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	/*
54	 * Following member retains the information to create a UDP header
55	 * when the socket is uncorked.
56	 */
57	__u16		 len;		/* total length of pending frames */
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	void (*encap_destroy)(struct sock *sk);
74};
75
76static inline struct udp_sock *udp_sk(const struct sock *sk)
77{
78	return (struct udp_sock *)sk;
79}
80
81static inline void udp_set_no_check6_tx(struct sock *sk, bool val)
82{
83	udp_sk(sk)->no_check6_tx = val;
84}
85
86static inline void udp_set_no_check6_rx(struct sock *sk, bool val)
87{
88	udp_sk(sk)->no_check6_rx = val;
89}
90
91static inline bool udp_get_no_check6_tx(struct sock *sk)
92{
93	return udp_sk(sk)->no_check6_tx;
94}
95
96static inline bool udp_get_no_check6_rx(struct sock *sk)
97{
98	return udp_sk(sk)->no_check6_rx;
99}
100
101#define udp_portaddr_for_each_entry(__sk, node, list) \
102	hlist_nulls_for_each_entry(__sk, node, list, __sk_common.skc_portaddr_node)
103
104#define udp_portaddr_for_each_entry_rcu(__sk, node, list) \
105	hlist_nulls_for_each_entry_rcu(__sk, node, list, __sk_common.skc_portaddr_node)
106
107#define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag)
108
109#endif	/* _LINUX_UDP_H */
110