1 /*        $NetBSD: route.c,v 1.237 2023/06/05 03:51:45 ozaki-r Exp $  */
2 
3 /*-
4  * Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Kevin M. Lahey of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
35  * All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. Neither the name of the project nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  */
61 
62 /*
63  * Copyright (c) 1980, 1986, 1991, 1993
64  *        The Regents of the University of California.  All rights reserved.
65  *
66  * Redistribution and use in source and binary forms, with or without
67  * modification, are permitted provided that the following conditions
68  * are met:
69  * 1. Redistributions of source code must retain the above copyright
70  *    notice, this list of conditions and the following disclaimer.
71  * 2. Redistributions in binary form must reproduce the above copyright
72  *    notice, this list of conditions and the following disclaimer in the
73  *    documentation and/or other materials provided with the distribution.
74  * 3. Neither the name of the University nor the names of its contributors
75  *    may be used to endorse or promote products derived from this software
76  *    without specific prior written permission.
77  *
78  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
79  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
80  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
81  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
82  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
83  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
84  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
85  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
86  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
87  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
88  * SUCH DAMAGE.
89  *
90  *        @(#)route.c         8.3 (Berkeley) 1/9/95
91  */
92 
93 #ifdef _KERNEL_OPT
94 #include "opt_inet.h"
95 #include "opt_route.h"
96 #include "opt_net_mpsafe.h"
97 #endif
98 
99 #include <sys/cdefs.h>
100 __KERNEL_RCSID(0, "$NetBSD: route.c,v 1.237 2023/06/05 03:51:45 ozaki-r Exp $");
101 
102 #include <sys/param.h>
103 #ifdef RTFLUSH_DEBUG
104 #include <sys/sysctl.h>
105 #endif
106 #include <sys/systm.h>
107 #include <sys/callout.h>
108 #include <sys/proc.h>
109 #include <sys/mbuf.h>
110 #include <sys/socket.h>
111 #include <sys/socketvar.h>
112 #include <sys/domain.h>
113 #include <sys/kernel.h>
114 #include <sys/ioctl.h>
115 #include <sys/pool.h>
116 #include <sys/kauth.h>
117 #include <sys/workqueue.h>
118 #include <sys/syslog.h>
119 #include <sys/rwlock.h>
120 #include <sys/mutex.h>
121 #include <sys/cpu.h>
122 #include <sys/kmem.h>
123 
124 #include <net/if.h>
125 #include <net/if_dl.h>
126 #include <net/route.h>
127 #if defined(INET) || defined(INET6)
128 #include <net/if_llatbl.h>
129 #endif
130 
131 #include <netinet/in.h>
132 #include <netinet/in_var.h>
133 
134 #define   PRESERVED_RTF       (RTF_UP | RTF_GATEWAY | RTF_HOST | RTF_DONE | RTF_MASK)
135 
136 #ifdef RTFLUSH_DEBUG
137 #define   rtcache_debug() __predict_false(_rtcache_debug)
138 #else /* RTFLUSH_DEBUG */
139 #define   rtcache_debug() 0
140 #endif /* RTFLUSH_DEBUG */
141 
142 #ifdef RT_DEBUG
143 #define RT_REFCNT_TRACE(rt)   printf("%s:%d: rt=%p refcnt=%d\n", \
144                                             __func__, __LINE__, (rt), (rt)->rt_refcnt)
145 #else
146 #define RT_REFCNT_TRACE(rt)   do {} while (0)
147 #endif
148 
149 #ifdef RT_DEBUG
150 #define dlog(level, fmt, args...)       log(level, fmt, ##args)
151 #else
152 #define dlog(level, fmt, args...)       do {} while (0)
153 #endif
154 
155 struct rtstat                 rtstat;
156 
157 static int                    rttrash;  /* routes not in table but not freed */
158 
159 static struct pool  rtentry_pool;
160 static struct pool  rttimer_pool;
161 
162 static struct callout         rt_timer_ch; /* callout for rt_timer_timer() */
163 static struct workqueue       *rt_timer_wq;
164 static struct work  rt_timer_wk;
165 
166 static void         rt_timer_init(void);
167 static void         rt_timer_queue_remove_all(struct rttimer_queue *);
168 static void         rt_timer_remove_all(struct rtentry *);
169 static void         rt_timer_timer(void *);
170 
171 /*
172  * Locking notes:
173  * - The routing table is protected by a global rwlock
174  *   - API: RT_RLOCK and friends
175  * - rtcaches are NOT protected by the framework
176  *   - Callers must guarantee a rtcache isn't accessed simultaneously
177  *   - How the constraint is guaranteed in the wild
178  *     - Protect a rtcache by a mutex (e.g., inp_route)
179  *     - Make rtcache per-CPU and allow only accesses from softint
180  *       (e.g., ipforward_rt_percpu)
181  * - References to a rtentry is managed by reference counting and psref
182  *   - Reference counting is used for temporal reference when a rtentry
183  *     is fetched from the routing table
184  *   - psref is used for temporal reference when a rtentry is fetched
185  *     from a rtcache
186  *     - struct route (rtcache) has struct psref, so we cannot obtain
187  *       a reference twice on the same struct route
188  *   - Before destroying or updating a rtentry, we have to wait for
189  *     all references left (see below for details)
190  *   - APIs
191  *     - An obtained rtentry via rtalloc1 or rtrequest* must be
192  *       unreferenced by rt_unref
193  *     - An obtained rtentry via rtcache_* must be unreferenced by
194  *       rtcache_unref
195  *   - TODO: once we get a lockless routing table, we should use only
196  *           psref for rtentries
197  * - rtentry destruction
198  *   - A rtentry is destroyed (freed) only when we call rtrequest(RTM_DELETE)
199  *   - If a caller of rtrequest grabs a reference of a rtentry, the caller
200  *     has a responsibility to destroy the rtentry by itself by calling
201  *     rt_free
202  *     - If not, rtrequest itself does that
203  *   - If rt_free is called in softint, the actual destruction routine is
204  *     deferred to a workqueue
205  * - rtentry update
206  *   - When updating a rtentry, RTF_UPDATING flag is set
207  *   - If a rtentry is set RTF_UPDATING, fetching the rtentry from
208  *     the routing table or a rtcache results in either of the following
209  *     cases:
210  *     - if the caller runs in softint, the caller fails to fetch
211  *     - otherwise, the caller waits for the update completed and retries
212  *       to fetch (probably succeed to fetch for the second time)
213  * - rtcache invalidation
214  *   - There is a global generation counter that is incremented when
215  *     any routes have been added or deleted
216  *   - When a rtcache caches a rtentry into itself, it also stores
217  *     a snapshot of the generation counter
218  *   - If the snapshot equals to the global counter, the cache is valid,
219  *     otherwise the cache is invalidated
220  */
221 
222 /*
223  * Global lock for the routing table.
224  */
225 static krwlock_t              rt_lock __cacheline_aligned;
226 #ifdef NET_MPSAFE
227 #define RT_RLOCK()            rw_enter(&rt_lock, RW_READER)
228 #define RT_WLOCK()            rw_enter(&rt_lock, RW_WRITER)
229 #define RT_UNLOCK()           rw_exit(&rt_lock)
230 #define RT_WLOCKED()                    rw_write_held(&rt_lock)
231 #define   RT_ASSERT_WLOCK()   KASSERT(rw_write_held(&rt_lock))
232 #define RT_WQ_FLAGS           WQ_MPSAFE
233 #else
234 #define RT_RLOCK()            do {} while (0)
235 #define RT_WLOCK()            do {} while (0)
236 #define RT_UNLOCK()           do {} while (0)
237 #define RT_WLOCKED()                    true
238 #define   RT_ASSERT_WLOCK()   do {} while (0)
239 #define RT_WQ_FLAGS           0
240 #endif
241 
242 static uint64_t rtcache_generation;
243 
244 /*
245  * mutex and cv that are used to wait for references to a rtentry left
246  * before updating the rtentry.
247  */
248 static struct {
249           kmutex_t            lock;
250           kcondvar_t                    cv;
251           bool                          ongoing;
252           const struct lwp    *lwp;
253 } rt_update_global __cacheline_aligned;
254 
255 /*
256  * A workqueue and stuff that are used to defer the destruction routine
257  * of rtentries.
258  */
259 static struct {
260           struct workqueue    *wq;
261           struct work                   wk;
262           kmutex_t            lock;
263           SLIST_HEAD(, rtentry)         queue;
264           bool                          enqueued;
265 } rt_free_global __cacheline_aligned;
266 
267 /* psref for rtentry */
268 static struct psref_class *rt_psref_class __read_mostly;
269 
270 #ifdef RTFLUSH_DEBUG
271 static int _rtcache_debug = 0;
272 #endif /* RTFLUSH_DEBUG */
273 
274 static kauth_listener_t route_listener;
275 
276 static int rtdeletemsg(struct rtentry *);
277 
278 static void rt_maskedcopy(const struct sockaddr *,
279     struct sockaddr *, const struct sockaddr *);
280 
281 static void rtcache_invalidate(void);
282 
283 static void rt_ref(struct rtentry *);
284 
285 static struct rtentry *
286     rtalloc1_locked(const struct sockaddr *, int, bool, bool);
287 
288 static struct ifaddr *rt_getifa(struct rt_addrinfo *, struct psref *);
289 static struct ifnet *rt_getifp(struct rt_addrinfo *, struct psref *);
290 static struct ifaddr *ifa_ifwithroute_psref(int, const struct sockaddr *,
291     const struct sockaddr *, struct psref *);
292 
293 static void rtcache_ref(struct rtentry *, struct route *);
294 
295 #ifdef NET_MPSAFE
296 static void rt_update_wait(void);
297 #endif
298 
299 static bool rt_wait_ok(void);
300 static void rt_wait_refcnt(const char *, struct rtentry *, int);
301 static void rt_wait_psref(struct rtentry *);
302 
303 #ifdef DDB
304 static void db_print_sa(const struct sockaddr *);
305 static void db_print_ifa(struct ifaddr *);
306 static int db_show_rtentry(struct rtentry *, void *);
307 #endif
308 
309 #ifdef RTFLUSH_DEBUG
310 static void sysctl_net_rtcache_setup(struct sysctllog **);
311 static void
sysctl_net_rtcache_setup(struct sysctllog ** clog)312 sysctl_net_rtcache_setup(struct sysctllog **clog)
313 {
314           const struct sysctlnode *rnode;
315 
316           if (sysctl_createv(clog, 0, NULL, &rnode, CTLFLAG_PERMANENT,
317               CTLTYPE_NODE,
318               "rtcache", SYSCTL_DESCR("Route cache related settings"),
319               NULL, 0, NULL, 0, CTL_NET, CTL_CREATE, CTL_EOL) != 0)
320                     return;
321           if (sysctl_createv(clog, 0, &rnode, &rnode,
322               CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT,
323               "debug", SYSCTL_DESCR("Debug route caches"),
324               NULL, 0, &_rtcache_debug, 0, CTL_CREATE, CTL_EOL) != 0)
325                     return;
326 }
327 #endif /* RTFLUSH_DEBUG */
328 
329 static inline void
rt_destroy(struct rtentry * rt)330 rt_destroy(struct rtentry *rt)
331 {
332           if (rt->_rt_key != NULL)
333                     sockaddr_free(rt->_rt_key);
334           if (rt->rt_gateway != NULL)
335                     sockaddr_free(rt->rt_gateway);
336           if (rt_gettag(rt) != NULL)
337                     sockaddr_free(rt_gettag(rt));
338           rt->_rt_key = rt->rt_gateway = rt->rt_tag = NULL;
339 }
340 
341 static inline const struct sockaddr *
rt_setkey(struct rtentry * rt,const struct sockaddr * key,int flags)342 rt_setkey(struct rtentry *rt, const struct sockaddr *key, int flags)
343 {
344           if (rt->_rt_key == key)
345                     goto out;
346 
347           if (rt->_rt_key != NULL)
348                     sockaddr_free(rt->_rt_key);
349           rt->_rt_key = sockaddr_dup(key, flags);
350 out:
351           rt->rt_nodes->rn_key = (const char *)rt->_rt_key;
352           return rt->_rt_key;
353 }
354 
355 struct ifaddr *
rt_get_ifa(struct rtentry * rt)356 rt_get_ifa(struct rtentry *rt)
357 {
358           struct ifaddr *ifa;
359 
360           ifa = rt->rt_ifa;
361           if (ifa->ifa_getifa == NULL)
362                     return ifa;
363 #if 0
364           else if (ifa->ifa_seqno != NULL && *ifa->ifa_seqno == rt->rt_ifa_seqno)
365                     return ifa;
366 #endif
367           else {
368                     ifa = (*ifa->ifa_getifa)(ifa, rt_getkey(rt));
369                     if (ifa == NULL)
370                               return NULL;
371                     rt_replace_ifa(rt, ifa);
372                     return ifa;
373           }
374 }
375 
376 static void
rt_set_ifa1(struct rtentry * rt,struct ifaddr * ifa)377 rt_set_ifa1(struct rtentry *rt, struct ifaddr *ifa)
378 {
379           rt->rt_ifa = ifa;
380           if (ifa->ifa_seqno != NULL)
381                     rt->rt_ifa_seqno = *ifa->ifa_seqno;
382 }
383 
384 /*
385  * Is this route the connected route for the ifa?
386  */
387 static int
rt_ifa_connected(const struct rtentry * rt,const struct ifaddr * ifa)388 rt_ifa_connected(const struct rtentry *rt, const struct ifaddr *ifa)
389 {
390           const struct sockaddr *key, *dst, *odst;
391           struct sockaddr_storage maskeddst;
392 
393           key = rt_getkey(rt);
394           dst = rt->rt_flags & RTF_HOST ? ifa->ifa_dstaddr : ifa->ifa_addr;
395           if (dst == NULL ||
396               dst->sa_family != key->sa_family ||
397               dst->sa_len != key->sa_len)
398                     return 0;
399           if ((rt->rt_flags & RTF_HOST) == 0 && ifa->ifa_netmask) {
400                     odst = dst;
401                     dst = (struct sockaddr *)&maskeddst;
402                     rt_maskedcopy(odst, (struct sockaddr *)&maskeddst,
403                         ifa->ifa_netmask);
404           }
405           return (memcmp(dst, key, dst->sa_len) == 0);
406 }
407 
408 void
rt_replace_ifa(struct rtentry * rt,struct ifaddr * ifa)409 rt_replace_ifa(struct rtentry *rt, struct ifaddr *ifa)
410 {
411           struct ifaddr *old;
412 
413           if (rt->rt_ifa == ifa)
414                     return;
415 
416           if (rt->rt_ifa != ifa &&
417               rt->rt_ifa->ifa_flags & IFA_ROUTE &&
418               rt_ifa_connected(rt, rt->rt_ifa))
419           {
420                     RT_DPRINTF("rt->_rt_key = %p, ifa = %p, "
421                         "replace deleted IFA_ROUTE\n",
422                         (void *)rt->_rt_key, (void *)rt->rt_ifa);
423                     rt->rt_ifa->ifa_flags &= ~IFA_ROUTE;
424                     if (rt_ifa_connected(rt, ifa)) {
425                               RT_DPRINTF("rt->_rt_key = %p, ifa = %p, "
426                                   "replace added IFA_ROUTE\n",
427                                   (void *)rt->_rt_key, (void *)ifa);
428                               ifa->ifa_flags |= IFA_ROUTE;
429                     }
430           }
431 
432           ifaref(ifa);
433           old = rt->rt_ifa;
434           rt_set_ifa1(rt, ifa);
435           ifafree(old);
436 }
437 
438 static void
rt_set_ifa(struct rtentry * rt,struct ifaddr * ifa)439 rt_set_ifa(struct rtentry *rt, struct ifaddr *ifa)
440 {
441           ifaref(ifa);
442           rt_set_ifa1(rt, ifa);
443 }
444 
445 static int
route_listener_cb(kauth_cred_t cred,kauth_action_t action,void * cookie,void * arg0,void * arg1,void * arg2,void * arg3)446 route_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
447     void *arg0, void *arg1, void *arg2, void *arg3)
448 {
449           struct rt_msghdr *rtm;
450           int result;
451 
452           result = KAUTH_RESULT_DEFER;
453           rtm = arg1;
454 
455           if (action != KAUTH_NETWORK_ROUTE)
456                     return result;
457 
458           if (rtm->rtm_type == RTM_GET)
459                     result = KAUTH_RESULT_ALLOW;
460 
461           return result;
462 }
463 
464 static void rt_free_work(struct work *, void *);
465 
466 void
rt_init(void)467 rt_init(void)
468 {
469           int error;
470 
471 #ifdef RTFLUSH_DEBUG
472           sysctl_net_rtcache_setup(NULL);
473 #endif
474 
475           mutex_init(&rt_free_global.lock, MUTEX_DEFAULT, IPL_SOFTNET);
476           SLIST_INIT(&rt_free_global.queue);
477           rt_free_global.enqueued = false;
478 
479           rt_psref_class = psref_class_create("rtentry", IPL_SOFTNET);
480 
481           error = workqueue_create(&rt_free_global.wq, "rt_free",
482               rt_free_work, NULL, PRI_SOFTNET, IPL_SOFTNET, RT_WQ_FLAGS);
483           if (error)
484                     panic("%s: workqueue_create failed (%d)\n", __func__, error);
485 
486           mutex_init(&rt_update_global.lock, MUTEX_DEFAULT, IPL_SOFTNET);
487           cv_init(&rt_update_global.cv, "rt_update");
488 
489           pool_init(&rtentry_pool, sizeof(struct rtentry), 0, 0, 0, "rtentpl",
490               NULL, IPL_SOFTNET);
491           pool_init(&rttimer_pool, sizeof(struct rttimer), 0, 0, 0, "rttmrpl",
492               NULL, IPL_SOFTNET);
493 
494           rn_init();          /* initialize all zeroes, all ones, mask table */
495           rtbl_init();
496 
497           route_listener = kauth_listen_scope(KAUTH_SCOPE_NETWORK,
498               route_listener_cb, NULL);
499 }
500 
501 static void
rtcache_invalidate(void)502 rtcache_invalidate(void)
503 {
504 
505           RT_ASSERT_WLOCK();
506 
507           if (rtcache_debug())
508                     printf("%s: enter\n", __func__);
509 
510           rtcache_generation++;
511 }
512 
513 #ifdef RT_DEBUG
514 static void
dump_rt(const struct rtentry * rt)515 dump_rt(const struct rtentry *rt)
516 {
517           char buf[512];
518 
519           log(LOG_DEBUG, "rt: ");
520           log(LOG_DEBUG, "p=%p ", rt);
521           if (rt->_rt_key == NULL) {
522                     log(LOG_DEBUG, "dst=(NULL) ");
523           } else {
524                     sockaddr_format(rt->_rt_key, buf, sizeof(buf));
525                     log(LOG_DEBUG, "dst=%s ", buf);
526           }
527           if (rt->rt_gateway == NULL) {
528                     log(LOG_DEBUG, "gw=(NULL) ");
529           } else {
530                     sockaddr_format(rt->_rt_key, buf, sizeof(buf));
531                     log(LOG_DEBUG, "gw=%s ", buf);
532           }
533           log(LOG_DEBUG, "flags=%x ", rt->rt_flags);
534           if (rt->rt_ifp == NULL) {
535                     log(LOG_DEBUG, "if=(NULL) ");
536           } else {
537                     log(LOG_DEBUG, "if=%s ", rt->rt_ifp->if_xname);
538           }
539           log(LOG_DEBUG, "\n");
540 }
541 #endif /* RT_DEBUG */
542 
543 /*
544  * Packet routing routines. If success, refcnt of a returned rtentry
545  * will be incremented. The caller has to rtfree it by itself.
546  */
547 struct rtentry *
rtalloc1_locked(const struct sockaddr * dst,int report,bool wait_ok,bool wlock)548 rtalloc1_locked(const struct sockaddr *dst, int report, bool wait_ok,
549     bool wlock)
550 {
551           rtbl_t *rtbl;
552           struct rtentry *rt;
553           int s;
554 
555 #ifdef NET_MPSAFE
556 retry:
557 #endif
558           s = splsoftnet();
559           rtbl = rt_gettable(dst->sa_family);
560           if (rtbl == NULL)
561                     goto miss;
562 
563           rt = rt_matchaddr(rtbl, dst);
564           if (rt == NULL)
565                     goto miss;
566 
567           if (!ISSET(rt->rt_flags, RTF_UP))
568                     goto miss;
569 
570 #ifdef NET_MPSAFE
571           if (ISSET(rt->rt_flags, RTF_UPDATING) &&
572               /* XXX updater should be always able to acquire */
573               curlwp != rt_update_global.lwp) {
574                     if (!wait_ok || !rt_wait_ok())
575                               goto miss;
576                     RT_UNLOCK();
577                     splx(s);
578 
579                     /* We can wait until the update is complete */
580                     rt_update_wait();
581 
582                     if (wlock)
583                               RT_WLOCK();
584                     else
585                               RT_RLOCK();
586                     goto retry;
587           }
588 #endif /* NET_MPSAFE */
589 
590           rt_ref(rt);
591           RT_REFCNT_TRACE(rt);
592 
593           splx(s);
594           return rt;
595 miss:
596           rtstat.rts_unreach++;
597           if (report) {
598                     struct rt_addrinfo info;
599 
600                     memset(&info, 0, sizeof(info));
601                     info.rti_info[RTAX_DST] = dst;
602                     rt_missmsg(RTM_MISS, &info, 0, 0);
603           }
604           splx(s);
605           return NULL;
606 }
607 
608 struct rtentry *
rtalloc1(const struct sockaddr * dst,int report)609 rtalloc1(const struct sockaddr *dst, int report)
610 {
611           struct rtentry *rt;
612 
613           RT_RLOCK();
614           rt = rtalloc1_locked(dst, report, true, false);
615           RT_UNLOCK();
616 
617           return rt;
618 }
619 
620 static void
rt_ref(struct rtentry * rt)621 rt_ref(struct rtentry *rt)
622 {
623 
624           KASSERTMSG(rt->rt_refcnt >= 0, "rt_refcnt=%d", rt->rt_refcnt);
625           atomic_inc_uint(&rt->rt_refcnt);
626 }
627 
628 void
rt_unref(struct rtentry * rt)629 rt_unref(struct rtentry *rt)
630 {
631 
632           KASSERT(rt != NULL);
633           KASSERTMSG(rt->rt_refcnt > 0, "refcnt=%d", rt->rt_refcnt);
634 
635           atomic_dec_uint(&rt->rt_refcnt);
636           if (!ISSET(rt->rt_flags, RTF_UP) || ISSET(rt->rt_flags, RTF_UPDATING)) {
637                     mutex_enter(&rt_free_global.lock);
638                     cv_broadcast(&rt->rt_cv);
639                     mutex_exit(&rt_free_global.lock);
640           }
641 }
642 
643 static bool
rt_wait_ok(void)644 rt_wait_ok(void)
645 {
646 
647           /*
648            * This originally returned !cpu_softintr_p(), but that doesn't
649            * work: the caller may hold a lock (probably softnet lock)
650            * that a softint is waiting for, in which case waiting here
651            * would cause a deadlock.  See https://gnats.netbsd.org/56844
652            * for details.  For now, until the locking paths are sorted
653            * out, we just disable the waiting option altogether and
654            * always defer to workqueue.
655            */
656           KASSERT(!cpu_intr_p());
657           return false;
658 }
659 
660 void
rt_wait_refcnt(const char * title,struct rtentry * rt,int cnt)661 rt_wait_refcnt(const char *title, struct rtentry *rt, int cnt)
662 {
663           mutex_enter(&rt_free_global.lock);
664           while (rt->rt_refcnt > cnt) {
665                     dlog(LOG_DEBUG, "%s: %s waiting (refcnt=%d)\n",
666                         __func__, title, rt->rt_refcnt);
667                     cv_wait(&rt->rt_cv, &rt_free_global.lock);
668                     dlog(LOG_DEBUG, "%s: %s waited (refcnt=%d)\n",
669                         __func__, title, rt->rt_refcnt);
670           }
671           mutex_exit(&rt_free_global.lock);
672 }
673 
674 void
rt_wait_psref(struct rtentry * rt)675 rt_wait_psref(struct rtentry *rt)
676 {
677 
678           psref_target_destroy(&rt->rt_psref, rt_psref_class);
679           psref_target_init(&rt->rt_psref, rt_psref_class);
680 }
681 
682 static void
_rt_free(struct rtentry * rt)683 _rt_free(struct rtentry *rt)
684 {
685           struct ifaddr *ifa;
686 
687           /*
688            * Need to avoid a deadlock on rt_wait_refcnt of update
689            * and a conflict on psref_target_destroy of update.
690            */
691 #ifdef NET_MPSAFE
692           rt_update_wait();
693 #endif
694 
695           RT_REFCNT_TRACE(rt);
696           KASSERTMSG(rt->rt_refcnt >= 0, "refcnt=%d", rt->rt_refcnt);
697           rt_wait_refcnt("free", rt, 0);
698 #ifdef NET_MPSAFE
699           psref_target_destroy(&rt->rt_psref, rt_psref_class);
700 #endif
701 
702           rt_assert_inactive(rt);
703           rttrash--;
704           ifa = rt->rt_ifa;
705           rt->rt_ifa = NULL;
706           ifafree(ifa);
707           rt->rt_ifp = NULL;
708           cv_destroy(&rt->rt_cv);
709           rt_destroy(rt);
710           pool_put(&rtentry_pool, rt);
711 }
712 
713 static void
rt_free_work(struct work * wk,void * arg)714 rt_free_work(struct work *wk, void *arg)
715 {
716 
717           for (;;) {
718                     struct rtentry *rt;
719 
720                     mutex_enter(&rt_free_global.lock);
721                     if ((rt = SLIST_FIRST(&rt_free_global.queue)) == NULL) {
722                               rt_free_global.enqueued = false;
723                               mutex_exit(&rt_free_global.lock);
724                               return;
725                     }
726                     SLIST_REMOVE_HEAD(&rt_free_global.queue, rt_free);
727                     mutex_exit(&rt_free_global.lock);
728                     atomic_dec_uint(&rt->rt_refcnt);
729                     _rt_free(rt);
730           }
731 }
732 
733 void
rt_free(struct rtentry * rt)734 rt_free(struct rtentry *rt)
735 {
736 
737           KASSERTMSG(rt->rt_refcnt > 0, "rt_refcnt=%d", rt->rt_refcnt);
738           if (rt_wait_ok()) {
739                     atomic_dec_uint(&rt->rt_refcnt);
740                     _rt_free(rt);
741                     return;
742           }
743 
744           mutex_enter(&rt_free_global.lock);
745           /* No need to add a reference here. */
746           SLIST_INSERT_HEAD(&rt_free_global.queue, rt, rt_free);
747           if (!rt_free_global.enqueued) {
748                     workqueue_enqueue(rt_free_global.wq, &rt_free_global.wk, NULL);
749                     rt_free_global.enqueued = true;
750           }
751           mutex_exit(&rt_free_global.lock);
752 }
753 
754 #ifdef NET_MPSAFE
755 static void
rt_update_wait(void)756 rt_update_wait(void)
757 {
758 
759           mutex_enter(&rt_update_global.lock);
760           while (rt_update_global.ongoing) {
761                     dlog(LOG_DEBUG, "%s: waiting lwp=%p\n", __func__, curlwp);
762                     cv_wait(&rt_update_global.cv, &rt_update_global.lock);
763                     dlog(LOG_DEBUG, "%s: waited lwp=%p\n", __func__, curlwp);
764           }
765           mutex_exit(&rt_update_global.lock);
766 }
767 #endif
768 
769 int
rt_update_prepare(struct rtentry * rt)770 rt_update_prepare(struct rtentry *rt)
771 {
772 
773           dlog(LOG_DEBUG, "%s: updating rt=%p lwp=%p\n", __func__, rt, curlwp);
774 
775           RT_WLOCK();
776           /* If the entry is being destroyed, don't proceed the update. */
777           if (!ISSET(rt->rt_flags, RTF_UP)) {
778                     RT_UNLOCK();
779                     return ESRCH;
780           }
781           rt->rt_flags |= RTF_UPDATING;
782           RT_UNLOCK();
783 
784           mutex_enter(&rt_update_global.lock);
785           while (rt_update_global.ongoing) {
786                     dlog(LOG_DEBUG, "%s: waiting ongoing updating rt=%p lwp=%p\n",
787                         __func__, rt, curlwp);
788                     cv_wait(&rt_update_global.cv, &rt_update_global.lock);
789                     dlog(LOG_DEBUG, "%s: waited ongoing updating rt=%p lwp=%p\n",
790                         __func__, rt, curlwp);
791           }
792           rt_update_global.ongoing = true;
793           /* XXX need it to avoid rt_update_wait by updater itself. */
794           rt_update_global.lwp = curlwp;
795           mutex_exit(&rt_update_global.lock);
796 
797           rt_wait_refcnt("update", rt, 1);
798           rt_wait_psref(rt);
799 
800           return 0;
801 }
802 
803 void
rt_update_finish(struct rtentry * rt)804 rt_update_finish(struct rtentry *rt)
805 {
806 
807           RT_WLOCK();
808           rt->rt_flags &= ~RTF_UPDATING;
809           RT_UNLOCK();
810 
811           mutex_enter(&rt_update_global.lock);
812           rt_update_global.ongoing = false;
813           rt_update_global.lwp = NULL;
814           cv_broadcast(&rt_update_global.cv);
815           mutex_exit(&rt_update_global.lock);
816 
817           dlog(LOG_DEBUG, "%s: updated rt=%p lwp=%p\n", __func__, rt, curlwp);
818 }
819 
820 /*
821  * Force a routing table entry to the specified
822  * destination to go through the given gateway.
823  * Normally called as a result of a routing redirect
824  * message from the network layer.
825  *
826  * N.B.: must be called at splsoftnet
827  */
828 void
rtredirect(const struct sockaddr * dst,const struct sockaddr * gateway,const struct sockaddr * netmask,int flags,const struct sockaddr * src,struct rtentry ** rtp)829 rtredirect(const struct sockaddr *dst, const struct sockaddr *gateway,
830           const struct sockaddr *netmask, int flags, const struct sockaddr *src,
831           struct rtentry **rtp)
832 {
833           struct rtentry *rt;
834           int error = 0;
835           uint64_t *stat = NULL;
836           struct rt_addrinfo info;
837           struct ifaddr *ifa;
838           struct psref psref;
839 
840           /* verify the gateway is directly reachable */
841           if ((ifa = ifa_ifwithnet_psref(gateway, &psref)) == NULL) {
842                     error = ENETUNREACH;
843                     goto out;
844           }
845           rt = rtalloc1(dst, 0);
846           /*
847            * If the redirect isn't from our current router for this dst,
848            * it's either old or wrong.  If it redirects us to ourselves,
849            * we have a routing loop, perhaps as a result of an interface
850            * going down recently.
851            */
852           if (!(flags & RTF_DONE) && rt &&
853                (sockaddr_cmp(src, rt->rt_gateway) != 0 || rt->rt_ifa != ifa))
854                     error = EINVAL;
855           else {
856                     int s = pserialize_read_enter();
857                     struct ifaddr *_ifa;
858 
859                     _ifa = ifa_ifwithaddr(gateway);
860                     if (_ifa != NULL)
861                               error = EHOSTUNREACH;
862                     pserialize_read_exit(s);
863           }
864           if (error)
865                     goto done;
866           /*
867            * Create a new entry if we just got back a wildcard entry
868            * or the lookup failed.  This is necessary for hosts
869            * which use routing redirects generated by smart gateways
870            * to dynamically build the routing tables.
871            */
872           if (rt == NULL || (rt_mask(rt) && rt_mask(rt)->sa_len < 2))
873                     goto create;
874           /*
875            * Don't listen to the redirect if it's
876            * for a route to an interface.
877            */
878           if (rt->rt_flags & RTF_GATEWAY) {
879                     if (((rt->rt_flags & RTF_HOST) == 0) && (flags & RTF_HOST)) {
880                               /*
881                                * Changing from route to net => route to host.
882                                * Create new route, rather than smashing route to net.
883                                */
884                     create:
885                               if (rt != NULL)
886                                         rt_unref(rt);
887                               flags |=  RTF_GATEWAY | RTF_DYNAMIC;
888                               memset(&info, 0, sizeof(info));
889                               info.rti_info[RTAX_DST] = dst;
890                               info.rti_info[RTAX_GATEWAY] = gateway;
891                               info.rti_info[RTAX_NETMASK] = netmask;
892                               info.rti_ifa = ifa;
893                               info.rti_flags = flags;
894                               rt = NULL;
895                               error = rtrequest1(RTM_ADD, &info, &rt);
896                               if (rt != NULL)
897                                         flags = rt->rt_flags;
898                               if (error == 0)
899                                         rt_newmsg_dynamic(RTM_ADD, rt);
900                               stat = &rtstat.rts_dynamic;
901                     } else {
902                               /*
903                                * Smash the current notion of the gateway to
904                                * this destination.  Should check about netmask!!!
905                                */
906 #ifdef NET_MPSAFE
907                               KASSERT(!cpu_softintr_p());
908 
909                               error = rt_update_prepare(rt);
910                               if (error == 0) {
911 #endif
912                                         RT_WLOCK();
913                                         error = rt_setgate(rt, gateway);
914                                         if (error == 0) {
915                                                   rt->rt_flags |= RTF_MODIFIED;
916                                                   flags |= RTF_MODIFIED;
917                                         }
918                                         RT_UNLOCK();
919 #ifdef NET_MPSAFE
920                                         rt_update_finish(rt);
921                               } else {
922                                         /*
923                                          * If error != 0, the rtentry is being
924                                          * destroyed, so doing nothing doesn't
925                                          * matter.
926                                          */
927                               }
928 #endif
929                               stat = &rtstat.rts_newgateway;
930                     }
931           } else
932                     error = EHOSTUNREACH;
933 done:
934           if (rt) {
935                     if (rtp != NULL && !error)
936                               *rtp = rt;
937                     else
938                               rt_unref(rt);
939           }
940 out:
941           if (error)
942                     rtstat.rts_badredirect++;
943           else if (stat != NULL)
944                     (*stat)++;
945           memset(&info, 0, sizeof(info));
946           info.rti_info[RTAX_DST] = dst;
947           info.rti_info[RTAX_GATEWAY] = gateway;
948           info.rti_info[RTAX_NETMASK] = netmask;
949           info.rti_info[RTAX_AUTHOR] = src;
950           rt_missmsg(RTM_REDIRECT, &info, flags, error);
951           ifa_release(ifa, &psref);
952 }
953 
954 /*
955  * Delete a route and generate a message.
956  * It doesn't free a passed rt.
957  */
958 static int
rtdeletemsg(struct rtentry * rt)959 rtdeletemsg(struct rtentry *rt)
960 {
961           int error;
962           struct rt_addrinfo info;
963           struct rtentry *retrt;
964 
965           /*
966            * Request the new route so that the entry is not actually
967            * deleted.  That will allow the information being reported to
968            * be accurate (and consistent with route_output()).
969            */
970           memset(&info, 0, sizeof(info));
971           info.rti_info[RTAX_DST] = rt_getkey(rt);
972           info.rti_info[RTAX_NETMASK] = rt_mask(rt);
973           info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
974           info.rti_flags = rt->rt_flags;
975           error = rtrequest1(RTM_DELETE, &info, &retrt);
976 
977           rt_missmsg(RTM_DELETE, &info, info.rti_flags, error);
978 
979           return error;
980 }
981 
982 static struct ifaddr *
ifa_ifwithroute_psref(int flags,const struct sockaddr * dst,const struct sockaddr * gateway,struct psref * psref)983 ifa_ifwithroute_psref(int flags, const struct sockaddr *dst,
984     const struct sockaddr *gateway, struct psref *psref)
985 {
986           struct ifaddr *ifa = NULL;
987 
988           if ((flags & RTF_GATEWAY) == 0) {
989                     /*
990                      * If we are adding a route to an interface,
991                      * and the interface is a pt to pt link
992                      * we should search for the destination
993                      * as our clue to the interface.  Otherwise
994                      * we can use the local address.
995                      */
996                     if ((flags & RTF_HOST) && gateway->sa_family != AF_LINK)
997                               ifa = ifa_ifwithdstaddr_psref(dst, psref);
998                     if (ifa == NULL)
999                               ifa = ifa_ifwithaddr_psref(gateway, psref);
1000           } else {
1001                     /*
1002                      * If we are adding a route to a remote net
1003                      * or host, the gateway may still be on the
1004                      * other end of a pt to pt link.
1005                      */
1006                     ifa = ifa_ifwithdstaddr_psref(gateway, psref);
1007           }
1008           if (ifa == NULL)
1009                     ifa = ifa_ifwithnet_psref(gateway, psref);
1010           if (ifa == NULL) {
1011                     int s;
1012                     struct rtentry *rt;
1013 
1014                     rt = rtalloc1_locked(gateway, 0, true, true);
1015                     if (rt == NULL)
1016                               return NULL;
1017                     if (rt->rt_flags & RTF_GATEWAY) {
1018                               rt_unref(rt);
1019                               return NULL;
1020                     }
1021                     /*
1022                      * Just in case. May not need to do this workaround.
1023                      * Revisit when working on rtentry MP-ification.
1024                      */
1025                     s = pserialize_read_enter();
1026                     IFADDR_READER_FOREACH(ifa, rt->rt_ifp) {
1027                               if (ifa == rt->rt_ifa)
1028                                         break;
1029                     }
1030                     if (ifa != NULL)
1031                               ifa_acquire(ifa, psref);
1032                     pserialize_read_exit(s);
1033                     rt_unref(rt);
1034                     if (ifa == NULL)
1035                               return NULL;
1036           }
1037           if (ifa->ifa_addr->sa_family != dst->sa_family) {
1038                     struct ifaddr *nifa;
1039                     int s;
1040 
1041                     s = pserialize_read_enter();
1042                     nifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
1043                     if (nifa != NULL) {
1044                               ifa_release(ifa, psref);
1045                               ifa_acquire(nifa, psref);
1046                               ifa = nifa;
1047                     }
1048                     pserialize_read_exit(s);
1049           }
1050           return ifa;
1051 }
1052 
1053 /*
1054  * If it suceeds and ret_nrt isn't NULL, refcnt of ret_nrt is incremented.
1055  * The caller has to rtfree it by itself.
1056  */
1057 int
rtrequest(int req,const struct sockaddr * dst,const struct sockaddr * gateway,const struct sockaddr * netmask,int flags,struct rtentry ** ret_nrt)1058 rtrequest(int req, const struct sockaddr *dst, const struct sockaddr *gateway,
1059           const struct sockaddr *netmask, int flags, struct rtentry **ret_nrt)
1060 {
1061           struct rt_addrinfo info;
1062 
1063           memset(&info, 0, sizeof(info));
1064           info.rti_flags = flags;
1065           info.rti_info[RTAX_DST] = dst;
1066           info.rti_info[RTAX_GATEWAY] = gateway;
1067           info.rti_info[RTAX_NETMASK] = netmask;
1068           return rtrequest1(req, &info, ret_nrt);
1069 }
1070 
1071 static struct ifnet *
rt_getifp(struct rt_addrinfo * info,struct psref * psref)1072 rt_getifp(struct rt_addrinfo *info, struct psref *psref)
1073 {
1074           const struct sockaddr *ifpaddr = info->rti_info[RTAX_IFP];
1075 
1076           if (info->rti_ifp != NULL)
1077                     return NULL;
1078           /*
1079            * ifp may be specified by sockaddr_dl when protocol address
1080            * is ambiguous
1081            */
1082           if (ifpaddr != NULL && ifpaddr->sa_family == AF_LINK) {
1083                     struct ifaddr *ifa;
1084                     int s = pserialize_read_enter();
1085 
1086                     ifa = ifa_ifwithnet(ifpaddr);
1087                     if (ifa != NULL)
1088                               info->rti_ifp = if_get_byindex(ifa->ifa_ifp->if_index,
1089                                   psref);
1090                     pserialize_read_exit(s);
1091           }
1092 
1093           return info->rti_ifp;
1094 }
1095 
1096 static struct ifaddr *
rt_getifa(struct rt_addrinfo * info,struct psref * psref)1097 rt_getifa(struct rt_addrinfo *info, struct psref *psref)
1098 {
1099           struct ifaddr *ifa = NULL;
1100           const struct sockaddr *dst = info->rti_info[RTAX_DST];
1101           const struct sockaddr *gateway = info->rti_info[RTAX_GATEWAY];
1102           const struct sockaddr *ifaaddr = info->rti_info[RTAX_IFA];
1103           int flags = info->rti_flags;
1104           const struct sockaddr *sa;
1105 
1106           if (info->rti_ifa == NULL && ifaaddr != NULL) {
1107                     ifa = ifa_ifwithaddr_psref(ifaaddr, psref);
1108                     if (ifa != NULL)
1109                               goto got;
1110           }
1111 
1112           sa = ifaaddr != NULL ? ifaaddr :
1113               (gateway != NULL ? gateway : dst);
1114           if (sa != NULL && info->rti_ifp != NULL)
1115                     ifa = ifaof_ifpforaddr_psref(sa, info->rti_ifp, psref);
1116           else if (dst != NULL && gateway != NULL)
1117                     ifa = ifa_ifwithroute_psref(flags, dst, gateway, psref);
1118           else if (sa != NULL)
1119                     ifa = ifa_ifwithroute_psref(flags, sa, sa, psref);
1120           if (ifa == NULL)
1121                     return NULL;
1122 got:
1123           if (ifa->ifa_getifa != NULL) {
1124                     /* FIXME ifa_getifa is NOMPSAFE */
1125                     ifa = (*ifa->ifa_getifa)(ifa, dst);
1126                     if (ifa == NULL)
1127                               return NULL;
1128                     ifa_acquire(ifa, psref);
1129           }
1130           info->rti_ifa = ifa;
1131           if (info->rti_ifp == NULL)
1132                     info->rti_ifp = ifa->ifa_ifp;
1133           return ifa;
1134 }
1135 
1136 /*
1137  * If it suceeds and ret_nrt isn't NULL, refcnt of ret_nrt is incremented.
1138  * The caller has to rtfree it by itself.
1139  */
1140 int
rtrequest1(int req,struct rt_addrinfo * info,struct rtentry ** ret_nrt)1141 rtrequest1(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt)
1142 {
1143           int s = splsoftnet(), ss;
1144           int error = 0, rc;
1145           struct rtentry *rt;
1146           rtbl_t *rtbl;
1147           struct ifaddr *ifa = NULL;
1148           struct sockaddr_storage maskeddst;
1149           const struct sockaddr *dst = info->rti_info[RTAX_DST];
1150           const struct sockaddr *gateway = info->rti_info[RTAX_GATEWAY];
1151           const struct sockaddr *netmask = info->rti_info[RTAX_NETMASK];
1152           int flags = info->rti_flags;
1153           struct psref psref_ifp, psref_ifa;
1154           int bound = 0;
1155           struct ifnet *ifp = NULL;
1156           bool need_to_release_ifa = true;
1157           bool need_unlock = true;
1158 #define senderr(x) { error = x ; goto bad; }
1159 
1160           RT_WLOCK();
1161 
1162           bound = curlwp_bind();
1163           if ((rtbl = rt_gettable(dst->sa_family)) == NULL)
1164                     senderr(ESRCH);
1165           if (flags & RTF_HOST)
1166                     netmask = NULL;
1167           switch (req) {
1168           case RTM_DELETE:
1169                     if (netmask) {
1170                               rt_maskedcopy(dst, (struct sockaddr *)&maskeddst,
1171                                   netmask);
1172                               dst = (struct sockaddr *)&maskeddst;
1173                     }
1174                     if ((rt = rt_lookup(rtbl, dst, netmask)) == NULL)
1175                               senderr(ESRCH);
1176                     if ((rt = rt_deladdr(rtbl, dst, netmask)) == NULL)
1177                               senderr(ESRCH);
1178                     rt->rt_flags &= ~RTF_UP;
1179                     ifa = rt->rt_ifa;
1180                     if (ifa->ifa_flags & IFA_ROUTE &&
1181                         rt_ifa_connected(rt, ifa)) {
1182                               RT_DPRINTF("rt->_rt_key = %p, ifa = %p, "
1183                                   "deleted IFA_ROUTE\n",
1184                                   (void *)rt->_rt_key, (void *)ifa);
1185                               ifa->ifa_flags &= ~IFA_ROUTE;
1186                     }
1187                     if (ifa->ifa_rtrequest)
1188                               ifa->ifa_rtrequest(RTM_DELETE, rt, info);
1189                     ifa = NULL;
1190                     rttrash++;
1191                     if (ret_nrt) {
1192                               *ret_nrt = rt;
1193                               rt_ref(rt);
1194                               RT_REFCNT_TRACE(rt);
1195                     }
1196                     rtcache_invalidate();
1197                     RT_UNLOCK();
1198                     need_unlock = false;
1199                     rt_timer_remove_all(rt);
1200 #if defined(INET) || defined(INET6)
1201                     if (netmask != NULL)
1202                               lltable_prefix_free(dst->sa_family, dst, netmask, 0);
1203 #endif
1204                     if (ret_nrt == NULL) {
1205                               /* Adjust the refcount */
1206                               rt_ref(rt);
1207                               RT_REFCNT_TRACE(rt);
1208                               rt_free(rt);
1209                     }
1210                     break;
1211 
1212           case RTM_ADD:
1213                     if (info->rti_ifa == NULL) {
1214                               ifp = rt_getifp(info, &psref_ifp);
1215                               ifa = rt_getifa(info, &psref_ifa);
1216                               if (ifa == NULL)
1217                                         senderr(ENETUNREACH);
1218                     } else {
1219                               /* Caller should have a reference of ifa */
1220                               ifa = info->rti_ifa;
1221                               need_to_release_ifa = false;
1222                     }
1223                     rt = pool_get(&rtentry_pool, PR_NOWAIT);
1224                     if (rt == NULL)
1225                               senderr(ENOBUFS);
1226                     memset(rt, 0, sizeof(*rt));
1227                     rt->rt_flags = RTF_UP | (flags & ~RTF_DONTCHANGEIFA);
1228                     LIST_INIT(&rt->rt_timer);
1229 
1230                     RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1231                     if (netmask) {
1232                               rt_maskedcopy(dst, (struct sockaddr *)&maskeddst,
1233                                   netmask);
1234                               rt_setkey(rt, (struct sockaddr *)&maskeddst, M_NOWAIT);
1235                     } else {
1236                               rt_setkey(rt, dst, M_NOWAIT);
1237                     }
1238                     RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1239                     if (rt_getkey(rt) == NULL ||
1240                         rt_setgate(rt, gateway) != 0) {
1241                               pool_put(&rtentry_pool, rt);
1242                               senderr(ENOBUFS);
1243                     }
1244 
1245                     rt_set_ifa(rt, ifa);
1246                     if (info->rti_info[RTAX_TAG] != NULL) {
1247                               const struct sockaddr *tag;
1248                               tag = rt_settag(rt, info->rti_info[RTAX_TAG]);
1249                               if (tag == NULL)
1250                                         senderr(ENOBUFS);
1251                     }
1252                     RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1253 
1254                     ss = pserialize_read_enter();
1255                     if (info->rti_info[RTAX_IFP] != NULL) {
1256                               struct ifaddr *ifa2;
1257                               ifa2 = ifa_ifwithnet(info->rti_info[RTAX_IFP]);
1258                               if (ifa2 != NULL)
1259                                         rt->rt_ifp = ifa2->ifa_ifp;
1260                               else
1261                                         rt->rt_ifp = ifa->ifa_ifp;
1262                     } else
1263                               rt->rt_ifp = ifa->ifa_ifp;
1264                     pserialize_read_exit(ss);
1265                     cv_init(&rt->rt_cv, "rtentry");
1266                     psref_target_init(&rt->rt_psref, rt_psref_class);
1267 
1268                     RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1269                     rc = rt_addaddr(rtbl, rt, netmask);
1270                     RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1271                     if (rc != 0) {
1272                               ifafree(ifa); /* for rt_set_ifa above */
1273                               cv_destroy(&rt->rt_cv);
1274                               rt_destroy(rt);
1275                               pool_put(&rtentry_pool, rt);
1276                               senderr(rc);
1277                     }
1278                     RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1279                     if (ifa->ifa_rtrequest)
1280                               ifa->ifa_rtrequest(req, rt, info);
1281                     if (need_to_release_ifa)
1282                               ifa_release(ifa, &psref_ifa);
1283                     ifa = NULL;
1284                     if_put(ifp, &psref_ifp);
1285                     ifp = NULL;
1286                     RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1287                     if (ret_nrt) {
1288                               *ret_nrt = rt;
1289                               rt_ref(rt);
1290                               RT_REFCNT_TRACE(rt);
1291                     }
1292                     rtcache_invalidate();
1293                     RT_UNLOCK();
1294                     need_unlock = false;
1295                     break;
1296           case RTM_GET:
1297                     if (netmask != NULL) {
1298                               rt_maskedcopy(dst, (struct sockaddr *)&maskeddst,
1299                                   netmask);
1300                               dst = (struct sockaddr *)&maskeddst;
1301                     }
1302                     if ((rt = rt_lookup(rtbl, dst, netmask)) == NULL)
1303                               senderr(ESRCH);
1304                     if (ret_nrt != NULL) {
1305                               *ret_nrt = rt;
1306                               rt_ref(rt);
1307                               RT_REFCNT_TRACE(rt);
1308                     }
1309                     break;
1310           }
1311 bad:
1312           if (need_to_release_ifa)
1313                     ifa_release(ifa, &psref_ifa);
1314           if_put(ifp, &psref_ifp);
1315           curlwp_bindx(bound);
1316           if (need_unlock)
1317                     RT_UNLOCK();
1318           splx(s);
1319           return error;
1320 }
1321 
1322 int
rt_setgate(struct rtentry * rt,const struct sockaddr * gate)1323 rt_setgate(struct rtentry *rt, const struct sockaddr *gate)
1324 {
1325           struct sockaddr *new, *old;
1326 
1327           KASSERT(RT_WLOCKED());
1328           KASSERT(rt->_rt_key != NULL);
1329           RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1330 
1331           new = sockaddr_dup(gate, M_ZERO | M_NOWAIT);
1332           if (new == NULL)
1333                     return ENOMEM;
1334 
1335           old = rt->rt_gateway;
1336           rt->rt_gateway = new;
1337           if (old != NULL)
1338                     sockaddr_free(old);
1339 
1340           KASSERT(rt->_rt_key != NULL);
1341           RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1342 
1343           if (rt->rt_flags & RTF_GATEWAY) {
1344                     struct rtentry *gwrt;
1345 
1346                     gwrt = rtalloc1_locked(gate, 1, false, true);
1347                     /*
1348                      * If we switched gateways, grab the MTU from the new
1349                      * gateway route if the current MTU, if the current MTU is
1350                      * greater than the MTU of gateway.
1351                      * Note that, if the MTU of gateway is 0, we will reset the
1352                      * MTU of the route to run PMTUD again from scratch. XXX
1353                      */
1354                     if (gwrt != NULL) {
1355                               KASSERT(gwrt->_rt_key != NULL);
1356                               RT_DPRINTF("gwrt->_rt_key = %p\n", gwrt->_rt_key);
1357                               if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 &&
1358                                   rt->rt_rmx.rmx_mtu &&
1359                                   rt->rt_rmx.rmx_mtu > gwrt->rt_rmx.rmx_mtu) {
1360                                         rt->rt_rmx.rmx_mtu = gwrt->rt_rmx.rmx_mtu;
1361                               }
1362                               rt_unref(gwrt);
1363                     }
1364           }
1365           KASSERT(rt->_rt_key != NULL);
1366           RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
1367           return 0;
1368 }
1369 
1370 static struct ifaddr *
rt_update_get_ifa(const struct rt_addrinfo * info,const struct rtentry * rt,struct ifnet ** ifp,struct psref * psref_ifp,struct psref * psref)1371 rt_update_get_ifa(const struct rt_addrinfo *info, const struct rtentry *rt,
1372     struct ifnet **ifp, struct psref *psref_ifp, struct psref *psref)
1373 {
1374           struct ifaddr *ifa = NULL;
1375 
1376           *ifp = NULL;
1377           if (info->rti_info[RTAX_IFP] != NULL) {
1378                     ifa = ifa_ifwithnet_psref(info->rti_info[RTAX_IFP], psref);
1379                     if (ifa == NULL)
1380                               goto next;
1381                     if (ifa->ifa_ifp->if_flags & IFF_UNNUMBERED) {
1382                               ifa_release(ifa, psref);
1383                               ifa = NULL;
1384                               goto next;
1385                     }
1386                     *ifp = ifa->ifa_ifp;
1387                     if_acquire(*ifp, psref_ifp);
1388                     if (info->rti_info[RTAX_IFA] == NULL &&
1389                         info->rti_info[RTAX_GATEWAY] == NULL)
1390                               goto out;
1391                     ifa_release(ifa, psref);
1392                     if (info->rti_info[RTAX_IFA] == NULL) {
1393                               /* route change <dst> <gw> -ifp <if> */
1394                               ifa = ifaof_ifpforaddr_psref(
1395                                   info->rti_info[RTAX_GATEWAY], *ifp, psref);
1396                     } else {
1397                               /* route change <dst> -ifp <if> -ifa <addr> */
1398                               ifa = ifa_ifwithaddr_psref(info->rti_info[RTAX_IFA],
1399                                   psref);
1400                               if (ifa != NULL)
1401                                         goto out;
1402                               ifa = ifaof_ifpforaddr_psref(info->rti_info[RTAX_IFA],
1403                                   *ifp, psref);
1404                     }
1405                     goto out;
1406           }
1407 next:
1408           if (info->rti_info[RTAX_IFA] != NULL) {
1409                     /* route change <dst> <gw> -ifa <addr> */
1410                     ifa = ifa_ifwithaddr_psref(info->rti_info[RTAX_IFA], psref);
1411                     if (ifa != NULL)
1412                               goto out;
1413           }
1414           if (info->rti_info[RTAX_GATEWAY] != NULL) {
1415                     /* route change <dst> <gw> */
1416                     ifa = ifa_ifwithroute_psref(rt->rt_flags, rt_getkey(rt),
1417                         info->rti_info[RTAX_GATEWAY], psref);
1418           }
1419 out:
1420           if (ifa != NULL && *ifp == NULL) {
1421                     *ifp = ifa->ifa_ifp;
1422                     if_acquire(*ifp, psref_ifp);
1423           }
1424           if (ifa == NULL && *ifp != NULL) {
1425                     if_put(*ifp, psref_ifp);
1426                     *ifp = NULL;
1427           }
1428           return ifa;
1429 }
1430 
1431 int
rt_update(struct rtentry * rt,struct rt_addrinfo * info,void * rtm)1432 rt_update(struct rtentry *rt, struct rt_addrinfo *info, void *rtm)
1433 {
1434           int error = 0;
1435           struct ifnet *ifp = NULL, *new_ifp = NULL;
1436           struct ifaddr *ifa = NULL, *new_ifa;
1437           struct psref psref_ifa, psref_new_ifa, psref_ifp, psref_new_ifp;
1438           bool newgw, ifp_changed = false;
1439 
1440           RT_WLOCK();
1441           /*
1442            * New gateway could require new ifaddr, ifp;
1443            * flags may also be different; ifp may be specified
1444            * by ll sockaddr when protocol address is ambiguous
1445            */
1446           newgw = info->rti_info[RTAX_GATEWAY] != NULL &&
1447               sockaddr_cmp(info->rti_info[RTAX_GATEWAY], rt->rt_gateway) != 0;
1448 
1449           if (newgw || info->rti_info[RTAX_IFP] != NULL ||
1450               info->rti_info[RTAX_IFA] != NULL) {
1451                     ifp = rt_getifp(info, &psref_ifp);
1452                     /* info refers ifp so we need to keep a reference */
1453                     ifa = rt_getifa(info, &psref_ifa);
1454                     if (ifa == NULL) {
1455                               error = ENETUNREACH;
1456                               goto out;
1457                     }
1458           }
1459           if (newgw) {
1460                     error = rt_setgate(rt, info->rti_info[RTAX_GATEWAY]);
1461                     if (error != 0)
1462                               goto out;
1463           }
1464           if (info->rti_info[RTAX_TAG]) {
1465                     const struct sockaddr *tag;
1466                     tag = rt_settag(rt, info->rti_info[RTAX_TAG]);
1467                     if (tag == NULL) {
1468                               error = ENOBUFS;
1469                               goto out;
1470                     }
1471           }
1472           /*
1473            * New gateway could require new ifaddr, ifp;
1474            * flags may also be different; ifp may be specified
1475            * by ll sockaddr when protocol address is ambiguous
1476            */
1477           new_ifa = rt_update_get_ifa(info, rt, &new_ifp, &psref_new_ifp,
1478               &psref_new_ifa);
1479           if (new_ifa != NULL) {
1480                     ifa_release(ifa, &psref_ifa);
1481                     ifa = new_ifa;
1482           }
1483           if (ifa) {
1484                     struct ifaddr *oifa = rt->rt_ifa;
1485                     if (oifa != ifa && !ifa_is_destroying(ifa) &&
1486                         new_ifp != NULL && !if_is_deactivated(new_ifp)) {
1487                               if (oifa && oifa->ifa_rtrequest)
1488                                         oifa->ifa_rtrequest(RTM_DELETE, rt, info);
1489                               rt_replace_ifa(rt, ifa);
1490                               rt->rt_ifp = new_ifp;
1491                               ifp_changed = true;
1492                     }
1493                     if (new_ifa == NULL)
1494                               ifa_release(ifa, &psref_ifa);
1495                     /* To avoid ifa_release below */
1496                     ifa = NULL;
1497           }
1498           ifa_release(new_ifa, &psref_new_ifa);
1499           if (new_ifp && rt->rt_ifp != new_ifp && !if_is_deactivated(new_ifp)) {
1500                     rt->rt_ifp = new_ifp;
1501                     ifp_changed = true;
1502           }
1503           rt_setmetrics(rtm, rt);
1504           if (rt->rt_flags != info->rti_flags) {
1505                     rt->rt_flags = (info->rti_flags & ~PRESERVED_RTF) |
1506                         (rt->rt_flags & PRESERVED_RTF);
1507           }
1508           if (rt->rt_ifa->ifa_rtrequest)
1509                     rt->rt_ifa->ifa_rtrequest(RTM_ADD, rt, info);
1510 #if defined(INET) || defined(INET6)
1511           if (ifp_changed && rt_mask(rt) != NULL)
1512                     lltable_prefix_free(rt_getkey(rt)->sa_family, rt_getkey(rt),
1513                         rt_mask(rt), 0);
1514 #else
1515           (void)ifp_changed; /* XXX gcc */
1516 #endif
1517 out:
1518           ifa_release(ifa, &psref_ifa);
1519           if_put(new_ifp, &psref_new_ifp);
1520           if_put(ifp, &psref_ifp);
1521 
1522           RT_UNLOCK();
1523 
1524           return error;
1525 }
1526 
1527 static void
rt_maskedcopy(const struct sockaddr * src,struct sockaddr * dst,const struct sockaddr * netmask)1528 rt_maskedcopy(const struct sockaddr *src, struct sockaddr *dst,
1529           const struct sockaddr *netmask)
1530 {
1531           const char *netmaskp = &netmask->sa_data[0],
1532                      *srcp = &src->sa_data[0];
1533           char *dstp = &dst->sa_data[0];
1534           const char *maskend = (char *)dst + MIN(netmask->sa_len, src->sa_len);
1535           const char *srcend = (char *)dst + src->sa_len;
1536 
1537           dst->sa_len = src->sa_len;
1538           dst->sa_family = src->sa_family;
1539 
1540           while (dstp < maskend)
1541                     *dstp++ = *srcp++ & *netmaskp++;
1542           if (dstp < srcend)
1543                     memset(dstp, 0, (size_t)(srcend - dstp));
1544 }
1545 
1546 /*
1547  * Inform the routing socket of a route change.
1548  */
1549 void
rt_newmsg(const int cmd,const struct rtentry * rt)1550 rt_newmsg(const int cmd, const struct rtentry *rt)
1551 {
1552           struct rt_addrinfo info;
1553 
1554           memset((void *)&info, 0, sizeof(info));
1555           info.rti_info[RTAX_DST] = rt_getkey(rt);
1556           info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
1557           info.rti_info[RTAX_NETMASK] = rt_mask(rt);
1558           if (rt->rt_ifp) {
1559                     info.rti_info[RTAX_IFP] = rt->rt_ifp->if_dl->ifa_addr;
1560                     info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
1561           }
1562 
1563           rt_missmsg(cmd, &info, rt->rt_flags, 0);
1564 }
1565 
1566 /*
1567  * Inform the routing socket of a route change for RTF_DYNAMIC.
1568  */
1569 void
rt_newmsg_dynamic(const int cmd,const struct rtentry * rt)1570 rt_newmsg_dynamic(const int cmd, const struct rtentry *rt)
1571 {
1572           struct rt_addrinfo info;
1573           struct sockaddr *gateway = rt->rt_gateway;
1574 
1575           if (gateway == NULL)
1576                     return;
1577 
1578           switch(gateway->sa_family) {
1579 #ifdef INET
1580           case AF_INET: {
1581                     extern bool icmp_dynamic_rt_msg;
1582                     if (!icmp_dynamic_rt_msg)
1583                               return;
1584                     break;
1585           }
1586 #endif
1587 #ifdef INET6
1588           case AF_INET6: {
1589                     extern bool icmp6_dynamic_rt_msg;
1590                     if (!icmp6_dynamic_rt_msg)
1591                               return;
1592                     break;
1593           }
1594 #endif
1595           default:
1596                     return;
1597           }
1598 
1599           memset((void *)&info, 0, sizeof(info));
1600           info.rti_info[RTAX_DST] = rt_getkey(rt);
1601           info.rti_info[RTAX_GATEWAY] = gateway;
1602           info.rti_info[RTAX_NETMASK] = rt_mask(rt);
1603           if (rt->rt_ifp) {
1604                     info.rti_info[RTAX_IFP] = rt->rt_ifp->if_dl->ifa_addr;
1605                     info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
1606           }
1607 
1608           rt_missmsg(cmd, &info, rt->rt_flags, 0);
1609 }
1610 
1611 /*
1612  * Set up or tear down a routing table entry, normally
1613  * for an interface.
1614  */
1615 int
rtinit(struct ifaddr * ifa,int cmd,int flags)1616 rtinit(struct ifaddr *ifa, int cmd, int flags)
1617 {
1618           struct rtentry *rt;
1619           struct sockaddr *dst, *odst;
1620           struct sockaddr_storage maskeddst;
1621           struct rtentry *nrt = NULL;
1622           int error;
1623           struct rt_addrinfo info;
1624 
1625           dst = flags & RTF_HOST ? ifa->ifa_dstaddr : ifa->ifa_addr;
1626           if (cmd == RTM_DELETE) {
1627                     if ((flags & RTF_HOST) == 0 && ifa->ifa_netmask) {
1628                               /* Delete subnet route for this interface */
1629                               odst = dst;
1630                               dst = (struct sockaddr *)&maskeddst;
1631                               rt_maskedcopy(odst, dst, ifa->ifa_netmask);
1632                     }
1633                     if ((rt = rtalloc1(dst, 0)) != NULL) {
1634                               if (rt->rt_ifa != ifa) {
1635                                         rt_unref(rt);
1636                                         return (flags & RTF_HOST) ? EHOSTUNREACH
1637                                                                       : ENETUNREACH;
1638                               }
1639                               rt_unref(rt);
1640                     }
1641           }
1642           memset(&info, 0, sizeof(info));
1643           info.rti_ifa = ifa;
1644           info.rti_flags = flags | ifa->ifa_flags | RTF_DONTCHANGEIFA;
1645           info.rti_info[RTAX_DST] = dst;
1646           info.rti_info[RTAX_GATEWAY] = ifa->ifa_addr;
1647 
1648           /*
1649            * XXX here, it seems that we are assuming that ifa_netmask is NULL
1650            * for RTF_HOST.  bsdi4 passes NULL explicitly (via intermediate
1651            * variable) when RTF_HOST is 1.  still not sure if i can safely
1652            * change it to meet bsdi4 behavior.
1653            */
1654           if (cmd != RTM_LLINFO_UPD)
1655                     info.rti_info[RTAX_NETMASK] = ifa->ifa_netmask;
1656           error = rtrequest1((cmd == RTM_LLINFO_UPD) ? RTM_GET : cmd, &info,
1657               &nrt);
1658           if (error != 0)
1659                     return error;
1660 
1661           rt = nrt;
1662           RT_REFCNT_TRACE(rt);
1663           switch (cmd) {
1664           case RTM_DELETE:
1665                     rt_newmsg(cmd, rt);
1666                     rt_free(rt);
1667                     break;
1668           case RTM_LLINFO_UPD:
1669                     if (cmd == RTM_LLINFO_UPD && ifa->ifa_rtrequest != NULL)
1670                               ifa->ifa_rtrequest(RTM_LLINFO_UPD, rt, &info);
1671                     rt_newmsg(RTM_CHANGE, rt);
1672                     rt_unref(rt);
1673                     break;
1674           case RTM_ADD:
1675                     KASSERT(rt->rt_ifa == ifa);
1676                     rt_newmsg(cmd, rt);
1677                     rt_unref(rt);
1678                     RT_REFCNT_TRACE(rt);
1679                     break;
1680           }
1681           return error;
1682 }
1683 
1684 /*
1685  * Create a local route entry for the address.
1686  * Announce the addition of the address and the route to the routing socket.
1687  */
1688 int
rt_ifa_addlocal(struct ifaddr * ifa)1689 rt_ifa_addlocal(struct ifaddr *ifa)
1690 {
1691           struct rtentry *rt;
1692           int e;
1693 
1694           /* If there is no loopback entry, allocate one. */
1695           rt = rtalloc1(ifa->ifa_addr, 0);
1696 #ifdef RT_DEBUG
1697           if (rt != NULL)
1698                     dump_rt(rt);
1699 #endif
1700           if (rt == NULL || (rt->rt_flags & RTF_HOST) == 0 ||
1701               (rt->rt_ifp->if_flags & IFF_LOOPBACK) == 0)
1702           {
1703                     struct rt_addrinfo info;
1704                     struct rtentry *nrt;
1705 
1706                     memset(&info, 0, sizeof(info));
1707                     info.rti_flags = RTF_HOST | RTF_LOCAL | RTF_DONTCHANGEIFA;
1708                     info.rti_info[RTAX_DST] = ifa->ifa_addr;
1709                     info.rti_info[RTAX_GATEWAY] =
1710                         (const struct sockaddr *)ifa->ifa_ifp->if_sadl;
1711                     info.rti_ifa = ifa;
1712                     nrt = NULL;
1713                     e = rtrequest1(RTM_ADD, &info, &nrt);
1714                     rt_addrmsg_rt(RTM_ADD, ifa, e, nrt);
1715                     if (nrt != NULL) {
1716                               KASSERT(nrt->rt_ifa == ifa);
1717 #ifdef RT_DEBUG
1718                               dump_rt(nrt);
1719 #endif
1720                               rt_unref(nrt);
1721                               RT_REFCNT_TRACE(nrt);
1722                     }
1723           } else {
1724                     e = 0;
1725                     rt_addrmsg(RTM_NEWADDR, ifa);
1726           }
1727           if (rt != NULL)
1728                     rt_unref(rt);
1729           return e;
1730 }
1731 
1732 /*
1733  * Remove the local route entry for the address.
1734  * Announce the removal of the address and the route to the routing socket.
1735  */
1736 int
rt_ifa_remlocal(struct ifaddr * ifa,struct ifaddr * alt_ifa)1737 rt_ifa_remlocal(struct ifaddr *ifa, struct ifaddr *alt_ifa)
1738 {
1739           struct rtentry *rt;
1740           int e = 0;
1741 
1742           rt = rtalloc1(ifa->ifa_addr, 0);
1743 
1744           /*
1745            * Before deleting, check if a corresponding loopbacked
1746            * host route surely exists.  With this check, we can avoid
1747            * deleting an interface direct route whose destination is
1748            * the same as the address being removed.  This can happen
1749            * when removing a subnet-router anycast address on an
1750            * interface attached to a shared medium.
1751            */
1752           if (rt != NULL &&
1753               (rt->rt_flags & RTF_HOST) &&
1754               (rt->rt_ifp->if_flags & IFF_LOOPBACK))
1755           {
1756                     /* If we cannot replace the route's ifaddr with the equivalent
1757                      * ifaddr of another interface, I believe it is safest to
1758                      * delete the route.
1759                      */
1760                     if (alt_ifa == NULL) {
1761                               e = rtdeletemsg(rt);
1762                               if (e == 0) {
1763                                         rt_unref(rt);
1764                                         rt_free(rt);
1765                                         rt = NULL;
1766                               }
1767                               rt_addrmsg(RTM_DELADDR, ifa);
1768                     } else {
1769 #ifdef NET_MPSAFE
1770                               int error = rt_update_prepare(rt);
1771                               if (error == 0) {
1772                                         rt_replace_ifa(rt, alt_ifa);
1773                                         rt_update_finish(rt);
1774                               } else {
1775                                         /*
1776                                          * If error != 0, the rtentry is being
1777                                          * destroyed, so doing nothing doesn't
1778                                          * matter.
1779                                          */
1780                               }
1781 #else
1782                               rt_replace_ifa(rt, alt_ifa);
1783 #endif
1784                               rt_newmsg(RTM_CHANGE, rt);
1785                     }
1786           } else
1787                     rt_addrmsg(RTM_DELADDR, ifa);
1788           if (rt != NULL)
1789                     rt_unref(rt);
1790           return e;
1791 }
1792 
1793 /*
1794  * Route timer routines.  These routes allow functions to be called
1795  * for various routes at any time.  This is useful in supporting
1796  * path MTU discovery and redirect route deletion.
1797  *
1798  * This is similar to some BSDI internal functions, but it provides
1799  * for multiple queues for efficiency's sake...
1800  */
1801 
1802 LIST_HEAD(, rttimer_queue) rttimer_queue_head;
1803 static int rt_init_done = 0;
1804 
1805 /*
1806  * Some subtle order problems with domain initialization mean that
1807  * we cannot count on this being run from rt_init before various
1808  * protocol initializations are done.  Therefore, we make sure
1809  * that this is run when the first queue is added...
1810  */
1811 
1812 static void rt_timer_work(struct work *, void *);
1813 
1814 static void
rt_timer_init(void)1815 rt_timer_init(void)
1816 {
1817           int error;
1818 
1819           assert(rt_init_done == 0);
1820 
1821           /* XXX should be in rt_init */
1822           rw_init(&rt_lock);
1823 
1824           LIST_INIT(&rttimer_queue_head);
1825           callout_init(&rt_timer_ch, CALLOUT_MPSAFE);
1826           error = workqueue_create(&rt_timer_wq, "rt_timer",
1827               rt_timer_work, NULL, PRI_SOFTNET, IPL_SOFTNET, RT_WQ_FLAGS);
1828           if (error)
1829                     panic("%s: workqueue_create failed (%d)\n", __func__, error);
1830           callout_reset(&rt_timer_ch, hz, rt_timer_timer, NULL);
1831           rt_init_done = 1;
1832 }
1833 
1834 struct rttimer_queue *
rt_timer_queue_create(u_int timeout)1835 rt_timer_queue_create(u_int timeout)
1836 {
1837           struct rttimer_queue *rtq;
1838 
1839           if (rt_init_done == 0)
1840                     rt_timer_init();
1841 
1842           R_Malloc(rtq, struct rttimer_queue *, sizeof *rtq);
1843           if (rtq == NULL)
1844                     return NULL;
1845           memset(rtq, 0, sizeof(*rtq));
1846 
1847           rtq->rtq_timeout = timeout;
1848           TAILQ_INIT(&rtq->rtq_head);
1849           RT_WLOCK();
1850           LIST_INSERT_HEAD(&rttimer_queue_head, rtq, rtq_link);
1851           RT_UNLOCK();
1852 
1853           return rtq;
1854 }
1855 
1856 void
rt_timer_queue_change(struct rttimer_queue * rtq,long timeout)1857 rt_timer_queue_change(struct rttimer_queue *rtq, long timeout)
1858 {
1859 
1860           rtq->rtq_timeout = timeout;
1861 }
1862 
1863 static void
rt_timer_queue_remove_all(struct rttimer_queue * rtq)1864 rt_timer_queue_remove_all(struct rttimer_queue *rtq)
1865 {
1866           struct rttimer *r;
1867 
1868           RT_ASSERT_WLOCK();
1869 
1870           while ((r = TAILQ_FIRST(&rtq->rtq_head)) != NULL) {
1871                     LIST_REMOVE(r, rtt_link);
1872                     TAILQ_REMOVE(&rtq->rtq_head, r, rtt_next);
1873                     rt_ref(r->rtt_rt); /* XXX */
1874                     RT_REFCNT_TRACE(r->rtt_rt);
1875                     RT_UNLOCK();
1876                     (*r->rtt_func)(r->rtt_rt, r);
1877                     pool_put(&rttimer_pool, r);
1878                     RT_WLOCK();
1879                     if (rtq->rtq_count > 0)
1880                               rtq->rtq_count--;
1881                     else
1882                               printf("rt_timer_queue_remove_all: "
1883                                   "rtq_count reached 0\n");
1884           }
1885 }
1886 
1887 void
rt_timer_queue_destroy(struct rttimer_queue * rtq)1888 rt_timer_queue_destroy(struct rttimer_queue *rtq)
1889 {
1890 
1891           RT_WLOCK();
1892           rt_timer_queue_remove_all(rtq);
1893           LIST_REMOVE(rtq, rtq_link);
1894           RT_UNLOCK();
1895 
1896           /*
1897            * Caller is responsible for freeing the rttimer_queue structure.
1898            */
1899 }
1900 
1901 unsigned long
rt_timer_count(struct rttimer_queue * rtq)1902 rt_timer_count(struct rttimer_queue *rtq)
1903 {
1904           return rtq->rtq_count;
1905 }
1906 
1907 static void
rt_timer_remove_all(struct rtentry * rt)1908 rt_timer_remove_all(struct rtentry *rt)
1909 {
1910           struct rttimer *r;
1911 
1912           RT_WLOCK();
1913           while ((r = LIST_FIRST(&rt->rt_timer)) != NULL) {
1914                     LIST_REMOVE(r, rtt_link);
1915                     TAILQ_REMOVE(&r->rtt_queue->rtq_head, r, rtt_next);
1916                     if (r->rtt_queue->rtq_count > 0)
1917                               r->rtt_queue->rtq_count--;
1918                     else
1919                               printf("rt_timer_remove_all: rtq_count reached 0\n");
1920                     pool_put(&rttimer_pool, r);
1921           }
1922           RT_UNLOCK();
1923 }
1924 
1925 int
rt_timer_add(struct rtentry * rt,void (* func)(struct rtentry *,struct rttimer *),struct rttimer_queue * queue)1926 rt_timer_add(struct rtentry *rt,
1927           void (*func)(struct rtentry *, struct rttimer *),
1928           struct rttimer_queue *queue)
1929 {
1930           struct rttimer *r;
1931 
1932           KASSERT(func != NULL);
1933           RT_WLOCK();
1934           /*
1935            * If there's already a timer with this action, destroy it before
1936            * we add a new one.
1937            */
1938           LIST_FOREACH(r, &rt->rt_timer, rtt_link) {
1939                     if (r->rtt_func == func)
1940                               break;
1941           }
1942           if (r != NULL) {
1943                     LIST_REMOVE(r, rtt_link);
1944                     TAILQ_REMOVE(&r->rtt_queue->rtq_head, r, rtt_next);
1945                     if (r->rtt_queue->rtq_count > 0)
1946                               r->rtt_queue->rtq_count--;
1947                     else
1948                               printf("rt_timer_add: rtq_count reached 0\n");
1949           } else {
1950                     r = pool_get(&rttimer_pool, PR_NOWAIT);
1951                     if (r == NULL) {
1952                               RT_UNLOCK();
1953                               return ENOBUFS;
1954                     }
1955           }
1956 
1957           memset(r, 0, sizeof(*r));
1958 
1959           r->rtt_rt = rt;
1960           r->rtt_time = time_uptime;
1961           r->rtt_func = func;
1962           r->rtt_queue = queue;
1963           LIST_INSERT_HEAD(&rt->rt_timer, r, rtt_link);
1964           TAILQ_INSERT_TAIL(&queue->rtq_head, r, rtt_next);
1965           r->rtt_queue->rtq_count++;
1966 
1967           RT_UNLOCK();
1968 
1969           return 0;
1970 }
1971 
1972 static void
rt_timer_work(struct work * wk,void * arg)1973 rt_timer_work(struct work *wk, void *arg)
1974 {
1975           struct rttimer_queue *rtq;
1976           struct rttimer *r;
1977 
1978           RT_WLOCK();
1979           LIST_FOREACH(rtq, &rttimer_queue_head, rtq_link) {
1980                     while ((r = TAILQ_FIRST(&rtq->rtq_head)) != NULL &&
1981                         (r->rtt_time + rtq->rtq_timeout) < time_uptime) {
1982                               LIST_REMOVE(r, rtt_link);
1983                               TAILQ_REMOVE(&rtq->rtq_head, r, rtt_next);
1984                               /*
1985                                * Take a reference to avoid the rtentry is freed
1986                                * accidentally after RT_UNLOCK.  The callback
1987                                * (rtt_func) must rt_unref it by itself.
1988                                */
1989                               rt_ref(r->rtt_rt);
1990                               RT_REFCNT_TRACE(r->rtt_rt);
1991                               RT_UNLOCK();
1992                               (*r->rtt_func)(r->rtt_rt, r);
1993                               pool_put(&rttimer_pool, r);
1994                               RT_WLOCK();
1995                               if (rtq->rtq_count > 0)
1996                                         rtq->rtq_count--;
1997                               else
1998                                         printf("rt_timer_timer: rtq_count reached 0\n");
1999                     }
2000           }
2001           RT_UNLOCK();
2002 
2003           callout_reset(&rt_timer_ch, hz, rt_timer_timer, NULL);
2004 }
2005 
2006 static void
rt_timer_timer(void * arg)2007 rt_timer_timer(void *arg)
2008 {
2009 
2010           workqueue_enqueue(rt_timer_wq, &rt_timer_wk, NULL);
2011 }
2012 
2013 static struct rtentry *
_rtcache_init(struct route * ro,int flag)2014 _rtcache_init(struct route *ro, int flag)
2015 {
2016           struct rtentry *rt;
2017 
2018           rtcache_invariants(ro);
2019           KASSERT(ro->_ro_rt == NULL);
2020 
2021           if (rtcache_getdst(ro) == NULL)
2022                     return NULL;
2023           rt = rtalloc1(rtcache_getdst(ro), flag);
2024           if (rt != NULL) {
2025                     RT_RLOCK();
2026                     if (ISSET(rt->rt_flags, RTF_UP)) {
2027                               ro->_ro_rt = rt;
2028                               ro->ro_rtcache_generation = rtcache_generation;
2029                               rtcache_ref(rt, ro);
2030                     }
2031                     RT_UNLOCK();
2032                     rt_unref(rt);
2033           }
2034 
2035           rtcache_invariants(ro);
2036           return ro->_ro_rt;
2037 }
2038 
2039 struct rtentry *
rtcache_init(struct route * ro)2040 rtcache_init(struct route *ro)
2041 {
2042 
2043           return _rtcache_init(ro, 1);
2044 }
2045 
2046 struct rtentry *
rtcache_init_noclone(struct route * ro)2047 rtcache_init_noclone(struct route *ro)
2048 {
2049 
2050           return _rtcache_init(ro, 0);
2051 }
2052 
2053 struct rtentry *
rtcache_update(struct route * ro,int clone)2054 rtcache_update(struct route *ro, int clone)
2055 {
2056 
2057           ro->_ro_rt = NULL;
2058           return _rtcache_init(ro, clone);
2059 }
2060 
2061 void
rtcache_copy(struct route * new_ro,struct route * old_ro)2062 rtcache_copy(struct route *new_ro, struct route *old_ro)
2063 {
2064           struct rtentry *rt;
2065           int ret;
2066 
2067           KASSERT(new_ro != old_ro);
2068           rtcache_invariants(new_ro);
2069           rtcache_invariants(old_ro);
2070 
2071           rt = rtcache_validate(old_ro);
2072 
2073           if (rtcache_getdst(old_ro) == NULL)
2074                     goto out;
2075           ret = rtcache_setdst(new_ro, rtcache_getdst(old_ro));
2076           if (ret != 0)
2077                     goto out;
2078 
2079           RT_RLOCK();
2080           new_ro->_ro_rt = rt;
2081           new_ro->ro_rtcache_generation = rtcache_generation;
2082           RT_UNLOCK();
2083           rtcache_invariants(new_ro);
2084 out:
2085           rtcache_unref(rt, old_ro);
2086           return;
2087 }
2088 
2089 #if defined(RT_DEBUG) && defined(NET_MPSAFE)
2090 static void
rtcache_trace(const char * func,struct rtentry * rt,struct route * ro)2091 rtcache_trace(const char *func, struct rtentry *rt, struct route *ro)
2092 {
2093           char dst[64];
2094 
2095           sockaddr_format(ro->ro_sa, dst, 64);
2096           printf("trace: %s:\tdst=%s cpu=%d lwp=%p psref=%p target=%p\n", func, dst,
2097               cpu_index(curcpu()), curlwp, &ro->ro_psref, &rt->rt_psref);
2098 }
2099 #define RTCACHE_PSREF_TRACE(rt, ro)     rtcache_trace(__func__, (rt), (ro))
2100 #else
2101 #define RTCACHE_PSREF_TRACE(rt, ro)     do {} while (0)
2102 #endif
2103 
2104 static void
rtcache_ref(struct rtentry * rt,struct route * ro)2105 rtcache_ref(struct rtentry *rt, struct route *ro)
2106 {
2107 
2108           KASSERT(rt != NULL);
2109 
2110 #ifdef NET_MPSAFE
2111           RTCACHE_PSREF_TRACE(rt, ro);
2112           ro->ro_bound = curlwp_bind();
2113           /* XXX Use a real caller's address */
2114           PSREF_DEBUG_FILL_RETURN_ADDRESS(&ro->ro_psref);
2115           psref_acquire(&ro->ro_psref, &rt->rt_psref, rt_psref_class);
2116 #endif
2117 }
2118 
2119 void
rtcache_unref(struct rtentry * rt,struct route * ro)2120 rtcache_unref(struct rtentry *rt, struct route *ro)
2121 {
2122 
2123           if (rt == NULL)
2124                     return;
2125 
2126 #ifdef NET_MPSAFE
2127           psref_release(&ro->ro_psref, &rt->rt_psref, rt_psref_class);
2128           curlwp_bindx(ro->ro_bound);
2129           RTCACHE_PSREF_TRACE(rt, ro);
2130 #endif
2131 }
2132 
2133 struct rtentry *
rtcache_validate(struct route * ro)2134 rtcache_validate(struct route *ro)
2135 {
2136           struct rtentry *rt = NULL;
2137 
2138 #ifdef NET_MPSAFE
2139 retry:
2140 #endif
2141           rtcache_invariants(ro);
2142           RT_RLOCK();
2143           if (ro->ro_rtcache_generation != rtcache_generation) {
2144                     /* The cache is invalidated */
2145                     rt = NULL;
2146                     goto out;
2147           }
2148 
2149           rt = ro->_ro_rt;
2150           if (rt == NULL)
2151                     goto out;
2152 
2153           if ((rt->rt_flags & RTF_UP) == 0) {
2154                     rt = NULL;
2155                     goto out;
2156           }
2157 #ifdef NET_MPSAFE
2158           if (ISSET(rt->rt_flags, RTF_UPDATING)) {
2159                     if (rt_wait_ok()) {
2160                               RT_UNLOCK();
2161 
2162                               /* We can wait until the update is complete */
2163                               rt_update_wait();
2164                               goto retry;
2165                     } else {
2166                               rt = NULL;
2167                     }
2168           } else
2169 #endif
2170                     rtcache_ref(rt, ro);
2171 out:
2172           RT_UNLOCK();
2173           return rt;
2174 }
2175 
2176 struct rtentry *
rtcache_lookup2(struct route * ro,const struct sockaddr * dst,int clone,int * hitp)2177 rtcache_lookup2(struct route *ro, const struct sockaddr *dst,
2178     int clone, int *hitp)
2179 {
2180           const struct sockaddr *odst;
2181           struct rtentry *rt = NULL;
2182 
2183           odst = rtcache_getdst(ro);
2184           if (odst == NULL)
2185                     goto miss;
2186 
2187           if (sockaddr_cmp(odst, dst) != 0) {
2188                     rtcache_free(ro);
2189                     goto miss;
2190           }
2191 
2192           rt = rtcache_validate(ro);
2193           if (rt == NULL) {
2194                     ro->_ro_rt = NULL;
2195                     goto miss;
2196           }
2197 
2198           rtcache_invariants(ro);
2199 
2200           if (hitp != NULL)
2201                     *hitp = 1;
2202           return rt;
2203 miss:
2204           if (hitp != NULL)
2205                     *hitp = 0;
2206           if (rtcache_setdst(ro, dst) == 0)
2207                     rt = _rtcache_init(ro, clone);
2208 
2209           rtcache_invariants(ro);
2210 
2211           return rt;
2212 }
2213 
2214 void
rtcache_free(struct route * ro)2215 rtcache_free(struct route *ro)
2216 {
2217 
2218           ro->_ro_rt = NULL;
2219           if (ro->ro_sa != NULL) {
2220                     sockaddr_free(ro->ro_sa);
2221                     ro->ro_sa = NULL;
2222           }
2223           rtcache_invariants(ro);
2224 }
2225 
2226 int
rtcache_setdst(struct route * ro,const struct sockaddr * sa)2227 rtcache_setdst(struct route *ro, const struct sockaddr *sa)
2228 {
2229           KASSERT(sa != NULL);
2230 
2231           rtcache_invariants(ro);
2232           if (ro->ro_sa != NULL) {
2233                     if (ro->ro_sa->sa_family == sa->sa_family) {
2234                               ro->_ro_rt = NULL;
2235                               sockaddr_copy(ro->ro_sa, ro->ro_sa->sa_len, sa);
2236                               rtcache_invariants(ro);
2237                               return 0;
2238                     }
2239                     /* free ro_sa, wrong family */
2240                     rtcache_free(ro);
2241           }
2242 
2243           KASSERT(ro->_ro_rt == NULL);
2244 
2245           if ((ro->ro_sa = sockaddr_dup(sa, M_ZERO | M_NOWAIT)) == NULL) {
2246                     rtcache_invariants(ro);
2247                     return ENOMEM;
2248           }
2249           rtcache_invariants(ro);
2250           return 0;
2251 }
2252 
2253 static void
rtcache_percpu_init_cpu(void * p,void * arg __unused,struct cpu_info * ci __unused)2254 rtcache_percpu_init_cpu(void *p, void *arg __unused, struct cpu_info *ci __unused)
2255 {
2256           struct route **rop = p;
2257 
2258           /*
2259            * We can't have struct route as percpu data because it can be destroyed
2260            * over a memory enlargement processing of percpu.
2261            */
2262           *rop = kmem_zalloc(sizeof(**rop), KM_SLEEP);
2263 }
2264 
2265 percpu_t *
rtcache_percpu_alloc(void)2266 rtcache_percpu_alloc(void)
2267 {
2268 
2269           return percpu_create(sizeof(struct route *),
2270               rtcache_percpu_init_cpu, NULL, NULL);
2271 }
2272 
2273 const struct sockaddr *
rt_settag(struct rtentry * rt,const struct sockaddr * tag)2274 rt_settag(struct rtentry *rt, const struct sockaddr *tag)
2275 {
2276           if (rt->rt_tag != tag) {
2277                     if (rt->rt_tag != NULL)
2278                               sockaddr_free(rt->rt_tag);
2279                     rt->rt_tag = sockaddr_dup(tag, M_ZERO | M_NOWAIT);
2280           }
2281           return rt->rt_tag;
2282 }
2283 
2284 struct sockaddr *
rt_gettag(const struct rtentry * rt)2285 rt_gettag(const struct rtentry *rt)
2286 {
2287           return rt->rt_tag;
2288 }
2289 
2290 int
rt_check_reject_route(const struct rtentry * rt,const struct ifnet * ifp)2291 rt_check_reject_route(const struct rtentry *rt, const struct ifnet *ifp)
2292 {
2293 
2294           if ((rt->rt_flags & RTF_REJECT) != 0) {
2295                     /* Mimic looutput */
2296                     if (ifp->if_flags & IFF_LOOPBACK)
2297                               return (rt->rt_flags & RTF_HOST) ?
2298                                   EHOSTUNREACH : ENETUNREACH;
2299                     else if (rt->rt_rmx.rmx_expire == 0 ||
2300                         time_uptime < rt->rt_rmx.rmx_expire)
2301                               return (rt->rt_flags & RTF_GATEWAY) ?
2302                                   EHOSTUNREACH : EHOSTDOWN;
2303           }
2304 
2305           return 0;
2306 }
2307 
2308 void
rt_delete_matched_entries(sa_family_t family,int (* f)(struct rtentry *,void *),void * v,bool notify)2309 rt_delete_matched_entries(sa_family_t family, int (*f)(struct rtentry *, void *),
2310     void *v, bool notify)
2311 {
2312 
2313           for (;;) {
2314                     int s;
2315                     int error;
2316                     struct rtentry *rt, *retrt = NULL;
2317 
2318                     RT_RLOCK();
2319                     s = splsoftnet();
2320                     rt = rtbl_search_matched_entry(family, f, v);
2321                     if (rt == NULL) {
2322                               splx(s);
2323                               RT_UNLOCK();
2324                               return;
2325                     }
2326                     rt_ref(rt);
2327                     RT_REFCNT_TRACE(rt);
2328                     splx(s);
2329                     RT_UNLOCK();
2330 
2331                     error = rtrequest(RTM_DELETE, rt_getkey(rt), rt->rt_gateway,
2332                         rt_mask(rt), rt->rt_flags, &retrt);
2333                     if (error == 0) {
2334                               KASSERT(retrt == rt);
2335                               KASSERT((retrt->rt_flags & RTF_UP) == 0);
2336                               if (notify)
2337                                         rt_newmsg(RTM_DELETE, retrt);
2338                               retrt->rt_ifp = NULL;
2339                               rt_unref(rt);
2340                               RT_REFCNT_TRACE(rt);
2341                               rt_free(retrt);
2342                     } else if (error == ESRCH) {
2343                               /* Someone deleted the entry already. */
2344                               rt_unref(rt);
2345                               RT_REFCNT_TRACE(rt);
2346                     } else {
2347                               log(LOG_ERR, "%s: unable to delete rtentry @ %p, "
2348                                   "error = %d\n", rt->rt_ifp->if_xname, rt, error);
2349                               /* XXX how to treat this case? */
2350                     }
2351           }
2352 }
2353 
2354 static int
rt_walktree_locked(sa_family_t family,int (* f)(struct rtentry *,void *),void * v)2355 rt_walktree_locked(sa_family_t family, int (*f)(struct rtentry *, void *),
2356     void *v)
2357 {
2358 
2359           return rtbl_walktree(family, f, v);
2360 }
2361 
2362 void
rt_replace_ifa_matched_entries(sa_family_t family,int (* f)(struct rtentry *,void *),void * v,struct ifaddr * ifa)2363 rt_replace_ifa_matched_entries(sa_family_t family,
2364     int (*f)(struct rtentry *, void *), void *v, struct ifaddr *ifa)
2365 {
2366 
2367           for (;;) {
2368                     int s;
2369 #ifdef NET_MPSAFE
2370                     int error;
2371 #endif
2372                     struct rtentry *rt;
2373 
2374                     RT_RLOCK();
2375                     s = splsoftnet();
2376                     rt = rtbl_search_matched_entry(family, f, v);
2377                     if (rt == NULL) {
2378                               splx(s);
2379                               RT_UNLOCK();
2380                               return;
2381                     }
2382                     rt_ref(rt);
2383                     RT_REFCNT_TRACE(rt);
2384                     splx(s);
2385                     RT_UNLOCK();
2386 
2387 #ifdef NET_MPSAFE
2388                     error = rt_update_prepare(rt);
2389                     if (error == 0) {
2390                               rt_replace_ifa(rt, ifa);
2391                               rt_update_finish(rt);
2392                               rt_newmsg(RTM_CHANGE, rt);
2393                     } else {
2394                               /*
2395                                * If error != 0, the rtentry is being
2396                                * destroyed, so doing nothing doesn't
2397                                * matter.
2398                                */
2399                     }
2400 #else
2401                     rt_replace_ifa(rt, ifa);
2402                     rt_newmsg(RTM_CHANGE, rt);
2403 #endif
2404                     rt_unref(rt);
2405                     RT_REFCNT_TRACE(rt);
2406           }
2407 }
2408 
2409 int
rt_walktree(sa_family_t family,int (* f)(struct rtentry *,void *),void * v)2410 rt_walktree(sa_family_t family, int (*f)(struct rtentry *, void *), void *v)
2411 {
2412           int error;
2413 
2414           RT_RLOCK();
2415           error = rt_walktree_locked(family, f, v);
2416           RT_UNLOCK();
2417 
2418           return error;
2419 }
2420 
2421 #ifdef DDB
2422 
2423 #include <machine/db_machdep.h>
2424 #include <ddb/db_interface.h>
2425 #include <ddb/db_output.h>
2426 
2427 #define   rt_expire rt_rmx.rmx_expire
2428 
2429 static void
db_print_sa(const struct sockaddr * sa)2430 db_print_sa(const struct sockaddr *sa)
2431 {
2432           int len;
2433           const u_char *p;
2434 
2435           if (sa == NULL) {
2436                     db_printf("[NULL]");
2437                     return;
2438           }
2439 
2440           p = (const u_char *)sa;
2441           len = sa->sa_len;
2442           db_printf("[");
2443           while (len > 0) {
2444                     db_printf("%d", *p);
2445                     p++; len--;
2446                     if (len) db_printf(",");
2447           }
2448           db_printf("]\n");
2449 }
2450 
2451 static void
db_print_ifa(struct ifaddr * ifa)2452 db_print_ifa(struct ifaddr *ifa)
2453 {
2454           if (ifa == NULL)
2455                     return;
2456           db_printf("  ifa_addr=");
2457           db_print_sa(ifa->ifa_addr);
2458           db_printf("  ifa_dsta=");
2459           db_print_sa(ifa->ifa_dstaddr);
2460           db_printf("  ifa_mask=");
2461           db_print_sa(ifa->ifa_netmask);
2462           db_printf("  flags=0x%x,refcnt=%d,metric=%d\n",
2463                                 ifa->ifa_flags,
2464                                 ifa->ifa_refcnt,
2465                                 ifa->ifa_metric);
2466 }
2467 
2468 /*
2469  * Function to pass to rt_walktree().
2470  * Return non-zero error to abort walk.
2471  */
2472 static int
db_show_rtentry(struct rtentry * rt,void * w)2473 db_show_rtentry(struct rtentry *rt, void *w)
2474 {
2475           db_printf("rtentry=%p", rt);
2476 
2477           db_printf(" flags=0x%x refcnt=%d use=%"PRId64" expire=%"PRId64"\n",
2478                                 rt->rt_flags, rt->rt_refcnt,
2479                                 rt->rt_use, (uint64_t)rt->rt_expire);
2480 
2481           db_printf(" key="); db_print_sa(rt_getkey(rt));
2482           db_printf(" mask="); db_print_sa(rt_mask(rt));
2483           db_printf(" gw="); db_print_sa(rt->rt_gateway);
2484 
2485           db_printf(" ifp=%p ", rt->rt_ifp);
2486           if (rt->rt_ifp)
2487                     db_printf("(%s)", rt->rt_ifp->if_xname);
2488           else
2489                     db_printf("(NULL)");
2490 
2491           db_printf(" ifa=%p\n", rt->rt_ifa);
2492           db_print_ifa(rt->rt_ifa);
2493 
2494           db_printf(" gwroute=%p llinfo=%p\n",
2495                                 rt->rt_gwroute, rt->rt_llinfo);
2496 
2497           return 0;
2498 }
2499 
2500 /*
2501  * Function to print all the route trees.
2502  * Use this from ddb:  "show routes"
2503  */
2504 void
db_show_routes(db_expr_t addr,bool have_addr,db_expr_t count,const char * modif)2505 db_show_routes(db_expr_t addr, bool have_addr,
2506     db_expr_t count, const char *modif)
2507 {
2508 
2509           /* Taking RT_LOCK will fail if LOCKDEBUG is enabled. */
2510           rt_walktree_locked(AF_INET, db_show_rtentry, NULL);
2511 }
2512 #endif
2513