xref: /freebsd/sys/net/route.h (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
1 /*-
2  * Copyright (c) 1980, 1986, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)route.h	8.4 (Berkeley) 1/9/95
30  * $FreeBSD$
31  */
32 
33 #ifndef _NET_ROUTE_H_
34 #define _NET_ROUTE_H_
35 
36 #include <sys/counter.h>
37 #include <net/vnet.h>
38 
39 /*
40  * Kernel resident routing tables.
41  *
42  * The routing tables are initialized when interface addresses
43  * are set by making entries for all directly connected interfaces.
44  */
45 
46 /*
47  * Struct route consiste of a destination address,
48  * a route entry pointer, link-layer prepend data pointer along
49  * with its length.
50  */
51 struct route {
52 	struct	rtentry *ro_rt;
53 	struct	llentry *ro_lle;
54 	/*
55 	 * ro_prepend and ro_plen are only used for bpf to pass in a
56 	 * preformed header.  They are not cacheable.
57 	 */
58 	char		*ro_prepend;
59 	uint16_t	ro_plen;
60 	uint16_t	ro_flags;
61 	uint16_t	ro_mtu;	/* saved ro_rt mtu */
62 	uint16_t	spare;
63 	struct	sockaddr ro_dst;
64 };
65 
66 #define	RT_L2_ME_BIT		2	/* dst L2 addr is our address */
67 #define	RT_MAY_LOOP_BIT		3	/* dst may require loop copy */
68 #define	RT_HAS_HEADER_BIT	4	/* mbuf already have its header prepended */
69 
70 #define	RT_CACHING_CONTEXT	0x1	/* XXX: not used anywhere */
71 #define	RT_NORTREF		0x2	/* doesn't hold reference on ro_rt */
72 #define	RT_L2_ME		(1 << RT_L2_ME_BIT)		/* 0x0004 */
73 #define	RT_MAY_LOOP		(1 << RT_MAY_LOOP_BIT)		/* 0x0008 */
74 #define	RT_HAS_HEADER		(1 << RT_HAS_HEADER_BIT)	/* 0x0010 */
75 
76 #define	RT_REJECT		0x0020		/* Destination is reject */
77 #define	RT_BLACKHOLE		0x0040		/* Destination is blackhole */
78 #define	RT_HAS_GW		0x0080		/* Destination has GW  */
79 #define	RT_LLE_CACHE		0x0100		/* Cache link layer  */
80 
81 struct rt_metrics {
82 	u_long	rmx_locks;	/* Kernel must leave these values alone */
83 	u_long	rmx_mtu;	/* MTU for this path */
84 	u_long	rmx_hopcount;	/* max hops expected */
85 	u_long	rmx_expire;	/* lifetime for route, e.g. redirect */
86 	u_long	rmx_recvpipe;	/* inbound delay-bandwidth product */
87 	u_long	rmx_sendpipe;	/* outbound delay-bandwidth product */
88 	u_long	rmx_ssthresh;	/* outbound gateway buffer limit */
89 	u_long	rmx_rtt;	/* estimated round trip time */
90 	u_long	rmx_rttvar;	/* estimated rtt variance */
91 	u_long	rmx_pksent;	/* packets sent using this route */
92 	u_long	rmx_weight;	/* route weight */
93 	u_long	rmx_filler[3];	/* will be used for T/TCP later */
94 };
95 
96 /*
97  * rmx_rtt and rmx_rttvar are stored as microseconds;
98  * RTTTOPRHZ(rtt) converts to a value suitable for use
99  * by a protocol slowtimo counter.
100  */
101 #define	RTM_RTTUNIT	1000000	/* units for rtt, rttvar, as units per sec */
102 #define	RTTTOPRHZ(r)	((r) / (RTM_RTTUNIT / PR_SLOWHZ))
103 
104 /* lle state is exported in rmx_state rt_metrics field */
105 #define	rmx_state	rmx_weight
106 
107 /*
108  * Keep a generation count of routing table, incremented on route addition,
109  * so we can invalidate caches.  This is accessed without a lock, as precision
110  * is not required.
111  */
112 typedef volatile u_int rt_gen_t;	/* tree generation (for adds) */
113 #define RT_GEN(fibnum, af)	rt_tables_get_gen(fibnum, af)
114 
115 #define	RT_DEFAULT_FIB	0	/* Explicitly mark fib=0 restricted cases */
116 #define	RT_ALL_FIBS	-1	/* Announce event for every fib */
117 #ifdef _KERNEL
118 extern u_int rt_numfibs;	/* number of usable routing tables */
119 VNET_DECLARE(u_int, rt_add_addr_allfibs); /* Announce interfaces to all fibs */
120 #define	V_rt_add_addr_allfibs	VNET(rt_add_addr_allfibs)
121 #endif
122 
123 /*
124  * We distinguish between routes to hosts and routes to networks,
125  * preferring the former if available.  For each route we infer
126  * the interface to use from the gateway address supplied when
127  * the route was entered.  Routes that forward packets through
128  * gateways are marked so that the output routines know to address the
129  * gateway rather than the ultimate destination.
130  */
131 #ifndef RNF_NORMAL
132 #include <net/radix.h>
133 #ifdef RADIX_MPATH
134 #include <net/radix_mpath.h>
135 #endif
136 #endif
137 
138 #if defined(_KERNEL)
139 struct rtentry {
140 	struct	radix_node rt_nodes[2];	/* tree glue, and other values */
141 	/*
142 	 * XXX struct rtentry must begin with a struct radix_node (or two!)
143 	 * because the code does some casts of a 'struct radix_node *'
144 	 * to a 'struct rtentry *'
145 	 */
146 #define	rt_key(r)	(*((struct sockaddr **)(&(r)->rt_nodes->rn_key)))
147 #define	rt_mask(r)	(*((struct sockaddr **)(&(r)->rt_nodes->rn_mask)))
148 	struct	sockaddr *rt_gateway;	/* value */
149 	struct	ifnet *rt_ifp;		/* the answer: interface to use */
150 	struct	ifaddr *rt_ifa;		/* the answer: interface address to use */
151 	int		rt_flags;	/* up/down?, host/net */
152 	int		rt_refcnt;	/* # held references */
153 	u_int		rt_fibnum;	/* which FIB */
154 	u_long		rt_mtu;		/* MTU for this path */
155 	u_long		rt_weight;	/* absolute weight */
156 	u_long		rt_expire;	/* lifetime for route, e.g. redirect */
157 #define	rt_endzero	rt_pksent
158 	counter_u64_t	rt_pksent;	/* packets sent using this route */
159 	struct mtx	rt_mtx;		/* mutex for routing entry */
160 	struct rtentry	*rt_chain;	/* pointer to next rtentry to delete */
161 };
162 #endif /* _KERNEL */
163 
164 #define	RTF_UP		0x1		/* route usable */
165 #define	RTF_GATEWAY	0x2		/* destination is a gateway */
166 #define	RTF_HOST	0x4		/* host entry (net otherwise) */
167 #define	RTF_REJECT	0x8		/* host or net unreachable */
168 #define	RTF_DYNAMIC	0x10		/* created dynamically (by redirect) */
169 #define	RTF_MODIFIED	0x20		/* modified dynamically (by redirect) */
170 #define RTF_DONE	0x40		/* message confirmed */
171 /*			0x80		   unused, was RTF_DELCLONE */
172 /*			0x100		   unused, was RTF_CLONING */
173 #define RTF_XRESOLVE	0x200		/* external daemon resolves name */
174 #define RTF_LLINFO	0x400		/* DEPRECATED - exists ONLY for backward
175 					   compatibility */
176 #define RTF_LLDATA	0x400		/* used by apps to add/del L2 entries */
177 #define RTF_STATIC	0x800		/* manually added */
178 #define RTF_BLACKHOLE	0x1000		/* just discard pkts (during updates) */
179 #define RTF_PROTO2	0x4000		/* protocol specific routing flag */
180 #define RTF_PROTO1	0x8000		/* protocol specific routing flag */
181 /*			0x10000		   unused, was RTF_PRCLONING */
182 /*			0x20000		   unused, was RTF_WASCLONED */
183 #define RTF_PROTO3	0x40000		/* protocol specific routing flag */
184 #define	RTF_FIXEDMTU	0x80000		/* MTU was explicitly specified */
185 #define RTF_PINNED	0x100000	/* route is immutable */
186 #define	RTF_LOCAL	0x200000 	/* route represents a local address */
187 #define	RTF_BROADCAST	0x400000	/* route represents a bcast address */
188 #define	RTF_MULTICAST	0x800000	/* route represents a mcast address */
189 					/* 0x8000000 and up unassigned */
190 #define	RTF_STICKY	 0x10000000	/* always route dst->src */
191 
192 #define	RTF_RNH_LOCKED	 0x40000000	/* unused */
193 
194 #define	RTF_GWFLAG_COMPAT 0x80000000	/* a compatibility bit for interacting
195 					   with existing routing apps */
196 
197 /* Mask of RTF flags that are allowed to be modified by RTM_CHANGE. */
198 #define RTF_FMASK	\
199 	(RTF_PROTO1 | RTF_PROTO2 | RTF_PROTO3 | RTF_BLACKHOLE | \
200 	 RTF_REJECT | RTF_STATIC | RTF_STICKY)
201 
202 /*
203  * fib_ nexthop API flags.
204  */
205 
206 /* Consumer-visible nexthop info flags */
207 #define	NHF_REJECT		0x0010	/* RTF_REJECT */
208 #define	NHF_BLACKHOLE		0x0020	/* RTF_BLACKHOLE */
209 #define	NHF_REDIRECT		0x0040	/* RTF_DYNAMIC|RTF_MODIFIED */
210 #define	NHF_DEFAULT		0x0080	/* Default route */
211 #define	NHF_BROADCAST		0x0100	/* RTF_BROADCAST */
212 #define	NHF_GATEWAY		0x0200	/* RTF_GATEWAY */
213 
214 /* Nexthop request flags */
215 #define	NHR_IFAIF		0x01	/* Return ifa_ifp interface */
216 #define	NHR_REF			0x02	/* For future use */
217 
218 /* Control plane route request flags */
219 #define	NHR_COPY		0x100	/* Copy rte data */
220 
221 #ifdef _KERNEL
222 /* rte<>ro_flags translation */
223 static inline void
224 rt_update_ro_flags(struct route *ro)
225 {
226 	int rt_flags = ro->ro_rt->rt_flags;
227 
228 	ro->ro_flags &= ~ (RT_REJECT|RT_BLACKHOLE|RT_HAS_GW);
229 
230 	ro->ro_flags |= (rt_flags & RTF_REJECT) ? RT_REJECT : 0;
231 	ro->ro_flags |= (rt_flags & RTF_BLACKHOLE) ? RT_BLACKHOLE : 0;
232 	ro->ro_flags |= (rt_flags & RTF_GATEWAY) ? RT_HAS_GW : 0;
233 }
234 #endif
235 
236 /*
237  * Routing statistics.
238  */
239 struct	rtstat {
240 	short	rts_badredirect;	/* bogus redirect calls */
241 	short	rts_dynamic;		/* routes created by redirects */
242 	short	rts_newgateway;		/* routes modified by redirects */
243 	short	rts_unreach;		/* lookups which failed */
244 	short	rts_wildcard;		/* lookups satisfied by a wildcard */
245 };
246 /*
247  * Structures for routing messages.
248  */
249 struct rt_msghdr {
250 	u_short	rtm_msglen;	/* to skip over non-understood messages */
251 	u_char	rtm_version;	/* future binary compatibility */
252 	u_char	rtm_type;	/* message type */
253 	u_short	rtm_index;	/* index for associated ifp */
254 	int	rtm_flags;	/* flags, incl. kern & message, e.g. DONE */
255 	int	rtm_addrs;	/* bitmask identifying sockaddrs in msg */
256 	pid_t	rtm_pid;	/* identify sender */
257 	int	rtm_seq;	/* for sender to identify action */
258 	int	rtm_errno;	/* why failed */
259 	int	rtm_fmask;	/* bitmask used in RTM_CHANGE message */
260 	u_long	rtm_inits;	/* which metrics we are initializing */
261 	struct	rt_metrics rtm_rmx; /* metrics themselves */
262 };
263 
264 #define RTM_VERSION	5	/* Up the ante and ignore older versions */
265 
266 /*
267  * Message types.
268  *
269  * The format for each message is annotated below using the following
270  * identifiers:
271  *
272  * (1) struct rt_msghdr
273  * (2) struct ifa_msghdr
274  * (3) struct if_msghdr
275  * (4) struct ifma_msghdr
276  * (5) struct if_announcemsghdr
277  *
278  */
279 #define	RTM_ADD		0x1	/* (1) Add Route */
280 #define	RTM_DELETE	0x2	/* (1) Delete Route */
281 #define	RTM_CHANGE	0x3	/* (1) Change Metrics or flags */
282 #define	RTM_GET		0x4	/* (1) Report Metrics */
283 #define	RTM_LOSING	0x5	/* (1) Kernel Suspects Partitioning */
284 #define	RTM_REDIRECT	0x6	/* (1) Told to use different route */
285 #define	RTM_MISS	0x7	/* (1) Lookup failed on this address */
286 #define	RTM_LOCK	0x8	/* (1) fix specified metrics */
287 		    /*	0x9  */
288 		    /*	0xa  */
289 #define	RTM_RESOLVE	0xb	/* (1) req to resolve dst to LL addr */
290 #define	RTM_NEWADDR	0xc	/* (2) address being added to iface */
291 #define	RTM_DELADDR	0xd	/* (2) address being removed from iface */
292 #define	RTM_IFINFO	0xe	/* (3) iface going up/down etc. */
293 #define	RTM_NEWMADDR	0xf	/* (4) mcast group membership being added to if */
294 #define	RTM_DELMADDR	0x10	/* (4) mcast group membership being deleted */
295 #define	RTM_IFANNOUNCE	0x11	/* (5) iface arrival/departure */
296 #define	RTM_IEEE80211	0x12	/* (5) IEEE80211 wireless event */
297 
298 /*
299  * Bitmask values for rtm_inits and rmx_locks.
300  */
301 #define RTV_MTU		0x1	/* init or lock _mtu */
302 #define RTV_HOPCOUNT	0x2	/* init or lock _hopcount */
303 #define RTV_EXPIRE	0x4	/* init or lock _expire */
304 #define RTV_RPIPE	0x8	/* init or lock _recvpipe */
305 #define RTV_SPIPE	0x10	/* init or lock _sendpipe */
306 #define RTV_SSTHRESH	0x20	/* init or lock _ssthresh */
307 #define RTV_RTT		0x40	/* init or lock _rtt */
308 #define RTV_RTTVAR	0x80	/* init or lock _rttvar */
309 #define RTV_WEIGHT	0x100	/* init or lock _weight */
310 
311 /*
312  * Bitmask values for rtm_addrs.
313  */
314 #define RTA_DST		0x1	/* destination sockaddr present */
315 #define RTA_GATEWAY	0x2	/* gateway sockaddr present */
316 #define RTA_NETMASK	0x4	/* netmask sockaddr present */
317 #define RTA_GENMASK	0x8	/* cloning mask sockaddr present */
318 #define RTA_IFP		0x10	/* interface name sockaddr present */
319 #define RTA_IFA		0x20	/* interface addr sockaddr present */
320 #define RTA_AUTHOR	0x40	/* sockaddr for author of redirect */
321 #define RTA_BRD		0x80	/* for NEWADDR, broadcast or p-p dest addr */
322 
323 /*
324  * Index offsets for sockaddr array for alternate internal encoding.
325  */
326 #define RTAX_DST	0	/* destination sockaddr present */
327 #define RTAX_GATEWAY	1	/* gateway sockaddr present */
328 #define RTAX_NETMASK	2	/* netmask sockaddr present */
329 #define RTAX_GENMASK	3	/* cloning mask sockaddr present */
330 #define RTAX_IFP	4	/* interface name sockaddr present */
331 #define RTAX_IFA	5	/* interface addr sockaddr present */
332 #define RTAX_AUTHOR	6	/* sockaddr for author of redirect */
333 #define RTAX_BRD	7	/* for NEWADDR, broadcast or p-p dest addr */
334 #define RTAX_MAX	8	/* size of array to allocate */
335 
336 typedef int rt_filter_f_t(const struct rtentry *, void *);
337 
338 struct rt_addrinfo {
339 	int	rti_addrs;			/* Route RTF_ flags */
340 	int	rti_flags;			/* Route RTF_ flags */
341 	struct	sockaddr *rti_info[RTAX_MAX];	/* Sockaddr data */
342 	struct	ifaddr *rti_ifa;		/* value of rt_ifa addr */
343 	struct	ifnet *rti_ifp;			/* route interface */
344 	rt_filter_f_t	*rti_filter;		/* filter function */
345 	void	*rti_filterdata;		/* filter paramenters */
346 	u_long	rti_mflags;			/* metrics RTV_ flags */
347 	u_long	rti_spare;			/* Will be used for fib */
348 	struct	rt_metrics *rti_rmx;		/* Pointer to route metrics */
349 };
350 
351 /*
352  * This macro returns the size of a struct sockaddr when passed
353  * through a routing socket. Basically we round up sa_len to
354  * a multiple of sizeof(long), with a minimum of sizeof(long).
355  * The case sa_len == 0 should only apply to empty structures.
356  */
357 #define SA_SIZE(sa)						\
358     (  (((struct sockaddr *)(sa))->sa_len == 0) ?		\
359 	sizeof(long)		:				\
360 	1 + ( (((struct sockaddr *)(sa))->sa_len - 1) | (sizeof(long) - 1) ) )
361 
362 #define	sa_equal(a, b) (	\
363     (((const struct sockaddr *)(a))->sa_len == ((const struct sockaddr *)(b))->sa_len) && \
364     (bcmp((a), (b), ((const struct sockaddr *)(b))->sa_len) == 0))
365 
366 #ifdef _KERNEL
367 
368 #define RT_LINK_IS_UP(ifp)	(!((ifp)->if_capabilities & IFCAP_LINKSTATE) \
369 				 || (ifp)->if_link_state == LINK_STATE_UP)
370 
371 #define	RT_LOCK_INIT(_rt) \
372 	mtx_init(&(_rt)->rt_mtx, "rtentry", NULL, MTX_DEF | MTX_DUPOK | MTX_NEW)
373 #define	RT_LOCK(_rt)		mtx_lock(&(_rt)->rt_mtx)
374 #define	RT_UNLOCK(_rt)		mtx_unlock(&(_rt)->rt_mtx)
375 #define	RT_LOCK_DESTROY(_rt)	mtx_destroy(&(_rt)->rt_mtx)
376 #define	RT_LOCK_ASSERT(_rt)	mtx_assert(&(_rt)->rt_mtx, MA_OWNED)
377 #define	RT_UNLOCK_COND(_rt)	do {				\
378 	if (mtx_owned(&(_rt)->rt_mtx))				\
379 		mtx_unlock(&(_rt)->rt_mtx);			\
380 } while (0)
381 
382 #define	RT_ADDREF(_rt)	do {					\
383 	RT_LOCK_ASSERT(_rt);					\
384 	KASSERT((_rt)->rt_refcnt >= 0,				\
385 		("negative refcnt %d", (_rt)->rt_refcnt));	\
386 	(_rt)->rt_refcnt++;					\
387 } while (0)
388 
389 #define	RT_REMREF(_rt)	do {					\
390 	RT_LOCK_ASSERT(_rt);					\
391 	KASSERT((_rt)->rt_refcnt > 0,				\
392 		("bogus refcnt %d", (_rt)->rt_refcnt));	\
393 	(_rt)->rt_refcnt--;					\
394 } while (0)
395 
396 #define	RTFREE_LOCKED(_rt) do {					\
397 	if ((_rt)->rt_refcnt <= 1)				\
398 		rtfree(_rt);					\
399 	else {							\
400 		RT_REMREF(_rt);					\
401 		RT_UNLOCK(_rt);					\
402 	}							\
403 	/* guard against invalid refs */			\
404 	_rt = 0;						\
405 } while (0)
406 
407 #define	RTFREE(_rt) do {					\
408 	RT_LOCK(_rt);						\
409 	RTFREE_LOCKED(_rt);					\
410 } while (0)
411 
412 #define	RO_RTFREE(_ro) do {					\
413 	if ((_ro)->ro_rt) {					\
414 		if ((_ro)->ro_flags & RT_NORTREF) {		\
415 			(_ro)->ro_flags &= ~RT_NORTREF;		\
416 			(_ro)->ro_rt = NULL;			\
417 			(_ro)->ro_lle = NULL;			\
418 		} else {					\
419 			RT_LOCK((_ro)->ro_rt);			\
420 			RTFREE_LOCKED((_ro)->ro_rt);		\
421 		}						\
422 	}							\
423 } while (0)
424 
425 /*
426  * Validate a cached route based on a supplied cookie.  If there is an
427  * out-of-date cache, simply free it.  Update the generation number
428  * for the new allocation
429  */
430 #define RT_VALIDATE(ro, cookiep, fibnum) do {				\
431 	rt_gen_t cookie = RT_GEN(fibnum, (ro)->ro_dst.sa_family);	\
432 	if (*(cookiep) != cookie) {					\
433 		if ((ro)->ro_rt != NULL) {				\
434 			RTFREE((ro)->ro_rt);				\
435 			(ro)->ro_rt = NULL;				\
436 		}							\
437 		*(cookiep) = cookie;					\
438 	}								\
439 } while (0)
440 
441 struct ifmultiaddr;
442 struct rib_head;
443 
444 void	 rt_ieee80211msg(struct ifnet *, int, void *, size_t);
445 void	 rt_ifannouncemsg(struct ifnet *, int);
446 void	 rt_ifmsg(struct ifnet *);
447 void	 rt_missmsg(int, struct rt_addrinfo *, int, int);
448 void	 rt_missmsg_fib(int, struct rt_addrinfo *, int, int, int);
449 void	 rt_newaddrmsg(int, struct ifaddr *, int, struct rtentry *);
450 void	 rt_newaddrmsg_fib(int, struct ifaddr *, int, struct rtentry *, int);
451 int	 rt_addrmsg(int, struct ifaddr *, int);
452 int	 rt_routemsg(int, struct ifnet *ifp, int, struct rtentry *, int);
453 void	 rt_newmaddrmsg(int, struct ifmultiaddr *);
454 int	 rt_setgate(struct rtentry *, struct sockaddr *, struct sockaddr *);
455 void 	 rt_maskedcopy(struct sockaddr *, struct sockaddr *, struct sockaddr *);
456 struct rib_head *rt_table_init(int);
457 void	rt_table_destroy(struct rib_head *);
458 u_int	rt_tables_get_gen(int table, int fam);
459 
460 int	rtsock_addrmsg(int, struct ifaddr *, int);
461 int	rtsock_routemsg(int, struct ifnet *ifp, int, struct rtentry *, int);
462 
463 /*
464  * Note the following locking behavior:
465  *
466  *    rtalloc1() returns a locked rtentry
467  *
468  *    rtfree() and RTFREE_LOCKED() require a locked rtentry
469  *
470  *    RTFREE() uses an unlocked entry.
471  */
472 
473 void	 rtfree(struct rtentry *);
474 void	rt_updatemtu(struct ifnet *);
475 
476 typedef int rt_walktree_f_t(struct rtentry *, void *);
477 typedef void rt_setwarg_t(struct rib_head *, uint32_t, int, void *);
478 void	rt_foreach_fib_walk(int af, rt_setwarg_t *, rt_walktree_f_t *, void *);
479 void	rt_foreach_fib_walk_del(int af, rt_filter_f_t *filter_f, void *arg);
480 void	rt_flushifroutes_af(struct ifnet *, int);
481 void	rt_flushifroutes(struct ifnet *ifp);
482 
483 /* XXX MRT COMPAT VERSIONS THAT SET UNIVERSE to 0 */
484 /* Thes are used by old code not yet converted to use multiple FIBS */
485 struct rtentry *rtalloc1(struct sockaddr *, int, u_long);
486 int	 rtinit(struct ifaddr *, int, int);
487 
488 /* XXX MRT NEW VERSIONS THAT USE FIBs
489  * For now the protocol indepedent versions are the same as the AF_INET ones
490  * but this will change..
491  */
492 int	 rt_getifa_fib(struct rt_addrinfo *, u_int fibnum);
493 void	 rtalloc_ign_fib(struct route *ro, u_long ignflags, u_int fibnum);
494 struct rtentry *rtalloc1_fib(struct sockaddr *, int, u_long, u_int);
495 int	 rtioctl_fib(u_long, caddr_t, u_int);
496 void	 rtredirect_fib(struct sockaddr *, struct sockaddr *,
497 	    struct sockaddr *, int, struct sockaddr *, u_int);
498 int	 rtrequest_fib(int, struct sockaddr *,
499 	    struct sockaddr *, struct sockaddr *, int, struct rtentry **, u_int);
500 int	 rtrequest1_fib(int, struct rt_addrinfo *, struct rtentry **, u_int);
501 int	rib_lookup_info(uint32_t, const struct sockaddr *, uint32_t, uint32_t,
502 	    struct rt_addrinfo *);
503 void	rib_free_info(struct rt_addrinfo *info);
504 
505 #endif
506 
507 #endif
508