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v3.15
  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 *
 10 * Authors:	Ross Biro
 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
 25#include <linux/types.h>
 26#include <linux/ip.h>
 27#include <linux/in.h>
 28#include <linux/skbuff.h>
 29
 30#include <net/inet_sock.h>
 31#include <net/route.h>
 32#include <net/snmp.h>
 33#include <net/flow.h>
 34
 35struct sock;
 36
 37struct inet_skb_parm {
 38	struct ip_options	opt;		/* Compiled IP options		*/
 39	unsigned char		flags;
 40
 41#define IPSKB_FORWARDED		1
 42#define IPSKB_XFRM_TUNNEL_SIZE	2
 43#define IPSKB_XFRM_TRANSFORMED	4
 44#define IPSKB_FRAG_COMPLETE	8
 45#define IPSKB_REROUTED		16
 46
 47	u16			frag_max_size;
 48};
 49
 50static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
 51{
 52	return ip_hdr(skb)->ihl * 4;
 53}
 54
 55struct ipcm_cookie {
 56	__be32			addr;
 57	int			oif;
 58	struct ip_options_rcu	*opt;
 59	__u8			tx_flags;
 60	__u8			ttl;
 61	__s16			tos;
 62	char			priority;
 63};
 64
 65#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
 66#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
 67
 68struct ip_ra_chain {
 69	struct ip_ra_chain __rcu *next;
 70	struct sock		*sk;
 71	union {
 72		void			(*destructor)(struct sock *);
 73		struct sock		*saved_sk;
 74	};
 75	struct rcu_head		rcu;
 76};
 77
 78extern struct ip_ra_chain __rcu *ip_ra_chain;
 79
 80/* IP flags. */
 81#define IP_CE		0x8000		/* Flag: "Congestion"		*/
 82#define IP_DF		0x4000		/* Flag: "Don't Fragment"	*/
 83#define IP_MF		0x2000		/* Flag: "More Fragments"	*/
 84#define IP_OFFSET	0x1FFF		/* "Fragment Offset" part	*/
 85
 86#define IP_FRAG_TIME	(30 * HZ)		/* fragment lifetime	*/
 87
 88struct msghdr;
 89struct net_device;
 90struct packet_type;
 91struct rtable;
 92struct sockaddr;
 93
 94int igmp_mc_init(void);
 95
 96/*
 97 *	Functions provided by ip.c
 98 */
 99
100int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
101			  __be32 saddr, __be32 daddr,
102			  struct ip_options_rcu *opt);
103int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
104	   struct net_device *orig_dev);
105int ip_local_deliver(struct sk_buff *skb);
106int ip_mr_input(struct sk_buff *skb);
107int ip_output(struct sock *sk, struct sk_buff *skb);
108int ip_mc_output(struct sock *sk, struct sk_buff *skb);
109int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
110int ip_do_nat(struct sk_buff *skb);
111void ip_send_check(struct iphdr *ip);
112int __ip_local_out(struct sk_buff *skb);
113int ip_local_out_sk(struct sock *sk, struct sk_buff *skb);
114static inline int ip_local_out(struct sk_buff *skb)
115{
116	return ip_local_out_sk(skb->sk, skb);
117}
118
119int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
120void ip_init(void);
121int ip_append_data(struct sock *sk, struct flowi4 *fl4,
122		   int getfrag(void *from, char *to, int offset, int len,
123			       int odd, struct sk_buff *skb),
124		   void *from, int len, int protolen,
125		   struct ipcm_cookie *ipc,
126		   struct rtable **rt,
127		   unsigned int flags);
128int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
129		       struct sk_buff *skb);
130ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
131		       int offset, size_t size, int flags);
132struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
133			      struct sk_buff_head *queue,
134			      struct inet_cork *cork);
135int ip_send_skb(struct net *net, struct sk_buff *skb);
136int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
137void ip_flush_pending_frames(struct sock *sk);
138struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
139			    int getfrag(void *from, char *to, int offset,
140					int len, int odd, struct sk_buff *skb),
141			    void *from, int length, int transhdrlen,
142			    struct ipcm_cookie *ipc, struct rtable **rtp,
143			    unsigned int flags);
144
145static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
146{
147	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
148}
149
150static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
151{
152	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
153}
154
155static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
156{
157	return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
158}
159
160/* datagram.c */
161int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
162
163void ip4_datagram_release_cb(struct sock *sk);
164
165struct ip_reply_arg {
166	struct kvec iov[1];   
167	int	    flags;
168	__wsum 	    csum;
169	int	    csumoffset; /* u16 offset of csum in iov[0].iov_base */
170				/* -1 if not needed */ 
171	int	    bound_dev_if;
172	u8  	    tos;
173}; 
174
175#define IP_REPLY_ARG_NOSRCCHECK 1
176
177static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
178{
179	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
180}
181
182void ip_send_unicast_reply(struct net *net, struct sk_buff *skb, __be32 daddr,
183			   __be32 saddr, const struct ip_reply_arg *arg,
184			   unsigned int len);
 
 
 
 
185
 
186#define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
187#define IP_INC_STATS_BH(net, field)	SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
188#define IP_ADD_STATS(net, field, val)	SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
189#define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
190#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
191#define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
192#define NET_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.net_statistics, field)
193#define NET_INC_STATS_BH(net, field)	SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
194#define NET_INC_STATS_USER(net, field) 	SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
195#define NET_ADD_STATS(net, field, adnd)	SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
196#define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
197#define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
198
199unsigned long snmp_fold_field(void __percpu *mib[], int offt);
200#if BITS_PER_LONG==32
201u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off);
202#else
203static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off)
204{
205	return snmp_fold_field(mib, offt);
206}
207#endif
208int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align);
209
210static inline void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ])
211{
212	int i;
213
214	BUG_ON(ptr == NULL);
215	for (i = 0; i < SNMP_ARRAY_SZ; i++) {
216		free_percpu(ptr[i]);
217		ptr[i] = NULL;
218	}
219}
220
221void inet_get_local_port_range(struct net *net, int *low, int *high);
222
223extern unsigned long *sysctl_local_reserved_ports;
224static inline int inet_is_reserved_local_port(int port)
225{
226	return test_bit(port, sysctl_local_reserved_ports);
227}
228
229extern int sysctl_ip_nonlocal_bind;
230
231/* From inetpeer.c */
232extern int inet_peer_threshold;
233extern int inet_peer_minttl;
234extern int inet_peer_maxttl;
235
236/* From ip_input.c */
237extern int sysctl_ip_early_demux;
238
239/* From ip_output.c */
240extern int sysctl_ip_dynaddr;
241
242void ipfrag_init(void);
243
244void ip_static_sysctl_init(void);
245
246static inline bool ip_is_fragment(const struct iphdr *iph)
247{
248	return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
249}
250
251#ifdef CONFIG_INET
252#include <net/dst.h>
253
254/* The function in 2.2 was invalid, producing wrong result for
255 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
256static inline
257int ip_decrease_ttl(struct iphdr *iph)
258{
259	u32 check = (__force u32)iph->check;
260	check += (__force u32)htons(0x0100);
261	iph->check = (__force __sum16)(check + (check>=0xFFFF));
262	return --iph->ttl;
263}
264
265static inline
266int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
267{
268	return  inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
269		(inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
270		 !(dst_metric_locked(dst, RTAX_MTU)));
271}
272
273static inline bool ip_sk_accept_pmtu(const struct sock *sk)
274{
275	return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
276	       inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
277}
278
279static inline bool ip_sk_use_pmtu(const struct sock *sk)
280{
281	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
282}
283
284static inline bool ip_sk_local_df(const struct sock *sk)
285{
286	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
287	       inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
288}
289
290static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
291						    bool forwarding)
292{
293	struct net *net = dev_net(dst->dev);
294
295	if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
296	    dst_metric_locked(dst, RTAX_MTU) ||
297	    !forwarding)
298		return dst_mtu(dst);
299
300	return min(dst->dev->mtu, IP_MAX_MTU);
301}
302
303static inline unsigned int ip_skb_dst_mtu(const struct sk_buff *skb)
304{
305	if (!skb->sk || ip_sk_use_pmtu(skb->sk)) {
306		bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
307		return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
308	} else {
309		return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
310	}
311}
312
313void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
314
315static inline void ip_select_ident(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk)
316{
317	struct iphdr *iph = ip_hdr(skb);
318
319	if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) {
320		/* This is only to work around buggy Windows95/2000
321		 * VJ compression implementations.  If the ID field
322		 * does not change, they drop every other packet in
323		 * a TCP stream using header compression.
324		 */
325		iph->id = (sk && inet_sk(sk)->inet_daddr) ?
326					htons(inet_sk(sk)->inet_id++) : 0;
327	} else
328		__ip_select_ident(iph, dst, 0);
329}
330
331static inline void ip_select_ident_more(struct sk_buff *skb, struct dst_entry *dst, struct sock *sk, int more)
332{
333	struct iphdr *iph = ip_hdr(skb);
334
335	if ((iph->frag_off & htons(IP_DF)) && !skb->local_df) {
336		if (sk && inet_sk(sk)->inet_daddr) {
337			iph->id = htons(inet_sk(sk)->inet_id);
338			inet_sk(sk)->inet_id += 1 + more;
339		} else
340			iph->id = 0;
341	} else
342		__ip_select_ident(iph, dst, more);
343}
344
345/*
346 *	Map a multicast IP onto multicast MAC for type ethernet.
347 */
348
349static inline void ip_eth_mc_map(__be32 naddr, char *buf)
350{
351	__u32 addr=ntohl(naddr);
352	buf[0]=0x01;
353	buf[1]=0x00;
354	buf[2]=0x5e;
355	buf[5]=addr&0xFF;
356	addr>>=8;
357	buf[4]=addr&0xFF;
358	addr>>=8;
359	buf[3]=addr&0x7F;
360}
361
362/*
363 *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
364 *	Leave P_Key as 0 to be filled in by driver.
365 */
366
367static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
368{
369	__u32 addr;
370	unsigned char scope = broadcast[5] & 0xF;
371
372	buf[0]  = 0;		/* Reserved */
373	buf[1]  = 0xff;		/* Multicast QPN */
374	buf[2]  = 0xff;
375	buf[3]  = 0xff;
376	addr    = ntohl(naddr);
377	buf[4]  = 0xff;
378	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
379	buf[6]  = 0x40;		/* IPv4 signature */
380	buf[7]  = 0x1b;
381	buf[8]  = broadcast[8];		/* P_Key */
382	buf[9]  = broadcast[9];
383	buf[10] = 0;
384	buf[11] = 0;
385	buf[12] = 0;
386	buf[13] = 0;
387	buf[14] = 0;
388	buf[15] = 0;
389	buf[19] = addr & 0xff;
390	addr  >>= 8;
391	buf[18] = addr & 0xff;
392	addr  >>= 8;
393	buf[17] = addr & 0xff;
394	addr  >>= 8;
395	buf[16] = addr & 0x0f;
396}
397
398static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
399{
400	if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
401		memcpy(buf, broadcast, 4);
402	else
403		memcpy(buf, &naddr, sizeof(naddr));
404}
405
406#if IS_ENABLED(CONFIG_IPV6)
407#include <linux/ipv6.h>
408#endif
409
410static __inline__ void inet_reset_saddr(struct sock *sk)
411{
412	inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
413#if IS_ENABLED(CONFIG_IPV6)
414	if (sk->sk_family == PF_INET6) {
415		struct ipv6_pinfo *np = inet6_sk(sk);
416
417		memset(&np->saddr, 0, sizeof(np->saddr));
418		memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
419	}
420#endif
421}
422
423#endif
424
425static inline int sk_mc_loop(struct sock *sk)
426{
427	if (!sk)
428		return 1;
429	switch (sk->sk_family) {
430	case AF_INET:
431		return inet_sk(sk)->mc_loop;
432#if IS_ENABLED(CONFIG_IPV6)
433	case AF_INET6:
434		return inet6_sk(sk)->mc_loop;
435#endif
436	}
437	WARN_ON(1);
438	return 1;
439}
440
441bool ip_call_ra_chain(struct sk_buff *skb);
442
443/*
444 *	Functions provided by ip_fragment.c
445 */
446
447enum ip_defrag_users {
448	IP_DEFRAG_LOCAL_DELIVER,
449	IP_DEFRAG_CALL_RA_CHAIN,
450	IP_DEFRAG_CONNTRACK_IN,
451	__IP_DEFRAG_CONNTRACK_IN_END	= IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
452	IP_DEFRAG_CONNTRACK_OUT,
453	__IP_DEFRAG_CONNTRACK_OUT_END	= IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
454	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
455	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
456	IP_DEFRAG_VS_IN,
457	IP_DEFRAG_VS_OUT,
458	IP_DEFRAG_VS_FWD,
459	IP_DEFRAG_AF_PACKET,
460	IP_DEFRAG_MACVLAN,
461};
462
463int ip_defrag(struct sk_buff *skb, u32 user);
464#ifdef CONFIG_INET
465struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user);
466#else
467static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
468{
469	return skb;
470}
471#endif
472int ip_frag_mem(struct net *net);
473int ip_frag_nqueues(struct net *net);
474
475/*
476 *	Functions provided by ip_forward.c
477 */
478 
479int ip_forward(struct sk_buff *skb);
480 
481/*
482 *	Functions provided by ip_options.c
483 */
484 
485void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
486		      __be32 daddr, struct rtable *rt, int is_frag);
487int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
488void ip_options_fragment(struct sk_buff *skb);
489int ip_options_compile(struct net *net, struct ip_options *opt,
490		       struct sk_buff *skb);
491int ip_options_get(struct net *net, struct ip_options_rcu **optp,
492		   unsigned char *data, int optlen);
493int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
494			     unsigned char __user *data, int optlen);
495void ip_options_undo(struct ip_options *opt);
496void ip_forward_options(struct sk_buff *skb);
497int ip_options_rcv_srr(struct sk_buff *skb);
498
499/*
500 *	Functions provided by ip_sockglue.c
501 */
502
503void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
504void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
505int ip_cmsg_send(struct net *net, struct msghdr *msg,
506		 struct ipcm_cookie *ipc, bool allow_ipv6);
507int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
508		  unsigned int optlen);
509int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
510		  int __user *optlen);
511int compat_ip_setsockopt(struct sock *sk, int level, int optname,
512			 char __user *optval, unsigned int optlen);
513int compat_ip_getsockopt(struct sock *sk, int level, int optname,
514			 char __user *optval, int __user *optlen);
515int ip_ra_control(struct sock *sk, unsigned char on,
516		  void (*destructor)(struct sock *));
517
518int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
519void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
520		   u32 info, u8 *payload);
521void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
522		    u32 info);
523
524#ifdef CONFIG_PROC_FS
525int ip_misc_proc_init(void);
526#endif
527
528#endif	/* _IP_H */
v3.5.6
  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 *
 10 * Authors:	Ross Biro
 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
 25#include <linux/types.h>
 26#include <linux/ip.h>
 27#include <linux/in.h>
 28#include <linux/skbuff.h>
 29
 30#include <net/inet_sock.h>
 
 31#include <net/snmp.h>
 32#include <net/flow.h>
 33
 34struct sock;
 35
 36struct inet_skb_parm {
 37	struct ip_options	opt;		/* Compiled IP options		*/
 38	unsigned char		flags;
 39
 40#define IPSKB_FORWARDED		1
 41#define IPSKB_XFRM_TUNNEL_SIZE	2
 42#define IPSKB_XFRM_TRANSFORMED	4
 43#define IPSKB_FRAG_COMPLETE	8
 44#define IPSKB_REROUTED		16
 
 
 45};
 46
 47static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
 48{
 49	return ip_hdr(skb)->ihl * 4;
 50}
 51
 52struct ipcm_cookie {
 53	__be32			addr;
 54	int			oif;
 55	struct ip_options_rcu	*opt;
 56	__u8			tx_flags;
 
 
 
 57};
 58
 59#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
 
 60
 61struct ip_ra_chain {
 62	struct ip_ra_chain __rcu *next;
 63	struct sock		*sk;
 64	union {
 65		void			(*destructor)(struct sock *);
 66		struct sock		*saved_sk;
 67	};
 68	struct rcu_head		rcu;
 69};
 70
 71extern struct ip_ra_chain __rcu *ip_ra_chain;
 72
 73/* IP flags. */
 74#define IP_CE		0x8000		/* Flag: "Congestion"		*/
 75#define IP_DF		0x4000		/* Flag: "Don't Fragment"	*/
 76#define IP_MF		0x2000		/* Flag: "More Fragments"	*/
 77#define IP_OFFSET	0x1FFF		/* "Fragment Offset" part	*/
 78
 79#define IP_FRAG_TIME	(30 * HZ)		/* fragment lifetime	*/
 80
 81struct msghdr;
 82struct net_device;
 83struct packet_type;
 84struct rtable;
 85struct sockaddr;
 86
 87extern int		igmp_mc_proc_init(void);
 88
 89/*
 90 *	Functions provided by ip.c
 91 */
 92
 93extern int		ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
 94					      __be32 saddr, __be32 daddr,
 95					      struct ip_options_rcu *opt);
 96extern int		ip_rcv(struct sk_buff *skb, struct net_device *dev,
 97			       struct packet_type *pt, struct net_device *orig_dev);
 98extern int		ip_local_deliver(struct sk_buff *skb);
 99extern int		ip_mr_input(struct sk_buff *skb);
100extern int		ip_output(struct sk_buff *skb);
101extern int		ip_mc_output(struct sk_buff *skb);
102extern int		ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
103extern int		ip_do_nat(struct sk_buff *skb);
104extern void		ip_send_check(struct iphdr *ip);
105extern int		__ip_local_out(struct sk_buff *skb);
106extern int		ip_local_out(struct sk_buff *skb);
107extern int		ip_queue_xmit(struct sk_buff *skb, struct flowi *fl);
108extern void		ip_init(void);
109extern int		ip_append_data(struct sock *sk, struct flowi4 *fl4,
110				       int getfrag(void *from, char *to, int offset, int len,
111						   int odd, struct sk_buff *skb),
112				void *from, int len, int protolen,
113				struct ipcm_cookie *ipc,
114				struct rtable **rt,
115				unsigned int flags);
116extern int		ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb);
117extern ssize_t		ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
118				int offset, size_t size, int flags);
119extern struct sk_buff  *__ip_make_skb(struct sock *sk,
120				      struct flowi4 *fl4,
121				      struct sk_buff_head *queue,
122				      struct inet_cork *cork);
123extern int		ip_send_skb(struct sk_buff *skb);
124extern int		ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
125extern void		ip_flush_pending_frames(struct sock *sk);
126extern struct sk_buff  *ip_make_skb(struct sock *sk,
127				    struct flowi4 *fl4,
128				    int getfrag(void *from, char *to, int offset, int len,
129						int odd, struct sk_buff *skb),
130				    void *from, int length, int transhdrlen,
131				    struct ipcm_cookie *ipc,
132				    struct rtable **rtp,
133				    unsigned int flags);
 
 
 
134
135static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
136{
137	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
138}
139
 
 
 
 
 
 
 
 
 
 
140/* datagram.c */
141extern int		ip4_datagram_connect(struct sock *sk, 
142					     struct sockaddr *uaddr, int addr_len);
 
143
144struct ip_reply_arg {
145	struct kvec iov[1];   
146	int	    flags;
147	__wsum 	    csum;
148	int	    csumoffset; /* u16 offset of csum in iov[0].iov_base */
149				/* -1 if not needed */ 
150	int	    bound_dev_if;
151	u8  	    tos;
152}; 
153
154#define IP_REPLY_ARG_NOSRCCHECK 1
155
156static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
157{
158	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
159}
160
161void ip_send_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr,
162		   const struct ip_reply_arg *arg, unsigned int len);
163
164struct ipv4_config {
165	int	log_martians;
166	int	no_pmtu_disc;
167};
168
169extern struct ipv4_config ipv4_config;
170#define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
171#define IP_INC_STATS_BH(net, field)	SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
172#define IP_ADD_STATS(net, field, val)	SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
173#define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
174#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
175#define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
176#define NET_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.net_statistics, field)
177#define NET_INC_STATS_BH(net, field)	SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
178#define NET_INC_STATS_USER(net, field) 	SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
 
179#define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
180#define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
181
182extern unsigned long snmp_fold_field(void __percpu *mib[], int offt);
183#if BITS_PER_LONG==32
184extern u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t sync_off);
185#else
186static inline u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_off)
187{
188	return snmp_fold_field(mib, offt);
189}
190#endif
191extern int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align);
192extern void snmp_mib_free(void __percpu *ptr[2]);
 
 
 
193
194extern struct local_ports {
195	seqlock_t	lock;
196	int		range[2];
197} sysctl_local_ports;
198extern void inet_get_local_port_range(int *low, int *high);
 
 
 
199
200extern unsigned long *sysctl_local_reserved_ports;
201static inline int inet_is_reserved_local_port(int port)
202{
203	return test_bit(port, sysctl_local_reserved_ports);
204}
205
206extern int sysctl_ip_nonlocal_bind;
207
208/* From inetpeer.c */
209extern int inet_peer_threshold;
210extern int inet_peer_minttl;
211extern int inet_peer_maxttl;
212
 
 
 
213/* From ip_output.c */
214extern int sysctl_ip_dynaddr;
215
216extern void ipfrag_init(void);
217
218extern void ip_static_sysctl_init(void);
219
220static inline bool ip_is_fragment(const struct iphdr *iph)
221{
222	return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
223}
224
225#ifdef CONFIG_INET
226#include <net/dst.h>
227
228/* The function in 2.2 was invalid, producing wrong result for
229 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
230static inline
231int ip_decrease_ttl(struct iphdr *iph)
232{
233	u32 check = (__force u32)iph->check;
234	check += (__force u32)htons(0x0100);
235	iph->check = (__force __sum16)(check + (check>=0xFFFF));
236	return --iph->ttl;
237}
238
239static inline
240int ip_dont_fragment(struct sock *sk, struct dst_entry *dst)
241{
242	return  inet_sk(sk)->pmtudisc == IP_PMTUDISC_DO ||
243		(inet_sk(sk)->pmtudisc == IP_PMTUDISC_WANT &&
244		 !(dst_metric_locked(dst, RTAX_MTU)));
245}
246
247extern void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
248
249static inline void ip_select_ident(struct iphdr *iph, struct dst_entry *dst, struct sock *sk)
250{
251	if (iph->frag_off & htons(IP_DF)) {
 
 
252		/* This is only to work around buggy Windows95/2000
253		 * VJ compression implementations.  If the ID field
254		 * does not change, they drop every other packet in
255		 * a TCP stream using header compression.
256		 */
257		iph->id = (sk && inet_sk(sk)->inet_daddr) ?
258					htons(inet_sk(sk)->inet_id++) : 0;
259	} else
260		__ip_select_ident(iph, dst, 0);
261}
262
263static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more)
264{
265	if (iph->frag_off & htons(IP_DF)) {
 
 
266		if (sk && inet_sk(sk)->inet_daddr) {
267			iph->id = htons(inet_sk(sk)->inet_id);
268			inet_sk(sk)->inet_id += 1 + more;
269		} else
270			iph->id = 0;
271	} else
272		__ip_select_ident(iph, dst, more);
273}
274
275/*
276 *	Map a multicast IP onto multicast MAC for type ethernet.
277 */
278
279static inline void ip_eth_mc_map(__be32 naddr, char *buf)
280{
281	__u32 addr=ntohl(naddr);
282	buf[0]=0x01;
283	buf[1]=0x00;
284	buf[2]=0x5e;
285	buf[5]=addr&0xFF;
286	addr>>=8;
287	buf[4]=addr&0xFF;
288	addr>>=8;
289	buf[3]=addr&0x7F;
290}
291
292/*
293 *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
294 *	Leave P_Key as 0 to be filled in by driver.
295 */
296
297static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
298{
299	__u32 addr;
300	unsigned char scope = broadcast[5] & 0xF;
301
302	buf[0]  = 0;		/* Reserved */
303	buf[1]  = 0xff;		/* Multicast QPN */
304	buf[2]  = 0xff;
305	buf[3]  = 0xff;
306	addr    = ntohl(naddr);
307	buf[4]  = 0xff;
308	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
309	buf[6]  = 0x40;		/* IPv4 signature */
310	buf[7]  = 0x1b;
311	buf[8]  = broadcast[8];		/* P_Key */
312	buf[9]  = broadcast[9];
313	buf[10] = 0;
314	buf[11] = 0;
315	buf[12] = 0;
316	buf[13] = 0;
317	buf[14] = 0;
318	buf[15] = 0;
319	buf[19] = addr & 0xff;
320	addr  >>= 8;
321	buf[18] = addr & 0xff;
322	addr  >>= 8;
323	buf[17] = addr & 0xff;
324	addr  >>= 8;
325	buf[16] = addr & 0x0f;
326}
327
328static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
329{
330	if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
331		memcpy(buf, broadcast, 4);
332	else
333		memcpy(buf, &naddr, sizeof(naddr));
334}
335
336#if IS_ENABLED(CONFIG_IPV6)
337#include <linux/ipv6.h>
338#endif
339
340static __inline__ void inet_reset_saddr(struct sock *sk)
341{
342	inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
343#if IS_ENABLED(CONFIG_IPV6)
344	if (sk->sk_family == PF_INET6) {
345		struct ipv6_pinfo *np = inet6_sk(sk);
346
347		memset(&np->saddr, 0, sizeof(np->saddr));
348		memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
349	}
350#endif
351}
352
353#endif
354
355static inline int sk_mc_loop(struct sock *sk)
356{
357	if (!sk)
358		return 1;
359	switch (sk->sk_family) {
360	case AF_INET:
361		return inet_sk(sk)->mc_loop;
362#if IS_ENABLED(CONFIG_IPV6)
363	case AF_INET6:
364		return inet6_sk(sk)->mc_loop;
365#endif
366	}
367	WARN_ON(1);
368	return 1;
369}
370
371extern bool ip_call_ra_chain(struct sk_buff *skb);
372
373/*
374 *	Functions provided by ip_fragment.c
375 */
376
377enum ip_defrag_users {
378	IP_DEFRAG_LOCAL_DELIVER,
379	IP_DEFRAG_CALL_RA_CHAIN,
380	IP_DEFRAG_CONNTRACK_IN,
381	__IP_DEFRAG_CONNTRACK_IN_END	= IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
382	IP_DEFRAG_CONNTRACK_OUT,
383	__IP_DEFRAG_CONNTRACK_OUT_END	= IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
384	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
385	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
386	IP_DEFRAG_VS_IN,
387	IP_DEFRAG_VS_OUT,
388	IP_DEFRAG_VS_FWD,
389	IP_DEFRAG_AF_PACKET,
390	IP_DEFRAG_MACVLAN,
391};
392
393int ip_defrag(struct sk_buff *skb, u32 user);
394#ifdef CONFIG_INET
395struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user);
396#else
397static inline struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user)
398{
399	return skb;
400}
401#endif
402int ip_frag_mem(struct net *net);
403int ip_frag_nqueues(struct net *net);
404
405/*
406 *	Functions provided by ip_forward.c
407 */
408 
409extern int ip_forward(struct sk_buff *skb);
410 
411/*
412 *	Functions provided by ip_options.c
413 */
414 
415extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
416			     __be32 daddr, struct rtable *rt, int is_frag);
417extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
418extern void ip_options_fragment(struct sk_buff *skb);
419extern int ip_options_compile(struct net *net,
420			      struct ip_options *opt, struct sk_buff *skb);
421extern int ip_options_get(struct net *net, struct ip_options_rcu **optp,
422			  unsigned char *data, int optlen);
423extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
424				    unsigned char __user *data, int optlen);
425extern void ip_options_undo(struct ip_options * opt);
426extern void ip_forward_options(struct sk_buff *skb);
427extern int ip_options_rcv_srr(struct sk_buff *skb);
428
429/*
430 *	Functions provided by ip_sockglue.c
431 */
432
433extern void	ipv4_pktinfo_prepare(struct sk_buff *skb);
434extern void	ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb);
435extern int	ip_cmsg_send(struct net *net,
436			     struct msghdr *msg, struct ipcm_cookie *ipc);
437extern int	ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen);
438extern int	ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);
439extern int	compat_ip_setsockopt(struct sock *sk, int level,
440			int optname, char __user *optval, unsigned int optlen);
441extern int	compat_ip_getsockopt(struct sock *sk, int level,
442			int optname, char __user *optval, int __user *optlen);
443extern int	ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *));
444
445extern int 	ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
446extern void	ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 
447			      __be16 port, u32 info, u8 *payload);
448extern void	ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
449			       u32 info);
 
 
 
450
451#ifdef CONFIG_PROC_FS
452extern int ip_misc_proc_init(void);
453#endif
454
455#endif	/* _IP_H */