xref: /xnu-10063.121.3/bsd/netinet/in_var.h (revision 2c2f96dc2b9a4408a43d3150ae9c105355ca3daa) !
1 /*
2  * Copyright (c) 2000-2021 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /*
29  * Copyright (c) 1985, 1986, 1993
30  *	The Regents of the University of California.  All rights reserved.
31  *
32  * Redistribution and use in source and binary forms, with or without
33  * modification, are permitted provided that the following conditions
34  * are met:
35  * 1. Redistributions of source code must retain the above copyright
36  *    notice, this list of conditions and the following disclaimer.
37  * 2. Redistributions in binary form must reproduce the above copyright
38  *    notice, this list of conditions and the following disclaimer in the
39  *    documentation and/or other materials provided with the distribution.
40  * 3. All advertising materials mentioning features or use of this software
41  *    must display the following acknowledgement:
42  *	This product includes software developed by the University of
43  *	California, Berkeley and its contributors.
44  * 4. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)in_var.h	8.2 (Berkeley) 1/9/95
61  */
62 
63 #ifndef _NETINET_IN_VAR_H_
64 #define _NETINET_IN_VAR_H_
65 #include <sys/appleapiopts.h>
66 
67 #include <sys/queue.h>
68 #include <sys/kern_event.h>
69 #include <net/if_var.h>
70 #include <net/net_kev.h>
71 #include <netinet/in.h>
72 
73 #ifdef BSD_KERNEL_PRIVATE
74 #include <net/route.h>
75 
76 /*
77  * Interface address, Internet version.  One of these structures
78  * is allocated for each Internet address on an interface.
79  * The ifaddr structure contains the protocol-independent part
80  * of the structure and is assumed to be first.
81  */
82 struct in_ifaddr {
83 	struct ifaddr ia_ifa;           /* protocol-independent info */
84 #define ia_ifp          ia_ifa.ifa_ifp
85 #define ia_flags        ia_ifa.ifa_flags
86 	/* ia_{,sub}net{,mask} in host order */
87 	u_int32_t ia_net;               /* network number of interface */
88 	u_int32_t ia_netmask;           /* mask of net part */
89 	u_int32_t ia_subnet;            /* subnet number, including net */
90 	u_int32_t ia_subnetmask;        /* mask of subnet part */
91 	struct in_addr ia_netbroadcast; /* to recognize net broadcasts */
92 	TAILQ_ENTRY(in_ifaddr) ia_link; /* tailq macro glue */
93 	struct sockaddr_in ia_addr;     /* reserve space for interface name */
94 	struct sockaddr_in ia_dstaddr;  /* reserve space for broadcast addr */
95 #define ia_broadaddr    ia_dstaddr
96 	struct sockaddr_in ia_sockmask; /* reserve space for general netmask */
97 	TAILQ_ENTRY(in_ifaddr) ia_hash; /* hash bucket entry */
98 };
99 
100 #define ifatoia(ifa)    ((struct in_ifaddr *)(void *)(ifa))
101 #endif /* BSD_KERNEL_PRIVATE */
102 
103 struct in_aliasreq {
104 	char ifra_name[IFNAMSIZ];       /* if name, e.g. "en0" */
105 	struct sockaddr_in ifra_addr;
106 	struct sockaddr_in ifra_broadaddr;
107 #define ifra_dstaddr    ifra_broadaddr
108 	struct sockaddr_in ifra_mask;
109 };
110 
111 /*
112  * Event data, inet style.
113  */
114 struct kev_in_data {
115 	struct net_event_data link_data;
116 	struct in_addr ia_addr;         /* interface address */
117 	u_int32_t ia_net;               /* network number of interface */
118 	u_int32_t ia_netmask;           /* mask of net part */
119 	u_int32_t ia_subnet;            /* subnet number, including net */
120 	u_int32_t ia_subnetmask;        /* mask of subnet part */
121 	struct in_addr ia_netbroadcast; /* to recognize net broadcasts */
122 	struct in_addr ia_dstaddr;
123 };
124 
125 struct kev_in_collision {
126 	struct net_event_data link_data; /* link where ARP was received on */
127 	struct in_addr ia_ipaddr;       /* conflicting IP address */
128 	u_char hw_len;                  /* length of hardware address */
129 	u_char hw_addr[0];              /* variable length hardware address */
130 };
131 
132 struct kev_in_arpfailure {
133 	struct net_event_data link_data; /* link where ARP is being sent */
134 };
135 
136 struct kev_in_arpalive {
137 	struct net_event_data link_data; /* link where ARP was received */
138 };
139 
140 #ifdef PRIVATE
141 /*
142  * Common structure for KEV_SOCKET_SUBCLASS
143  * Have to place here to avoid declaration dependencies.
144  */
145 struct kev_socket_event_data {
146 	union sockaddr_in_4_6 kev_sockname;
147 	union sockaddr_in_4_6 kev_peername;
148 };
149 
150 struct kev_socket_closed {
151 	struct kev_socket_event_data ev_data;
152 };
153 #endif /* PRIVATE */
154 
155 #ifdef __APPLE_API_PRIVATE
156 struct kev_in_portinuse {
157 	u_int16_t port;         /* conflicting port number in host order */
158 	u_int32_t req_pid;      /* PID port requestor */
159 	u_int32_t reserved[2];
160 };
161 #endif /* __APPLE_API_PRIVATE */
162 
163 #ifdef BSD_KERNEL_PRIVATE
164 extern void socket_post_kev_msg(uint32_t, struct kev_socket_event_data *,
165     uint32_t);
166 extern void socket_post_kev_msg_closed(struct socket *);
167 
168 #include <net/if.h>
169 #include <net/if_var.h>
170 #include <kern/locks.h>
171 #include <sys/tree.h>
172 /*
173  * Given a pointer to an in_ifaddr (ifaddr),
174  * return a pointer to the addr as a sockaddr_in.
175  */
176 #define IA_SIN(ia)    (&(((struct in_ifaddr *)(ia))->ia_addr))
177 #define IA_DSTSIN(ia) (&(((struct in_ifaddr *)(ia))->ia_dstaddr))
178 
179 #define IN_LNAOF(in, ifa) \
180 	((ntohl((in).s_addr) & ~((struct in_ifaddr *)(ifa)->ia_subnetmask))
181 
182 /*
183  * Hash table for IPv4 addresses.
184  */
185 extern TAILQ_HEAD(in_ifaddrhead, in_ifaddr) in_ifaddrhead;
186 TAILQ_HEAD(in_ifaddrhashhead, in_ifaddr);
187 extern lck_rw_t in_ifaddr_rwlock;
188 
189 #define INADDR_HASH(x)  inaddr_hashlookup(x)
190 
191 extern  u_char  inetctlerrmap[];
192 
193 /*
194  * Macro for finding the interface (ifnet structure) corresponding to one
195  * of our IP addresses.
196  */
197 #define INADDR_TO_IFP(addr, ifp)                                        \
198 	/* struct in_addr addr; */                                      \
199 	/* struct ifnet *ifp; */                                        \
200 {                                                                       \
201 	struct in_ifaddr *ia;                                           \
202                                                                         \
203 	lck_rw_lock_shared(&in_ifaddr_rwlock);                          \
204 	TAILQ_FOREACH(ia, INADDR_HASH((addr).s_addr), ia_hash) {        \
205 	        IFA_LOCK_SPIN(&ia->ia_ifa);                             \
206 	        if (IA_SIN(ia)->sin_addr.s_addr == (addr).s_addr) {     \
207 	                IFA_UNLOCK(&ia->ia_ifa);                        \
208 	                break;                                          \
209 	        }                                                       \
210 	        IFA_UNLOCK(&ia->ia_ifa);                                \
211 	}                                                               \
212 	(ifp) = (ia == NULL) ? NULL : ia->ia_ifp;                       \
213 	lck_rw_done(&in_ifaddr_rwlock);                                 \
214 }
215 
216 /*
217  * Macro for finding the internet address structure (in_ifaddr) corresponding
218  * to a given interface (ifnet structure).  Caller is responsible for freeing
219  * the reference.
220  */
221 #define IFP_TO_IA(ifp, ia)                                              \
222 	/* struct ifnet *ifp; */                                        \
223 	/* struct in_ifaddr *ia; */                                     \
224 {                                                                       \
225 	lck_rw_lock_shared(&in_ifaddr_rwlock);                          \
226 	for ((ia) = TAILQ_FIRST(&in_ifaddrhead);                        \
227 	    (ia) != NULL && (ia)->ia_ifp != (ifp);                      \
228 	    (ia) = TAILQ_NEXT((ia), ia_link))                           \
229 	        continue;                                               \
230 	if ((ia) != NULL)                                               \
231 	        ifa_addref(&(ia)->ia_ifa);                              \
232 	lck_rw_done(&in_ifaddr_rwlock);                                 \
233 }
234 
235 /*
236  * This information should be part of the ifnet structure but we don't wish
237  * to change that - as it might break a number of things
238  */
239 
240 /*
241  * Legacy IPv4 IGMP per-link structure.
242  */
243 struct router_info {
244 	struct ifnet *rti_ifp;
245 	int    rti_type; /* type of router which is querier on this interface */
246 	int    rti_time; /* # of slow timeouts since last old query */
247 	SLIST_ENTRY(router_info) rti_list;
248 };
249 
250 /*
251  * IPv4 multicast IGMP-layer source entry.
252  */
253 struct ip_msource {
254 	RB_ENTRY(ip_msource)    ims_link;       /* RB tree links */
255 	in_addr_t               ims_haddr;      /* host byte order */
256 	struct ims_st {
257 		uint16_t        ex;             /* # of exclusive members */
258 		uint16_t        in;             /* # of inclusive members */
259 	}                       ims_st[2];      /* state at t0, t1 */
260 	uint8_t                 ims_stp;        /* pending query */
261 };
262 
263 /*
264  * IPv4 multicast PCB-layer source entry.
265  */
266 struct in_msource {
267 	RB_ENTRY(ip_msource)    ims_link;       /* RB tree links */
268 	in_addr_t               ims_haddr;      /* host byte order */
269 	uint8_t                 imsl_st[2];     /* state before/at commit */
270 };
271 
272 RB_HEAD(ip_msource_tree, ip_msource);   /* define struct ip_msource_tree */
273 
274 RB_PROTOTYPE_SC_PREV(__private_extern__, ip_msource_tree, ip_msource,
275     ims_link, ip_msource_cmp);
276 
277 /*
278  * IPv4 multicast PCB-layer group filter descriptor.
279  */
280 struct in_mfilter {
281 	struct ip_msource_tree  imf_sources; /* source list for (S,G) */
282 	u_long                  imf_nsrc;    /* # of source entries */
283 	uint8_t                 imf_st[2];   /* state before/at commit */
284 };
285 
286 struct igmp_ifinfo;
287 
288 /*
289  * IPv4 group descriptor.
290  *
291  * For every entry on an ifnet's if_multiaddrs list which represents
292  * an IP multicast group, there is one of these structures.
293  *
294  * If any source filters are present, then a node will exist in the RB-tree
295  * to permit fast lookup by source whenever an operation takes place.
296  * This permits pre-order traversal when we issue reports.
297  * Source filter trees are kept separately from the socket layer to
298  * greatly simplify locking.
299  *
300  * When IGMPv3 is active, inm_timer is the response to group query timer.
301  * The state-change timer inm_sctimer is separate; whenever state changes
302  * for the group the state change record is generated and transmitted,
303  * and kept if retransmissions are necessary.
304  *
305  * The request count here is a count of requests for this address, not a
306  * count of pointers to this structure.
307  *
308  * FUTURE: inm_link is now only used when groups are being purged
309  * on a detaching ifnet.  It could be demoted to a SLIST_ENTRY.
310  */
311 struct in_multi {
312 	decl_lck_mtx_data(, inm_lock);
313 	u_int32_t inm_refcount;         /* reference count */
314 	u_int32_t inm_reqcnt;           /* request count for this address */
315 	u_int32_t inm_debug;            /* see ifa_debug flags */
316 	LIST_ENTRY(in_multi) inm_link;  /* queue macro glue */
317 	struct  in_addr inm_addr;       /* IP multicast address, convenience */
318 	struct  ifnet *inm_ifp;         /* back pointer to ifnet */
319 	struct  ifmultiaddr *inm_ifma;  /* back pointer to ifmultiaddr */
320 	u_int   inm_timer;              /* IGMPv1/v2 group / v3 query timer  */
321 	u_int   inm_state;              /* state of the membership */
322 	bool    inm_in_nrele;           /* if in nrele list */
323 
324 	/* New fields for IGMPv3 follow. */
325 	struct igmp_ifinfo      *inm_igi;       /* IGMP info */
326 	SLIST_ENTRY(in_multi)    inm_dtle;      /* detached waiting for rele */
327 	SLIST_ENTRY(in_multi)    inm_nrele;     /* to-be-released by IGMP */
328 	u_int32_t                inm_nrelecnt;  /* deferred release count */
329 	struct ip_msource_tree   inm_srcs;      /* tree of sources */
330 	u_long                   inm_nsrc;      /* # of tree entries */
331 
332 	struct ifqueue           inm_scq;       /* queue of pending
333 	                                         * state-change packets */
334 	struct timeval           inm_lastgsrtv; /* Time of last G-S-R query */
335 	uint16_t                 inm_sctimer;   /* state-change timer */
336 	uint16_t                 inm_scrv;      /* state-change rexmit count */
337 
338 	/*
339 	 * SSM state counters which track state at T0 (the time the last
340 	 * state-change report's RV timer went to zero) and T1
341 	 * (time of pending report, i.e. now).
342 	 * Used for computing IGMPv3 state-change reports. Several refcounts
343 	 * are maintained here to optimize for common use-cases.
344 	 */
345 	struct inm_st {
346 		uint16_t        iss_fmode;      /* IGMP filter mode */
347 		uint16_t        iss_asm;        /* # of ASM listeners */
348 		uint16_t        iss_ex;         /* # of exclusive members */
349 		uint16_t        iss_in;         /* # of inclusive members */
350 		uint16_t        iss_rec;        /* # of recorded sources */
351 	}                       inm_st[2];      /* state at t0, t1 */
352 
353 	void (*inm_trace)               /* callback fn for tracing refs */
354 	(struct in_multi *, int);
355 };
356 
357 #define INM_LOCK_ASSERT_HELD(_inm)                                      \
358 	LCK_MTX_ASSERT(&(_inm)->inm_lock, LCK_MTX_ASSERT_OWNED)
359 
360 #define INM_LOCK_ASSERT_NOTHELD(_inm)                                   \
361 	LCK_MTX_ASSERT(&(_inm)->inm_lock, LCK_MTX_ASSERT_NOTOWNED)
362 
363 #define INM_LOCK(_inm)                                                  \
364 	lck_mtx_lock(&(_inm)->inm_lock)
365 
366 #define INM_LOCK_SPIN(_inm)                                             \
367 	lck_mtx_lock_spin(&(_inm)->inm_lock)
368 
369 #define INM_CONVERT_LOCK(_inm) do {                                     \
370 	INM_LOCK_ASSERT_HELD(_inm);                                     \
371 	lck_mtx_convert_spin(&(_inm)->inm_lock);                        \
372 } while (0)
373 
374 #define INM_UNLOCK(_inm)                                                \
375 	lck_mtx_unlock(&(_inm)->inm_lock)
376 
377 #define INM_ADDREF(_inm)                                                \
378 	inm_addref(_inm, 0)
379 
380 #define INM_ADDREF_LOCKED(_inm)                                         \
381 	inm_addref(_inm, 1)
382 
383 #define INM_REMREF(_inm)                                                \
384 	inm_remref(_inm, 0)
385 
386 #define INM_REMREF_LOCKED(_inm)                                         \
387 	inm_remref(_inm, 1)
388 
389 #ifdef SYSCTL_DECL
390 SYSCTL_DECL(_net_inet_ip);
391 SYSCTL_DECL(_net_inet_raw);
392 #endif
393 
394 extern LIST_HEAD(in_multihead, in_multi) in_multihead;
395 
396 /*
397  * Structure used by macros below to remember position when stepping through
398  * all of the in_multi records.
399  */
400 struct in_multistep {
401 	struct in_multi *i_inm;
402 };
403 
404 /*
405  * Macro for looking up the in_multi record for a given IP multicast address
406  * on a given interface.  If no matching record is found, "inm" is set null.
407  *
408  * We do this differently compared other BSD implementations; instead of
409  * walking the if_multiaddrs list at the interface and returning the
410  * ifma_protospec value of a matching entry, we search the global list
411  * of in_multi records and find it that way.  Otherwise either the two
412  * structures (in_multi, ifmultiaddr) need to be ref counted both ways,
413  * which will make things too complicated, or they need to reside in the
414  * same protected domain, which they aren't.
415  *
416  * Must be called with in_multihead_lock held.
417  */
418 #define IN_LOOKUP_MULTI(addr, ifp, inm)                                 \
419 	/* struct in_addr *addr; */                                     \
420 	/* struct ifnet *ifp; */                                        \
421 	/* struct in_multi *inm; */                                     \
422 do {                                                                    \
423 	struct in_multistep _step;                                      \
424 	IN_FIRST_MULTI(_step, inm);                                     \
425 	while ((inm) != NULL) {                                         \
426 	        INM_LOCK_SPIN(inm);                                     \
427 	        if ((inm)->inm_ifp == (ifp) &&                          \
428 	            (inm)->inm_addr.s_addr == (addr)->s_addr) {         \
429 	                INM_ADDREF_LOCKED(inm);                         \
430 	                INM_UNLOCK(inm);                                \
431 	                break;                                          \
432 	        }                                                       \
433 	        INM_UNLOCK(inm);                                        \
434 	        IN_NEXT_MULTI(_step, inm);                              \
435 	}                                                               \
436 } while (0)
437 
438 /*
439  * Macro to step through all of the in_multi records, one at a time.
440  * The current position is remembered in "step", which the caller must
441  * provide.  IN_FIRST_MULTI(), below, must be called to initialize "step"
442  * and get the first record.  Both macros return a NULL "inm" when there
443  * are no remaining records.
444  *
445  * Must be called with in_multihead_lock held.
446  */
447 #define IN_NEXT_MULTI(step, inm)                                        \
448 	/* struct in_multistep  step; */                                \
449 	/* struct in_multi *inm; */                                     \
450 do {                                                                    \
451 	in_multihead_lock_assert(LCK_RW_ASSERT_HELD);                   \
452 	if (((inm) = (step).i_inm) != NULL)                             \
453 	        (step).i_inm = LIST_NEXT((step).i_inm, inm_link);       \
454 } while (0)
455 
456 #define IN_FIRST_MULTI(step, inm)                                       \
457 	/* struct in_multistep step; */                                 \
458 	/* struct in_multi *inm; */                                     \
459 do {                                                                    \
460 	in_multihead_lock_assert(LCK_RW_ASSERT_HELD);                   \
461 	(step).i_inm = LIST_FIRST(&in_multihead);                       \
462 	IN_NEXT_MULTI((step), (inm));                                   \
463 } while (0)
464 
465 extern lck_mtx_t *inet_domain_mutex;
466 extern struct domain *inetdomain;
467 
468 struct ip_moptions;
469 struct inpcb;
470 
471 /*
472  * Return values for imo_multi_filter().
473  */
474 #define MCAST_PASS              0       /* Pass */
475 #define MCAST_NOTGMEMBER        1       /* This host not a member of group */
476 #define MCAST_NOTSMEMBER        2       /* This host excluded source */
477 #define MCAST_MUTED             3       /* [deprecated] */
478 
479 /*
480  * Per-interface IPv4 structures.
481  */
482 struct in_ifextra {
483 	uint32_t                netsig_len;
484 	u_int8_t                netsig[IFNET_SIGNATURELEN];
485 };
486 #define IN_IFEXTRA(_ifp)        (_ifp->if_inetdata)
487 
488 extern u_int32_t ipv4_ll_arp_aware;
489 
490 extern int imo_multi_filter(const struct ip_moptions *,
491     const struct ifnet *, const struct sockaddr_in *,
492     const struct sockaddr_in *);
493 extern int imo_clone(struct inpcb *, struct inpcb *);
494 extern void inm_commit(struct in_multi *);
495 extern void inm_clear_recorded(struct in_multi *);
496 extern void inm_print(const struct in_multi *);
497 extern int inm_record_source(struct in_multi *inm, const in_addr_t);
498 extern void inm_release(struct in_multi *);
499 extern struct in_multi *in_addmulti(struct in_addr *, struct ifnet *);
500 extern void in_delmulti(struct in_multi *);
501 extern int in_leavegroup(struct in_multi *, struct in_mfilter *);
502 extern int in_multi_detach(struct in_multi *);
503 extern void inm_addref(struct in_multi *, int);
504 extern void inm_remref(struct in_multi *, int);
505 extern void inm_purge(struct in_multi *);
506 extern uint8_t ims_get_mode(const struct in_multi *,
507     const struct ip_msource *, uint8_t);
508 extern int in_control(struct socket *, u_long, caddr_t, struct ifnet *,
509     struct proc *);
510 extern int in_inithead(void **, int);
511 extern void in_rtqdrain(void);
512 extern struct radix_node *in_validate(struct radix_node *);
513 extern void ip_input(struct mbuf *);
514 extern void ip_input_process_list(struct mbuf *);
515 extern int in_ifadown(struct ifaddr *ifa, int);
516 extern void in_ifscrub(struct ifnet *, struct in_ifaddr *, int);
517 extern uint32_t inaddr_hashval(uint32_t);
518 extern struct in_ifaddrhashhead *inaddr_hashlookup(uint32_t);
519 extern void in_purgeaddrs(struct ifnet *);
520 extern void gre_input(struct mbuf *, int);
521 extern void imf_leave(struct in_mfilter *);
522 extern void imf_purge(struct in_mfilter *);
523 extern int inp_join_group(struct inpcb *, struct sockopt *);
524 extern int inp_leave_group(struct inpcb *, struct sockopt *);
525 extern void in_multihead_lock_exclusive(void);
526 extern void in_multihead_lock_shared(void);
527 extern void in_multihead_lock_assert(int);
528 extern void in_multihead_lock_done(void);
529 #endif /* BSD_KERNEL_PRIVATE */
530 /* INET6 stuff */
531 #include <netinet6/in6_var.h>
532 #endif /* _NETINET_IN_VAR_H_ */
533