linux/include/net/udp.h
Gerrit Renker ba4e58eca8 [NET]: Supporting UDP-Lite (RFC 3828) in Linux
This is a revision of the previously submitted patch, which alters
the way files are organized and compiled in the following manner:

	* UDP and UDP-Lite now use separate object files
	* source file dependencies resolved via header files
	  net/ipv{4,6}/udp_impl.h
	* order of inclusion files in udp.c/udplite.c adapted
	  accordingly

[NET/IPv4]: Support for the UDP-Lite protocol (RFC 3828)

This patch adds support for UDP-Lite to the IPv4 stack, provided as an
extension to the existing UDPv4 code:
        * generic routines are all located in net/ipv4/udp.c
        * UDP-Lite specific routines are in net/ipv4/udplite.c
        * MIB/statistics support in /proc/net/snmp and /proc/net/udplite
        * shared API with extensions for partial checksum coverage

[NET/IPv6]: Extension for UDP-Lite over IPv6

It extends the existing UDPv6 code base with support for UDP-Lite
in the same manner as per UDPv4. In particular,
        * UDPv6 generic and shared code is in net/ipv6/udp.c
        * UDP-Litev6 specific extensions are in net/ipv6/udplite.c
        * MIB/statistics support in /proc/net/snmp6 and /proc/net/udplite6
        * support for IPV6_ADDRFORM
        * aligned the coding style of protocol initialisation with af_inet6.c
        * made the error handling in udpv6_queue_rcv_skb consistent;
          to return `-1' on error on all error cases
        * consolidation of shared code

[NET]: UDP-Lite Documentation and basic XFRM/Netfilter support

The UDP-Lite patch further provides
        * API documentation for UDP-Lite
        * basic xfrm support
        * basic netfilter support for IPv4 and IPv6 (LOG target)

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:22:46 -08:00

174 lines
4.7 KiB
C

/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Definitions for the UDP module.
*
* Version: @(#)udp.h 1.0.2 05/07/93
*
* Authors: Ross Biro
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
*
* Fixes:
* Alan Cox : Turned on udp checksums. I don't want to
* chase 'memory corruption' bugs that aren't!
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _UDP_H
#define _UDP_H
#include <linux/list.h>
#include <net/inet_sock.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/ip.h>
#include <linux/ipv6.h>
#include <linux/seq_file.h>
/**
* struct udp_skb_cb - UDP(-Lite) private variables
*
* @header: private variables used by IPv4/IPv6
* @cscov: checksum coverage length (UDP-Lite only)
* @partial_cov: if set indicates partial csum coverage
*/
struct udp_skb_cb {
union {
struct inet_skb_parm h4;
#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
struct inet6_skb_parm h6;
#endif
} header;
__u16 cscov;
__u8 partial_cov;
};
#define UDP_SKB_CB(__skb) ((struct udp_skb_cb *)((__skb)->cb))
extern struct hlist_head udp_hash[UDP_HTABLE_SIZE];
extern rwlock_t udp_hash_lock;
/* Note: this must match 'valbool' in sock_setsockopt */
#define UDP_CSUM_NOXMIT 1
/* Used by SunRPC/xprt layer. */
#define UDP_CSUM_NORCV 2
/* Default, as per the RFC, is to always do csums. */
#define UDP_CSUM_DEFAULT 0
extern struct proto udp_prot;
struct sk_buff;
/*
* Generic checksumming routines for UDP(-Lite) v4 and v6
*/
static inline u16 __udp_lib_checksum_complete(struct sk_buff *skb)
{
if (! UDP_SKB_CB(skb)->partial_cov)
return __skb_checksum_complete(skb);
return csum_fold(skb_checksum(skb, 0, UDP_SKB_CB(skb)->cscov,
skb->csum));
}
static __inline__ int udp_lib_checksum_complete(struct sk_buff *skb)
{
return skb->ip_summed != CHECKSUM_UNNECESSARY &&
__udp_lib_checksum_complete(skb);
}
/**
* udp_csum_outgoing - compute UDPv4/v6 checksum over fragments
* @sk: socket we are writing to
* @skb: sk_buff containing the filled-in UDP header
* (checksum field must be zeroed out)
*/
static inline u32 udp_csum_outgoing(struct sock *sk, struct sk_buff *skb)
{
u32 csum = csum_partial(skb->h.raw, sizeof(struct udphdr), 0);
skb_queue_walk(&sk->sk_write_queue, skb) {
csum = csum_add(csum, skb->csum);
}
return csum;
}
/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
static inline void udp_lib_hash(struct sock *sk)
{
BUG();
}
static inline void udp_lib_unhash(struct sock *sk)
{
write_lock_bh(&udp_hash_lock);
if (sk_del_node_init(sk)) {
inet_sk(sk)->num = 0;
sock_prot_dec_use(sk->sk_prot);
}
write_unlock_bh(&udp_hash_lock);
}
static inline void udp_lib_close(struct sock *sk, long timeout)
{
sk_common_release(sk);
}
/* net/ipv4/udp.c */
extern int udp_get_port(struct sock *sk, unsigned short snum,
int (*saddr_cmp)(const struct sock *, const struct sock *));
extern void udp_err(struct sk_buff *, u32);
extern int udp_sendmsg(struct kiocb *iocb, struct sock *sk,
struct msghdr *msg, size_t len);
extern int udp_rcv(struct sk_buff *skb);
extern int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
extern int udp_disconnect(struct sock *sk, int flags);
extern unsigned int udp_poll(struct file *file, struct socket *sock,
poll_table *wait);
DECLARE_SNMP_STAT(struct udp_mib, udp_statistics);
/*
* SNMP statistics for UDP and UDP-Lite
*/
#define UDP_INC_STATS_USER(field, is_udplite) do { \
if (is_udplite) SNMP_INC_STATS_USER(udplite_statistics, field); \
else SNMP_INC_STATS_USER(udp_statistics, field); } while(0)
#define UDP_INC_STATS_BH(field, is_udplite) do { \
if (is_udplite) SNMP_INC_STATS_BH(udplite_statistics, field); \
else SNMP_INC_STATS_BH(udp_statistics, field); } while(0)
/* /proc */
struct udp_seq_afinfo {
struct module *owner;
char *name;
sa_family_t family;
struct hlist_head *hashtable;
int (*seq_show) (struct seq_file *m, void *v);
struct file_operations *seq_fops;
};
struct udp_iter_state {
sa_family_t family;
struct hlist_head *hashtable;
int bucket;
struct seq_operations seq_ops;
};
#ifdef CONFIG_PROC_FS
extern int udp_proc_register(struct udp_seq_afinfo *afinfo);
extern void udp_proc_unregister(struct udp_seq_afinfo *afinfo);
extern int udp4_proc_init(void);
extern void udp4_proc_exit(void);
#endif
#endif /* _UDP_H */