xref: /openbmc/linux/include/net/ip.h (revision 1c2dd16a)
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 
36 #define IPV4_MAX_PMTU		65535U		/* RFC 2675, Section 5.1 */
37 
38 struct sock;
39 
40 struct inet_skb_parm {
41 	int			iif;
42 	struct ip_options	opt;		/* Compiled IP options		*/
43 	u16			flags;
44 
45 #define IPSKB_FORWARDED		BIT(0)
46 #define IPSKB_XFRM_TUNNEL_SIZE	BIT(1)
47 #define IPSKB_XFRM_TRANSFORMED	BIT(2)
48 #define IPSKB_FRAG_COMPLETE	BIT(3)
49 #define IPSKB_REROUTED		BIT(4)
50 #define IPSKB_DOREDIRECT	BIT(5)
51 #define IPSKB_FRAG_PMTU		BIT(6)
52 #define IPSKB_L3SLAVE		BIT(7)
53 
54 	u16			frag_max_size;
55 };
56 
57 static inline bool ipv4_l3mdev_skb(u16 flags)
58 {
59 	return !!(flags & IPSKB_L3SLAVE);
60 }
61 
62 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
63 {
64 	return ip_hdr(skb)->ihl * 4;
65 }
66 
67 struct ipcm_cookie {
68 	struct sockcm_cookie	sockc;
69 	__be32			addr;
70 	int			oif;
71 	struct ip_options_rcu	*opt;
72 	__u8			tx_flags;
73 	__u8			ttl;
74 	__s16			tos;
75 	char			priority;
76 };
77 
78 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
79 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
80 
81 struct ip_ra_chain {
82 	struct ip_ra_chain __rcu *next;
83 	struct sock		*sk;
84 	union {
85 		void			(*destructor)(struct sock *);
86 		struct sock		*saved_sk;
87 	};
88 	struct rcu_head		rcu;
89 };
90 
91 extern struct ip_ra_chain __rcu *ip_ra_chain;
92 
93 /* IP flags. */
94 #define IP_CE		0x8000		/* Flag: "Congestion"		*/
95 #define IP_DF		0x4000		/* Flag: "Don't Fragment"	*/
96 #define IP_MF		0x2000		/* Flag: "More Fragments"	*/
97 #define IP_OFFSET	0x1FFF		/* "Fragment Offset" part	*/
98 
99 #define IP_FRAG_TIME	(30 * HZ)		/* fragment lifetime	*/
100 
101 struct msghdr;
102 struct net_device;
103 struct packet_type;
104 struct rtable;
105 struct sockaddr;
106 
107 int igmp_mc_init(void);
108 
109 /*
110  *	Functions provided by ip.c
111  */
112 
113 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
114 			  __be32 saddr, __be32 daddr,
115 			  struct ip_options_rcu *opt);
116 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
117 	   struct net_device *orig_dev);
118 int ip_local_deliver(struct sk_buff *skb);
119 int ip_mr_input(struct sk_buff *skb);
120 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
121 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
122 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
123 		   int (*output)(struct net *, struct sock *, struct sk_buff *));
124 void ip_send_check(struct iphdr *ip);
125 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
126 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
127 
128 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
129 void ip_init(void);
130 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
131 		   int getfrag(void *from, char *to, int offset, int len,
132 			       int odd, struct sk_buff *skb),
133 		   void *from, int len, int protolen,
134 		   struct ipcm_cookie *ipc,
135 		   struct rtable **rt,
136 		   unsigned int flags);
137 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
138 		       struct sk_buff *skb);
139 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
140 		       int offset, size_t size, int flags);
141 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
142 			      struct sk_buff_head *queue,
143 			      struct inet_cork *cork);
144 int ip_send_skb(struct net *net, struct sk_buff *skb);
145 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
146 void ip_flush_pending_frames(struct sock *sk);
147 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
148 			    int getfrag(void *from, char *to, int offset,
149 					int len, int odd, struct sk_buff *skb),
150 			    void *from, int length, int transhdrlen,
151 			    struct ipcm_cookie *ipc, struct rtable **rtp,
152 			    unsigned int flags);
153 
154 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
155 {
156 	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
157 }
158 
159 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
160 {
161 	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
162 }
163 
164 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
165 {
166 	return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
167 }
168 
169 /* datagram.c */
170 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
171 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
172 
173 void ip4_datagram_release_cb(struct sock *sk);
174 
175 struct ip_reply_arg {
176 	struct kvec iov[1];
177 	int	    flags;
178 	__wsum 	    csum;
179 	int	    csumoffset; /* u16 offset of csum in iov[0].iov_base */
180 				/* -1 if not needed */
181 	int	    bound_dev_if;
182 	u8  	    tos;
183 	kuid_t	    uid;
184 };
185 
186 #define IP_REPLY_ARG_NOSRCCHECK 1
187 
188 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
189 {
190 	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
191 }
192 
193 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
194 			   const struct ip_options *sopt,
195 			   __be32 daddr, __be32 saddr,
196 			   const struct ip_reply_arg *arg,
197 			   unsigned int len);
198 
199 #define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
200 #define __IP_INC_STATS(net, field)	__SNMP_INC_STATS64((net)->mib.ip_statistics, field)
201 #define IP_ADD_STATS(net, field, val)	SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
202 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
203 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
204 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
205 #define NET_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.net_statistics, field)
206 #define __NET_INC_STATS(net, field)	__SNMP_INC_STATS((net)->mib.net_statistics, field)
207 #define NET_ADD_STATS(net, field, adnd)	SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
208 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
209 
210 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
211 unsigned long snmp_fold_field(void __percpu *mib, int offt);
212 #if BITS_PER_LONG==32
213 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
214 			 size_t syncp_offset);
215 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
216 #else
217 static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
218 					size_t syncp_offset)
219 {
220 	return snmp_get_cpu_field(mib, cpu, offct);
221 
222 }
223 
224 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
225 {
226 	return snmp_fold_field(mib, offt);
227 }
228 #endif
229 
230 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
231 { \
232 	int i, c; \
233 	for_each_possible_cpu(c) { \
234 		for (i = 0; stats_list[i].name; i++) \
235 			buff64[i] += snmp_get_cpu_field64( \
236 					mib_statistic, \
237 					c, stats_list[i].entry, \
238 					offset); \
239 	} \
240 }
241 
242 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
243 { \
244 	int i, c; \
245 	for_each_possible_cpu(c) { \
246 		for (i = 0; stats_list[i].name; i++) \
247 			buff[i] += snmp_get_cpu_field( \
248 						mib_statistic, \
249 						c, stats_list[i].entry); \
250 	} \
251 }
252 
253 void inet_get_local_port_range(struct net *net, int *low, int *high);
254 
255 #ifdef CONFIG_SYSCTL
256 static inline int inet_is_local_reserved_port(struct net *net, int port)
257 {
258 	if (!net->ipv4.sysctl_local_reserved_ports)
259 		return 0;
260 	return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
261 }
262 
263 static inline bool sysctl_dev_name_is_allowed(const char *name)
264 {
265 	return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
266 }
267 
268 static inline int inet_prot_sock(struct net *net)
269 {
270 	return net->ipv4.sysctl_ip_prot_sock;
271 }
272 
273 #else
274 static inline int inet_is_local_reserved_port(struct net *net, int port)
275 {
276 	return 0;
277 }
278 
279 static inline int inet_prot_sock(struct net *net)
280 {
281 	return PROT_SOCK;
282 }
283 #endif
284 
285 __be32 inet_current_timestamp(void);
286 
287 /* From inetpeer.c */
288 extern int inet_peer_threshold;
289 extern int inet_peer_minttl;
290 extern int inet_peer_maxttl;
291 
292 void ipfrag_init(void);
293 
294 void ip_static_sysctl_init(void);
295 
296 #define IP4_REPLY_MARK(net, mark) \
297 	((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
298 
299 static inline bool ip_is_fragment(const struct iphdr *iph)
300 {
301 	return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
302 }
303 
304 #ifdef CONFIG_INET
305 #include <net/dst.h>
306 
307 /* The function in 2.2 was invalid, producing wrong result for
308  * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
309 static inline
310 int ip_decrease_ttl(struct iphdr *iph)
311 {
312 	u32 check = (__force u32)iph->check;
313 	check += (__force u32)htons(0x0100);
314 	iph->check = (__force __sum16)(check + (check>=0xFFFF));
315 	return --iph->ttl;
316 }
317 
318 static inline
319 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
320 {
321 	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
322 
323 	return  pmtudisc == IP_PMTUDISC_DO ||
324 		(pmtudisc == IP_PMTUDISC_WANT &&
325 		 !(dst_metric_locked(dst, RTAX_MTU)));
326 }
327 
328 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
329 {
330 	return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
331 	       inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
332 }
333 
334 static inline bool ip_sk_use_pmtu(const struct sock *sk)
335 {
336 	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
337 }
338 
339 static inline bool ip_sk_ignore_df(const struct sock *sk)
340 {
341 	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
342 	       inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
343 }
344 
345 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
346 						    bool forwarding)
347 {
348 	struct net *net = dev_net(dst->dev);
349 
350 	if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
351 	    dst_metric_locked(dst, RTAX_MTU) ||
352 	    !forwarding)
353 		return dst_mtu(dst);
354 
355 	return min(dst->dev->mtu, IP_MAX_MTU);
356 }
357 
358 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
359 					  const struct sk_buff *skb)
360 {
361 	if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
362 		bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
363 
364 		return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
365 	}
366 
367 	return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
368 }
369 
370 u32 ip_idents_reserve(u32 hash, int segs);
371 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
372 
373 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
374 					struct sock *sk, int segs)
375 {
376 	struct iphdr *iph = ip_hdr(skb);
377 
378 	if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
379 		/* This is only to work around buggy Windows95/2000
380 		 * VJ compression implementations.  If the ID field
381 		 * does not change, they drop every other packet in
382 		 * a TCP stream using header compression.
383 		 */
384 		if (sk && inet_sk(sk)->inet_daddr) {
385 			iph->id = htons(inet_sk(sk)->inet_id);
386 			inet_sk(sk)->inet_id += segs;
387 		} else {
388 			iph->id = 0;
389 		}
390 	} else {
391 		__ip_select_ident(net, iph, segs);
392 	}
393 }
394 
395 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
396 				   struct sock *sk)
397 {
398 	ip_select_ident_segs(net, skb, sk, 1);
399 }
400 
401 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
402 {
403 	return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
404 				  skb->len, proto, 0);
405 }
406 
407 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
408  * Equivalent to :	flow->v4addrs.src = iph->saddr;
409  *			flow->v4addrs.dst = iph->daddr;
410  */
411 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
412 					    const struct iphdr *iph)
413 {
414 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
415 		     offsetof(typeof(flow->addrs), v4addrs.src) +
416 			      sizeof(flow->addrs.v4addrs.src));
417 	memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
418 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
419 }
420 
421 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
422 {
423 	const struct iphdr *iph = skb_gro_network_header(skb);
424 
425 	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
426 				  skb_gro_len(skb), proto, 0);
427 }
428 
429 /*
430  *	Map a multicast IP onto multicast MAC for type ethernet.
431  */
432 
433 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
434 {
435 	__u32 addr=ntohl(naddr);
436 	buf[0]=0x01;
437 	buf[1]=0x00;
438 	buf[2]=0x5e;
439 	buf[5]=addr&0xFF;
440 	addr>>=8;
441 	buf[4]=addr&0xFF;
442 	addr>>=8;
443 	buf[3]=addr&0x7F;
444 }
445 
446 /*
447  *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
448  *	Leave P_Key as 0 to be filled in by driver.
449  */
450 
451 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
452 {
453 	__u32 addr;
454 	unsigned char scope = broadcast[5] & 0xF;
455 
456 	buf[0]  = 0;		/* Reserved */
457 	buf[1]  = 0xff;		/* Multicast QPN */
458 	buf[2]  = 0xff;
459 	buf[3]  = 0xff;
460 	addr    = ntohl(naddr);
461 	buf[4]  = 0xff;
462 	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
463 	buf[6]  = 0x40;		/* IPv4 signature */
464 	buf[7]  = 0x1b;
465 	buf[8]  = broadcast[8];		/* P_Key */
466 	buf[9]  = broadcast[9];
467 	buf[10] = 0;
468 	buf[11] = 0;
469 	buf[12] = 0;
470 	buf[13] = 0;
471 	buf[14] = 0;
472 	buf[15] = 0;
473 	buf[19] = addr & 0xff;
474 	addr  >>= 8;
475 	buf[18] = addr & 0xff;
476 	addr  >>= 8;
477 	buf[17] = addr & 0xff;
478 	addr  >>= 8;
479 	buf[16] = addr & 0x0f;
480 }
481 
482 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
483 {
484 	if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
485 		memcpy(buf, broadcast, 4);
486 	else
487 		memcpy(buf, &naddr, sizeof(naddr));
488 }
489 
490 #if IS_ENABLED(CONFIG_IPV6)
491 #include <linux/ipv6.h>
492 #endif
493 
494 static __inline__ void inet_reset_saddr(struct sock *sk)
495 {
496 	inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
497 #if IS_ENABLED(CONFIG_IPV6)
498 	if (sk->sk_family == PF_INET6) {
499 		struct ipv6_pinfo *np = inet6_sk(sk);
500 
501 		memset(&np->saddr, 0, sizeof(np->saddr));
502 		memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
503 	}
504 #endif
505 }
506 
507 #endif
508 
509 static inline unsigned int ipv4_addr_hash(__be32 ip)
510 {
511 	return (__force unsigned int) ip;
512 }
513 
514 bool ip_call_ra_chain(struct sk_buff *skb);
515 
516 /*
517  *	Functions provided by ip_fragment.c
518  */
519 
520 enum ip_defrag_users {
521 	IP_DEFRAG_LOCAL_DELIVER,
522 	IP_DEFRAG_CALL_RA_CHAIN,
523 	IP_DEFRAG_CONNTRACK_IN,
524 	__IP_DEFRAG_CONNTRACK_IN_END	= IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
525 	IP_DEFRAG_CONNTRACK_OUT,
526 	__IP_DEFRAG_CONNTRACK_OUT_END	= IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
527 	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
528 	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
529 	IP_DEFRAG_VS_IN,
530 	IP_DEFRAG_VS_OUT,
531 	IP_DEFRAG_VS_FWD,
532 	IP_DEFRAG_AF_PACKET,
533 	IP_DEFRAG_MACVLAN,
534 };
535 
536 /* Return true if the value of 'user' is between 'lower_bond'
537  * and 'upper_bond' inclusively.
538  */
539 static inline bool ip_defrag_user_in_between(u32 user,
540 					     enum ip_defrag_users lower_bond,
541 					     enum ip_defrag_users upper_bond)
542 {
543 	return user >= lower_bond && user <= upper_bond;
544 }
545 
546 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
547 #ifdef CONFIG_INET
548 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
549 #else
550 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
551 {
552 	return skb;
553 }
554 #endif
555 int ip_frag_mem(struct net *net);
556 
557 /*
558  *	Functions provided by ip_forward.c
559  */
560 
561 int ip_forward(struct sk_buff *skb);
562 
563 /*
564  *	Functions provided by ip_options.c
565  */
566 
567 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
568 		      __be32 daddr, struct rtable *rt, int is_frag);
569 
570 int __ip_options_echo(struct ip_options *dopt, struct sk_buff *skb,
571 		      const struct ip_options *sopt);
572 static inline int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
573 {
574 	return __ip_options_echo(dopt, skb, &IPCB(skb)->opt);
575 }
576 
577 void ip_options_fragment(struct sk_buff *skb);
578 int ip_options_compile(struct net *net, struct ip_options *opt,
579 		       struct sk_buff *skb);
580 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
581 		   unsigned char *data, int optlen);
582 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
583 			     unsigned char __user *data, int optlen);
584 void ip_options_undo(struct ip_options *opt);
585 void ip_forward_options(struct sk_buff *skb);
586 int ip_options_rcv_srr(struct sk_buff *skb);
587 
588 /*
589  *	Functions provided by ip_sockglue.c
590  */
591 
592 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
593 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
594 			 struct sk_buff *skb, int tlen, int offset);
595 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
596 		 struct ipcm_cookie *ipc, bool allow_ipv6);
597 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
598 		  unsigned int optlen);
599 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
600 		  int __user *optlen);
601 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
602 			 char __user *optval, unsigned int optlen);
603 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
604 			 char __user *optval, int __user *optlen);
605 int ip_ra_control(struct sock *sk, unsigned char on,
606 		  void (*destructor)(struct sock *));
607 
608 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
609 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
610 		   u32 info, u8 *payload);
611 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
612 		    u32 info);
613 
614 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
615 {
616 	ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
617 }
618 
619 bool icmp_global_allow(void);
620 extern int sysctl_icmp_msgs_per_sec;
621 extern int sysctl_icmp_msgs_burst;
622 
623 #ifdef CONFIG_PROC_FS
624 int ip_misc_proc_init(void);
625 #endif
626 
627 #endif	/* _IP_H */
628