xref: /linux/include/net/ip.h (revision b24413180f5600bcb3bb70fbed5cf186b60864bd)
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 /* return enslaved device index if relevant */
82 static inline int inet_sdif(struct sk_buff *skb)
83 {
84 #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
85 	if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
86 		return IPCB(skb)->iif;
87 #endif
88 	return 0;
89 }
90 
91 struct ip_ra_chain {
92 	struct ip_ra_chain __rcu *next;
93 	struct sock		*sk;
94 	union {
95 		void			(*destructor)(struct sock *);
96 		struct sock		*saved_sk;
97 	};
98 	struct rcu_head		rcu;
99 };
100 
101 extern struct ip_ra_chain __rcu *ip_ra_chain;
102 
103 /* IP flags. */
104 #define IP_CE		0x8000		/* Flag: "Congestion"		*/
105 #define IP_DF		0x4000		/* Flag: "Don't Fragment"	*/
106 #define IP_MF		0x2000		/* Flag: "More Fragments"	*/
107 #define IP_OFFSET	0x1FFF		/* "Fragment Offset" part	*/
108 
109 #define IP_FRAG_TIME	(30 * HZ)		/* fragment lifetime	*/
110 
111 struct msghdr;
112 struct net_device;
113 struct packet_type;
114 struct rtable;
115 struct sockaddr;
116 
117 int igmp_mc_init(void);
118 
119 /*
120  *	Functions provided by ip.c
121  */
122 
123 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
124 			  __be32 saddr, __be32 daddr,
125 			  struct ip_options_rcu *opt);
126 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
127 	   struct net_device *orig_dev);
128 int ip_local_deliver(struct sk_buff *skb);
129 int ip_mr_input(struct sk_buff *skb);
130 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
131 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
132 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
133 		   int (*output)(struct net *, struct sock *, struct sk_buff *));
134 void ip_send_check(struct iphdr *ip);
135 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
136 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
137 
138 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
139 void ip_init(void);
140 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
141 		   int getfrag(void *from, char *to, int offset, int len,
142 			       int odd, struct sk_buff *skb),
143 		   void *from, int len, int protolen,
144 		   struct ipcm_cookie *ipc,
145 		   struct rtable **rt,
146 		   unsigned int flags);
147 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
148 		       struct sk_buff *skb);
149 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
150 		       int offset, size_t size, int flags);
151 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
152 			      struct sk_buff_head *queue,
153 			      struct inet_cork *cork);
154 int ip_send_skb(struct net *net, struct sk_buff *skb);
155 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
156 void ip_flush_pending_frames(struct sock *sk);
157 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
158 			    int getfrag(void *from, char *to, int offset,
159 					int len, int odd, struct sk_buff *skb),
160 			    void *from, int length, int transhdrlen,
161 			    struct ipcm_cookie *ipc, struct rtable **rtp,
162 			    unsigned int flags);
163 
164 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
165 {
166 	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
167 }
168 
169 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
170 {
171 	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
172 }
173 
174 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
175 {
176 	return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
177 }
178 
179 /* datagram.c */
180 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
181 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
182 
183 void ip4_datagram_release_cb(struct sock *sk);
184 
185 struct ip_reply_arg {
186 	struct kvec iov[1];
187 	int	    flags;
188 	__wsum 	    csum;
189 	int	    csumoffset; /* u16 offset of csum in iov[0].iov_base */
190 				/* -1 if not needed */
191 	int	    bound_dev_if;
192 	u8  	    tos;
193 	kuid_t	    uid;
194 };
195 
196 #define IP_REPLY_ARG_NOSRCCHECK 1
197 
198 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
199 {
200 	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
201 }
202 
203 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
204 			   const struct ip_options *sopt,
205 			   __be32 daddr, __be32 saddr,
206 			   const struct ip_reply_arg *arg,
207 			   unsigned int len);
208 
209 #define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
210 #define __IP_INC_STATS(net, field)	__SNMP_INC_STATS64((net)->mib.ip_statistics, field)
211 #define IP_ADD_STATS(net, field, val)	SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
212 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
213 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
214 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
215 #define NET_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.net_statistics, field)
216 #define __NET_INC_STATS(net, field)	__SNMP_INC_STATS((net)->mib.net_statistics, field)
217 #define NET_ADD_STATS(net, field, adnd)	SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
218 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
219 
220 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
221 unsigned long snmp_fold_field(void __percpu *mib, int offt);
222 #if BITS_PER_LONG==32
223 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
224 			 size_t syncp_offset);
225 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
226 #else
227 static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
228 					size_t syncp_offset)
229 {
230 	return snmp_get_cpu_field(mib, cpu, offct);
231 
232 }
233 
234 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
235 {
236 	return snmp_fold_field(mib, offt);
237 }
238 #endif
239 
240 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
241 { \
242 	int i, c; \
243 	for_each_possible_cpu(c) { \
244 		for (i = 0; stats_list[i].name; i++) \
245 			buff64[i] += snmp_get_cpu_field64( \
246 					mib_statistic, \
247 					c, stats_list[i].entry, \
248 					offset); \
249 	} \
250 }
251 
252 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
253 { \
254 	int i, c; \
255 	for_each_possible_cpu(c) { \
256 		for (i = 0; stats_list[i].name; i++) \
257 			buff[i] += snmp_get_cpu_field( \
258 						mib_statistic, \
259 						c, stats_list[i].entry); \
260 	} \
261 }
262 
263 void inet_get_local_port_range(struct net *net, int *low, int *high);
264 
265 #ifdef CONFIG_SYSCTL
266 static inline int inet_is_local_reserved_port(struct net *net, int port)
267 {
268 	if (!net->ipv4.sysctl_local_reserved_ports)
269 		return 0;
270 	return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
271 }
272 
273 static inline bool sysctl_dev_name_is_allowed(const char *name)
274 {
275 	return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
276 }
277 
278 static inline int inet_prot_sock(struct net *net)
279 {
280 	return net->ipv4.sysctl_ip_prot_sock;
281 }
282 
283 #else
284 static inline int inet_is_local_reserved_port(struct net *net, int port)
285 {
286 	return 0;
287 }
288 
289 static inline int inet_prot_sock(struct net *net)
290 {
291 	return PROT_SOCK;
292 }
293 #endif
294 
295 __be32 inet_current_timestamp(void);
296 
297 /* From inetpeer.c */
298 extern int inet_peer_threshold;
299 extern int inet_peer_minttl;
300 extern int inet_peer_maxttl;
301 
302 void ipfrag_init(void);
303 
304 void ip_static_sysctl_init(void);
305 
306 #define IP4_REPLY_MARK(net, mark) \
307 	((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
308 
309 static inline bool ip_is_fragment(const struct iphdr *iph)
310 {
311 	return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
312 }
313 
314 #ifdef CONFIG_INET
315 #include <net/dst.h>
316 
317 /* The function in 2.2 was invalid, producing wrong result for
318  * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
319 static inline
320 int ip_decrease_ttl(struct iphdr *iph)
321 {
322 	u32 check = (__force u32)iph->check;
323 	check += (__force u32)htons(0x0100);
324 	iph->check = (__force __sum16)(check + (check>=0xFFFF));
325 	return --iph->ttl;
326 }
327 
328 static inline
329 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
330 {
331 	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
332 
333 	return  pmtudisc == IP_PMTUDISC_DO ||
334 		(pmtudisc == IP_PMTUDISC_WANT &&
335 		 !(dst_metric_locked(dst, RTAX_MTU)));
336 }
337 
338 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
339 {
340 	return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
341 	       inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
342 }
343 
344 static inline bool ip_sk_use_pmtu(const struct sock *sk)
345 {
346 	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
347 }
348 
349 static inline bool ip_sk_ignore_df(const struct sock *sk)
350 {
351 	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
352 	       inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
353 }
354 
355 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
356 						    bool forwarding)
357 {
358 	struct net *net = dev_net(dst->dev);
359 
360 	if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
361 	    dst_metric_locked(dst, RTAX_MTU) ||
362 	    !forwarding)
363 		return dst_mtu(dst);
364 
365 	return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
366 }
367 
368 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
369 					  const struct sk_buff *skb)
370 {
371 	if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
372 		bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
373 
374 		return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
375 	}
376 
377 	return min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
378 }
379 
380 u32 ip_idents_reserve(u32 hash, int segs);
381 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
382 
383 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
384 					struct sock *sk, int segs)
385 {
386 	struct iphdr *iph = ip_hdr(skb);
387 
388 	if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
389 		/* This is only to work around buggy Windows95/2000
390 		 * VJ compression implementations.  If the ID field
391 		 * does not change, they drop every other packet in
392 		 * a TCP stream using header compression.
393 		 */
394 		if (sk && inet_sk(sk)->inet_daddr) {
395 			iph->id = htons(inet_sk(sk)->inet_id);
396 			inet_sk(sk)->inet_id += segs;
397 		} else {
398 			iph->id = 0;
399 		}
400 	} else {
401 		__ip_select_ident(net, iph, segs);
402 	}
403 }
404 
405 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
406 				   struct sock *sk)
407 {
408 	ip_select_ident_segs(net, skb, sk, 1);
409 }
410 
411 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
412 {
413 	return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
414 				  skb->len, proto, 0);
415 }
416 
417 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
418  * Equivalent to :	flow->v4addrs.src = iph->saddr;
419  *			flow->v4addrs.dst = iph->daddr;
420  */
421 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
422 					    const struct iphdr *iph)
423 {
424 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
425 		     offsetof(typeof(flow->addrs), v4addrs.src) +
426 			      sizeof(flow->addrs.v4addrs.src));
427 	memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
428 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
429 }
430 
431 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
432 {
433 	const struct iphdr *iph = skb_gro_network_header(skb);
434 
435 	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
436 				  skb_gro_len(skb), proto, 0);
437 }
438 
439 /*
440  *	Map a multicast IP onto multicast MAC for type ethernet.
441  */
442 
443 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
444 {
445 	__u32 addr=ntohl(naddr);
446 	buf[0]=0x01;
447 	buf[1]=0x00;
448 	buf[2]=0x5e;
449 	buf[5]=addr&0xFF;
450 	addr>>=8;
451 	buf[4]=addr&0xFF;
452 	addr>>=8;
453 	buf[3]=addr&0x7F;
454 }
455 
456 /*
457  *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
458  *	Leave P_Key as 0 to be filled in by driver.
459  */
460 
461 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
462 {
463 	__u32 addr;
464 	unsigned char scope = broadcast[5] & 0xF;
465 
466 	buf[0]  = 0;		/* Reserved */
467 	buf[1]  = 0xff;		/* Multicast QPN */
468 	buf[2]  = 0xff;
469 	buf[3]  = 0xff;
470 	addr    = ntohl(naddr);
471 	buf[4]  = 0xff;
472 	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
473 	buf[6]  = 0x40;		/* IPv4 signature */
474 	buf[7]  = 0x1b;
475 	buf[8]  = broadcast[8];		/* P_Key */
476 	buf[9]  = broadcast[9];
477 	buf[10] = 0;
478 	buf[11] = 0;
479 	buf[12] = 0;
480 	buf[13] = 0;
481 	buf[14] = 0;
482 	buf[15] = 0;
483 	buf[19] = addr & 0xff;
484 	addr  >>= 8;
485 	buf[18] = addr & 0xff;
486 	addr  >>= 8;
487 	buf[17] = addr & 0xff;
488 	addr  >>= 8;
489 	buf[16] = addr & 0x0f;
490 }
491 
492 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
493 {
494 	if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
495 		memcpy(buf, broadcast, 4);
496 	else
497 		memcpy(buf, &naddr, sizeof(naddr));
498 }
499 
500 #if IS_ENABLED(CONFIG_IPV6)
501 #include <linux/ipv6.h>
502 #endif
503 
504 static __inline__ void inet_reset_saddr(struct sock *sk)
505 {
506 	inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
507 #if IS_ENABLED(CONFIG_IPV6)
508 	if (sk->sk_family == PF_INET6) {
509 		struct ipv6_pinfo *np = inet6_sk(sk);
510 
511 		memset(&np->saddr, 0, sizeof(np->saddr));
512 		memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
513 	}
514 #endif
515 }
516 
517 #endif
518 
519 static inline unsigned int ipv4_addr_hash(__be32 ip)
520 {
521 	return (__force unsigned int) ip;
522 }
523 
524 bool ip_call_ra_chain(struct sk_buff *skb);
525 
526 /*
527  *	Functions provided by ip_fragment.c
528  */
529 
530 enum ip_defrag_users {
531 	IP_DEFRAG_LOCAL_DELIVER,
532 	IP_DEFRAG_CALL_RA_CHAIN,
533 	IP_DEFRAG_CONNTRACK_IN,
534 	__IP_DEFRAG_CONNTRACK_IN_END	= IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
535 	IP_DEFRAG_CONNTRACK_OUT,
536 	__IP_DEFRAG_CONNTRACK_OUT_END	= IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
537 	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
538 	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
539 	IP_DEFRAG_VS_IN,
540 	IP_DEFRAG_VS_OUT,
541 	IP_DEFRAG_VS_FWD,
542 	IP_DEFRAG_AF_PACKET,
543 	IP_DEFRAG_MACVLAN,
544 };
545 
546 /* Return true if the value of 'user' is between 'lower_bond'
547  * and 'upper_bond' inclusively.
548  */
549 static inline bool ip_defrag_user_in_between(u32 user,
550 					     enum ip_defrag_users lower_bond,
551 					     enum ip_defrag_users upper_bond)
552 {
553 	return user >= lower_bond && user <= upper_bond;
554 }
555 
556 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
557 #ifdef CONFIG_INET
558 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
559 #else
560 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
561 {
562 	return skb;
563 }
564 #endif
565 int ip_frag_mem(struct net *net);
566 
567 /*
568  *	Functions provided by ip_forward.c
569  */
570 
571 int ip_forward(struct sk_buff *skb);
572 
573 /*
574  *	Functions provided by ip_options.c
575  */
576 
577 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
578 		      __be32 daddr, struct rtable *rt, int is_frag);
579 
580 int __ip_options_echo(struct net *net, struct ip_options *dopt,
581 		      struct sk_buff *skb, const struct ip_options *sopt);
582 static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
583 				  struct sk_buff *skb)
584 {
585 	return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
586 }
587 
588 void ip_options_fragment(struct sk_buff *skb);
589 int ip_options_compile(struct net *net, struct ip_options *opt,
590 		       struct sk_buff *skb);
591 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
592 		   unsigned char *data, int optlen);
593 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
594 			     unsigned char __user *data, int optlen);
595 void ip_options_undo(struct ip_options *opt);
596 void ip_forward_options(struct sk_buff *skb);
597 int ip_options_rcv_srr(struct sk_buff *skb);
598 
599 /*
600  *	Functions provided by ip_sockglue.c
601  */
602 
603 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
604 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
605 			 struct sk_buff *skb, int tlen, int offset);
606 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
607 		 struct ipcm_cookie *ipc, bool allow_ipv6);
608 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
609 		  unsigned int optlen);
610 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
611 		  int __user *optlen);
612 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
613 			 char __user *optval, unsigned int optlen);
614 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
615 			 char __user *optval, int __user *optlen);
616 int ip_ra_control(struct sock *sk, unsigned char on,
617 		  void (*destructor)(struct sock *));
618 
619 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
620 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
621 		   u32 info, u8 *payload);
622 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
623 		    u32 info);
624 
625 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
626 {
627 	ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
628 }
629 
630 bool icmp_global_allow(void);
631 extern int sysctl_icmp_msgs_per_sec;
632 extern int sysctl_icmp_msgs_burst;
633 
634 #ifdef CONFIG_PROC_FS
635 int ip_misc_proc_init(void);
636 #endif
637 
638 #endif	/* _IP_H */
639