[mirror_ubuntu-artful-kernel.git] / include / net / ip.h

/*
 * 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 IP module.
 *
 * Version:	@(#)ip.h	1.0.2	05/07/93
 *
 * Authors:	Ross Biro
 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Alan Cox, <gw4pts@gw4pts.ampr.org>
 *
 * Changes:
 *		Mike McLagan    :       Routing by source
 *
 *		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 _IP_H
#define _IP_H

#include <linux/types.h>
#include <linux/ip.h>
#include <linux/in.h>
#include <linux/skbuff.h>

#include <net/inet_sock.h>
#include <net/snmp.h>

struct sock;

struct inet_skb_parm
{
	struct ip_options	opt;		/* Compiled IP options		*/
	unsigned char		flags;

#define IPSKB_FORWARDED		1
#define IPSKB_XFRM_TUNNEL_SIZE	2
#define IPSKB_XFRM_TRANSFORMED	4
#define IPSKB_FRAG_COMPLETE	8
#define IPSKB_REROUTED		16
};

static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
{
	return ip_hdr(skb)->ihl * 4;
}

struct ipcm_cookie
{
	__be32			addr;
	int			oif;
	struct ip_options	*opt;
};

#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))

struct ip_ra_chain
{
	struct ip_ra_chain	*next;
	struct sock		*sk;
	void			(*destructor)(struct sock *);
};

extern struct ip_ra_chain *ip_ra_chain;
extern rwlock_t ip_ra_lock;

/* IP flags. */
#define IP_CE		0x8000		/* Flag: "Congestion"		*/
#define IP_DF		0x4000		/* Flag: "Don't Fragment"	*/
#define IP_MF		0x2000		/* Flag: "More Fragments"	*/
#define IP_OFFSET	0x1FFF		/* "Fragment Offset" part	*/

#define IP_FRAG_TIME	(30 * HZ)		/* fragment lifetime	*/

struct msghdr;
struct net_device;
struct packet_type;
struct rtable;
struct sockaddr;

extern void		ip_mc_dropsocket(struct sock *);
extern void		ip_mc_dropdevice(struct net_device *dev);
extern int		igmp_mc_proc_init(void);

/*
 *	Functions provided by ip.c
 */

extern int		ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
					      __be32 saddr, __be32 daddr,
					      struct ip_options *opt);
extern int		ip_rcv(struct sk_buff *skb, struct net_device *dev,
			       struct packet_type *pt, struct net_device *orig_dev);
extern int		ip_local_deliver(struct sk_buff *skb);
extern int		ip_mr_input(struct sk_buff *skb);
extern int		ip_output(struct sk_buff *skb);
extern int		ip_mc_output(struct sk_buff *skb);
extern int		ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
extern int		ip_do_nat(struct sk_buff *skb);
extern void		ip_send_check(struct iphdr *ip);
extern int		ip_queue_xmit(struct sk_buff *skb, int ipfragok);
extern void		ip_init(void);
extern int		ip_append_data(struct sock *sk,
				       int getfrag(void *from, char *to, int offset, int len,
						   int odd, struct sk_buff *skb),
				void *from, int len, int protolen,
				struct ipcm_cookie *ipc,
				struct rtable *rt,
				unsigned int flags);
extern int		ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
extern ssize_t		ip_append_page(struct sock *sk, struct page *page,
				int offset, size_t size, int flags);
extern int		ip_push_pending_frames(struct sock *sk);
extern void		ip_flush_pending_frames(struct sock *sk);

/* datagram.c */
extern int		ip4_datagram_connect(struct sock *sk, 
					     struct sockaddr *uaddr, int addr_len);

/*
 *	Map a multicast IP onto multicast MAC for type Token Ring.
 *      This conforms to RFC1469 Option 2 Multicasting i.e.
 *      using a functional address to transmit / receive 
 *      multicast packets.
 */

static inline void ip_tr_mc_map(__be32 addr, char *buf)
{
	buf[0]=0xC0;
	buf[1]=0x00;
	buf[2]=0x00;
	buf[3]=0x04;
	buf[4]=0x00;
	buf[5]=0x00;
}

struct ip_reply_arg {
	struct kvec iov[1];   
	__wsum 	    csum;
	int	    csumoffset; /* u16 offset of csum in iov[0].iov_base */
				/* -1 if not needed */ 
	int	    bound_dev_if;
}; 

void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
		   unsigned int len); 

struct ipv4_config
{
	int	log_martians;
	int	no_pmtu_disc;
};

extern struct ipv4_config ipv4_config;
DECLARE_SNMP_STAT(struct ipstats_mib, ip_statistics);
#define IP_INC_STATS(field)		SNMP_INC_STATS(ip_statistics, field)
#define IP_INC_STATS_BH(field)		SNMP_INC_STATS_BH(ip_statistics, field)
#define IP_INC_STATS_USER(field) 	SNMP_INC_STATS_USER(ip_statistics, field)
#define IP_ADD_STATS_BH(field, val)	SNMP_ADD_STATS_BH(ip_statistics, field, val)
DECLARE_SNMP_STAT(struct linux_mib, net_statistics);
#define NET_INC_STATS(field)		SNMP_INC_STATS(net_statistics, field)
#define NET_INC_STATS_BH(field)		SNMP_INC_STATS_BH(net_statistics, field)
#define NET_INC_STATS_USER(field) 	SNMP_INC_STATS_USER(net_statistics, field)
#define NET_ADD_STATS_BH(field, adnd)	SNMP_ADD_STATS_BH(net_statistics, field, adnd)
#define NET_ADD_STATS_USER(field, adnd)	SNMP_ADD_STATS_USER(net_statistics, field, adnd)

extern unsigned long snmp_fold_field(void *mib[], int offt);
extern int snmp_mib_init(void *ptr[2], size_t mibsize, size_t mibalign);
extern void snmp_mib_free(void *ptr[2]);

extern void inet_get_local_port_range(int *low, int *high);

extern int sysctl_ip_default_ttl;
extern int sysctl_ip_nonlocal_bind;

/* From ip_fragment.c */
struct inet_frags_ctl;
extern struct inet_frags_ctl ip4_frags_ctl;
extern int sysctl_ipfrag_max_dist;

/* From inetpeer.c */
extern int inet_peer_threshold;
extern int inet_peer_minttl;
extern int inet_peer_maxttl;
extern int inet_peer_gc_mintime;
extern int inet_peer_gc_maxtime;

/* From ip_output.c */
extern int sysctl_ip_dynaddr;

extern void ipfrag_init(void);

#ifdef CONFIG_INET
#include <net/dst.h>

/* The function in 2.2 was invalid, producing wrong result for
 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
static inline
int ip_decrease_ttl(struct iphdr *iph)
{
	u32 check = (__force u32)iph->check;
	check += (__force u32)htons(0x0100);
	iph->check = (__force __sum16)(check + (check>=0xFFFF));
	return --iph->ttl;
}

static inline
int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
{
	return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
		(inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
		 !(dst_metric(dst, RTAX_LOCK)&(1<<RTAX_MTU))));
}

extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);

static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
{
	if (iph->frag_off & htons(IP_DF)) {
		/* This is only to work around buggy Windows95/2000
		 * VJ compression implementations.  If the ID field
		 * does not change, they drop every other packet in
		 * a TCP stream using header compression.
		 */
		iph->id = (sk && inet_sk(sk)->daddr) ?
					htons(inet_sk(sk)->id++) : 0;
	} else
		__ip_select_ident(iph, dst, 0);
}

static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
{
	if (iph->frag_off & htons(IP_DF)) {
		if (sk && inet_sk(sk)->daddr) {
			iph->id = htons(inet_sk(sk)->id);
			inet_sk(sk)->id += 1 + more;
		} else
			iph->id = 0;
	} else
		__ip_select_ident(iph, dst, more);
}

/*
 *	Map a multicast IP onto multicast MAC for type ethernet.
 */

static inline void ip_eth_mc_map(__be32 naddr, char *buf)
{
	__u32 addr=ntohl(naddr);
	buf[0]=0x01;
	buf[1]=0x00;
	buf[2]=0x5e;
	buf[5]=addr&0xFF;
	addr>>=8;
	buf[4]=addr&0xFF;
	addr>>=8;
	buf[3]=addr&0x7F;
}

/*
 *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
 *	Leave P_Key as 0 to be filled in by driver.
 */

static inline void ip_ib_mc_map(__be32 naddr, char *buf)
{
	__u32 addr;
	buf[0]  = 0;		/* Reserved */
	buf[1]  = 0xff;		/* Multicast QPN */
	buf[2]  = 0xff;
	buf[3]  = 0xff;
	addr    = ntohl(naddr);
	buf[4]  = 0xff;
	buf[5]  = 0x12;		/* link local scope */
	buf[6]  = 0x40;		/* IPv4 signature */
	buf[7]  = 0x1b;
	buf[8]  = 0;		/* P_Key */
	buf[9]  = 0;
	buf[10] = 0;
	buf[11] = 0;
	buf[12] = 0;
	buf[13] = 0;
	buf[14] = 0;
	buf[15] = 0;
	buf[19] = addr & 0xff;
	addr  >>= 8;
	buf[18] = addr & 0xff;
	addr  >>= 8;
	buf[17] = addr & 0xff;
	addr  >>= 8;
	buf[16] = addr & 0x0f;
}

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
#include <linux/ipv6.h>
#endif

static __inline__ void inet_reset_saddr(struct sock *sk)
{
	inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	if (sk->sk_family == PF_INET6) {
		struct ipv6_pinfo *np = inet6_sk(sk);

		memset(&np->saddr, 0, sizeof(np->saddr));
		memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
	}
#endif
}

#endif

extern int	ip_call_ra_chain(struct sk_buff *skb);

/*
 *	Functions provided by ip_fragment.o
 */

enum ip_defrag_users
{
	IP_DEFRAG_LOCAL_DELIVER,
	IP_DEFRAG_CALL_RA_CHAIN,
	IP_DEFRAG_CONNTRACK_IN,
	IP_DEFRAG_CONNTRACK_OUT,
	IP_DEFRAG_VS_IN,
	IP_DEFRAG_VS_OUT,
	IP_DEFRAG_VS_FWD
};

int ip_defrag(struct sk_buff *skb, u32 user);
int ip_frag_mem(void);
int ip_frag_nqueues(void);

/*
 *	Functions provided by ip_forward.c
 */
 
extern int ip_forward(struct sk_buff *skb);
extern int ip_net_unreachable(struct sk_buff *skb);
 
/*
 *	Functions provided by ip_options.c
 */
 
extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag);
extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
extern void ip_options_fragment(struct sk_buff *skb);
extern int ip_options_compile(struct ip_options *opt, struct sk_buff *skb);
extern int ip_options_get(struct ip_options **optp,
			  unsigned char *data, int optlen);
extern int ip_options_get_from_user(struct ip_options **optp,
				    unsigned char __user *data, int optlen);
extern void ip_options_undo(struct ip_options * opt);
extern void ip_forward_options(struct sk_buff *skb);
extern int ip_options_rcv_srr(struct sk_buff *skb);

/*
 *	Functions provided by ip_sockglue.c
 */

extern void	ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
extern int	ip_cmsg_send(struct msghdr *msg, struct ipcm_cookie *ipc);
extern int	ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen);
extern int	ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
extern int	compat_ip_setsockopt(struct sock *sk, int level,
			int optname, char __user *optval, int optlen);
extern int	compat_ip_getsockopt(struct sock *sk, int level,
			int optname, char __user *optval, int __user *optlen);
extern int	ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));

extern int 	ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
extern void	ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 
			      __be16 port, u32 info, u8 *payload);
extern void	ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
			       u32 info);

/* sysctl helpers - any sysctl which holds a value that ends up being
 * fed into the routing cache should use these handlers.
 */
int ipv4_doint_and_flush(ctl_table *ctl, int write,
			 struct file* filp, void __user *buffer,
			 size_t *lenp, loff_t *ppos);
int ipv4_doint_and_flush_strategy(ctl_table *table, int __user *name, int nlen,
				  void __user *oldval, size_t __user *oldlenp,
				  void __user *newval, size_t newlen);
#ifdef CONFIG_PROC_FS
extern int ip_misc_proc_init(void);
#endif

extern struct ctl_table ipv4_table[];

#endif	/* _IP_H */
Commit	Line	Data
1da177e4 LT	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 IP module.
	7	*
	8	* Version: @(#)ip.h 1.0.2 05/07/93
	9	*
02c30a84	10	* Authors: Ross Biro
1da177e4 LT	11	* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
	12	* Alan Cox, <gw4pts@gw4pts.ampr.org>
	13	*
	14	* Changes:
	15	* Mike McLagan : Routing by source
	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 _IP_H
	23	#define _IP_H
	24
1da177e4	25	#include <linux/types.h>
1da177e4 LT	26	#include <linux/ip.h>
1da177e4 LT	27	#include <linux/in.h>
c9bdd4b5	28	#include <linux/skbuff.h>
14c85021 ACM	29
14c85021 ACM	30	#include <net/inet_sock.h>
1da177e4 LT	31	#include <net/snmp.h>
	32
	33	struct sock;
	34
	35	struct inet_skb_parm
	36	{
	37	struct ip_options opt; /* Compiled IP options */
	38	unsigned char flags;
	39
8cdfab8a PM	40	#define IPSKB_FORWARDED 1
8cdfab8a PM	41	#define IPSKB_XFRM_TUNNEL_SIZE 2
3e3850e9 PM	42	#define IPSKB_XFRM_TRANSFORMED 4
3e3850e9 PM	43	#define IPSKB_FRAG_COMPLETE 8
48d5cad8	44	#define IPSKB_REROUTED 16
1da177e4 LT	45	};
1da177e4 LT	46
c9bdd4b5 ACM	47	static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
c9bdd4b5 ACM	48	{
eddc9ec5	49	return ip_hdr(skb)->ihl * 4;
c9bdd4b5 ACM	50	}
c9bdd4b5 ACM	51
1da177e4 LT	52	struct ipcm_cookie
1da177e4 LT	53	{
c1d18f9f	54	__be32 addr;
1da177e4 LT	55	int oif;
	56	struct ip_options *opt;
	57	};
	58
	59	#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
	60
	61	struct ip_ra_chain
	62	{
	63	struct ip_ra_chain *next;
	64	struct sock *sk;
	65	void (destructor)(struct sock );
	66	};
	67
	68	extern struct ip_ra_chain *ip_ra_chain;
	69	extern rwlock_t ip_ra_lock;
	70
	71	/* IP flags. */
	72	#define IP_CE 0x8000 /* Flag: "Congestion" */
	73	#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
	74	#define IP_MF 0x2000 /* Flag: "More Fragments" */
	75	#define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
	76
	77	#define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
	78
14c85021 ACM	79	struct msghdr;
	80	struct net_device;
	81	struct packet_type;
	82	struct rtable;
14c85021 ACM	83	struct sockaddr;
14c85021 ACM	84
1da177e4 LT	85	extern void ip_mc_dropsocket(struct sock *);
	86	extern void ip_mc_dropdevice(struct net_device *dev);
	87	extern int igmp_mc_proc_init(void);
	88
	89	/*
	90	* Functions provided by ip.c
	91	*/
	92
	93	extern int ip_build_and_send_pkt(struct sk_buff skb, struct sock sk,
13d8eaa0	94	__be32 saddr, __be32 daddr,
1da177e4 LT	95	struct ip_options *opt);
1da177e4 LT	96	extern int ip_rcv(struct sk_buff skb, struct net_device dev,
f2ccd8fa	97	struct packet_type pt, struct net_device orig_dev);
1da177e4 LT	98	extern int ip_local_deliver(struct sk_buff *skb);
	99	extern int ip_mr_input(struct sk_buff *skb);
	100	extern int ip_output(struct sk_buff *skb);
	101	extern int ip_mc_output(struct sk_buff *skb);
2e2f7aef	102	extern int ip_fragment(struct sk_buff skb, int (output)(struct sk_buff *));
1da177e4 LT	103	extern int ip_do_nat(struct sk_buff *skb);
1da177e4 LT	104	extern void ip_send_check(struct iphdr *ip);
e89862f4	105	extern int ip_queue_xmit(struct sk_buff *skb, int ipfragok);
1da177e4 LT	106	extern void ip_init(void);
	107	extern int ip_append_data(struct sock *sk,
	108	int getfrag(void from, char to, int offset, int len,
	109	int odd, struct sk_buff *skb),
	110	void *from, int len, int protolen,
	111	struct ipcm_cookie *ipc,
	112	struct rtable *rt,
	113	unsigned int flags);
	114	extern int ip_generic_getfrag(void from, char to, int offset, int len, int odd, struct sk_buff *skb);
	115	extern ssize_t ip_append_page(struct sock sk, struct page page,
	116	int offset, size_t size, int flags);
	117	extern int ip_push_pending_frames(struct sock *sk);
	118	extern void ip_flush_pending_frames(struct sock *sk);
	119
	120	/* datagram.c */
	121	extern int ip4_datagram_connect(struct sock *sk,
	122	struct sockaddr *uaddr, int addr_len);
	123
	124	/*
	125	* Map a multicast IP onto multicast MAC for type Token Ring.
	126	* This conforms to RFC1469 Option 2 Multicasting i.e.
	127	* using a functional address to transmit / receive
	128	* multicast packets.
	129	*/
	130
714e85be	131	static inline void ip_tr_mc_map(__be32 addr, char *buf)
1da177e4 LT	132	{
	133	buf[0]=0xC0;
	134	buf[1]=0x00;
	135	buf[2]=0x00;
	136	buf[3]=0x04;
	137	buf[4]=0x00;
	138	buf[5]=0x00;
	139	}
	140
	141	struct ip_reply_arg {
	142	struct kvec iov[1];
d6f5493c	143	__wsum csum;
1da177e4 LT	144	int csumoffset; /* u16 offset of csum in iov[0].iov_base */
1da177e4 LT	145	/* -1 if not needed */
f0e48dbf	146	int bound_dev_if;
1da177e4 LT	147	};
	148
	149	void ip_send_reply(struct sock sk, struct sk_buff skb, struct ip_reply_arg *arg,
	150	unsigned int len);
	151
1da177e4 LT	152	struct ipv4_config
	153	{
	154	int log_martians;
1da177e4 LT	155	int no_pmtu_disc;
	156	};
	157
	158	extern struct ipv4_config ipv4_config;
	159	DECLARE_SNMP_STAT(struct ipstats_mib, ip_statistics);
	160	#define IP_INC_STATS(field) SNMP_INC_STATS(ip_statistics, field)
	161	#define IP_INC_STATS_BH(field) SNMP_INC_STATS_BH(ip_statistics, field)
	162	#define IP_INC_STATS_USER(field) SNMP_INC_STATS_USER(ip_statistics, field)
8e7999c4	163	#define IP_ADD_STATS_BH(field, val) SNMP_ADD_STATS_BH(ip_statistics, field, val)
1da177e4 LT	164	DECLARE_SNMP_STAT(struct linux_mib, net_statistics);
	165	#define NET_INC_STATS(field) SNMP_INC_STATS(net_statistics, field)
	166	#define NET_INC_STATS_BH(field) SNMP_INC_STATS_BH(net_statistics, field)
	167	#define NET_INC_STATS_USER(field) SNMP_INC_STATS_USER(net_statistics, field)
	168	#define NET_ADD_STATS_BH(field, adnd) SNMP_ADD_STATS_BH(net_statistics, field, adnd)
	169	#define NET_ADD_STATS_USER(field, adnd) SNMP_ADD_STATS_USER(net_statistics, field, adnd)
	170
5e0f0435	171	extern unsigned long snmp_fold_field(void *mib[], int offt);
33490170 YH	172	extern int snmp_mib_init(void *ptr[2], size_t mibsize, size_t mibalign);
	173	extern void snmp_mib_free(void *ptr[2]);
	174
227b60f5 SH	175	extern void inet_get_local_port_range(int low, int high);
227b60f5 SH	176
1da177e4	177	extern int sysctl_ip_default_ttl;
cdac4e07	178	extern int sysctl_ip_nonlocal_bind;
1da177e4	179
20380731	180	/* From ip_fragment.c */
04128f23 PE	181	struct inet_frags_ctl;
04128f23 PE	182	extern struct inet_frags_ctl ip4_frags_ctl;
89cee8b1	183	extern int sysctl_ipfrag_max_dist;
20380731 ACM	184
	185	/* From inetpeer.c */
	186	extern int inet_peer_threshold;
	187	extern int inet_peer_minttl;
	188	extern int inet_peer_maxttl;
	189	extern int inet_peer_gc_mintime;
	190	extern int inet_peer_gc_maxtime;
	191
	192	/* From ip_output.c */
	193	extern int sysctl_ip_dynaddr;
	194
	195	extern void ipfrag_init(void);
	196
1da177e4	197	#ifdef CONFIG_INET
14c85021 ACM	198	#include <net/dst.h>
14c85021 ACM	199
1da177e4 LT	200	/* The function in 2.2 was invalid, producing wrong result for
	201	* check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
	202	static inline
	203	int ip_decrease_ttl(struct iphdr *iph)
	204	{
5c78f275 AV	205	u32 check = (__force u32)iph->check;
	206	check += (__force u32)htons(0x0100);
	207	iph->check = (__force __sum16)(check + (check>=0xFFFF));
1da177e4 LT	208	return --iph->ttl;
	209	}
	210
	211	static inline
	212	int ip_dont_fragment(struct sock sk, struct dst_entry dst)
	213	{
	214	return (inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO \|\|
	215	(inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
	216	!(dst_metric(dst, RTAX_LOCK)&(1<<RTAX_MTU))));
	217	}
	218
	219	extern void __ip_select_ident(struct iphdr iph, struct dst_entry dst, int more);
	220
	221	static inline void ip_select_ident(struct iphdr iph, struct dst_entry dst, struct sock *sk)
	222	{
	223	if (iph->frag_off & htons(IP_DF)) {
	224	/* This is only to work around buggy Windows95/2000
	225	* VJ compression implementations. If the ID field
	226	* does not change, they drop every other packet in
	227	* a TCP stream using header compression.
	228	*/
	229	iph->id = (sk && inet_sk(sk)->daddr) ?
	230	htons(inet_sk(sk)->id++) : 0;
	231	} else
	232	__ip_select_ident(iph, dst, 0);
	233	}
	234
	235	static inline void ip_select_ident_more(struct iphdr iph, struct dst_entry dst, struct sock *sk, int more)
	236	{
	237	if (iph->frag_off & htons(IP_DF)) {
	238	if (sk && inet_sk(sk)->daddr) {
	239	iph->id = htons(inet_sk(sk)->id);
	240	inet_sk(sk)->id += 1 + more;
	241	} else
	242	iph->id = 0;
	243	} else
	244	__ip_select_ident(iph, dst, more);
	245	}
	246
	247	/*
	248	* Map a multicast IP onto multicast MAC for type ethernet.
	249	*/
	250
714e85be	251	static inline void ip_eth_mc_map(__be32 naddr, char *buf)
1da177e4	252	{
714e85be	253	__u32 addr=ntohl(naddr);
1da177e4 LT	254	buf[0]=0x01;
	255	buf[1]=0x00;
	256	buf[2]=0x5e;
	257	buf[5]=addr&0xFF;
	258	addr>>=8;
	259	buf[4]=addr&0xFF;
	260	addr>>=8;
	261	buf[3]=addr&0x7F;
	262	}
	263
	264	/*
	265	* Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
	266	* Leave P_Key as 0 to be filled in by driver.
	267	*/
	268
714e85be	269	static inline void ip_ib_mc_map(__be32 naddr, char *buf)
1da177e4	270	{
714e85be	271	__u32 addr;
1da177e4 LT	272	buf[0] = 0; /* Reserved */
	273	buf[1] = 0xff; /* Multicast QPN */
	274	buf[2] = 0xff;
	275	buf[3] = 0xff;
714e85be	276	addr = ntohl(naddr);
1da177e4 LT	277	buf[4] = 0xff;
	278	buf[5] = 0x12; /* link local scope */
	279	buf[6] = 0x40; /* IPv4 signature */
	280	buf[7] = 0x1b;
	281	buf[8] = 0; /* P_Key */
	282	buf[9] = 0;
	283	buf[10] = 0;
	284	buf[11] = 0;
	285	buf[12] = 0;
	286	buf[13] = 0;
	287	buf[14] = 0;
	288	buf[15] = 0;
	289	buf[19] = addr & 0xff;
	290	addr >>= 8;
	291	buf[18] = addr & 0xff;
	292	addr >>= 8;
	293	buf[17] = addr & 0xff;
	294	addr >>= 8;
	295	buf[16] = addr & 0x0f;
	296	}
	297
	298	#if defined(CONFIG_IPV6) \|\| defined(CONFIG_IPV6_MODULE)
	299	#include <linux/ipv6.h>
	300	#endif
	301
	302	static __inline__ void inet_reset_saddr(struct sock *sk)
	303	{
	304	inet_sk(sk)->rcv_saddr = inet_sk(sk)->saddr = 0;
	305	#if defined(CONFIG_IPV6) \|\| defined(CONFIG_IPV6_MODULE)
	306	if (sk->sk_family == PF_INET6) {
	307	struct ipv6_pinfo *np = inet6_sk(sk);
	308
	309	memset(&np->saddr, 0, sizeof(np->saddr));
	310	memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
	311	}
	312	#endif
	313	}
	314
	315	#endif
	316
	317	extern int ip_call_ra_chain(struct sk_buff *skb);
	318
	319	/*
	320	* Functions provided by ip_fragment.o
	321	*/
	322
	323	enum ip_defrag_users
	324	{
	325	IP_DEFRAG_LOCAL_DELIVER,
	326	IP_DEFRAG_CALL_RA_CHAIN,
	327	IP_DEFRAG_CONNTRACK_IN,
	328	IP_DEFRAG_CONNTRACK_OUT,
1da177e4 LT	329	IP_DEFRAG_VS_IN,
	330	IP_DEFRAG_VS_OUT,
	331	IP_DEFRAG_VS_FWD
	332	};
	333
776c729e	334	int ip_defrag(struct sk_buff *skb, u32 user);
7eb95156 PE	335	int ip_frag_mem(void);
7eb95156 PE	336	int ip_frag_nqueues(void);
1da177e4 LT	337
	338	/*
	339	* Functions provided by ip_forward.c
	340	*/
	341
	342	extern int ip_forward(struct sk_buff *skb);
	343	extern int ip_net_unreachable(struct sk_buff *skb);
	344
	345	/*
	346	* Functions provided by ip_options.c
	347	*/
	348
8712f774	349	extern void ip_options_build(struct sk_buff skb, struct ip_options opt, __be32 daddr, struct rtable *rt, int is_frag);
1da177e4 LT	350	extern int ip_options_echo(struct ip_options dopt, struct sk_buff skb);
	351	extern void ip_options_fragment(struct sk_buff *skb);
	352	extern int ip_options_compile(struct ip_options opt, struct sk_buff skb);
4c6ea29d ACM	353	extern int ip_options_get(struct ip_options **optp,
	354	unsigned char *data, int optlen);
	355	extern int ip_options_get_from_user(struct ip_options **optp,
	356	unsigned char __user *data, int optlen);
1da177e4 LT	357	extern void ip_options_undo(struct ip_options * opt);
	358	extern void ip_forward_options(struct sk_buff *skb);
	359	extern int ip_options_rcv_srr(struct sk_buff *skb);
	360
	361	/*
	362	* Functions provided by ip_sockglue.c
	363	*/
	364
	365	extern void ip_cmsg_recv(struct msghdr msg, struct sk_buff skb);
	366	extern int ip_cmsg_send(struct msghdr msg, struct ipcm_cookie ipc);
	367	extern int ip_setsockopt(struct sock sk, int level, int optname, char __user optval, int optlen);
	368	extern int ip_getsockopt(struct sock sk, int level, int optname, char __user optval, int __user *optlen);
3fdadf7d DM	369	extern int compat_ip_setsockopt(struct sock *sk, int level,
	370	int optname, char __user *optval, int optlen);
	371	extern int compat_ip_getsockopt(struct sock *sk, int level,
	372	int optname, char __user optval, int __user optlen);
1da177e4 LT	373	extern int ip_ra_control(struct sock sk, unsigned char on, void (destructor)(struct sock *));
	374
	375	extern int ip_recv_error(struct sock sk, struct msghdr msg, int len);
	376	extern void ip_icmp_error(struct sock sk, struct sk_buff skb, int err,
35986b32	377	__be16 port, u32 info, u8 *payload);
0579016e	378	extern void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
1da177e4 LT	379	u32 info);
	380
	381	/* sysctl helpers - any sysctl which holds a value that ends up being
	382	* fed into the routing cache should use these handlers.
	383	*/
	384	int ipv4_doint_and_flush(ctl_table *ctl, int write,
	385	struct file* filp, void __user *buffer,
	386	size_t lenp, loff_t ppos);
	387	int ipv4_doint_and_flush_strategy(ctl_table table, int __user name, int nlen,
	388	void __user oldval, size_t __user oldlenp,
1f29bcd7	389	void __user *newval, size_t newlen);
20380731 ACM	390	#ifdef CONFIG_PROC_FS
	391	extern int ip_misc_proc_init(void);
	392	#endif
	393
	394	extern struct ctl_table ipv4_table[];
1da177e4 LT	395
1da177e4 LT	396	#endif /* _IP_H */