UDPLITE_BIT 0x1 /* set by udplite proto init function */
67#define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */
68#define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */
69 __u8 pcflag; /* marks socket as UDP-Lite if > 0 */
70 __u8 unused[3];
71 /*
72 * For encapsulation sockets.
73 */
74 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
75 void (*encap_err_rcv)(struct sock *sk, struct sk_buff *skb, int err,
76 __be16 port, u32 info, u8 *payload);
77 int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb);
78 void (*encap_destroy)(struct sock *sk);
79
80 /* GRO functions for UDP socket */
81 struct sk_buff * (*gro_receive)(struct sock *sk,
82 struct list_head *head,
83 struct sk_buff *skb);
84 int (*gro_complete)(struct sock *sk,
85 struct sk_buff *skb,
86 int nhoff);
87
88 /* udp_recvmsg try to use this before splicing sk_receive_queue */
89 struct sk_buff_head reader_queue ____cacheline_aligned_in_smp;
90
91 /* This field is dirtied by udp_recvmsg() */
92 int forward_deficit;
93
94 /* This fields follows rcvbuf value, and is touched by udp_recvmsg */
95 int forward_threshold;
96};
97
98#define UDP_MAX_SEGMENTS (1 << 6UL)
99
100static inline struct udp_sock *udp_sk(const struct sock *sk)
101{
102 return (struct udp_sock *)sk;
103}
104
105static inline void udp_set_no_check6_tx(struct sock *sk, bool val)
106{
107 udp_sk(sk)->no_check6_tx = val;
108}
109
110static inline void udp_set_no_check6_rx(struct sock *sk, bool val)
111{
112 udp_sk(sk)->no_check6_rx = val;
113}
114
115static inline bool udp_get_no_check6_tx(struct sock *sk)
116{
117 return udp_sk(sk)->no_check6_tx;
118}
119
120static inline bool udp_get_no_check6_rx(struct sock *sk)
121{
122 return udp_sk(sk)->no_check6_rx;
123}
124
125static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk,
126 struct sk_buff *skb)
127{
128 int gso_size;
129
130 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
131 gso_size = skb_shinfo(skb)->gso_size;
132 put_cmsg(msg, SOL_UDP, UDP_GRO, sizeof(gso_size), &gso_size);
133 }
134}
135
136static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb)
137{
138 if (!skb_is_gso(skb))
139 return false;
140
141 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->accept_udp_l4)
142 return true;
143
144 if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && !udp_sk(sk)->accept_udp_fraglist)
145 return true;
146
147 return false;
148}
149
150static inline void udp_allow_gso(struct sock *sk)
151{
152 udp_sk(sk)->accept_udp_l4 = 1;
153 udp_sk(sk)->accept_udp_fraglist = 1;
154}
155
156#define udp_portaddr_for_each_entry(__sk, list) \
157 hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)
158
159#define udp_portaddr_for_each_entry_rcu(__sk, list) \
160 hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)
161
162#define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE)
163
164#endif /* _LINUX_UDP_H */