xref: /openbmc/linux/include/net/ip.h (revision 60772e48)
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 
41 struct sock;
42 
43 struct 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 
60 static inline bool ipv4_l3mdev_skb(u16 flags)
61 {
62 	return !!(flags & IPSKB_L3SLAVE);
63 }
64 
65 static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
66 {
67 	return ip_hdr(skb)->ihl * 4;
68 }
69 
70 struct 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 */
85 static 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 struct ip_ra_chain {
95 	struct ip_ra_chain __rcu *next;
96 	struct sock		*sk;
97 	union {
98 		void			(*destructor)(struct sock *);
99 		struct sock		*saved_sk;
100 	};
101 	struct rcu_head		rcu;
102 };
103 
104 extern struct ip_ra_chain __rcu *ip_ra_chain;
105 
106 /* IP flags. */
107 #define IP_CE		0x8000		/* Flag: "Congestion"		*/
108 #define IP_DF		0x4000		/* Flag: "Don't Fragment"	*/
109 #define IP_MF		0x2000		/* Flag: "More Fragments"	*/
110 #define IP_OFFSET	0x1FFF		/* "Fragment Offset" part	*/
111 
112 #define IP_FRAG_TIME	(30 * HZ)		/* fragment lifetime	*/
113 
114 struct msghdr;
115 struct net_device;
116 struct packet_type;
117 struct rtable;
118 struct sockaddr;
119 
120 int igmp_mc_init(void);
121 
122 /*
123  *	Functions provided by ip.c
124  */
125 
126 int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
127 			  __be32 saddr, __be32 daddr,
128 			  struct ip_options_rcu *opt);
129 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
130 	   struct net_device *orig_dev);
131 int ip_local_deliver(struct sk_buff *skb);
132 int ip_mr_input(struct sk_buff *skb);
133 int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
134 int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
135 int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
136 		   int (*output)(struct net *, struct sock *, struct sk_buff *));
137 void ip_send_check(struct iphdr *ip);
138 int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
139 int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
140 
141 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
142 void ip_init(void);
143 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
144 		   int getfrag(void *from, char *to, int offset, int len,
145 			       int odd, struct sk_buff *skb),
146 		   void *from, int len, int protolen,
147 		   struct ipcm_cookie *ipc,
148 		   struct rtable **rt,
149 		   unsigned int flags);
150 int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
151 		       struct sk_buff *skb);
152 ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
153 		       int offset, size_t size, int flags);
154 struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
155 			      struct sk_buff_head *queue,
156 			      struct inet_cork *cork);
157 int ip_send_skb(struct net *net, struct sk_buff *skb);
158 int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
159 void ip_flush_pending_frames(struct sock *sk);
160 struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
161 			    int getfrag(void *from, char *to, int offset,
162 					int len, int odd, struct sk_buff *skb),
163 			    void *from, int length, int transhdrlen,
164 			    struct ipcm_cookie *ipc, struct rtable **rtp,
165 			    unsigned int flags);
166 
167 static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
168 {
169 	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
170 }
171 
172 static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
173 {
174 	return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
175 }
176 
177 static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
178 {
179 	return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
180 }
181 
182 /* datagram.c */
183 int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
184 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
185 
186 void ip4_datagram_release_cb(struct sock *sk);
187 
188 struct ip_reply_arg {
189 	struct kvec iov[1];
190 	int	    flags;
191 	__wsum 	    csum;
192 	int	    csumoffset; /* u16 offset of csum in iov[0].iov_base */
193 				/* -1 if not needed */
194 	int	    bound_dev_if;
195 	u8  	    tos;
196 	kuid_t	    uid;
197 };
198 
199 #define IP_REPLY_ARG_NOSRCCHECK 1
200 
201 static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
202 {
203 	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
204 }
205 
206 void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
207 			   const struct ip_options *sopt,
208 			   __be32 daddr, __be32 saddr,
209 			   const struct ip_reply_arg *arg,
210 			   unsigned int len);
211 
212 #define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
213 #define __IP_INC_STATS(net, field)	__SNMP_INC_STATS64((net)->mib.ip_statistics, field)
214 #define IP_ADD_STATS(net, field, val)	SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
215 #define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
216 #define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
217 #define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
218 #define NET_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.net_statistics, field)
219 #define __NET_INC_STATS(net, field)	__SNMP_INC_STATS((net)->mib.net_statistics, field)
220 #define NET_ADD_STATS(net, field, adnd)	SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
221 #define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
222 
223 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
224 unsigned long snmp_fold_field(void __percpu *mib, int offt);
225 #if BITS_PER_LONG==32
226 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
227 			 size_t syncp_offset);
228 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
229 #else
230 static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
231 					size_t syncp_offset)
232 {
233 	return snmp_get_cpu_field(mib, cpu, offct);
234 
235 }
236 
237 static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
238 {
239 	return snmp_fold_field(mib, offt);
240 }
241 #endif
242 
243 #define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
244 { \
245 	int i, c; \
246 	for_each_possible_cpu(c) { \
247 		for (i = 0; stats_list[i].name; i++) \
248 			buff64[i] += snmp_get_cpu_field64( \
249 					mib_statistic, \
250 					c, stats_list[i].entry, \
251 					offset); \
252 	} \
253 }
254 
255 #define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
256 { \
257 	int i, c; \
258 	for_each_possible_cpu(c) { \
259 		for (i = 0; stats_list[i].name; i++) \
260 			buff[i] += snmp_get_cpu_field( \
261 						mib_statistic, \
262 						c, stats_list[i].entry); \
263 	} \
264 }
265 
266 void inet_get_local_port_range(struct net *net, int *low, int *high);
267 
268 #ifdef CONFIG_SYSCTL
269 static inline int inet_is_local_reserved_port(struct net *net, int port)
270 {
271 	if (!net->ipv4.sysctl_local_reserved_ports)
272 		return 0;
273 	return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
274 }
275 
276 static inline bool sysctl_dev_name_is_allowed(const char *name)
277 {
278 	return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
279 }
280 
281 static inline int inet_prot_sock(struct net *net)
282 {
283 	return net->ipv4.sysctl_ip_prot_sock;
284 }
285 
286 #else
287 static inline int inet_is_local_reserved_port(struct net *net, int port)
288 {
289 	return 0;
290 }
291 
292 static inline int inet_prot_sock(struct net *net)
293 {
294 	return PROT_SOCK;
295 }
296 #endif
297 
298 __be32 inet_current_timestamp(void);
299 
300 /* From inetpeer.c */
301 extern int inet_peer_threshold;
302 extern int inet_peer_minttl;
303 extern int inet_peer_maxttl;
304 
305 void ipfrag_init(void);
306 
307 void ip_static_sysctl_init(void);
308 
309 #define IP4_REPLY_MARK(net, mark) \
310 	((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
311 
312 static inline bool ip_is_fragment(const struct iphdr *iph)
313 {
314 	return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
315 }
316 
317 #ifdef CONFIG_INET
318 #include <net/dst.h>
319 
320 /* The function in 2.2 was invalid, producing wrong result for
321  * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
322 static inline
323 int ip_decrease_ttl(struct iphdr *iph)
324 {
325 	u32 check = (__force u32)iph->check;
326 	check += (__force u32)htons(0x0100);
327 	iph->check = (__force __sum16)(check + (check>=0xFFFF));
328 	return --iph->ttl;
329 }
330 
331 static inline
332 int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
333 {
334 	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
335 
336 	return  pmtudisc == IP_PMTUDISC_DO ||
337 		(pmtudisc == IP_PMTUDISC_WANT &&
338 		 !(dst_metric_locked(dst, RTAX_MTU)));
339 }
340 
341 static inline bool ip_sk_accept_pmtu(const struct sock *sk)
342 {
343 	return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
344 	       inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
345 }
346 
347 static inline bool ip_sk_use_pmtu(const struct sock *sk)
348 {
349 	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
350 }
351 
352 static inline bool ip_sk_ignore_df(const struct sock *sk)
353 {
354 	return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
355 	       inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
356 }
357 
358 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
359 						    bool forwarding)
360 {
361 	struct net *net = dev_net(dst->dev);
362 
363 	if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
364 	    dst_metric_locked(dst, RTAX_MTU) ||
365 	    !forwarding)
366 		return dst_mtu(dst);
367 
368 	return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
369 }
370 
371 static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
372 					  const struct sk_buff *skb)
373 {
374 	if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
375 		bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
376 
377 		return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
378 	}
379 
380 	return min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
381 }
382 
383 u32 ip_idents_reserve(u32 hash, int segs);
384 void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
385 
386 static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
387 					struct sock *sk, int segs)
388 {
389 	struct iphdr *iph = ip_hdr(skb);
390 
391 	if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
392 		/* This is only to work around buggy Windows95/2000
393 		 * VJ compression implementations.  If the ID field
394 		 * does not change, they drop every other packet in
395 		 * a TCP stream using header compression.
396 		 */
397 		if (sk && inet_sk(sk)->inet_daddr) {
398 			iph->id = htons(inet_sk(sk)->inet_id);
399 			inet_sk(sk)->inet_id += segs;
400 		} else {
401 			iph->id = 0;
402 		}
403 	} else {
404 		__ip_select_ident(net, iph, segs);
405 	}
406 }
407 
408 static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
409 				   struct sock *sk)
410 {
411 	ip_select_ident_segs(net, skb, sk, 1);
412 }
413 
414 static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
415 {
416 	return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
417 				  skb->len, proto, 0);
418 }
419 
420 /* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
421  * Equivalent to :	flow->v4addrs.src = iph->saddr;
422  *			flow->v4addrs.dst = iph->daddr;
423  */
424 static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
425 					    const struct iphdr *iph)
426 {
427 	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
428 		     offsetof(typeof(flow->addrs), v4addrs.src) +
429 			      sizeof(flow->addrs.v4addrs.src));
430 	memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
431 	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
432 }
433 
434 static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
435 {
436 	const struct iphdr *iph = skb_gro_network_header(skb);
437 
438 	return csum_tcpudp_nofold(iph->saddr, iph->daddr,
439 				  skb_gro_len(skb), proto, 0);
440 }
441 
442 /*
443  *	Map a multicast IP onto multicast MAC for type ethernet.
444  */
445 
446 static inline void ip_eth_mc_map(__be32 naddr, char *buf)
447 {
448 	__u32 addr=ntohl(naddr);
449 	buf[0]=0x01;
450 	buf[1]=0x00;
451 	buf[2]=0x5e;
452 	buf[5]=addr&0xFF;
453 	addr>>=8;
454 	buf[4]=addr&0xFF;
455 	addr>>=8;
456 	buf[3]=addr&0x7F;
457 }
458 
459 /*
460  *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
461  *	Leave P_Key as 0 to be filled in by driver.
462  */
463 
464 static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
465 {
466 	__u32 addr;
467 	unsigned char scope = broadcast[5] & 0xF;
468 
469 	buf[0]  = 0;		/* Reserved */
470 	buf[1]  = 0xff;		/* Multicast QPN */
471 	buf[2]  = 0xff;
472 	buf[3]  = 0xff;
473 	addr    = ntohl(naddr);
474 	buf[4]  = 0xff;
475 	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
476 	buf[6]  = 0x40;		/* IPv4 signature */
477 	buf[7]  = 0x1b;
478 	buf[8]  = broadcast[8];		/* P_Key */
479 	buf[9]  = broadcast[9];
480 	buf[10] = 0;
481 	buf[11] = 0;
482 	buf[12] = 0;
483 	buf[13] = 0;
484 	buf[14] = 0;
485 	buf[15] = 0;
486 	buf[19] = addr & 0xff;
487 	addr  >>= 8;
488 	buf[18] = addr & 0xff;
489 	addr  >>= 8;
490 	buf[17] = addr & 0xff;
491 	addr  >>= 8;
492 	buf[16] = addr & 0x0f;
493 }
494 
495 static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
496 {
497 	if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
498 		memcpy(buf, broadcast, 4);
499 	else
500 		memcpy(buf, &naddr, sizeof(naddr));
501 }
502 
503 #if IS_ENABLED(CONFIG_IPV6)
504 #include <linux/ipv6.h>
505 #endif
506 
507 static __inline__ void inet_reset_saddr(struct sock *sk)
508 {
509 	inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
510 #if IS_ENABLED(CONFIG_IPV6)
511 	if (sk->sk_family == PF_INET6) {
512 		struct ipv6_pinfo *np = inet6_sk(sk);
513 
514 		memset(&np->saddr, 0, sizeof(np->saddr));
515 		memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
516 	}
517 #endif
518 }
519 
520 #endif
521 
522 static inline unsigned int ipv4_addr_hash(__be32 ip)
523 {
524 	return (__force unsigned int) ip;
525 }
526 
527 static inline u32 ipv4_portaddr_hash(const struct net *net,
528 				     __be32 saddr,
529 				     unsigned int port)
530 {
531 	return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
532 }
533 
534 bool ip_call_ra_chain(struct sk_buff *skb);
535 
536 /*
537  *	Functions provided by ip_fragment.c
538  */
539 
540 enum ip_defrag_users {
541 	IP_DEFRAG_LOCAL_DELIVER,
542 	IP_DEFRAG_CALL_RA_CHAIN,
543 	IP_DEFRAG_CONNTRACK_IN,
544 	__IP_DEFRAG_CONNTRACK_IN_END	= IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
545 	IP_DEFRAG_CONNTRACK_OUT,
546 	__IP_DEFRAG_CONNTRACK_OUT_END	= IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
547 	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
548 	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
549 	IP_DEFRAG_VS_IN,
550 	IP_DEFRAG_VS_OUT,
551 	IP_DEFRAG_VS_FWD,
552 	IP_DEFRAG_AF_PACKET,
553 	IP_DEFRAG_MACVLAN,
554 };
555 
556 /* Return true if the value of 'user' is between 'lower_bond'
557  * and 'upper_bond' inclusively.
558  */
559 static inline bool ip_defrag_user_in_between(u32 user,
560 					     enum ip_defrag_users lower_bond,
561 					     enum ip_defrag_users upper_bond)
562 {
563 	return user >= lower_bond && user <= upper_bond;
564 }
565 
566 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
567 #ifdef CONFIG_INET
568 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
569 #else
570 static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
571 {
572 	return skb;
573 }
574 #endif
575 int ip_frag_mem(struct net *net);
576 
577 /*
578  *	Functions provided by ip_forward.c
579  */
580 
581 int ip_forward(struct sk_buff *skb);
582 
583 /*
584  *	Functions provided by ip_options.c
585  */
586 
587 void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
588 		      __be32 daddr, struct rtable *rt, int is_frag);
589 
590 int __ip_options_echo(struct net *net, struct ip_options *dopt,
591 		      struct sk_buff *skb, const struct ip_options *sopt);
592 static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
593 				  struct sk_buff *skb)
594 {
595 	return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
596 }
597 
598 void ip_options_fragment(struct sk_buff *skb);
599 int ip_options_compile(struct net *net, struct ip_options *opt,
600 		       struct sk_buff *skb);
601 int ip_options_get(struct net *net, struct ip_options_rcu **optp,
602 		   unsigned char *data, int optlen);
603 int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
604 			     unsigned char __user *data, int optlen);
605 void ip_options_undo(struct ip_options *opt);
606 void ip_forward_options(struct sk_buff *skb);
607 int ip_options_rcv_srr(struct sk_buff *skb);
608 
609 /*
610  *	Functions provided by ip_sockglue.c
611  */
612 
613 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
614 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
615 			 struct sk_buff *skb, int tlen, int offset);
616 int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
617 		 struct ipcm_cookie *ipc, bool allow_ipv6);
618 int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
619 		  unsigned int optlen);
620 int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
621 		  int __user *optlen);
622 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
623 			 char __user *optval, unsigned int optlen);
624 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
625 			 char __user *optval, int __user *optlen);
626 int ip_ra_control(struct sock *sk, unsigned char on,
627 		  void (*destructor)(struct sock *));
628 
629 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
630 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
631 		   u32 info, u8 *payload);
632 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
633 		    u32 info);
634 
635 static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
636 {
637 	ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
638 }
639 
640 bool icmp_global_allow(void);
641 extern int sysctl_icmp_msgs_per_sec;
642 extern int sysctl_icmp_msgs_burst;
643 
644 #ifdef CONFIG_PROC_FS
645 int ip_misc_proc_init(void);
646 #endif
647 
648 #endif	/* _IP_H */
649