1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Definitions for the UDP protocol.
7 *
8 * Version: @(#)udp.h 1.0.2 04/28/93
9 *
10 * Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17#ifndef _LINUX_UDP_H
18#define _LINUX_UDP_H
19
20#include <net/inet_sock.h>
21#include <linux/skbuff.h>
22#include <net/netns/hash.h>
23#include <uapi/linux/udp.h>
24
25static inline struct udphdr *udp_hdr(const struct sk_buff *skb)
26{
27 return (struct udphdr *)skb_transport_header(skb);
28}
29
30static inline struct udphdr *inner_udp_hdr(const struct sk_buff *skb)
31{
32 return (struct udphdr *)skb_inner_transport_header(skb);
33}
34
35#define UDP_HTABLE_SIZE_MIN (CONFIG_BASE_SMALL ? 128 : 256)
36
37static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask)
38{
39 return (num + net_hash_mix(net)) & mask;
40}
41
42struct udp_sock {
43 /* inet_sock has to be the first member */
44 struct inet_sock inet;
45#define udp_port_hash inet.sk.__sk_common.skc_u16hashes[0]
46#define udp_portaddr_hash inet.sk.__sk_common.skc_u16hashes[1]
47#define udp_portaddr_node inet.sk.__sk_common.skc_portaddr_node
48 int pending; /* Any pending frames ? */
49 unsigned int corkflag; /* Cork is required */
50 __u8 encap_type; /* Is this an Encapsulation socket? */
51 unsigned char no_check6_tx:1,/* Send zero UDP6 checksums on TX? */
52 no_check6_rx:1,/* Allow zero UDP6 checksums on RX? */
53 encap_enabled:1, /* This socket enabled encap
54 * processing; UDP tunnels and
55 * different encapsulation layer set
56 * this
57 */
58 gro_enabled:1; /* Can accept GRO packets */
59 /*
60 * Following member retains the information to create a UDP header
61 * when the socket is uncorked.
62 */
63 __u16 len; /* total length of pending frames */
64 __u16 gso_size;
65 /*
66 * Fields specific to UDP-Lite.
67 */
68 __u16 pcslen;
69 __u16 pcrlen;
70/* indicator bits used by pcflag: */
71#define UDPLITE_BIT 0x1 /* set by udplite proto init function */
72#define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */
73#define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */
74 __u8 pcflag; /* marks socket as UDP-Lite if > 0 */
75 __u8 unused[3];
76 /*
77 * For encapsulation sockets.
78 */
79 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
80 int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb);
81 void (*encap_destroy)(struct sock *sk);
82
83 /* GRO functions for UDP socket */
84 struct sk_buff * (*gro_receive)(struct sock *sk,
85 struct list_head *head,
86 struct sk_buff *skb);
87 int (*gro_complete)(struct sock *sk,
88 struct sk_buff *skb,
89 int nhoff);
90
91 /* udp_recvmsg try to use this before splicing sk_receive_queue */
92 struct sk_buff_head reader_queue ____cacheline_aligned_in_smp;
93
94 /* This field is dirtied by udp_recvmsg() */
95 int forward_deficit;
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 return !udp_sk(sk)->gro_enabled && skb_is_gso(skb) &&
139 skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4;
140}
141
142#define udp_portaddr_for_each_entry(__sk, list) \
143 hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)
144
145#define udp_portaddr_for_each_entry_rcu(__sk, list) \
146 hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)
147
148#define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE)
149
150#endif /* _LINUX_UDP_H */
151