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 
udp_hdr(const struct sk_buff * skb)25 static inline struct udphdr *udp_hdr(const struct sk_buff *skb)
26 {
27 	return (struct udphdr *)skb_transport_header(skb);
28 }
29 
inner_udp_hdr(const struct sk_buff * skb)30 static 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 
udp_hashfn(const struct net * net,u32 num,u32 mask)37 static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask)
38 {
39 	return (num + net_hash_mix(net)) & mask;
40 }
41 
42 struct 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 	__u16		 gso_size;
59 	/*
60 	 * Fields specific to UDP-Lite.
61 	 */
62 	__u16		 pcslen;
63 	__u16		 pcrlen;
64 /* indicator bits used by pcflag: */
65 #define UDPLITE_BIT      0x1  		/* set by udplite proto init function */
66 #define UDPLITE_SEND_CC  0x2  		/* set via udplite setsockopt         */
67 #define UDPLITE_RECV_CC  0x4		/* set via udplite setsocktopt        */
68 	__u8		 pcflag;        /* marks socket as UDP-Lite if > 0    */
69 	__u8		 unused[3];
70 	/*
71 	 * For encapsulation sockets.
72 	 */
73 	int (*encap_rcv)(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 
udp_sk(const struct sock * sk)93 static inline struct udp_sock *udp_sk(const struct sock *sk)
94 {
95 	return (struct udp_sock *)sk;
96 }
97 
udp_set_no_check6_tx(struct sock * sk,bool val)98 static inline void udp_set_no_check6_tx(struct sock *sk, bool val)
99 {
100 	udp_sk(sk)->no_check6_tx = val;
101 }
102 
udp_set_no_check6_rx(struct sock * sk,bool val)103 static inline void udp_set_no_check6_rx(struct sock *sk, bool val)
104 {
105 	udp_sk(sk)->no_check6_rx = val;
106 }
107 
udp_get_no_check6_tx(struct sock * sk)108 static inline bool udp_get_no_check6_tx(struct sock *sk)
109 {
110 	return udp_sk(sk)->no_check6_tx;
111 }
112 
udp_get_no_check6_rx(struct sock * sk)113 static inline bool udp_get_no_check6_rx(struct sock *sk)
114 {
115 	return udp_sk(sk)->no_check6_rx;
116 }
117 
118 #define udp_portaddr_for_each_entry(__sk, list) \
119 	hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)
120 
121 #define udp_portaddr_for_each_entry_rcu(__sk, list) \
122 	hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)
123 
124 #define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE)
125 
126 #endif	/* _LINUX_UDP_H */
127