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 (CONFIG_BASE_SMALL ? 128 : 256)
27
28static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask)
29{
30 return (num + net_hash_mix(net)) & mask;
31}
32
33struct udp_sock {
34 /* inet_sock has to be the first member */
35 struct inet_sock inet;
36#define udp_port_hash inet.sk.__sk_common.skc_u16hashes[0]
37#define udp_portaddr_hash inet.sk.__sk_common.skc_u16hashes[1]
38#define udp_portaddr_node inet.sk.__sk_common.skc_portaddr_node
39 int pending; /* Any pending frames ? */
40 unsigned int corkflag; /* Cork is required */
41 __u8 encap_type; /* Is this an Encapsulation socket? */
42 unsigned char no_check6_tx:1,/* Send zero UDP6 checksums on TX? */
43 no_check6_rx:1,/* Allow zero UDP6 checksums on RX? */
44 encap_enabled:1, /* This socket enabled encap
45 * processing; UDP tunnels and
46 * different encapsulation layer set
47 * this
48 */
49 gro_enabled:1, /* Request GRO aggregation */
50 accept_udp_l4:1,
51 accept_udp_fraglist:1;
52 /*
53 * Following member retains the information to create a UDP header
54 * when the socket is uncorked.
55 */
56 __u16 len; /* total length of pending frames */
57 __u16 gso_size;
58 /*
59 * Fields specific to UDP-Lite.
60 */
61 __u16 pcslen;
62 __u16 pcrlen;
63/* indicator bits used by pcflag: */
64#define UDPLITE_BIT 0x1 /* set by udplite proto init function */
65#define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */
66#define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */
67 __u8 pcflag; /* marks socket as UDP-Lite if > 0 */
68 __u8 unused[3];
69 /*
70 * For encapsulation sockets.
71 */
72 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
73 int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb);
74 void (*encap_destroy)(struct sock *sk);
75
76 /* GRO functions for UDP socket */
77 struct sk_buff * (*gro_receive)(struct sock *sk,
78 struct list_head *head,
79 struct sk_buff *skb);
80 int (*gro_complete)(struct sock *sk,
81 struct sk_buff *skb,
82 int nhoff);
83
84 /* udp_recvmsg try to use this before splicing sk_receive_queue */
85 struct sk_buff_head reader_queue ____cacheline_aligned_in_smp;
86
87 /* This field is dirtied by udp_recvmsg() */
88 int forward_deficit;
89};
90
91#define UDP_MAX_SEGMENTS (1 << 6UL)
92
93static inline struct udp_sock *udp_sk(const struct sock *sk)
94{
95 return (struct udp_sock *)sk;
96}
97
98static inline void udp_set_no_check6_tx(struct sock *sk, bool val)
99{
100 udp_sk(sk)->no_check6_tx = val;
101}
102
103static inline void udp_set_no_check6_rx(struct sock *sk, bool val)
104{
105 udp_sk(sk)->no_check6_rx = val;
106}
107
108static inline bool udp_get_no_check6_tx(struct sock *sk)
109{
110 return udp_sk(sk)->no_check6_tx;
111}
112
113static inline bool udp_get_no_check6_rx(struct sock *sk)
114{
115 return udp_sk(sk)->no_check6_rx;
116}
117
118static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk,
119 struct sk_buff *skb)
120{
121 int gso_size;
122
123 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
124 gso_size = skb_shinfo(skb)->gso_size;
125 put_cmsg(msg, SOL_UDP, UDP_GRO, sizeof(gso_size), &gso_size);
126 }
127}
128
129static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb)
130{
131 if (!skb_is_gso(skb))
132 return false;
133
134 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->accept_udp_l4)
135 return true;
136
137 if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && !udp_sk(sk)->accept_udp_fraglist)
138 return true;
139
140 return false;
141}
142
143static inline void udp_allow_gso(struct sock *sk)
144{
145 udp_sk(sk)->accept_udp_l4 = 1;
146 udp_sk(sk)->accept_udp_fraglist = 1;
147}
148
149#define udp_portaddr_for_each_entry(__sk, list) \
150 hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)
151
152#define udp_portaddr_for_each_entry_rcu(__sk, list) \
153 hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)
154
155#define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE)
156
157#endif /* _LINUX_UDP_H */
158

source code of linux/include/linux/udp.h