[linux.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, <[email protected]>
 *		Alan Cox, <[email protected]>
 *
 * 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/route.h>
#include <net/snmp.h>
#include <net/flow.h>
#include <net/flow_keys.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

	u16			frag_max_size;
};

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_rcu	*opt;
	__u8			tx_flags;
	__u8			ttl;
	__s16			tos;
	char			priority;
};

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

struct ip_ra_chain {
	struct ip_ra_chain __rcu *next;
	struct sock		*sk;
	union {
		void			(*destructor)(struct sock *);
		struct sock		*saved_sk;
	};
	struct rcu_head		rcu;
};

extern struct ip_ra_chain __rcu *ip_ra_chain;

/* 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;

int igmp_mc_init(void);

/*
 *	Functions provided by ip.c
 */

int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
			  __be32 saddr, __be32 daddr,
			  struct ip_options_rcu *opt);
int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
	   struct net_device *orig_dev);
int ip_local_deliver(struct sk_buff *skb);
int ip_mr_input(struct sk_buff *skb);
int ip_output(struct sock *sk, struct sk_buff *skb);
int ip_mc_output(struct sock *sk, struct sk_buff *skb);
int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
int ip_do_nat(struct sk_buff *skb);
void ip_send_check(struct iphdr *ip);
int __ip_local_out(struct sk_buff *skb);
int ip_local_out_sk(struct sock *sk, struct sk_buff *skb);
static inline int ip_local_out(struct sk_buff *skb)
{
	return ip_local_out_sk(skb->sk, skb);
}

int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
void ip_init(void);
int ip_append_data(struct sock *sk, struct flowi4 *fl4,
		   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);
int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
		       struct sk_buff *skb);
ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
		       int offset, size_t size, int flags);
struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
			      struct sk_buff_head *queue,
			      struct inet_cork *cork);
int ip_send_skb(struct net *net, struct sk_buff *skb);
int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
void ip_flush_pending_frames(struct sock *sk);
struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
			    int getfrag(void *from, char *to, int offset,
					int len, int odd, struct sk_buff *skb),
			    void *from, int length, int transhdrlen,
			    struct ipcm_cookie *ipc, struct rtable **rtp,
			    unsigned int flags);

static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
{
	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
}

static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
{
	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
}

static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
{
	return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
}

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

void ip4_datagram_release_cb(struct sock *sk);

struct ip_reply_arg {
	struct kvec iov[1];   
	int	    flags;
	__wsum 	    csum;
	int	    csumoffset; /* u16 offset of csum in iov[0].iov_base */
				/* -1 if not needed */ 
	int	    bound_dev_if;
	u8  	    tos;
}; 

#define IP_REPLY_ARG_NOSRCCHECK 1

static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
{
	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
}

void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr,
			   __be32 saddr, const struct ip_reply_arg *arg,
			   unsigned int len);

#define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
#define IP_INC_STATS_BH(net, field)	SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
#define IP_ADD_STATS(net, field, val)	SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
#define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
#define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
#define NET_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.net_statistics, field)
#define NET_INC_STATS_BH(net, field)	SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
#define NET_INC_STATS_USER(net, field) 	SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
#define NET_ADD_STATS(net, field, adnd)	SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
#define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
#define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)

unsigned long snmp_fold_field(void __percpu *mib, int offt);
#if BITS_PER_LONG==32
u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
#else
static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
{
	return snmp_fold_field(mib, offt);
}
#endif

void inet_get_local_port_range(struct net *net, int *low, int *high);

#ifdef CONFIG_SYSCTL
static inline int inet_is_local_reserved_port(struct net *net, int port)
{
	if (!net->ipv4.sysctl_local_reserved_ports)
		return 0;
	return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
}

static inline bool sysctl_dev_name_is_allowed(const char *name)
{
	return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
}

#else
static inline int inet_is_local_reserved_port(struct net *net, int port)
{
	return 0;
}
#endif

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

/* From ip_input.c */
extern int sysctl_ip_early_demux;

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

void ipfrag_init(void);

void ip_static_sysctl_init(void);

#define IP4_REPLY_MARK(net, mark) \
	((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)

static inline bool ip_is_fragment(const struct iphdr *iph)
{
	return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
}

#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_locked(dst, RTAX_MTU)));
}

static inline bool ip_sk_accept_pmtu(const struct sock *sk)
{
	return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
	       inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
}

static inline bool ip_sk_use_pmtu(const struct sock *sk)
{
	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
}

static inline bool ip_sk_ignore_df(const struct sock *sk)
{
	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
	       inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
}

static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
						    bool forwarding)
{
	struct net *net = dev_net(dst->dev);

	if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
	    dst_metric_locked(dst, RTAX_MTU) ||
	    !forwarding)
		return dst_mtu(dst);

	return min(dst->dev->mtu, IP_MAX_MTU);
}

static inline unsigned int ip_skb_dst_mtu(const struct sk_buff *skb)
{
	if (!skb->sk || ip_sk_use_pmtu(skb->sk)) {
		bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
		return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
	} else {
		return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
	}
}

u32 ip_idents_reserve(u32 hash, int segs);
void __ip_select_ident(struct iphdr *iph, int segs);

static inline void ip_select_ident_segs(struct sk_buff *skb, struct sock *sk, int segs)
{
	struct iphdr *iph = ip_hdr(skb);

	if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_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.
		 */
		if (sk && inet_sk(sk)->inet_daddr) {
			iph->id = htons(inet_sk(sk)->inet_id);
			inet_sk(sk)->inet_id += segs;
		} else {
			iph->id = 0;
		}
	} else {
		__ip_select_ident(iph, segs);
	}
}

static inline void ip_select_ident(struct sk_buff *skb, struct sock *sk)
{
	ip_select_ident_segs(skb, sk, 1);
}

static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
{
	return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
				  skb->len, proto, 0);
}

static inline void inet_set_txhash(struct sock *sk)
{
	struct inet_sock *inet = inet_sk(sk);
	struct flow_keys keys;

	keys.src = inet->inet_saddr;
	keys.dst = inet->inet_daddr;
	keys.port16[0] = inet->inet_sport;
	keys.port16[1] = inet->inet_dport;

	sk->sk_txhash = flow_hash_from_keys(&keys);
}

static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
{
	const struct iphdr *iph = skb_gro_network_header(skb);

	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
				  skb_gro_len(skb), proto, 0);
}

/*
 *	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, const unsigned char *broadcast, char *buf)
{
	__u32 addr;
	unsigned char scope = broadcast[5] & 0xF;

	buf[0]  = 0;		/* Reserved */
	buf[1]  = 0xff;		/* Multicast QPN */
	buf[2]  = 0xff;
	buf[3]  = 0xff;
	addr    = ntohl(naddr);
	buf[4]  = 0xff;
	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
	buf[6]  = 0x40;		/* IPv4 signature */
	buf[7]  = 0x1b;
	buf[8]  = broadcast[8];		/* P_Key */
	buf[9]  = broadcast[9];
	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;
}

static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
{
	if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
		memcpy(buf, broadcast, 4);
	else
		memcpy(buf, &naddr, sizeof(naddr));
}

#if IS_ENABLED(CONFIG_IPV6)
#include <linux/ipv6.h>
#endif

static __inline__ void inet_reset_saddr(struct sock *sk)
{
	inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
#if IS_ENABLED(CONFIG_IPV6)
	if (sk->sk_family == PF_INET6) {
		struct ipv6_pinfo *np = inet6_sk(sk);

		memset(&np->saddr, 0, sizeof(np->saddr));
		memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
	}
#endif
}

#endif

static inline int sk_mc_loop(struct sock *sk)
{
	if (!sk)
		return 1;
	switch (sk->sk_family) {
	case AF_INET:
		return inet_sk(sk)->mc_loop;
#if IS_ENABLED(CONFIG_IPV6)
	case AF_INET6:
		return inet6_sk(sk)->mc_loop;
#endif
	}
	WARN_ON(1);
	return 1;
}

bool ip_call_ra_chain(struct sk_buff *skb);

/*
 *	Functions provided by ip_fragment.c
 */

enum ip_defrag_users {
	IP_DEFRAG_LOCAL_DELIVER,
	IP_DEFRAG_CALL_RA_CHAIN,
	IP_DEFRAG_CONNTRACK_IN,
	__IP_DEFRAG_CONNTRACK_IN_END	= IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
	IP_DEFRAG_CONNTRACK_OUT,
	__IP_DEFRAG_CONNTRACK_OUT_END	= IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
	IP_DEFRAG_VS_IN,
	IP_DEFRAG_VS_OUT,
	IP_DEFRAG_VS_FWD,
	IP_DEFRAG_AF_PACKET,
	IP_DEFRAG_MACVLAN,
};

int ip_defrag(struct sk_buff *skb, u32 user);
#ifdef CONFIG_INET
struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user);
#else
static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
{
	return skb;
}
#endif
int ip_frag_mem(struct net *net);

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

/*
 *	Functions provided by ip_sockglue.c
 */

void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
int ip_cmsg_send(struct net *net, struct msghdr *msg,
		 struct ipcm_cookie *ipc, bool allow_ipv6);
int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
		  unsigned int optlen);
int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
		  int __user *optlen);
int compat_ip_setsockopt(struct sock *sk, int level, int optname,
			 char __user *optval, unsigned int optlen);
int compat_ip_getsockopt(struct sock *sk, int level, int optname,
			 char __user *optval, int __user *optlen);
int ip_ra_control(struct sock *sk, unsigned char on,
		  void (*destructor)(struct sock *));

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

#ifdef CONFIG_PROC_FS
int ip_misc_proc_init(void);
#endif

#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, <[email protected]>
	12	* Alan Cox, <[email protected]>
	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>
aa661581	31	#include <net/route.h>
1da177e4	32	#include <net/snmp.h>
86b08d86	33	#include <net/flow.h>
b73c3d0e	34	#include <net/flow_keys.h>
1da177e4 LT	35
	36	struct sock;
	37
fd2c3ef7	38	struct inet_skb_parm {
1da177e4 LT	39	struct ip_options opt; /* Compiled IP options */
	40	unsigned char flags;
	41
8cdfab8a PM	42	#define IPSKB_FORWARDED 1
8cdfab8a PM	43	#define IPSKB_XFRM_TUNNEL_SIZE 2
3e3850e9 PM	44	#define IPSKB_XFRM_TRANSFORMED 4
3e3850e9 PM	45	#define IPSKB_FRAG_COMPLETE 8
48d5cad8	46	#define IPSKB_REROUTED 16
5f2d04f1 PM	47
5f2d04f1 PM	48	u16 frag_max_size;
1da177e4 LT	49	};
1da177e4 LT	50
c9bdd4b5 ACM	51	static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
c9bdd4b5 ACM	52	{
eddc9ec5	53	return ip_hdr(skb)->ihl * 4;
c9bdd4b5 ACM	54	}
c9bdd4b5 ACM	55
fd2c3ef7	56	struct ipcm_cookie {
c1d18f9f	57	__be32 addr;
1da177e4	58	int oif;
f6d8bd05	59	struct ip_options_rcu *opt;
2244d07b	60	__u8 tx_flags;
f02db315 FF	61	__u8 ttl;
	62	__s16 tos;
	63	char priority;
1da177e4 LT	64	};
	65
	66	#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
4b261c75	67	#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
1da177e4	68
fd2c3ef7	69	struct ip_ra_chain {
43a951e9	70	struct ip_ra_chain __rcu *next;
1da177e4	71	struct sock *sk;
592fcb9d ED	72	union {
	73	void (destructor)(struct sock );
	74	struct sock *saved_sk;
	75	};
66018506	76	struct rcu_head rcu;
1da177e4 LT	77	};
1da177e4 LT	78
43a951e9	79	extern struct ip_ra_chain __rcu *ip_ra_chain;
1da177e4 LT	80
	81	/* IP flags. */
	82	#define IP_CE 0x8000 /* Flag: "Congestion" */
	83	#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
	84	#define IP_MF 0x2000 /* Flag: "More Fragments" */
	85	#define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
	86
	87	#define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
	88
14c85021 ACM	89	struct msghdr;
	90	struct net_device;
	91	struct packet_type;
	92	struct rtable;
14c85021 ACM	93	struct sockaddr;
14c85021 ACM	94
72c1d3bd	95	int igmp_mc_init(void);
1da177e4 LT	96
	97	/*
	98	* Functions provided by ip.c
	99	*/
	100
5c3a0fd7 JP	101	int ip_build_and_send_pkt(struct sk_buff skb, struct sock sk,
	102	__be32 saddr, __be32 daddr,
	103	struct ip_options_rcu *opt);
	104	int ip_rcv(struct sk_buff skb, struct net_device dev, struct packet_type *pt,
	105	struct net_device *orig_dev);
	106	int ip_local_deliver(struct sk_buff *skb);
	107	int ip_mr_input(struct sk_buff *skb);
aad88724 ED	108	int ip_output(struct sock sk, struct sk_buff skb);
aad88724 ED	109	int ip_mc_output(struct sock sk, struct sk_buff skb);
5c3a0fd7 JP	110	int ip_fragment(struct sk_buff skb, int (output)(struct sk_buff *));
	111	int ip_do_nat(struct sk_buff *skb);
	112	void ip_send_check(struct iphdr *ip);
	113	int __ip_local_out(struct sk_buff *skb);
aad88724 ED	114	int ip_local_out_sk(struct sock sk, struct sk_buff skb);
	115	static inline int ip_local_out(struct sk_buff *skb)
	116	{
	117	return ip_local_out_sk(skb->sk, skb);
	118	}
	119
b0270e91	120	int ip_queue_xmit(struct sock sk, struct sk_buff skb, struct flowi *fl);
5c3a0fd7 JP	121	void ip_init(void);
	122	int ip_append_data(struct sock sk, struct flowi4 fl4,
	123	int getfrag(void from, char to, int offset, int len,
	124	int odd, struct sk_buff *skb),
	125	void *from, int len, int protolen,
	126	struct ipcm_cookie *ipc,
	127	struct rtable **rt,
	128	unsigned int flags);
	129	int ip_generic_getfrag(void from, char to, int offset, int len, int odd,
	130	struct sk_buff *skb);
	131	ssize_t ip_append_page(struct sock sk, struct flowi4 fl4, struct page *page,
	132	int offset, size_t size, int flags);
	133	struct sk_buff __ip_make_skb(struct sock sk, struct flowi4 *fl4,
	134	struct sk_buff_head *queue,
	135	struct inet_cork *cork);
	136	int ip_send_skb(struct net net, struct sk_buff skb);
	137	int ip_push_pending_frames(struct sock sk, struct flowi4 fl4);
	138	void ip_flush_pending_frames(struct sock *sk);
	139	struct sk_buff ip_make_skb(struct sock sk, struct flowi4 *fl4,
	140	int getfrag(void from, char to, int offset,
	141	int len, int odd, struct sk_buff *skb),
	142	void *from, int length, int transhdrlen,
	143	struct ipcm_cookie ipc, struct rtable *rtp,
	144	unsigned int flags);
1c32c5ad	145
77968b78	146	static inline struct sk_buff ip_finish_skb(struct sock sk, struct flowi4 *fl4)
1c32c5ad	147	{
77968b78	148	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
1c32c5ad	149	}
1da177e4	150
aa661581 FF	151	static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
	152	{
	153	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
	154	}
	155
	156	static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
	157	{
	158	return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
	159	}
	160
1da177e4	161	/* datagram.c */
5c3a0fd7	162	int ip4_datagram_connect(struct sock sk, struct sockaddr uaddr, int addr_len);
1da177e4	163
5c3a0fd7	164	void ip4_datagram_release_cb(struct sock *sk);
8141ed9f	165
1da177e4 LT	166	struct ip_reply_arg {
1da177e4 LT	167	struct kvec iov[1];
88ef4a5a	168	int flags;
d6f5493c	169	__wsum csum;
1da177e4 LT	170	int csumoffset; /* u16 offset of csum in iov[0].iov_base */
1da177e4 LT	171	/* -1 if not needed */
f0e48dbf	172	int bound_dev_if;
66b13d99	173	u8 tos;
1da177e4 LT	174	};
1da177e4 LT	175
88ef4a5a KK	176	#define IP_REPLY_ARG_NOSRCCHECK 1
88ef4a5a KK	177
86b08d86 KK	178	static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
	179	{
	180	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
	181	}
	182
be9f4a44	183	void ip_send_unicast_reply(struct net net, struct sk_buff skb, __be32 daddr,
70e73416 DM	184	__be32 saddr, const struct ip_reply_arg *arg,
70e73416 DM	185	unsigned int len);
1da177e4	186
4ce3c183 ED	187	#define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
	188	#define IP_INC_STATS_BH(net, field) SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
	189	#define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
	190	#define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
	191	#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
	192	#define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
61a7e260 PE	193	#define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
	194	#define NET_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
	195	#define NET_INC_STATS_USER(net, field) SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
f7324acd	196	#define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
61a7e260 PE	197	#define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
61a7e260 PE	198	#define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
1da177e4	199
698365fa	200	unsigned long snmp_fold_field(void __percpu *mib, int offt);
4ce3c183	201	#if BITS_PER_LONG==32
698365fa	202	u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
4ce3c183	203	#else
698365fa	204	static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
4ce3c183 ED	205	{
	206	return snmp_fold_field(mib, offt);
	207	}
	208	#endif
33490170	209
0bbf87d8	210	void inet_get_local_port_range(struct net net, int low, int *high);
227b60f5	211
fcd77db0	212	#ifdef CONFIG_SYSCTL
122ff243	213	static inline int inet_is_local_reserved_port(struct net *net, int port)
e3826f1e	214	{
122ff243 WC	215	if (!net->ipv4.sysctl_local_reserved_ports)
	216	return 0;
	217	return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
e3826f1e	218	}
20e61da7 WC	219
	220	static inline bool sysctl_dev_name_is_allowed(const char *name)
	221	{
	222	return strcmp(name, "default") != 0 && strcmp(name, "all") != 0;
	223	}
	224
122ff243 WC	225	#else
	226	static inline int inet_is_local_reserved_port(struct net *net, int port)
	227	{
	228	return 0;
	229	}
	230	#endif
e3826f1e	231
20380731 ACM	232	/* From inetpeer.c */
	233	extern int inet_peer_threshold;
	234	extern int inet_peer_minttl;
	235	extern int inet_peer_maxttl;
20380731	236
6648bd7e AD	237	/* From ip_input.c */
	238	extern int sysctl_ip_early_demux;
	239
20380731 ACM	240	/* From ip_output.c */
	241	extern int sysctl_ip_dynaddr;
	242
5c3a0fd7	243	void ipfrag_init(void);
20380731	244
5c3a0fd7	245	void ip_static_sysctl_init(void);
bd7b1533	246
e110861f LC	247	#define IP4_REPLY_MARK(net, mark) \
	248	((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
	249
d18cd551 DM	250	static inline bool ip_is_fragment(const struct iphdr *iph)
	251	{
	252	return (iph->frag_off & htons(IP_MF \| IP_OFFSET)) != 0;
	253	}
	254
1da177e4	255	#ifdef CONFIG_INET
14c85021 ACM	256	#include <net/dst.h>
14c85021 ACM	257
1da177e4 LT	258	/* The function in 2.2 was invalid, producing wrong result for
	259	* check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
	260	static inline
	261	int ip_decrease_ttl(struct iphdr *iph)
	262	{
5c78f275 AV	263	u32 check = (__force u32)iph->check;
	264	check += (__force u32)htons(0x0100);
	265	iph->check = (__force __sum16)(check + (check>=0xFFFF));
1da177e4 LT	266	return --iph->ttl;
	267	}
	268
	269	static inline
	270	int ip_dont_fragment(struct sock sk, struct dst_entry dst)
	271	{
a02cec21	272	return inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO \|\|
1da177e4	273	(inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
a02cec21	274	!(dst_metric_locked(dst, RTAX_MTU)));
1da177e4 LT	275	}
1da177e4 LT	276
f87c10a8 HFS	277	static inline bool ip_sk_accept_pmtu(const struct sock *sk)
f87c10a8 HFS	278	{
1b346576 HFS	279	return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
1b346576 HFS	280	inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
f87c10a8 HFS	281	}
	282
	283	static inline bool ip_sk_use_pmtu(const struct sock *sk)
	284	{
	285	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
	286	}
	287
60ff7467	288	static inline bool ip_sk_ignore_df(const struct sock *sk)
1b346576 HFS	289	{
	290	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO \|\|
	291	inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
	292	}
	293
f87c10a8 HFS	294	static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
	295	bool forwarding)
	296	{
	297	struct net *net = dev_net(dst->dev);
	298
	299	if (net->ipv4.sysctl_ip_fwd_use_pmtu \|\|
	300	dst_metric_locked(dst, RTAX_MTU) \|\|
	301	!forwarding)
	302	return dst_mtu(dst);
	303
	304	return min(dst->dev->mtu, IP_MAX_MTU);
	305	}
	306
	307	static inline unsigned int ip_skb_dst_mtu(const struct sk_buff *skb)
	308	{
	309	if (!skb->sk \|\| ip_sk_use_pmtu(skb->sk)) {
	310	bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
	311	return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
	312	} else {
	313	return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
	314	}
	315	}
	316
04ca6973	317	u32 ip_idents_reserve(u32 hash, int segs);
73f156a6 ED	318	void __ip_select_ident(struct iphdr *iph, int segs);
	319
	320	static inline void ip_select_ident_segs(struct sk_buff skb, struct sock sk, int segs)
1da177e4	321	{
703133de AA	322	struct iphdr *iph = ip_hdr(skb);
703133de AA	323
60ff7467	324	if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
1da177e4 LT	325	/* This is only to work around buggy Windows95/2000
	326	* VJ compression implementations. If the ID field
	327	* does not change, they drop every other packet in
	328	* a TCP stream using header compression.
	329	*/
c720c7e8 ED	330	if (sk && inet_sk(sk)->inet_daddr) {
c720c7e8 ED	331	iph->id = htons(inet_sk(sk)->inet_id);
73f156a6 ED	332	inet_sk(sk)->inet_id += segs;
73f156a6 ED	333	} else {
1da177e4	334	iph->id = 0;
73f156a6 ED	335	}
	336	} else {
	337	__ip_select_ident(iph, segs);
	338	}
	339	}
	340
	341	static inline void ip_select_ident(struct sk_buff skb, struct sock sk)
	342	{
	343	ip_select_ident_segs(skb, sk, 1);
1da177e4 LT	344	}
1da177e4 LT	345
ed70fcfc TH	346	static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
	347	{
	348	return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
	349	skb->len, proto, 0);
	350	}
	351
b73c3d0e TH	352	static inline void inet_set_txhash(struct sock *sk)
	353	{
	354	struct inet_sock *inet = inet_sk(sk);
	355	struct flow_keys keys;
	356
	357	keys.src = inet->inet_saddr;
	358	keys.dst = inet->inet_daddr;
	359	keys.port16[0] = inet->inet_sport;
	360	keys.port16[1] = inet->inet_dport;
	361
	362	sk->sk_txhash = flow_hash_from_keys(&keys);
	363	}
	364
1933a785 TH	365	static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
	366	{
	367	const struct iphdr *iph = skb_gro_network_header(skb);
	368
	369	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
	370	skb_gro_len(skb), proto, 0);
	371	}
	372
1da177e4 LT	373	/*
	374	* Map a multicast IP onto multicast MAC for type ethernet.
	375	*/
	376
714e85be	377	static inline void ip_eth_mc_map(__be32 naddr, char *buf)
1da177e4	378	{
714e85be	379	__u32 addr=ntohl(naddr);
1da177e4 LT	380	buf[0]=0x01;
	381	buf[1]=0x00;
	382	buf[2]=0x5e;
	383	buf[5]=addr&0xFF;
	384	addr>>=8;
	385	buf[4]=addr&0xFF;
	386	addr>>=8;
	387	buf[3]=addr&0x7F;
	388	}
	389
	390	/*
	391	* Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
	392	* Leave P_Key as 0 to be filled in by driver.
	393	*/
	394
a9e527e3	395	static inline void ip_ib_mc_map(__be32 naddr, const unsigned char broadcast, char buf)
1da177e4	396	{
714e85be	397	__u32 addr;
a9e527e3 RM	398	unsigned char scope = broadcast[5] & 0xF;
a9e527e3 RM	399
1da177e4 LT	400	buf[0] = 0; /* Reserved */
	401	buf[1] = 0xff; /* Multicast QPN */
	402	buf[2] = 0xff;
	403	buf[3] = 0xff;
714e85be	404	addr = ntohl(naddr);
1da177e4	405	buf[4] = 0xff;
a9e527e3	406	buf[5] = 0x10 \| scope; /* scope from broadcast address */
1da177e4 LT	407	buf[6] = 0x40; /* IPv4 signature */
1da177e4 LT	408	buf[7] = 0x1b;
a9e527e3 RM	409	buf[8] = broadcast[8]; /* P_Key */
a9e527e3 RM	410	buf[9] = broadcast[9];
1da177e4 LT	411	buf[10] = 0;
	412	buf[11] = 0;
	413	buf[12] = 0;
	414	buf[13] = 0;
	415	buf[14] = 0;
	416	buf[15] = 0;
	417	buf[19] = addr & 0xff;
	418	addr >>= 8;
	419	buf[18] = addr & 0xff;
	420	addr >>= 8;
	421	buf[17] = addr & 0xff;
	422	addr >>= 8;
	423	buf[16] = addr & 0x0f;
	424	}
	425
93ca3bb5 TT	426	static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char broadcast, char buf)
	427	{
	428	if ((broadcast[0] \| broadcast[1] \| broadcast[2] \| broadcast[3]) != 0)
	429	memcpy(buf, broadcast, 4);
	430	else
	431	memcpy(buf, &naddr, sizeof(naddr));
	432	}
	433
dfd56b8b	434	#if IS_ENABLED(CONFIG_IPV6)
1da177e4 LT	435	#include <linux/ipv6.h>
	436	#endif
	437
	438	static __inline__ void inet_reset_saddr(struct sock *sk)
	439	{
c720c7e8	440	inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
dfd56b8b	441	#if IS_ENABLED(CONFIG_IPV6)
1da177e4 LT	442	if (sk->sk_family == PF_INET6) {
	443	struct ipv6_pinfo *np = inet6_sk(sk);
	444
	445	memset(&np->saddr, 0, sizeof(np->saddr));
efe4208f	446	memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
1da177e4 LT	447	}
	448	#endif
	449	}
	450
	451	#endif
	452
7ad6848c OP	453	static inline int sk_mc_loop(struct sock *sk)
	454	{
	455	if (!sk)
	456	return 1;
	457	switch (sk->sk_family) {
	458	case AF_INET:
	459	return inet_sk(sk)->mc_loop;
dfd56b8b	460	#if IS_ENABLED(CONFIG_IPV6)
7ad6848c OP	461	case AF_INET6:
	462	return inet6_sk(sk)->mc_loop;
	463	#endif
	464	}
cd65c3c7	465	WARN_ON(1);
7ad6848c OP	466	return 1;
	467	}
	468
5c3a0fd7	469	bool ip_call_ra_chain(struct sk_buff *skb);
1da177e4 LT	470
1da177e4 LT	471	/*
b798232f	472	* Functions provided by ip_fragment.c
1da177e4 LT	473	*/
1da177e4 LT	474
fd2c3ef7	475	enum ip_defrag_users {
1da177e4 LT	476	IP_DEFRAG_LOCAL_DELIVER,
	477	IP_DEFRAG_CALL_RA_CHAIN,
	478	IP_DEFRAG_CONNTRACK_IN,
4be929be	479	__IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
1da177e4	480	IP_DEFRAG_CONNTRACK_OUT,
4be929be	481	__IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
8fa9ff68	482	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
4be929be	483	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
1da177e4 LT	484	IP_DEFRAG_VS_IN,
1da177e4 LT	485	IP_DEFRAG_VS_OUT,
595fc71b DM	486	IP_DEFRAG_VS_FWD,
595fc71b DM	487	IP_DEFRAG_AF_PACKET,
bc416d97	488	IP_DEFRAG_MACVLAN,
1da177e4 LT	489	};
1da177e4 LT	490
776c729e	491	int ip_defrag(struct sk_buff *skb, u32 user);
bc416d97 ED	492	#ifdef CONFIG_INET
	493	struct sk_buff ip_check_defrag(struct sk_buff skb, u32 user);
	494	#else
	495	static inline struct sk_buff ip_check_defrag(struct sk_buff skb, u32 user)
	496	{
	497	return skb;
	498	}
	499	#endif
6ddc0822	500	int ip_frag_mem(struct net *net);
1da177e4 LT	501
	502	/*
	503	* Functions provided by ip_forward.c
	504	*/
	505
5c3a0fd7	506	int ip_forward(struct sk_buff *skb);
1da177e4 LT	507
	508	/*
	509	* Functions provided by ip_options.c
	510	*/
	511
5c3a0fd7 JP	512	void ip_options_build(struct sk_buff skb, struct ip_options opt,
	513	__be32 daddr, struct rtable *rt, int is_frag);
	514	int ip_options_echo(struct ip_options dopt, struct sk_buff skb);
	515	void ip_options_fragment(struct sk_buff *skb);
	516	int ip_options_compile(struct net net, struct ip_options opt,
	517	struct sk_buff *skb);
	518	int ip_options_get(struct net net, struct ip_options_rcu *optp,
	519	unsigned char *data, int optlen);
	520	int ip_options_get_from_user(struct net net, struct ip_options_rcu *optp,
	521	unsigned char __user *data, int optlen);
	522	void ip_options_undo(struct ip_options *opt);
	523	void ip_forward_options(struct sk_buff *skb);
	524	int ip_options_rcv_srr(struct sk_buff *skb);
1da177e4 LT	525
	526	/*
	527	* Functions provided by ip_sockglue.c
	528	*/
	529
fbf8866d	530	void ipv4_pktinfo_prepare(const struct sock sk, struct sk_buff skb);
5c3a0fd7	531	void ip_cmsg_recv(struct msghdr msg, struct sk_buff skb);
c8e6ad08 HFS	532	int ip_cmsg_send(struct net net, struct msghdr msg,
c8e6ad08 HFS	533	struct ipcm_cookie *ipc, bool allow_ipv6);
5c3a0fd7 JP	534	int ip_setsockopt(struct sock sk, int level, int optname, char __user optval,
	535	unsigned int optlen);
	536	int ip_getsockopt(struct sock sk, int level, int optname, char __user optval,
	537	int __user *optlen);
	538	int compat_ip_setsockopt(struct sock *sk, int level, int optname,
	539	char __user *optval, unsigned int optlen);
	540	int compat_ip_getsockopt(struct sock *sk, int level, int optname,
	541	char __user optval, int __user optlen);
	542	int ip_ra_control(struct sock *sk, unsigned char on,
	543	void (destructor)(struct sock ));
	544
85fbaa75	545	int ip_recv_error(struct sock sk, struct msghdr msg, int len, int *addr_len);
5c3a0fd7 JP	546	void ip_icmp_error(struct sock sk, struct sk_buff skb, int err, __be16 port,
	547	u32 info, u8 *payload);
	548	void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
	549	u32 info);
1da177e4	550
20380731	551	#ifdef CONFIG_PROC_FS
5c3a0fd7	552	int ip_misc_proc_init(void);
20380731 ACM	553	#endif
20380731 ACM	554
1da177e4	555	#endif /* _IP_H */