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 module.
7 *
8 * Version:	@(#)udp.h	1.0.2	05/07/93
9 *
10 * Authors:	Ross Biro
11 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 *
13 * Fixes:
14 *		Alan Cox	: Turned on udp checksums. I don't want to
15 *				  chase 'memory corruption' bugs that aren't!
16 *
17 *		This program is free software; you can redistribute it and/or
18 *		modify it under the terms of the GNU General Public License
19 *		as published by the Free Software Foundation; either version
20 *		2 of the License, or (at your option) any later version.
21 */
22#ifndef _UDP_H
23#define _UDP_H
24
25#include <linux/list.h>
26#include <net/inet_sock.h>
27#include <net/sock.h>
28#include <net/snmp.h>
29#include <net/ip.h>
30#include <linux/ipv6.h>
31#include <linux/seq_file.h>
32#include <linux/poll.h>
33
34/**
35 *	struct udp_skb_cb  -  UDP(-Lite) private variables
36 *
37 *	@header:      private variables used by IPv4/IPv6
38 *	@cscov:       checksum coverage length (UDP-Lite only)
39 *	@partial_cov: if set indicates partial csum coverage
40 */
41struct udp_skb_cb {
42	union {
43		struct inet_skb_parm	h4;
44#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
45		struct inet6_skb_parm	h6;
46#endif
47	} header;
48	__u16		cscov;
49	__u8		partial_cov;
50};
51#define UDP_SKB_CB(__skb)	((struct udp_skb_cb *)((__skb)->cb))
52
53extern struct hlist_head udp_hash[UDP_HTABLE_SIZE];
54extern rwlock_t udp_hash_lock;
55
56
57/* Note: this must match 'valbool' in sock_setsockopt */
58#define UDP_CSUM_NOXMIT		1
59
60/* Used by SunRPC/xprt layer. */
61#define UDP_CSUM_NORCV		2
62
63/* Default, as per the RFC, is to always do csums. */
64#define UDP_CSUM_DEFAULT	0
65
66extern struct proto udp_prot;
67
68struct sk_buff;
69
70/*
71 *	Generic checksumming routines for UDP(-Lite) v4 and v6
72 */
73static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb)
74{
75	return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov);
76}
77
78static inline int udp_lib_checksum_complete(struct sk_buff *skb)
79{
80	return !skb_csum_unnecessary(skb) &&
81		__udp_lib_checksum_complete(skb);
82}
83
84/**
85 * 	udp_csum_outgoing  -  compute UDPv4/v6 checksum over fragments
86 * 	@sk: 	socket we are writing to
87 * 	@skb: 	sk_buff containing the filled-in UDP header
88 * 	        (checksum field must be zeroed out)
89 */
90static inline __wsum udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
91{
92	__wsum csum = csum_partial(skb_transport_header(skb),
93				   sizeof(struct udphdr), 0);
94	skb_queue_walk(&sk->sk_write_queue, skb) {
95		csum = csum_add(csum, skb->csum);
96	}
97	return csum;
98}
99
100/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
101static inline void udp_lib_hash(struct sock *sk)
102{
103	BUG();
104}
105
106static inline void udp_lib_unhash(struct sock *sk)
107{
108	write_lock_bh(&udp_hash_lock);
109	if (sk_del_node_init(sk)) {
110		inet_sk(sk)->num = 0;
111		sock_prot_dec_use(sk->sk_prot);
112	}
113	write_unlock_bh(&udp_hash_lock);
114}
115
116static inline void udp_lib_close(struct sock *sk, long timeout)
117{
118	sk_common_release(sk);
119}
120
121
122/* net/ipv4/udp.c */
123extern int	udp_get_port(struct sock *sk, unsigned short snum,
124			     int (*saddr_cmp)(const struct sock *, const struct sock *));
125extern void	udp_err(struct sk_buff *, u32);
126
127extern int	udp_sendmsg(struct kiocb *iocb, struct sock *sk,
128			    struct msghdr *msg, size_t len);
129
130extern int	udp_rcv(struct sk_buff *skb);
131extern int	udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
132extern int	udp_disconnect(struct sock *sk, int flags);
133extern unsigned int udp_poll(struct file *file, struct socket *sock,
134			     poll_table *wait);
135extern int 	udp_lib_getsockopt(struct sock *sk, int level, int optname,
136			           char __user *optval, int __user *optlen);
137extern int 	udp_lib_setsockopt(struct sock *sk, int level, int optname,
138				   char __user *optval, int optlen,
139				   int (*push_pending_frames)(struct sock *));
140
141DECLARE_SNMP_STAT(struct udp_mib, udp_statistics);
142/*
143 * 	SNMP statistics for UDP and UDP-Lite
144 */
145#define UDP_INC_STATS_USER(field, is_udplite)			       do {   \
146	if (is_udplite) SNMP_INC_STATS_USER(udplite_statistics, field);       \
147	else		SNMP_INC_STATS_USER(udp_statistics, field);  }  while(0)
148#define UDP_INC_STATS_BH(field, is_udplite) 			       do  {  \
149	if (is_udplite) SNMP_INC_STATS_BH(udplite_statistics, field);         \
150	else		SNMP_INC_STATS_BH(udp_statistics, field);    }  while(0)
151
152/* /proc */
153struct udp_seq_afinfo {
154	struct module		*owner;
155	char			*name;
156	sa_family_t		family;
157	struct hlist_head	*hashtable;
158	int 			(*seq_show) (struct seq_file *m, void *v);
159	struct file_operations	*seq_fops;
160};
161
162struct udp_iter_state {
163	sa_family_t		family;
164	struct hlist_head	*hashtable;
165	int			bucket;
166	struct seq_operations	seq_ops;
167};
168
169#ifdef CONFIG_PROC_FS
170extern int udp_proc_register(struct udp_seq_afinfo *afinfo);
171extern void udp_proc_unregister(struct udp_seq_afinfo *afinfo);
172
173extern int  udp4_proc_init(void);
174extern void udp4_proc_exit(void);
175#endif
176#endif	/* _UDP_H */
177