xref: /freebsd/sys/net/route.h (revision 3360a15898ce6cd06aad5afd9b48c8a5454cf952)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1980, 1986, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef _NET_ROUTE_H_
33 #define _NET_ROUTE_H_
34 
35 #include <net/vnet.h>
36 
37 /*
38  * Kernel resident routing tables.
39  *
40  * The routing tables are initialized when interface addresses
41  * are set by making entries for all directly connected interfaces.
42  */
43 
44 /*
45  * Struct route consiste of a destination address,
46  * a route entry pointer, link-layer prepend data pointer along
47  * with its length.
48  */
49 struct route {
50 	struct	nhop_object *ro_nh;
51 	struct	llentry *ro_lle;
52 	/*
53 	 * ro_prepend and ro_plen are only used for bpf to pass in a
54 	 * preformed header.  They are not cacheable.
55 	 */
56 	char		*ro_prepend;
57 	uint16_t	ro_plen;
58 	uint16_t	ro_flags;
59 	uint16_t	ro_mtu;	/* saved ro_rt mtu */
60 	uint16_t	spare;
61 	struct	sockaddr ro_dst;
62 };
63 
64 #define	RT_L2_ME_BIT		2	/* dst L2 addr is our address */
65 #define	RT_MAY_LOOP_BIT		3	/* dst may require loop copy */
66 #define	RT_HAS_HEADER_BIT	4	/* mbuf already have its header prepended */
67 
68 #define	RT_L2_ME		(1 << RT_L2_ME_BIT)		/* 0x0004 */
69 #define	RT_MAY_LOOP		(1 << RT_MAY_LOOP_BIT)		/* 0x0008 */
70 #define	RT_HAS_HEADER		(1 << RT_HAS_HEADER_BIT)	/* 0x0010 */
71 
72 #define	RT_REJECT		0x0020		/* Destination is reject */
73 #define	RT_BLACKHOLE		0x0040		/* Destination is blackhole */
74 #define	RT_HAS_GW		0x0080		/* Destination has GW  */
75 #define	RT_LLE_CACHE		0x0100		/* Cache link layer  */
76 
77 struct rt_metrics {
78 	u_long	rmx_locks;	/* Kernel must leave these values alone */
79 	u_long	rmx_mtu;	/* MTU for this path */
80 	u_long	rmx_hopcount;	/* max hops expected */
81 	u_long	rmx_expire;	/* lifetime for route, e.g. redirect */
82 	u_long	rmx_recvpipe;	/* inbound delay-bandwidth product */
83 	u_long	rmx_sendpipe;	/* outbound delay-bandwidth product */
84 	u_long	rmx_ssthresh;	/* outbound gateway buffer limit */
85 	u_long	rmx_rtt;	/* estimated round trip time */
86 	u_long	rmx_rttvar;	/* estimated rtt variance */
87 	u_long	rmx_pksent;	/* packets sent using this route */
88 	u_long	rmx_weight;	/* route weight */
89 	u_long	rmx_nhidx;	/* route nexhop index */
90 	u_long	rmx_filler[2];	/* will be used for T/TCP later */
91 };
92 
93 /*
94  * rmx_rtt and rmx_rttvar are stored as microseconds;
95  */
96 #define	RTM_RTTUNIT	1000000	/* units for rtt, rttvar, as units per sec */
97 
98 /* lle state is exported in rmx_state rt_metrics field */
99 #define	rmx_state	rmx_weight
100 
101 /* default route weight */
102 #define	RT_DEFAULT_WEIGHT	1
103 #define	RT_MAX_WEIGHT		16777215	/* 3 bytes */
104 
105 /*
106  * Keep a generation count of routing table, incremented on route addition,
107  * so we can invalidate caches.  This is accessed without a lock, as precision
108  * is not required.
109  */
110 typedef volatile u_int rt_gen_t;	/* tree generation (for adds) */
111 #define RT_GEN(fibnum, af)	rt_tables_get_gen(fibnum, af)
112 
113 #define	RT_DEFAULT_FIB	0	/* Explicitly mark fib=0 restricted cases */
114 #define	RT_ALL_FIBS	-1	/* Announce event for every fib */
115 #ifdef _KERNEL
116 VNET_DECLARE(uint32_t, _rt_numfibs);	/* number of existing route tables */
117 #define	V_rt_numfibs		VNET(_rt_numfibs)
118 /* temporary compat arg */
119 #define	rt_numfibs		V_rt_numfibs
120 VNET_DECLARE(u_int, rt_add_addr_allfibs); /* Announce interfaces to all fibs */
121 #define	V_rt_add_addr_allfibs	VNET(rt_add_addr_allfibs)
122 
123 /* Calculate flowid for locally-originated packets */
124 #define	V_fib_hash_outbound	VNET(fib_hash_outbound)
125 VNET_DECLARE(u_int, fib_hash_outbound);
126 
127 /* Outbound flowid generation rules */
128 #ifdef RSS
129 
130 #define fib4_calc_packet_hash		xps_proto_software_hash_v4
131 #define fib6_calc_packet_hash		xps_proto_software_hash_v6
132 #define	CALC_FLOWID_OUTBOUND_SENDTO	true
133 
134 #ifdef ROUTE_MPATH
135 #define	CALC_FLOWID_OUTBOUND		V_fib_hash_outbound
136 #else
137 #define	CALC_FLOWID_OUTBOUND		false
138 #endif
139 
140 #else /* !RSS */
141 
142 #define fib4_calc_packet_hash		fib4_calc_software_hash
143 #define fib6_calc_packet_hash		fib6_calc_software_hash
144 
145 #ifdef ROUTE_MPATH
146 #define	CALC_FLOWID_OUTBOUND_SENDTO	V_fib_hash_outbound
147 #define	CALC_FLOWID_OUTBOUND		V_fib_hash_outbound
148 #else
149 #define	CALC_FLOWID_OUTBOUND_SENDTO	false
150 #define	CALC_FLOWID_OUTBOUND		false
151 #endif
152 
153 #endif /* RSS */
154 
155 
156 #endif /* _KERNEL */
157 
158 /*
159  * We distinguish between routes to hosts and routes to networks,
160  * preferring the former if available.  For each route we infer
161  * the interface to use from the gateway address supplied when
162  * the route was entered.  Routes that forward packets through
163  * gateways are marked so that the output routines know to address the
164  * gateway rather than the ultimate destination.
165  */
166 #define	RTF_UP		0x1		/* route usable */
167 #define	RTF_GATEWAY	0x2		/* destination is a gateway */
168 #define	RTF_HOST	0x4		/* host entry (net otherwise) */
169 #define	RTF_REJECT	0x8		/* host or net unreachable */
170 #define	RTF_DYNAMIC	0x10		/* created dynamically (by redirect) */
171 #define	RTF_MODIFIED	0x20		/* modified dynamically (by redirect) */
172 #define RTF_DONE	0x40		/* message confirmed */
173 /*			0x80		   unused, was RTF_DELCLONE */
174 /*			0x100		   unused, was RTF_CLONING */
175 #define RTF_XRESOLVE	0x200		/* external daemon resolves name */
176 #define RTF_LLINFO	0x400		/* DEPRECATED - exists ONLY for backward
177 					   compatibility */
178 #define RTF_LLDATA	0x400		/* used by apps to add/del L2 entries */
179 #define RTF_STATIC	0x800		/* manually added */
180 #define RTF_BLACKHOLE	0x1000		/* just discard pkts (during updates) */
181 #define RTF_PROTO2	0x4000		/* protocol specific routing flag */
182 #define RTF_PROTO1	0x8000		/* protocol specific routing flag */
183 /*			0x10000		   unused, was RTF_PRCLONING */
184 /*			0x20000		   unused, was RTF_WASCLONED */
185 #define RTF_PROTO3	0x40000		/* protocol specific routing flag */
186 #define	RTF_FIXEDMTU	0x80000		/* MTU was explicitly specified */
187 #define RTF_PINNED	0x100000	/* route is immutable */
188 #define	RTF_LOCAL	0x200000 	/* route represents a local address */
189 #define	RTF_BROADCAST	0x400000	/* route represents a bcast address */
190 #define	RTF_MULTICAST	0x800000	/* route represents a mcast address */
191 					/* 0x8000000 and up unassigned */
192 #define	RTF_STICKY	 0x10000000	/* always route dst->src */
193 
194 /*			0x40000000	   unused, was RTF_RNH_LOCKED */
195 
196 #define	RTF_GWFLAG_COMPAT 0x80000000	/* a compatibility bit for interacting
197 					   with existing routing apps */
198 
199 /* Mask of RTF flags that are allowed to be modified by RTM_CHANGE. */
200 #define RTF_FMASK	\
201 	(RTF_PROTO1 | RTF_PROTO2 | RTF_PROTO3 | RTF_BLACKHOLE | \
202 	 RTF_REJECT | RTF_STATIC | RTF_STICKY)
203 
204 /*
205  * fib_ nexthop API flags.
206  */
207 
208 /* Consumer-visible nexthop info flags */
209 #define	NHF_MULTIPATH		0x0008	/* Nexhop is a nexthop group */
210 #define	NHF_REJECT		0x0010	/* RTF_REJECT */
211 #define	NHF_BLACKHOLE		0x0020	/* RTF_BLACKHOLE */
212 #define	NHF_REDIRECT		0x0040	/* RTF_DYNAMIC|RTF_MODIFIED */
213 #define	NHF_DEFAULT		0x0080	/* Default route */
214 #define	NHF_BROADCAST		0x0100	/* RTF_BROADCAST */
215 #define	NHF_GATEWAY		0x0200	/* RTF_GATEWAY */
216 #define	NHF_HOST		0x0400	/* RTF_HOST */
217 
218 /* Nexthop request flags */
219 #define	NHR_NONE		0x00	/* empty flags field */
220 #define	NHR_REF			0x01	/* reference nexhop */
221 #define	NHR_NODEFAULT		0x02	/* uRPF: do not consider default route */
222 
223 /* Control plane route request flags */
224 #define	NHR_COPY		0x100	/* Copy rte data */
225 #define	NHR_UNLOCKED		0x200	/* Do not lock table */
226 
227 /*
228  * Routing statistics.
229  */
230 struct rtstat {
231 	uint64_t rts_badredirect;	/* bogus redirect calls */
232 	uint64_t rts_dynamic;		/* routes created by redirects */
233 	uint64_t rts_newgateway;	/* routes modified by redirects */
234 	uint64_t rts_unreach;		/* lookups which failed */
235 	uint64_t rts_wildcard;		/* lookups satisfied by a wildcard */
236 	uint64_t rts_nh_idx_alloc_failure;	/* nexthop index alloc failure*/
237 	uint64_t rts_nh_alloc_failure;	/* nexthop allocation failure*/
238 	uint64_t rts_add_failure;	/* # of route addition failures */
239 	uint64_t rts_add_retry;		/* # of route addition retries */
240 	uint64_t rts_del_failure;	/* # of route deletion failure */
241 	uint64_t rts_del_retry;		/* # of route deletion retries */
242 	uint64_t rts_spare[5];
243 };
244 
245 /*
246  * Structures for routing messages.
247  */
248 struct rt_msghdr {
249 	u_short	rtm_msglen;	/* to skip over non-understood messages */
250 	u_char	rtm_version;	/* future binary compatibility */
251 	u_char	rtm_type;	/* message type */
252 	u_short	rtm_index;	/* index for associated ifp */
253 	u_short _rtm_spare1;
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 #ifndef NETLINK_COMPAT
267 /*
268  * Message types.
269  *
270  * The format for each message is annotated below using the following
271  * identifiers:
272  *
273  * (1) struct rt_msghdr
274  * (2) struct ifa_msghdr
275  * (3) struct if_msghdr
276  * (4) struct ifma_msghdr
277  * (5) struct if_announcemsghdr
278  *
279  */
280 #define	RTM_ADD		0x1	/* (1) Add Route */
281 #define	RTM_DELETE	0x2	/* (1) Delete Route */
282 #define	RTM_CHANGE	0x3	/* (1) Change Metrics or flags */
283 #define	RTM_GET		0x4	/* (1) Report Metrics */
284 #define	RTM_LOSING	0x5	/* (1) Kernel Suspects Partitioning */
285 #define	RTM_REDIRECT	0x6	/* (1) Told to use different route */
286 #define	RTM_MISS	0x7	/* (1) Lookup failed on this address */
287 #define	RTM_LOCK	0x8	/* (1) fix specified metrics */
288 		    /*	0x9  */
289 		    /*	0xa  */
290 #define	RTM_RESOLVE	0xb	/* (1) req to resolve dst to LL addr */
291 #define	RTM_NEWADDR	0xc	/* (2) address being added to iface */
292 #define	RTM_DELADDR	0xd	/* (2) address being removed from iface */
293 #define	RTM_IFINFO	0xe	/* (3) iface going up/down etc. */
294 #define	RTM_NEWMADDR	0xf	/* (4) mcast group membership being added to if */
295 #define	RTM_DELMADDR	0x10	/* (4) mcast group membership being deleted */
296 #define	RTM_IFANNOUNCE	0x11	/* (5) iface arrival/departure */
297 #define	RTM_IEEE80211	0x12	/* (5) IEEE80211 wireless event */
298 
299 #endif /* NETLINK_COMPAT*/
300 
301 /*
302  * Bitmask values for rtm_inits and rmx_locks.
303  */
304 #define RTV_MTU		0x1	/* init or lock _mtu */
305 #define RTV_HOPCOUNT	0x2	/* init or lock _hopcount */
306 #define RTV_EXPIRE	0x4	/* init or lock _expire */
307 #define RTV_RPIPE	0x8	/* init or lock _recvpipe */
308 #define RTV_SPIPE	0x10	/* init or lock _sendpipe */
309 #define RTV_SSTHRESH	0x20	/* init or lock _ssthresh */
310 #define RTV_RTT		0x40	/* init or lock _rtt */
311 #define RTV_RTTVAR	0x80	/* init or lock _rttvar */
312 #define RTV_WEIGHT	0x100	/* init or lock _weight */
313 
314 #ifndef NETLINK_COMPAT
315 
316 /*
317  * Bitmask values for rtm_addrs.
318  */
319 #define RTA_DST		0x1	/* destination sockaddr present */
320 #define RTA_GATEWAY	0x2	/* gateway sockaddr present */
321 #define RTA_NETMASK	0x4	/* netmask sockaddr present */
322 #define RTA_GENMASK	0x8	/* cloning mask sockaddr present */
323 #define RTA_IFP		0x10	/* interface name sockaddr present */
324 #define RTA_IFA		0x20	/* interface addr sockaddr present */
325 #define RTA_AUTHOR	0x40	/* sockaddr for author of redirect */
326 #define RTA_BRD		0x80	/* for NEWADDR, broadcast or p-p dest addr */
327 
328 #endif /* NETLINK_COMPAT*/
329 
330 /*
331  * Index offsets for sockaddr array for alternate internal encoding.
332  */
333 #define RTAX_DST	0	/* destination sockaddr present */
334 #define RTAX_GATEWAY	1	/* gateway sockaddr present */
335 #define RTAX_NETMASK	2	/* netmask sockaddr present */
336 #define RTAX_GENMASK	3	/* cloning mask sockaddr present */
337 #define RTAX_IFP	4	/* interface name sockaddr present */
338 #define RTAX_IFA	5	/* interface addr sockaddr present */
339 #define RTAX_AUTHOR	6	/* sockaddr for author of redirect */
340 #define RTAX_BRD	7	/* for NEWADDR, broadcast or p-p dest addr */
341 #define RTAX_MAX	8	/* size of array to allocate */
342 
343 struct rtentry;
344 struct nhop_object;
345 typedef int rib_filter_f_t(const struct rtentry *, const struct nhop_object *,
346     void *);
347 
348 struct rt_addrinfo {
349 	int	rti_addrs;			/* Route RTF_ flags */
350 	int	rti_flags;			/* Route RTF_ flags */
351 	struct	sockaddr *rti_info[RTAX_MAX];	/* Sockaddr data */
352 	struct	ifaddr *rti_ifa;		/* value of rt_ifa addr */
353 	struct	ifnet *rti_ifp;			/* route interface */
354 	rib_filter_f_t	*rti_filter;		/* filter function */
355 	void	*rti_filterdata;		/* filter parameters */
356 	u_long	rti_mflags;			/* metrics RTV_ flags */
357 	u_long	rti_spare;			/* Will be used for fib */
358 	struct	rt_metrics *rti_rmx;		/* Pointer to route metrics */
359 };
360 
361 /*
362  * This macro returns the size of a struct sockaddr when passed
363  * through a routing socket. Basically we round up sa_len to
364  * a multiple of sizeof(long), with a minimum of sizeof(long).
365  * The case sa_len == 0 should only apply to empty structures.
366  */
367 #define SA_SIZE(sa)						\
368     (  (((struct sockaddr *)(sa))->sa_len == 0) ?		\
369 	sizeof(long)		:				\
370 	1 + ( (((struct sockaddr *)(sa))->sa_len - 1) | (sizeof(long) - 1) ) )
371 
372 #define	sa_equal(a, b) (	\
373     (((const struct sockaddr *)(a))->sa_len == ((const struct sockaddr *)(b))->sa_len) && \
374     (bcmp((a), (b), ((const struct sockaddr *)(b))->sa_len) == 0))
375 
376 #ifdef _KERNEL
377 
378 #define RT_LINK_IS_UP(ifp)	(!((ifp)->if_capabilities & IFCAP_LINKSTATE) \
379 				 || (ifp)->if_link_state == LINK_STATE_UP)
380 
381 #define	RO_NHFREE(_ro) do {					\
382 	if ((_ro)->ro_nh) {					\
383 		NH_FREE((_ro)->ro_nh);				\
384 		(_ro)->ro_nh = NULL;				\
385 	}							\
386 } while (0)
387 
388 #define	RO_INVALIDATE_CACHE(ro) do {					\
389 		if ((ro)->ro_lle != NULL) {				\
390 			LLE_FREE((ro)->ro_lle);				\
391 			(ro)->ro_lle = NULL;				\
392 		}							\
393 		if ((ro)->ro_nh != NULL) {				\
394 			NH_FREE((ro)->ro_nh);				\
395 			(ro)->ro_nh = NULL;				\
396 		}							\
397 	} while (0)
398 
399 #define RO_GET_FAMILY(ro, dst)	((ro) != NULL &&		\
400 	(ro)->ro_flags & RT_HAS_GW				\
401 	? (ro)->ro_dst.sa_family : (dst)->sa_family)
402 
403 /*
404  * Validate a cached route based on a supplied cookie.  If there is an
405  * out-of-date cache, simply free it.  Update the generation number
406  * for the new allocation
407  */
408 #define NH_VALIDATE(ro, cookiep, fibnum) do {				\
409 	rt_gen_t cookie = RT_GEN(fibnum, (ro)->ro_dst.sa_family);	\
410 	if (*(cookiep) != cookie) {					\
411 		RO_INVALIDATE_CACHE(ro);				\
412 		*(cookiep) = cookie;					\
413 	}								\
414 } while (0)
415 
416 struct ifmultiaddr;
417 struct rib_head;
418 
419 void	 rt_ieee80211msg(struct ifnet *, int, void *, size_t);
420 void	 rt_ifmsg(struct ifnet *, int);
421 void	 rt_missmsg(int, struct rt_addrinfo *, int, int);
422 void	 rt_missmsg_fib(int, struct rt_addrinfo *, int, int, int);
423 int	 rt_addrmsg(int, struct ifaddr *, int);
424 int	 rt_routemsg(int, struct rtentry *, struct nhop_object *, int);
425 int	 rt_routemsg_info(int, struct rt_addrinfo *, int);
426 void	 rt_newmaddrmsg(int, struct ifmultiaddr *);
427 void 	 rt_maskedcopy(const struct sockaddr *, struct sockaddr *,
428 	    const struct sockaddr *);
429 struct rib_head *rt_table_init(int, int, u_int);
430 void	rt_table_destroy(struct rib_head *);
431 u_int	rt_tables_get_gen(uint32_t table, sa_family_t family);
432 
433 struct sockaddr *rtsock_fix_netmask(const struct sockaddr *dst,
434 	    const struct sockaddr *smask, struct sockaddr_storage *dmask);
435 
436 void	rt_updatemtu(struct ifnet *);
437 
438 void	rt_flushifroutes(struct ifnet *ifp);
439 
440 /* XXX MRT NEW VERSIONS THAT USE FIBs
441  * For now the protocol indepedent versions are the same as the AF_INET ones
442  * but this will change..
443  */
444 int	rtioctl_fib(u_long, caddr_t, u_int);
445 
446 /* New API */
447 void rib_flush_routes_family(int family);
448 struct nhop_object *rib_lookup(uint32_t fibnum, const struct sockaddr *dst,
449 	    uint32_t flags, uint32_t flowid);
450 const char *rib_print_family(int family);
451 #endif
452 
453 #endif
454