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v4.6
  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/route.h>
 32#include <net/snmp.h>
 33#include <net/flow.h>
 34#include <net/flow_dissector.h>
 
 
 
 
 35
 36struct sock;
 37
 38struct inet_skb_parm {
 
 39	struct ip_options	opt;		/* Compiled IP options		*/
 40	unsigned char		flags;
 41
 42#define IPSKB_FORWARDED		BIT(0)
 43#define IPSKB_XFRM_TUNNEL_SIZE	BIT(1)
 44#define IPSKB_XFRM_TRANSFORMED	BIT(2)
 45#define IPSKB_FRAG_COMPLETE	BIT(3)
 46#define IPSKB_REROUTED		BIT(4)
 47#define IPSKB_DOREDIRECT	BIT(5)
 48#define IPSKB_FRAG_PMTU		BIT(6)
 
 49
 50	u16			frag_max_size;
 51};
 52
 
 
 
 
 
 53static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
 54{
 55	return ip_hdr(skb)->ihl * 4;
 56}
 57
 58struct ipcm_cookie {
 
 59	__be32			addr;
 60	int			oif;
 61	struct ip_options_rcu	*opt;
 62	__u8			tx_flags;
 63	__u8			ttl;
 64	__s16			tos;
 65	char			priority;
 66};
 67
 68#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
 69#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
 70
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 71struct ip_ra_chain {
 72	struct ip_ra_chain __rcu *next;
 73	struct sock		*sk;
 74	union {
 75		void			(*destructor)(struct sock *);
 76		struct sock		*saved_sk;
 77	};
 78	struct rcu_head		rcu;
 79};
 80
 81extern struct ip_ra_chain __rcu *ip_ra_chain;
 82
 83/* IP flags. */
 84#define IP_CE		0x8000		/* Flag: "Congestion"		*/
 85#define IP_DF		0x4000		/* Flag: "Don't Fragment"	*/
 86#define IP_MF		0x2000		/* Flag: "More Fragments"	*/
 87#define IP_OFFSET	0x1FFF		/* "Fragment Offset" part	*/
 88
 89#define IP_FRAG_TIME	(30 * HZ)		/* fragment lifetime	*/
 90
 91struct msghdr;
 92struct net_device;
 93struct packet_type;
 94struct rtable;
 95struct sockaddr;
 96
 97int igmp_mc_init(void);
 98
 99/*
100 *	Functions provided by ip.c
101 */
102
103int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
104			  __be32 saddr, __be32 daddr,
105			  struct ip_options_rcu *opt);
106int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
107	   struct net_device *orig_dev);
108int ip_local_deliver(struct sk_buff *skb);
109int ip_mr_input(struct sk_buff *skb);
110int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
111int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
112int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
113		   int (*output)(struct net *, struct sock *, struct sk_buff *));
114void ip_send_check(struct iphdr *ip);
115int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
116int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
117
118int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
119void ip_init(void);
120int ip_append_data(struct sock *sk, struct flowi4 *fl4,
121		   int getfrag(void *from, char *to, int offset, int len,
122			       int odd, struct sk_buff *skb),
123		   void *from, int len, int protolen,
124		   struct ipcm_cookie *ipc,
125		   struct rtable **rt,
126		   unsigned int flags);
127int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
128		       struct sk_buff *skb);
129ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
130		       int offset, size_t size, int flags);
131struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
132			      struct sk_buff_head *queue,
133			      struct inet_cork *cork);
134int ip_send_skb(struct net *net, struct sk_buff *skb);
135int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
136void ip_flush_pending_frames(struct sock *sk);
137struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
138			    int getfrag(void *from, char *to, int offset,
139					int len, int odd, struct sk_buff *skb),
140			    void *from, int length, int transhdrlen,
141			    struct ipcm_cookie *ipc, struct rtable **rtp,
142			    unsigned int flags);
143
144static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
145{
146	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
147}
148
149static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
150{
151	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
152}
153
154static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
155{
156	return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
157}
158
159/* datagram.c */
160int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
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 sock *sk, struct sk_buff *skb,
183			   const struct ip_options *sopt,
184			   __be32 daddr, __be32 saddr,
185			   const struct ip_reply_arg *arg,
186			   unsigned int len);
187
188#define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
189#define IP_INC_STATS_BH(net, field)	SNMP_INC_STATS64_BH((net)->mib.ip_statistics, field)
190#define IP_ADD_STATS(net, field, val)	SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
191#define IP_ADD_STATS_BH(net, field, val) SNMP_ADD_STATS64_BH((net)->mib.ip_statistics, field, val)
192#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
193#define IP_UPD_PO_STATS_BH(net, field, val) SNMP_UPD_PO_STATS64_BH((net)->mib.ip_statistics, field, val)
194#define NET_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.net_statistics, field)
195#define NET_INC_STATS_BH(net, field)	SNMP_INC_STATS_BH((net)->mib.net_statistics, field)
196#define NET_INC_STATS_USER(net, field) 	SNMP_INC_STATS_USER((net)->mib.net_statistics, field)
197#define NET_ADD_STATS(net, field, adnd)	SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
198#define NET_ADD_STATS_BH(net, field, adnd) SNMP_ADD_STATS_BH((net)->mib.net_statistics, field, adnd)
199#define NET_ADD_STATS_USER(net, field, adnd) SNMP_ADD_STATS_USER((net)->mib.net_statistics, field, adnd)
200
201u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
202unsigned long snmp_fold_field(void __percpu *mib, int offt);
203#if BITS_PER_LONG==32
204u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
205			 size_t syncp_offset);
206u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
207#else
208static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
209					size_t syncp_offset)
210{
211	return snmp_get_cpu_field(mib, cpu, offct);
212
213}
214
215static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
216{
217	return snmp_fold_field(mib, offt);
218}
219#endif
220
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
221void inet_get_local_port_range(struct net *net, int *low, int *high);
222
223#ifdef CONFIG_SYSCTL
224static inline int inet_is_local_reserved_port(struct net *net, int port)
225{
226	if (!net->ipv4.sysctl_local_reserved_ports)
227		return 0;
228	return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
229}
230
231static inline bool sysctl_dev_name_is_allowed(const char *name)
232{
233	return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
234}
235
 
 
 
 
 
236#else
237static inline int inet_is_local_reserved_port(struct net *net, int port)
238{
239	return 0;
240}
 
 
 
 
 
241#endif
242
243__be32 inet_current_timestamp(void);
244
245/* From inetpeer.c */
246extern int inet_peer_threshold;
247extern int inet_peer_minttl;
248extern int inet_peer_maxttl;
249
250void ipfrag_init(void);
251
252void ip_static_sysctl_init(void);
253
254#define IP4_REPLY_MARK(net, mark) \
255	((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
256
257static inline bool ip_is_fragment(const struct iphdr *iph)
258{
259	return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
260}
261
262#ifdef CONFIG_INET
263#include <net/dst.h>
264
265/* The function in 2.2 was invalid, producing wrong result for
266 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
267static inline
268int ip_decrease_ttl(struct iphdr *iph)
269{
270	u32 check = (__force u32)iph->check;
271	check += (__force u32)htons(0x0100);
272	iph->check = (__force __sum16)(check + (check>=0xFFFF));
273	return --iph->ttl;
274}
275
 
 
 
 
 
 
 
276static inline
277int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
278{
279	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
280
281	return  pmtudisc == IP_PMTUDISC_DO ||
282		(pmtudisc == IP_PMTUDISC_WANT &&
283		 !(dst_metric_locked(dst, RTAX_MTU)));
284}
285
286static inline bool ip_sk_accept_pmtu(const struct sock *sk)
287{
288	return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
289	       inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
290}
291
292static inline bool ip_sk_use_pmtu(const struct sock *sk)
293{
294	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
295}
296
297static inline bool ip_sk_ignore_df(const struct sock *sk)
298{
299	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
300	       inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
301}
302
303static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
304						    bool forwarding)
305{
306	struct net *net = dev_net(dst->dev);
307
308	if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
309	    dst_metric_locked(dst, RTAX_MTU) ||
310	    !forwarding)
311		return dst_mtu(dst);
312
313	return min(dst->dev->mtu, IP_MAX_MTU);
314}
315
316static inline unsigned int ip_skb_dst_mtu(const struct sk_buff *skb)
 
317{
318	struct sock *sk = skb->sk;
319
320	if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
321		bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
322
323		return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
324	}
325
326	return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
327}
328
329u32 ip_idents_reserve(u32 hash, int segs);
330void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
331
332static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
333					struct sock *sk, int segs)
334{
335	struct iphdr *iph = ip_hdr(skb);
336
337	if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
338		/* This is only to work around buggy Windows95/2000
339		 * VJ compression implementations.  If the ID field
340		 * does not change, they drop every other packet in
341		 * a TCP stream using header compression.
342		 */
343		if (sk && inet_sk(sk)->inet_daddr) {
344			iph->id = htons(inet_sk(sk)->inet_id);
345			inet_sk(sk)->inet_id += segs;
346		} else {
347			iph->id = 0;
348		}
349	} else {
350		__ip_select_ident(net, iph, segs);
351	}
352}
353
354static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
355				   struct sock *sk)
356{
357	ip_select_ident_segs(net, skb, sk, 1);
358}
359
360static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
361{
362	return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
363				  skb->len, proto, 0);
364}
365
366/* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
367 * Equivalent to :	flow->v4addrs.src = iph->saddr;
368 *			flow->v4addrs.dst = iph->daddr;
369 */
370static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
371					    const struct iphdr *iph)
372{
373	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
374		     offsetof(typeof(flow->addrs), v4addrs.src) +
375			      sizeof(flow->addrs.v4addrs.src));
376	memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
377	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
378}
379
380static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
381{
382	const struct iphdr *iph = skb_gro_network_header(skb);
383
384	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
385				  skb_gro_len(skb), proto, 0);
386}
387
388/*
389 *	Map a multicast IP onto multicast MAC for type ethernet.
390 */
391
392static inline void ip_eth_mc_map(__be32 naddr, char *buf)
393{
394	__u32 addr=ntohl(naddr);
395	buf[0]=0x01;
396	buf[1]=0x00;
397	buf[2]=0x5e;
398	buf[5]=addr&0xFF;
399	addr>>=8;
400	buf[4]=addr&0xFF;
401	addr>>=8;
402	buf[3]=addr&0x7F;
403}
404
405/*
406 *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
407 *	Leave P_Key as 0 to be filled in by driver.
408 */
409
410static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
411{
412	__u32 addr;
413	unsigned char scope = broadcast[5] & 0xF;
414
415	buf[0]  = 0;		/* Reserved */
416	buf[1]  = 0xff;		/* Multicast QPN */
417	buf[2]  = 0xff;
418	buf[3]  = 0xff;
419	addr    = ntohl(naddr);
420	buf[4]  = 0xff;
421	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
422	buf[6]  = 0x40;		/* IPv4 signature */
423	buf[7]  = 0x1b;
424	buf[8]  = broadcast[8];		/* P_Key */
425	buf[9]  = broadcast[9];
426	buf[10] = 0;
427	buf[11] = 0;
428	buf[12] = 0;
429	buf[13] = 0;
430	buf[14] = 0;
431	buf[15] = 0;
432	buf[19] = addr & 0xff;
433	addr  >>= 8;
434	buf[18] = addr & 0xff;
435	addr  >>= 8;
436	buf[17] = addr & 0xff;
437	addr  >>= 8;
438	buf[16] = addr & 0x0f;
439}
440
441static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
442{
443	if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
444		memcpy(buf, broadcast, 4);
445	else
446		memcpy(buf, &naddr, sizeof(naddr));
447}
448
449#if IS_ENABLED(CONFIG_IPV6)
450#include <linux/ipv6.h>
451#endif
452
453static __inline__ void inet_reset_saddr(struct sock *sk)
454{
455	inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
456#if IS_ENABLED(CONFIG_IPV6)
457	if (sk->sk_family == PF_INET6) {
458		struct ipv6_pinfo *np = inet6_sk(sk);
459
460		memset(&np->saddr, 0, sizeof(np->saddr));
461		memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
462	}
463#endif
464}
465
466#endif
467
468static inline unsigned int ipv4_addr_hash(__be32 ip)
469{
470	return (__force unsigned int) ip;
471}
472
 
 
 
 
 
 
 
473bool ip_call_ra_chain(struct sk_buff *skb);
474
475/*
476 *	Functions provided by ip_fragment.c
477 */
478
479enum ip_defrag_users {
480	IP_DEFRAG_LOCAL_DELIVER,
481	IP_DEFRAG_CALL_RA_CHAIN,
482	IP_DEFRAG_CONNTRACK_IN,
483	__IP_DEFRAG_CONNTRACK_IN_END	= IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
484	IP_DEFRAG_CONNTRACK_OUT,
485	__IP_DEFRAG_CONNTRACK_OUT_END	= IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
486	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
487	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
488	IP_DEFRAG_VS_IN,
489	IP_DEFRAG_VS_OUT,
490	IP_DEFRAG_VS_FWD,
491	IP_DEFRAG_AF_PACKET,
492	IP_DEFRAG_MACVLAN,
493};
494
495/* Return true if the value of 'user' is between 'lower_bond'
496 * and 'upper_bond' inclusively.
497 */
498static inline bool ip_defrag_user_in_between(u32 user,
499					     enum ip_defrag_users lower_bond,
500					     enum ip_defrag_users upper_bond)
501{
502	return user >= lower_bond && user <= upper_bond;
503}
504
505int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
506#ifdef CONFIG_INET
507struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
508#else
509static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
510{
511	return skb;
512}
513#endif
514int ip_frag_mem(struct net *net);
515
516/*
517 *	Functions provided by ip_forward.c
518 */
519 
520int ip_forward(struct sk_buff *skb);
521 
522/*
523 *	Functions provided by ip_options.c
524 */
525 
526void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
527		      __be32 daddr, struct rtable *rt, int is_frag);
528
529int __ip_options_echo(struct ip_options *dopt, struct sk_buff *skb,
530		      const struct ip_options *sopt);
531static inline int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
 
532{
533	return __ip_options_echo(dopt, skb, &IPCB(skb)->opt);
534}
535
536void ip_options_fragment(struct sk_buff *skb);
537int ip_options_compile(struct net *net, struct ip_options *opt,
538		       struct sk_buff *skb);
539int ip_options_get(struct net *net, struct ip_options_rcu **optp,
540		   unsigned char *data, int optlen);
541int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
542			     unsigned char __user *data, int optlen);
543void ip_options_undo(struct ip_options *opt);
544void ip_forward_options(struct sk_buff *skb);
545int ip_options_rcv_srr(struct sk_buff *skb);
546
547/*
548 *	Functions provided by ip_sockglue.c
549 */
550
551void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
552void ip_cmsg_recv_offset(struct msghdr *msg, struct sk_buff *skb, int offset);
553int ip_cmsg_send(struct net *net, struct msghdr *msg,
 
554		 struct ipcm_cookie *ipc, bool allow_ipv6);
555int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
556		  unsigned int optlen);
557int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
558		  int __user *optlen);
559int compat_ip_setsockopt(struct sock *sk, int level, int optname,
560			 char __user *optval, unsigned int optlen);
561int compat_ip_getsockopt(struct sock *sk, int level, int optname,
562			 char __user *optval, int __user *optlen);
563int ip_ra_control(struct sock *sk, unsigned char on,
564		  void (*destructor)(struct sock *));
565
566int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
567void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
568		   u32 info, u8 *payload);
569void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
570		    u32 info);
571
572static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
573{
574	ip_cmsg_recv_offset(msg, skb, 0);
575}
576
577bool icmp_global_allow(void);
578extern int sysctl_icmp_msgs_per_sec;
579extern int sysctl_icmp_msgs_burst;
580
581#ifdef CONFIG_PROC_FS
582int ip_misc_proc_init(void);
583#endif
584
585#endif	/* _IP_H */
v4.17
  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#include <linux/jhash.h>
 30
 31#include <net/inet_sock.h>
 32#include <net/route.h>
 33#include <net/snmp.h>
 34#include <net/flow.h>
 35#include <net/flow_dissector.h>
 36#include <net/netns/hash.h>
 37
 38#define IPV4_MAX_PMTU		65535U		/* RFC 2675, Section 5.1 */
 39#define IPV4_MIN_MTU		68			/* RFC 791 */
 40
 41struct sock;
 42
 43struct inet_skb_parm {
 44	int			iif;
 45	struct ip_options	opt;		/* Compiled IP options		*/
 46	u16			flags;
 47
 48#define IPSKB_FORWARDED		BIT(0)
 49#define IPSKB_XFRM_TUNNEL_SIZE	BIT(1)
 50#define IPSKB_XFRM_TRANSFORMED	BIT(2)
 51#define IPSKB_FRAG_COMPLETE	BIT(3)
 52#define IPSKB_REROUTED		BIT(4)
 53#define IPSKB_DOREDIRECT	BIT(5)
 54#define IPSKB_FRAG_PMTU		BIT(6)
 55#define IPSKB_L3SLAVE		BIT(7)
 56
 57	u16			frag_max_size;
 58};
 59
 60static inline bool ipv4_l3mdev_skb(u16 flags)
 61{
 62	return !!(flags & IPSKB_L3SLAVE);
 63}
 64
 65static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
 66{
 67	return ip_hdr(skb)->ihl * 4;
 68}
 69
 70struct ipcm_cookie {
 71	struct sockcm_cookie	sockc;
 72	__be32			addr;
 73	int			oif;
 74	struct ip_options_rcu	*opt;
 75	__u8			tx_flags;
 76	__u8			ttl;
 77	__s16			tos;
 78	char			priority;
 79};
 80
 81#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
 82#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
 83
 84/* return enslaved device index if relevant */
 85static inline int inet_sdif(struct sk_buff *skb)
 86{
 87#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
 88	if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
 89		return IPCB(skb)->iif;
 90#endif
 91	return 0;
 92}
 93
 94/* Special input handler for packets caught by router alert option.
 95   They are selected only by protocol field, and then processed likely
 96   local ones; but only if someone wants them! Otherwise, router
 97   not running rsvpd will kill RSVP.
 98
 99   It is user level problem, what it will make with them.
100   I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
101   but receiver should be enough clever f.e. to forward mtrace requests,
102   sent to multicast group to reach destination designated router.
103 */
104
105struct ip_ra_chain {
106	struct ip_ra_chain __rcu *next;
107	struct sock		*sk;
108	union {
109		void			(*destructor)(struct sock *);
110		struct sock		*saved_sk;
111	};
112	struct rcu_head		rcu;
113};
114
 
 
115/* IP flags. */
116#define IP_CE		0x8000		/* Flag: "Congestion"		*/
117#define IP_DF		0x4000		/* Flag: "Don't Fragment"	*/
118#define IP_MF		0x2000		/* Flag: "More Fragments"	*/
119#define IP_OFFSET	0x1FFF		/* "Fragment Offset" part	*/
120
121#define IP_FRAG_TIME	(30 * HZ)		/* fragment lifetime	*/
122
123struct msghdr;
124struct net_device;
125struct packet_type;
126struct rtable;
127struct sockaddr;
128
129int igmp_mc_init(void);
130
131/*
132 *	Functions provided by ip.c
133 */
134
135int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
136			  __be32 saddr, __be32 daddr,
137			  struct ip_options_rcu *opt);
138int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
139	   struct net_device *orig_dev);
140int ip_local_deliver(struct sk_buff *skb);
141int ip_mr_input(struct sk_buff *skb);
142int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
143int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
144int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
145		   int (*output)(struct net *, struct sock *, struct sk_buff *));
146void ip_send_check(struct iphdr *ip);
147int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
148int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
149
150int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
151void ip_init(void);
152int ip_append_data(struct sock *sk, struct flowi4 *fl4,
153		   int getfrag(void *from, char *to, int offset, int len,
154			       int odd, struct sk_buff *skb),
155		   void *from, int len, int protolen,
156		   struct ipcm_cookie *ipc,
157		   struct rtable **rt,
158		   unsigned int flags);
159int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
160		       struct sk_buff *skb);
161ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
162		       int offset, size_t size, int flags);
163struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
164			      struct sk_buff_head *queue,
165			      struct inet_cork *cork);
166int ip_send_skb(struct net *net, struct sk_buff *skb);
167int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
168void ip_flush_pending_frames(struct sock *sk);
169struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
170			    int getfrag(void *from, char *to, int offset,
171					int len, int odd, struct sk_buff *skb),
172			    void *from, int length, int transhdrlen,
173			    struct ipcm_cookie *ipc, struct rtable **rtp,
174			    unsigned int flags);
175
176static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
177{
178	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
179}
180
181static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
182{
183	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
184}
185
186static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
187{
188	return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
189}
190
191/* datagram.c */
192int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
193int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
194
195void ip4_datagram_release_cb(struct sock *sk);
196
197struct ip_reply_arg {
198	struct kvec iov[1];
199	int	    flags;
200	__wsum 	    csum;
201	int	    csumoffset; /* u16 offset of csum in iov[0].iov_base */
202				/* -1 if not needed */
203	int	    bound_dev_if;
204	u8  	    tos;
205	kuid_t	    uid;
206};
207
208#define IP_REPLY_ARG_NOSRCCHECK 1
209
210static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
211{
212	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
213}
214
215void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
216			   const struct ip_options *sopt,
217			   __be32 daddr, __be32 saddr,
218			   const struct ip_reply_arg *arg,
219			   unsigned int len);
220
221#define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
222#define __IP_INC_STATS(net, field)	__SNMP_INC_STATS64((net)->mib.ip_statistics, field)
223#define IP_ADD_STATS(net, field, val)	SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
224#define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
225#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
226#define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
227#define NET_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.net_statistics, field)
228#define __NET_INC_STATS(net, field)	__SNMP_INC_STATS((net)->mib.net_statistics, field)
 
229#define NET_ADD_STATS(net, field, adnd)	SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
230#define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
 
231
232u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
233unsigned long snmp_fold_field(void __percpu *mib, int offt);
234#if BITS_PER_LONG==32
235u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
236			 size_t syncp_offset);
237u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
238#else
239static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
240					size_t syncp_offset)
241{
242	return snmp_get_cpu_field(mib, cpu, offct);
243
244}
245
246static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
247{
248	return snmp_fold_field(mib, offt);
249}
250#endif
251
252#define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
253{ \
254	int i, c; \
255	for_each_possible_cpu(c) { \
256		for (i = 0; stats_list[i].name; i++) \
257			buff64[i] += snmp_get_cpu_field64( \
258					mib_statistic, \
259					c, stats_list[i].entry, \
260					offset); \
261	} \
262}
263
264#define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
265{ \
266	int i, c; \
267	for_each_possible_cpu(c) { \
268		for (i = 0; stats_list[i].name; i++) \
269			buff[i] += snmp_get_cpu_field( \
270						mib_statistic, \
271						c, stats_list[i].entry); \
272	} \
273}
274
275void inet_get_local_port_range(struct net *net, int *low, int *high);
276
277#ifdef CONFIG_SYSCTL
278static inline int inet_is_local_reserved_port(struct net *net, int port)
279{
280	if (!net->ipv4.sysctl_local_reserved_ports)
281		return 0;
282	return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
283}
284
285static inline bool sysctl_dev_name_is_allowed(const char *name)
286{
287	return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
288}
289
290static inline int inet_prot_sock(struct net *net)
291{
292	return net->ipv4.sysctl_ip_prot_sock;
293}
294
295#else
296static inline int inet_is_local_reserved_port(struct net *net, int port)
297{
298	return 0;
299}
300
301static inline int inet_prot_sock(struct net *net)
302{
303	return PROT_SOCK;
304}
305#endif
306
307__be32 inet_current_timestamp(void);
308
309/* From inetpeer.c */
310extern int inet_peer_threshold;
311extern int inet_peer_minttl;
312extern int inet_peer_maxttl;
313
314void ipfrag_init(void);
315
316void ip_static_sysctl_init(void);
317
318#define IP4_REPLY_MARK(net, mark) \
319	((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
320
321static inline bool ip_is_fragment(const struct iphdr *iph)
322{
323	return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
324}
325
326#ifdef CONFIG_INET
327#include <net/dst.h>
328
329/* The function in 2.2 was invalid, producing wrong result for
330 * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
331static inline
332int ip_decrease_ttl(struct iphdr *iph)
333{
334	u32 check = (__force u32)iph->check;
335	check += (__force u32)htons(0x0100);
336	iph->check = (__force __sum16)(check + (check>=0xFFFF));
337	return --iph->ttl;
338}
339
340static inline int ip_mtu_locked(const struct dst_entry *dst)
341{
342	const struct rtable *rt = (const struct rtable *)dst;
343
344	return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
345}
346
347static inline
348int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
349{
350	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
351
352	return  pmtudisc == IP_PMTUDISC_DO ||
353		(pmtudisc == IP_PMTUDISC_WANT &&
354		 !ip_mtu_locked(dst));
355}
356
357static inline bool ip_sk_accept_pmtu(const struct sock *sk)
358{
359	return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
360	       inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
361}
362
363static inline bool ip_sk_use_pmtu(const struct sock *sk)
364{
365	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
366}
367
368static inline bool ip_sk_ignore_df(const struct sock *sk)
369{
370	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
371	       inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
372}
373
374static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
375						    bool forwarding)
376{
377	struct net *net = dev_net(dst->dev);
378
379	if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
380	    ip_mtu_locked(dst) ||
381	    !forwarding)
382		return dst_mtu(dst);
383
384	return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
385}
386
387static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
388					  const struct sk_buff *skb)
389{
 
 
390	if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
391		bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
392
393		return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
394	}
395
396	return min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
397}
398
399u32 ip_idents_reserve(u32 hash, int segs);
400void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
401
402static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
403					struct sock *sk, int segs)
404{
405	struct iphdr *iph = ip_hdr(skb);
406
407	if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
408		/* This is only to work around buggy Windows95/2000
409		 * VJ compression implementations.  If the ID field
410		 * does not change, they drop every other packet in
411		 * a TCP stream using header compression.
412		 */
413		if (sk && inet_sk(sk)->inet_daddr) {
414			iph->id = htons(inet_sk(sk)->inet_id);
415			inet_sk(sk)->inet_id += segs;
416		} else {
417			iph->id = 0;
418		}
419	} else {
420		__ip_select_ident(net, iph, segs);
421	}
422}
423
424static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
425				   struct sock *sk)
426{
427	ip_select_ident_segs(net, skb, sk, 1);
428}
429
430static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
431{
432	return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
433				  skb->len, proto, 0);
434}
435
436/* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
437 * Equivalent to :	flow->v4addrs.src = iph->saddr;
438 *			flow->v4addrs.dst = iph->daddr;
439 */
440static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
441					    const struct iphdr *iph)
442{
443	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
444		     offsetof(typeof(flow->addrs), v4addrs.src) +
445			      sizeof(flow->addrs.v4addrs.src));
446	memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
447	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
448}
449
450static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
451{
452	const struct iphdr *iph = skb_gro_network_header(skb);
453
454	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
455				  skb_gro_len(skb), proto, 0);
456}
457
458/*
459 *	Map a multicast IP onto multicast MAC for type ethernet.
460 */
461
462static inline void ip_eth_mc_map(__be32 naddr, char *buf)
463{
464	__u32 addr=ntohl(naddr);
465	buf[0]=0x01;
466	buf[1]=0x00;
467	buf[2]=0x5e;
468	buf[5]=addr&0xFF;
469	addr>>=8;
470	buf[4]=addr&0xFF;
471	addr>>=8;
472	buf[3]=addr&0x7F;
473}
474
475/*
476 *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
477 *	Leave P_Key as 0 to be filled in by driver.
478 */
479
480static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
481{
482	__u32 addr;
483	unsigned char scope = broadcast[5] & 0xF;
484
485	buf[0]  = 0;		/* Reserved */
486	buf[1]  = 0xff;		/* Multicast QPN */
487	buf[2]  = 0xff;
488	buf[3]  = 0xff;
489	addr    = ntohl(naddr);
490	buf[4]  = 0xff;
491	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
492	buf[6]  = 0x40;		/* IPv4 signature */
493	buf[7]  = 0x1b;
494	buf[8]  = broadcast[8];		/* P_Key */
495	buf[9]  = broadcast[9];
496	buf[10] = 0;
497	buf[11] = 0;
498	buf[12] = 0;
499	buf[13] = 0;
500	buf[14] = 0;
501	buf[15] = 0;
502	buf[19] = addr & 0xff;
503	addr  >>= 8;
504	buf[18] = addr & 0xff;
505	addr  >>= 8;
506	buf[17] = addr & 0xff;
507	addr  >>= 8;
508	buf[16] = addr & 0x0f;
509}
510
511static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
512{
513	if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
514		memcpy(buf, broadcast, 4);
515	else
516		memcpy(buf, &naddr, sizeof(naddr));
517}
518
519#if IS_ENABLED(CONFIG_IPV6)
520#include <linux/ipv6.h>
521#endif
522
523static __inline__ void inet_reset_saddr(struct sock *sk)
524{
525	inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
526#if IS_ENABLED(CONFIG_IPV6)
527	if (sk->sk_family == PF_INET6) {
528		struct ipv6_pinfo *np = inet6_sk(sk);
529
530		memset(&np->saddr, 0, sizeof(np->saddr));
531		memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
532	}
533#endif
534}
535
536#endif
537
538static inline unsigned int ipv4_addr_hash(__be32 ip)
539{
540	return (__force unsigned int) ip;
541}
542
543static inline u32 ipv4_portaddr_hash(const struct net *net,
544				     __be32 saddr,
545				     unsigned int port)
546{
547	return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
548}
549
550bool ip_call_ra_chain(struct sk_buff *skb);
551
552/*
553 *	Functions provided by ip_fragment.c
554 */
555
556enum ip_defrag_users {
557	IP_DEFRAG_LOCAL_DELIVER,
558	IP_DEFRAG_CALL_RA_CHAIN,
559	IP_DEFRAG_CONNTRACK_IN,
560	__IP_DEFRAG_CONNTRACK_IN_END	= IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
561	IP_DEFRAG_CONNTRACK_OUT,
562	__IP_DEFRAG_CONNTRACK_OUT_END	= IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
563	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
564	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
565	IP_DEFRAG_VS_IN,
566	IP_DEFRAG_VS_OUT,
567	IP_DEFRAG_VS_FWD,
568	IP_DEFRAG_AF_PACKET,
569	IP_DEFRAG_MACVLAN,
570};
571
572/* Return true if the value of 'user' is between 'lower_bond'
573 * and 'upper_bond' inclusively.
574 */
575static inline bool ip_defrag_user_in_between(u32 user,
576					     enum ip_defrag_users lower_bond,
577					     enum ip_defrag_users upper_bond)
578{
579	return user >= lower_bond && user <= upper_bond;
580}
581
582int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
583#ifdef CONFIG_INET
584struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
585#else
586static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
587{
588	return skb;
589}
590#endif
 
591
592/*
593 *	Functions provided by ip_forward.c
594 */
595
596int ip_forward(struct sk_buff *skb);
597
598/*
599 *	Functions provided by ip_options.c
600 */
601
602void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
603		      __be32 daddr, struct rtable *rt, int is_frag);
604
605int __ip_options_echo(struct net *net, struct ip_options *dopt,
606		      struct sk_buff *skb, const struct ip_options *sopt);
607static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
608				  struct sk_buff *skb)
609{
610	return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
611}
612
613void ip_options_fragment(struct sk_buff *skb);
614int ip_options_compile(struct net *net, struct ip_options *opt,
615		       struct sk_buff *skb);
616int ip_options_get(struct net *net, struct ip_options_rcu **optp,
617		   unsigned char *data, int optlen);
618int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
619			     unsigned char __user *data, int optlen);
620void ip_options_undo(struct ip_options *opt);
621void ip_forward_options(struct sk_buff *skb);
622int ip_options_rcv_srr(struct sk_buff *skb);
623
624/*
625 *	Functions provided by ip_sockglue.c
626 */
627
628void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
629void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
630			 struct sk_buff *skb, int tlen, int offset);
631int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
632		 struct ipcm_cookie *ipc, bool allow_ipv6);
633int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
634		  unsigned int optlen);
635int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
636		  int __user *optlen);
637int compat_ip_setsockopt(struct sock *sk, int level, int optname,
638			 char __user *optval, unsigned int optlen);
639int compat_ip_getsockopt(struct sock *sk, int level, int optname,
640			 char __user *optval, int __user *optlen);
641int ip_ra_control(struct sock *sk, unsigned char on,
642		  void (*destructor)(struct sock *));
643
644int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
645void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
646		   u32 info, u8 *payload);
647void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
648		    u32 info);
649
650static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
651{
652	ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
653}
654
655bool icmp_global_allow(void);
656extern int sysctl_icmp_msgs_per_sec;
657extern int sysctl_icmp_msgs_burst;
658
659#ifdef CONFIG_PROC_FS
660int ip_misc_proc_init(void);
661#endif
662
663#endif	/* _IP_H */