xref: /openbmc/linux/include/net/ip.h (revision 8730046c)
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 struct sock;
37 
38 struct inet_skb_parm {
39 	int			iif;
40 	struct ip_options	opt;		/* Compiled IP options		*/
41 	u16			flags;
42 
43 #define IPSKB_FORWARDED		BIT(0)
44 #define IPSKB_XFRM_TUNNEL_SIZE	BIT(1)
45 #define IPSKB_XFRM_TRANSFORMED	BIT(2)
46 #define IPSKB_FRAG_COMPLETE	BIT(3)
47 #define IPSKB_REROUTED		BIT(4)
48 #define IPSKB_DOREDIRECT	BIT(5)
49 #define IPSKB_FRAG_PMTU		BIT(6)
50 #define IPSKB_L3SLAVE		BIT(7)
51 
52 	u16			frag_max_size;
53 };
54 
55 static inline bool ipv4_l3mdev_skb(u16 flags)
56 {
57 	return !!(flags & IPSKB_L3SLAVE);
58 }
59 
60 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
61 {
62 	return ip_hdr(skb)->ihl * 4;
63 }
64 
65 struct ipcm_cookie {
66 	struct sockcm_cookie	sockc;
67 	__be32			addr;
68 	int			oif;
69 	struct ip_options_rcu	*opt;
70 	__u8			tx_flags;
71 	__u8			ttl;
72 	__s16			tos;
73 	char			priority;
74 };
75 
76 #define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
77 #define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
78 
79 struct ip_ra_chain {
80 	struct ip_ra_chain __rcu *next;
81 	struct sock		*sk;
82 	union {
83 		void			(*destructor)(struct sock *);
84 		struct sock		*saved_sk;
85 	};
86 	struct rcu_head		rcu;
87 };
88 
89 extern struct ip_ra_chain __rcu *ip_ra_chain;
90 
91 /* IP flags. */
92 #define IP_CE		0x8000		/* Flag: "Congestion"		*/
93 #define IP_DF		0x4000		/* Flag: "Don't Fragment"	*/
94 #define IP_MF		0x2000		/* Flag: "More Fragments"	*/
95 #define IP_OFFSET	0x1FFF		/* "Fragment Offset" part	*/
96 
97 #define IP_FRAG_TIME	(30 * HZ)		/* fragment lifetime	*/
98 
99 struct msghdr;
100 struct net_device;
101 struct packet_type;
102 struct rtable;
103 struct sockaddr;
104 
105 int igmp_mc_init(void);
106 
107 /*
108  *	Functions provided by ip.c
109  */
110 
111 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
112 			  __be32 saddr, __be32 daddr,
113 			  struct ip_options_rcu *opt);
114 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
115 	   struct net_device *orig_dev);
116 int ip_local_deliver(struct sk_buff *skb);
117 int ip_mr_input(struct sk_buff *skb);
118 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
119 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
120 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
121 		   int (*output)(struct net *, struct sock *, struct sk_buff *));
122 void ip_send_check(struct iphdr *ip);
123 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
124 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
125 
126 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
127 void ip_init(void);
128 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
129 		   int getfrag(void *from, char *to, int offset, int len,
130 			       int odd, struct sk_buff *skb),
131 		   void *from, int len, int protolen,
132 		   struct ipcm_cookie *ipc,
133 		   struct rtable **rt,
134 		   unsigned int flags);
135 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
136 		       struct sk_buff *skb);
137 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
138 		       int offset, size_t size, int flags);
139 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
140 			      struct sk_buff_head *queue,
141 			      struct inet_cork *cork);
142 int ip_send_skb(struct net *net, struct sk_buff *skb);
143 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
144 void ip_flush_pending_frames(struct sock *sk);
145 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
146 			    int getfrag(void *from, char *to, int offset,
147 					int len, int odd, struct sk_buff *skb),
148 			    void *from, int length, int transhdrlen,
149 			    struct ipcm_cookie *ipc, struct rtable **rtp,
150 			    unsigned int flags);
151 
152 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
153 {
154 	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
155 }
156 
157 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
158 {
159 	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
160 }
161 
162 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
163 {
164 	return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
165 }
166 
167 /* datagram.c */
168 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
169 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
170 
171 void ip4_datagram_release_cb(struct sock *sk);
172 
173 struct ip_reply_arg {
174 	struct kvec iov[1];
175 	int	    flags;
176 	__wsum 	    csum;
177 	int	    csumoffset; /* u16 offset of csum in iov[0].iov_base */
178 				/* -1 if not needed */
179 	int	    bound_dev_if;
180 	u8  	    tos;
181 	kuid_t	    uid;
182 };
183 
184 #define IP_REPLY_ARG_NOSRCCHECK 1
185 
186 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
187 {
188 	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
189 }
190 
191 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
192 			   const struct ip_options *sopt,
193 			   __be32 daddr, __be32 saddr,
194 			   const struct ip_reply_arg *arg,
195 			   unsigned int len);
196 
197 #define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
198 #define __IP_INC_STATS(net, field)	__SNMP_INC_STATS64((net)->mib.ip_statistics, field)
199 #define IP_ADD_STATS(net, field, val)	SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
200 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
201 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
202 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
203 #define NET_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.net_statistics, field)
204 #define __NET_INC_STATS(net, field)	__SNMP_INC_STATS((net)->mib.net_statistics, field)
205 #define NET_ADD_STATS(net, field, adnd)	SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
206 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
207 
208 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
209 unsigned long snmp_fold_field(void __percpu *mib, int offt);
210 #if BITS_PER_LONG==32
211 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
212 			 size_t syncp_offset);
213 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
214 #else
215 static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
216 					size_t syncp_offset)
217 {
218 	return snmp_get_cpu_field(mib, cpu, offct);
219 
220 }
221 
222 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
223 {
224 	return snmp_fold_field(mib, offt);
225 }
226 #endif
227 
228 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
229 { \
230 	int i, c; \
231 	for_each_possible_cpu(c) { \
232 		for (i = 0; stats_list[i].name; i++) \
233 			buff64[i] += snmp_get_cpu_field64( \
234 					mib_statistic, \
235 					c, stats_list[i].entry, \
236 					offset); \
237 	} \
238 }
239 
240 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
241 { \
242 	int i, c; \
243 	for_each_possible_cpu(c) { \
244 		for (i = 0; stats_list[i].name; i++) \
245 			buff[i] += snmp_get_cpu_field( \
246 						mib_statistic, \
247 						c, stats_list[i].entry); \
248 	} \
249 }
250 
251 void inet_get_local_port_range(struct net *net, int *low, int *high);
252 
253 #ifdef CONFIG_SYSCTL
254 static inline int inet_is_local_reserved_port(struct net *net, int port)
255 {
256 	if (!net->ipv4.sysctl_local_reserved_ports)
257 		return 0;
258 	return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
259 }
260 
261 static inline bool sysctl_dev_name_is_allowed(const char *name)
262 {
263 	return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
264 }
265 
266 #else
267 static inline int inet_is_local_reserved_port(struct net *net, int port)
268 {
269 	return 0;
270 }
271 #endif
272 
273 __be32 inet_current_timestamp(void);
274 
275 /* From inetpeer.c */
276 extern int inet_peer_threshold;
277 extern int inet_peer_minttl;
278 extern int inet_peer_maxttl;
279 
280 void ipfrag_init(void);
281 
282 void ip_static_sysctl_init(void);
283 
284 #define IP4_REPLY_MARK(net, mark) \
285 	((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
286 
287 static inline bool ip_is_fragment(const struct iphdr *iph)
288 {
289 	return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
290 }
291 
292 #ifdef CONFIG_INET
293 #include <net/dst.h>
294 
295 /* The function in 2.2 was invalid, producing wrong result for
296  * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
297 static inline
298 int ip_decrease_ttl(struct iphdr *iph)
299 {
300 	u32 check = (__force u32)iph->check;
301 	check += (__force u32)htons(0x0100);
302 	iph->check = (__force __sum16)(check + (check>=0xFFFF));
303 	return --iph->ttl;
304 }
305 
306 static inline
307 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
308 {
309 	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
310 
311 	return  pmtudisc == IP_PMTUDISC_DO ||
312 		(pmtudisc == IP_PMTUDISC_WANT &&
313 		 !(dst_metric_locked(dst, RTAX_MTU)));
314 }
315 
316 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
317 {
318 	return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
319 	       inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
320 }
321 
322 static inline bool ip_sk_use_pmtu(const struct sock *sk)
323 {
324 	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
325 }
326 
327 static inline bool ip_sk_ignore_df(const struct sock *sk)
328 {
329 	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
330 	       inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
331 }
332 
333 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
334 						    bool forwarding)
335 {
336 	struct net *net = dev_net(dst->dev);
337 
338 	if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
339 	    dst_metric_locked(dst, RTAX_MTU) ||
340 	    !forwarding)
341 		return dst_mtu(dst);
342 
343 	return min(dst->dev->mtu, IP_MAX_MTU);
344 }
345 
346 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
347 					  const struct sk_buff *skb)
348 {
349 	if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
350 		bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
351 
352 		return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
353 	}
354 
355 	return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
356 }
357 
358 u32 ip_idents_reserve(u32 hash, int segs);
359 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
360 
361 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
362 					struct sock *sk, int segs)
363 {
364 	struct iphdr *iph = ip_hdr(skb);
365 
366 	if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
367 		/* This is only to work around buggy Windows95/2000
368 		 * VJ compression implementations.  If the ID field
369 		 * does not change, they drop every other packet in
370 		 * a TCP stream using header compression.
371 		 */
372 		if (sk && inet_sk(sk)->inet_daddr) {
373 			iph->id = htons(inet_sk(sk)->inet_id);
374 			inet_sk(sk)->inet_id += segs;
375 		} else {
376 			iph->id = 0;
377 		}
378 	} else {
379 		__ip_select_ident(net, iph, segs);
380 	}
381 }
382 
383 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
384 				   struct sock *sk)
385 {
386 	ip_select_ident_segs(net, skb, sk, 1);
387 }
388 
389 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
390 {
391 	return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
392 				  skb->len, proto, 0);
393 }
394 
395 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
396  * Equivalent to :	flow->v4addrs.src = iph->saddr;
397  *			flow->v4addrs.dst = iph->daddr;
398  */
399 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
400 					    const struct iphdr *iph)
401 {
402 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
403 		     offsetof(typeof(flow->addrs), v4addrs.src) +
404 			      sizeof(flow->addrs.v4addrs.src));
405 	memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
406 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
407 }
408 
409 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
410 {
411 	const struct iphdr *iph = skb_gro_network_header(skb);
412 
413 	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
414 				  skb_gro_len(skb), proto, 0);
415 }
416 
417 /*
418  *	Map a multicast IP onto multicast MAC for type ethernet.
419  */
420 
421 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
422 {
423 	__u32 addr=ntohl(naddr);
424 	buf[0]=0x01;
425 	buf[1]=0x00;
426 	buf[2]=0x5e;
427 	buf[5]=addr&0xFF;
428 	addr>>=8;
429 	buf[4]=addr&0xFF;
430 	addr>>=8;
431 	buf[3]=addr&0x7F;
432 }
433 
434 /*
435  *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
436  *	Leave P_Key as 0 to be filled in by driver.
437  */
438 
439 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
440 {
441 	__u32 addr;
442 	unsigned char scope = broadcast[5] & 0xF;
443 
444 	buf[0]  = 0;		/* Reserved */
445 	buf[1]  = 0xff;		/* Multicast QPN */
446 	buf[2]  = 0xff;
447 	buf[3]  = 0xff;
448 	addr    = ntohl(naddr);
449 	buf[4]  = 0xff;
450 	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
451 	buf[6]  = 0x40;		/* IPv4 signature */
452 	buf[7]  = 0x1b;
453 	buf[8]  = broadcast[8];		/* P_Key */
454 	buf[9]  = broadcast[9];
455 	buf[10] = 0;
456 	buf[11] = 0;
457 	buf[12] = 0;
458 	buf[13] = 0;
459 	buf[14] = 0;
460 	buf[15] = 0;
461 	buf[19] = addr & 0xff;
462 	addr  >>= 8;
463 	buf[18] = addr & 0xff;
464 	addr  >>= 8;
465 	buf[17] = addr & 0xff;
466 	addr  >>= 8;
467 	buf[16] = addr & 0x0f;
468 }
469 
470 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
471 {
472 	if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
473 		memcpy(buf, broadcast, 4);
474 	else
475 		memcpy(buf, &naddr, sizeof(naddr));
476 }
477 
478 #if IS_ENABLED(CONFIG_IPV6)
479 #include <linux/ipv6.h>
480 #endif
481 
482 static __inline__ void inet_reset_saddr(struct sock *sk)
483 {
484 	inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
485 #if IS_ENABLED(CONFIG_IPV6)
486 	if (sk->sk_family == PF_INET6) {
487 		struct ipv6_pinfo *np = inet6_sk(sk);
488 
489 		memset(&np->saddr, 0, sizeof(np->saddr));
490 		memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
491 	}
492 #endif
493 }
494 
495 #endif
496 
497 static inline unsigned int ipv4_addr_hash(__be32 ip)
498 {
499 	return (__force unsigned int) ip;
500 }
501 
502 bool ip_call_ra_chain(struct sk_buff *skb);
503 
504 /*
505  *	Functions provided by ip_fragment.c
506  */
507 
508 enum ip_defrag_users {
509 	IP_DEFRAG_LOCAL_DELIVER,
510 	IP_DEFRAG_CALL_RA_CHAIN,
511 	IP_DEFRAG_CONNTRACK_IN,
512 	__IP_DEFRAG_CONNTRACK_IN_END	= IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
513 	IP_DEFRAG_CONNTRACK_OUT,
514 	__IP_DEFRAG_CONNTRACK_OUT_END	= IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
515 	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
516 	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
517 	IP_DEFRAG_VS_IN,
518 	IP_DEFRAG_VS_OUT,
519 	IP_DEFRAG_VS_FWD,
520 	IP_DEFRAG_AF_PACKET,
521 	IP_DEFRAG_MACVLAN,
522 };
523 
524 /* Return true if the value of 'user' is between 'lower_bond'
525  * and 'upper_bond' inclusively.
526  */
527 static inline bool ip_defrag_user_in_between(u32 user,
528 					     enum ip_defrag_users lower_bond,
529 					     enum ip_defrag_users upper_bond)
530 {
531 	return user >= lower_bond && user <= upper_bond;
532 }
533 
534 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
535 #ifdef CONFIG_INET
536 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
537 #else
538 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
539 {
540 	return skb;
541 }
542 #endif
543 int ip_frag_mem(struct net *net);
544 
545 /*
546  *	Functions provided by ip_forward.c
547  */
548 
549 int ip_forward(struct sk_buff *skb);
550 
551 /*
552  *	Functions provided by ip_options.c
553  */
554 
555 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
556 		      __be32 daddr, struct rtable *rt, int is_frag);
557 
558 int __ip_options_echo(struct ip_options *dopt, struct sk_buff *skb,
559 		      const struct ip_options *sopt);
560 static inline int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
561 {
562 	return __ip_options_echo(dopt, skb, &IPCB(skb)->opt);
563 }
564 
565 void ip_options_fragment(struct sk_buff *skb);
566 int ip_options_compile(struct net *net, struct ip_options *opt,
567 		       struct sk_buff *skb);
568 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
569 		   unsigned char *data, int optlen);
570 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
571 			     unsigned char __user *data, int optlen);
572 void ip_options_undo(struct ip_options *opt);
573 void ip_forward_options(struct sk_buff *skb);
574 int ip_options_rcv_srr(struct sk_buff *skb);
575 
576 /*
577  *	Functions provided by ip_sockglue.c
578  */
579 
580 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
581 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
582 			 struct sk_buff *skb, int tlen, int offset);
583 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
584 		 struct ipcm_cookie *ipc, bool allow_ipv6);
585 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
586 		  unsigned int optlen);
587 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
588 		  int __user *optlen);
589 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
590 			 char __user *optval, unsigned int optlen);
591 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
592 			 char __user *optval, int __user *optlen);
593 int ip_ra_control(struct sock *sk, unsigned char on,
594 		  void (*destructor)(struct sock *));
595 
596 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
597 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
598 		   u32 info, u8 *payload);
599 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
600 		    u32 info);
601 
602 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
603 {
604 	ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
605 }
606 
607 bool icmp_global_allow(void);
608 extern int sysctl_icmp_msgs_per_sec;
609 extern int sysctl_icmp_msgs_burst;
610 
611 #ifdef CONFIG_PROC_FS
612 int ip_misc_proc_init(void);
613 #endif
614 
615 #endif	/* _IP_H */
616