X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/4452a7af2eac33dbad800bcc91f2399d62c18f53..a39ff7e25e19b3a8c3020042a3872ca9ec9659f1:/bsd/netinet/in_arp.c diff --git a/bsd/netinet/in_arp.c b/bsd/netinet/in_arp.c index ed713b2b0..674da52bf 100644 --- a/bsd/netinet/in_arp.c +++ b/bsd/netinet/in_arp.c @@ -1,8 +1,8 @@ /* - * Copyright (c) 2004 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2004-2017 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ - * + * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in @@ -11,10 +11,10 @@ * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. - * + * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. - * + * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, @@ -22,7 +22,7 @@ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. - * + * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* @@ -70,255 +70,1009 @@ #include #include #include +#include +#include #include #include #include #include +#include +#include #include +#include + #include #include +#include + +#include +#include -#define SIN(s) ((struct sockaddr_in *)s) -#define CONST_LLADDR(s) ((const u_char*)((s)->sdl_data + (s)->sdl_nlen)) -#define rt_expire rt_rmx.rmx_expire +#define CONST_LLADDR(s) ((const u_char*)((s)->sdl_data + (s)->sdl_nlen)) static const size_t MAX_HW_LEN = 10; +/* + * Synchronization notes: + * + * The global list of ARP entries are stored in llinfo_arp; an entry + * gets inserted into the list when the route is created and gets + * removed from the list when it is deleted; this is done as part + * of RTM_ADD/RTM_RESOLVE/RTM_DELETE in arp_rtrequest(). + * + * Because rnh_lock and rt_lock for the entry are held during those + * operations, the same locks (and thus lock ordering) must be used + * elsewhere to access the relevant data structure fields: + * + * la_le.{le_next,le_prev}, la_rt + * + * - Routing lock (rnh_lock) + * + * la_holdq, la_asked, la_llreach, la_lastused, la_flags + * + * - Routing entry lock (rt_lock) + * + * Due to the dependency on rt_lock, llinfo_arp has the same lifetime + * as the route entry itself. When a route is deleted (RTM_DELETE), + * it is simply removed from the global list but the memory is not + * freed until the route itself is freed. + */ +struct llinfo_arp { + /* + * The following are protected by rnh_lock + */ + LIST_ENTRY(llinfo_arp) la_le; + struct rtentry *la_rt; + /* + * The following are protected by rt_lock + */ + class_queue_t la_holdq; /* packets awaiting resolution */ + struct if_llreach *la_llreach; /* link-layer reachability record */ + u_int64_t la_lastused; /* last used timestamp */ + u_int32_t la_asked; /* # of requests sent */ + u_int32_t la_maxtries; /* retry limit */ + u_int64_t la_probeexp; /* probe deadline timestamp */ + u_int32_t la_prbreq_cnt; /* probe request count */ + u_int32_t la_flags; +#define LLINFO_RTRFAIL_EVTSENT 0x1 /* sent an ARP event */ +#define LLINFO_PROBING 0x2 /* waiting for an ARP reply */ +}; + +static LIST_HEAD(, llinfo_arp) llinfo_arp; + +static thread_call_t arp_timeout_tcall; +static int arp_timeout_run; /* arp_timeout is scheduled to run */ +static void arp_timeout(thread_call_param_t arg0, thread_call_param_t arg1); +static void arp_sched_timeout(struct timeval *); + +static thread_call_t arp_probe_tcall; +static int arp_probe_run; /* arp_probe is scheduled to run */ +static void arp_probe(thread_call_param_t arg0, thread_call_param_t arg1); +static void arp_sched_probe(struct timeval *); + +static void arptfree(struct llinfo_arp *, void *); +static errno_t arp_lookup_route(const struct in_addr *, int, + int, route_t *, unsigned int); +static int arp_getstat SYSCTL_HANDLER_ARGS; + +static struct llinfo_arp *arp_llinfo_alloc(int); +static void arp_llinfo_free(void *); +static uint32_t arp_llinfo_flushq(struct llinfo_arp *); +static void arp_llinfo_purge(struct rtentry *); +static void arp_llinfo_get_ri(struct rtentry *, struct rt_reach_info *); +static void arp_llinfo_get_iflri(struct rtentry *, struct ifnet_llreach_info *); +static void arp_llinfo_refresh(struct rtentry *); + +static __inline void arp_llreach_use(struct llinfo_arp *); +static __inline int arp_llreach_reachable(struct llinfo_arp *); +static void arp_llreach_alloc(struct rtentry *, struct ifnet *, void *, + unsigned int, boolean_t, uint32_t *); + +extern int tvtohz(struct timeval *); + +static int arpinit_done; + SYSCTL_DECL(_net_link_ether); -SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, ""); +SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW|CTLFLAG_LOCKED, 0, ""); -/* timer values */ static int arpt_prune = (5*60*1); /* walk list every 5 minutes */ +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, + CTLFLAG_RW | CTLFLAG_LOCKED, &arpt_prune, 0, ""); + +#define ARP_PROBE_TIME 7 /* seconds */ +static u_int32_t arpt_probe = ARP_PROBE_TIME; +SYSCTL_UINT(_net_link_ether_inet, OID_AUTO, probe_intvl, + CTLFLAG_RW | CTLFLAG_LOCKED, &arpt_probe, 0, ""); + static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, + CTLFLAG_RW | CTLFLAG_LOCKED, &arpt_keep, 0, ""); + static int arpt_down = 20; /* once declared down, don't send for 20 sec */ +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, + CTLFLAG_RW | CTLFLAG_LOCKED, &arpt_down, 0, ""); -/* Apple Hardware SUM16 checksuming */ -int apple_hwcksum_tx = 1; -int apple_hwcksum_rx = 1; - -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW, - &arpt_prune, 0, ""); -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW, - &arpt_keep, 0, ""); -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW, - &arpt_down, 0, ""); -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, apple_hwcksum_tx, CTLFLAG_RW, - &apple_hwcksum_tx, 0, ""); -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, apple_hwcksum_rx, CTLFLAG_RW, - &apple_hwcksum_rx, 0, ""); +static int arp_llreach_base = 120; /* seconds */ +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, arp_llreach_base, + CTLFLAG_RW | CTLFLAG_LOCKED, &arp_llreach_base, 0, + "default ARP link-layer reachability max lifetime (in seconds)"); -struct llinfo_arp { - LIST_ENTRY(llinfo_arp) la_le; - struct rtentry *la_rt; - struct mbuf *la_hold; /* last packet until resolved/timeout */ - long la_asked; /* last time we QUERIED for this addr */ -}; +#define ARP_UNICAST_LIMIT 3 /* # of probes until ARP refresh broadcast */ +static u_int32_t arp_unicast_lim = ARP_UNICAST_LIMIT; +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, arp_unicast_lim, + CTLFLAG_RW | CTLFLAG_LOCKED, &arp_unicast_lim, ARP_UNICAST_LIMIT, + "number of unicast ARP refresh probes before using broadcast"); -static LIST_HEAD(, llinfo_arp) llinfo_arp; +static u_int32_t arp_maxtries = 5; +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, + CTLFLAG_RW | CTLFLAG_LOCKED, &arp_maxtries, 0, ""); -static int arp_inuse, arp_allocated; +static u_int32_t arp_maxhold = 16; +SYSCTL_UINT(_net_link_ether_inet, OID_AUTO, maxhold, + CTLFLAG_RW | CTLFLAG_LOCKED, &arp_maxhold, 0, ""); -static int arp_maxtries = 5; -static int useloopback = 1; /* use loopback interface for local traffic */ -static int arp_proxyall = 0; +static int useloopback = 1; /* use loopback interface for local traffic */ +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, + CTLFLAG_RW | CTLFLAG_LOCKED, &useloopback, 0, ""); -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, - &arp_maxtries, 0, ""); -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, - &useloopback, 0, ""); -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, - &arp_proxyall, 0, ""); +static int arp_proxyall = 0; +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, + CTLFLAG_RW | CTLFLAG_LOCKED, &arp_proxyall, 0, ""); -static int log_arp_warnings = 0; +static int arp_sendllconflict = 0; +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, sendllconflict, + CTLFLAG_RW | CTLFLAG_LOCKED, &arp_sendllconflict, 0, ""); -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_warnings, CTLFLAG_RW, +static int log_arp_warnings = 0; /* Thread safe: no accumulated state */ +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_warnings, + CTLFLAG_RW | CTLFLAG_LOCKED, &log_arp_warnings, 0, "log arp warning messages"); -extern u_int32_t ipv4_ll_arp_aware; +static int keep_announcements = 1; /* Thread safe: no aging of state */ +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, keep_announcements, + CTLFLAG_RW | CTLFLAG_LOCKED, + &keep_announcements, 0, + "keep arp announcements"); + +static int send_conflicting_probes = 1; /* Thread safe: no accumulated state */ +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, send_conflicting_probes, + CTLFLAG_RW | CTLFLAG_LOCKED, + &send_conflicting_probes, 0, + "send conflicting link-local arp probes"); + +static int arp_verbose; +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, verbose, + CTLFLAG_RW | CTLFLAG_LOCKED, &arp_verbose, 0, ""); + +/* + * Generally protected by rnh_lock; use atomic operations on fields + * that are also modified outside of that lock (if needed). + */ +struct arpstat arpstat __attribute__((aligned(sizeof (uint64_t)))); +SYSCTL_PROC(_net_link_ether_inet, OID_AUTO, stats, + CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED, + 0, 0, arp_getstat, "S,arpstat", + "ARP statistics (struct arpstat, net/if_arp.h)"); + +static struct zone *llinfo_arp_zone; +#define LLINFO_ARP_ZONE_MAX 256 /* maximum elements in zone */ +#define LLINFO_ARP_ZONE_NAME "llinfo_arp" /* name for zone */ + +void +arp_init(void) +{ + VERIFY(!arpinit_done); + + LIST_INIT(&llinfo_arp); + + llinfo_arp_zone = zinit(sizeof (struct llinfo_arp), + LLINFO_ARP_ZONE_MAX * sizeof (struct llinfo_arp), 0, + LLINFO_ARP_ZONE_NAME); + if (llinfo_arp_zone == NULL) + panic("%s: failed allocating llinfo_arp_zone", __func__); + + zone_change(llinfo_arp_zone, Z_EXPAND, TRUE); + zone_change(llinfo_arp_zone, Z_CALLERACCT, FALSE); + + arpinit_done = 1; +} + +static struct llinfo_arp * +arp_llinfo_alloc(int how) +{ + struct llinfo_arp *la; + + la = (how == M_WAITOK) ? zalloc(llinfo_arp_zone) : + zalloc_noblock(llinfo_arp_zone); + if (la != NULL) { + bzero(la, sizeof (*la)); + /* + * The type of queue (Q_DROPHEAD) here is just a hint; + * the actual logic that works on this queue performs + * a head drop, details in arp_llinfo_addq(). + */ + _qinit(&la->la_holdq, Q_DROPHEAD, (arp_maxhold == 0) ? + (uint32_t)-1 : arp_maxhold, QP_MBUF); + } + + return (la); +} + +static void +arp_llinfo_free(void *arg) +{ + struct llinfo_arp *la = arg; + + if (la->la_le.le_next != NULL || la->la_le.le_prev != NULL) { + panic("%s: trying to free %p when it is in use", __func__, la); + /* NOTREACHED */ + } + + /* Free any held packets */ + (void) arp_llinfo_flushq(la); + + /* Purge any link-layer info caching */ + VERIFY(la->la_rt->rt_llinfo == la); + if (la->la_rt->rt_llinfo_purge != NULL) + la->la_rt->rt_llinfo_purge(la->la_rt); + + zfree(llinfo_arp_zone, la); +} + +static void +arp_llinfo_addq(struct llinfo_arp *la, struct mbuf *m) +{ + if (qlen(&la->la_holdq) >= qlimit(&la->la_holdq)) { + struct mbuf *_m; + /* prune less than CTL, else take what's at the head */ + _m = _getq_scidx_lt(&la->la_holdq, SCIDX_CTL); + if (_m == NULL) + _m = _getq(&la->la_holdq); + VERIFY(_m != NULL); + if (arp_verbose) { + log(LOG_DEBUG, "%s: dropping packet (scidx %u)\n", + __func__, MBUF_SCIDX(mbuf_get_service_class(_m))); + } + m_freem(_m); + atomic_add_32(&arpstat.dropped, 1); + atomic_add_32(&arpstat.held, -1); + } + _addq(&la->la_holdq, m); + atomic_add_32(&arpstat.held, 1); + if (arp_verbose) { + log(LOG_DEBUG, "%s: enqueued packet (scidx %u), qlen now %u\n", + __func__, MBUF_SCIDX(mbuf_get_service_class(m)), + qlen(&la->la_holdq)); + } +} + +static uint32_t +arp_llinfo_flushq(struct llinfo_arp *la) +{ + uint32_t held = qlen(&la->la_holdq); + + if (held != 0) { + atomic_add_32(&arpstat.purged, held); + atomic_add_32(&arpstat.held, -held); + _flushq(&la->la_holdq); + } + la->la_prbreq_cnt = 0; + VERIFY(qempty(&la->la_holdq)); + return (held); +} + +static void +arp_llinfo_purge(struct rtentry *rt) +{ + struct llinfo_arp *la = rt->rt_llinfo; + + RT_LOCK_ASSERT_HELD(rt); + VERIFY(rt->rt_llinfo_purge == arp_llinfo_purge && la != NULL); + + if (la->la_llreach != NULL) { + RT_CONVERT_LOCK(rt); + ifnet_llreach_free(la->la_llreach); + la->la_llreach = NULL; + } + la->la_lastused = 0; +} + +static void +arp_llinfo_get_ri(struct rtentry *rt, struct rt_reach_info *ri) +{ + struct llinfo_arp *la = rt->rt_llinfo; + struct if_llreach *lr = la->la_llreach; + + if (lr == NULL) { + bzero(ri, sizeof (*ri)); + ri->ri_rssi = IFNET_RSSI_UNKNOWN; + ri->ri_lqm = IFNET_LQM_THRESH_OFF; + ri->ri_npm = IFNET_NPM_THRESH_UNKNOWN; + } else { + IFLR_LOCK(lr); + /* Export to rt_reach_info structure */ + ifnet_lr2ri(lr, ri); + /* Export ARP send expiration (calendar) time */ + ri->ri_snd_expire = + ifnet_llreach_up2calexp(lr, la->la_lastused); + IFLR_UNLOCK(lr); + } +} + +static void +arp_llinfo_get_iflri(struct rtentry *rt, struct ifnet_llreach_info *iflri) +{ + struct llinfo_arp *la = rt->rt_llinfo; + struct if_llreach *lr = la->la_llreach; + + if (lr == NULL) { + bzero(iflri, sizeof (*iflri)); + iflri->iflri_rssi = IFNET_RSSI_UNKNOWN; + iflri->iflri_lqm = IFNET_LQM_THRESH_OFF; + iflri->iflri_npm = IFNET_NPM_THRESH_UNKNOWN; + } else { + IFLR_LOCK(lr); + /* Export to ifnet_llreach_info structure */ + ifnet_lr2iflri(lr, iflri); + /* Export ARP send expiration (uptime) time */ + iflri->iflri_snd_expire = + ifnet_llreach_up2upexp(lr, la->la_lastused); + IFLR_UNLOCK(lr); + } +} + +static void +arp_llinfo_refresh(struct rtentry *rt) +{ + uint64_t timenow = net_uptime(); + /* + * If route entry is permanent or if expiry is less + * than timenow and extra time taken for unicast probe + * we can't expedite the refresh + */ + if ((rt->rt_expire == 0) || + (rt->rt_flags & RTF_STATIC) || + !(rt->rt_flags & RTF_LLINFO)) { + return; + } + + if (rt->rt_expire > timenow) + rt->rt_expire = timenow; + return; +} + +void +arp_llreach_set_reachable(struct ifnet *ifp, void *addr, unsigned int alen) +{ + /* Nothing more to do if it's disabled */ + if (arp_llreach_base == 0) + return; + + ifnet_llreach_set_reachable(ifp, ETHERTYPE_IP, addr, alen); +} + +static __inline void +arp_llreach_use(struct llinfo_arp *la) +{ + if (la->la_llreach != NULL) + la->la_lastused = net_uptime(); +} + +static __inline int +arp_llreach_reachable(struct llinfo_arp *la) +{ + struct if_llreach *lr; + const char *why = NULL; + + /* Nothing more to do if it's disabled; pretend it's reachable */ + if (arp_llreach_base == 0) + return (1); + + if ((lr = la->la_llreach) == NULL) { + /* + * Link-layer reachability record isn't present for this + * ARP entry; pretend it's reachable and use it as is. + */ + return (1); + } else if (ifnet_llreach_reachable(lr)) { + /* + * Record is present, it's not shared with other ARP + * entries and a packet has recently been received + * from the remote host; consider it reachable. + */ + if (lr->lr_reqcnt == 1) + return (1); + + /* Prime it up, if this is the first time */ + if (la->la_lastused == 0) { + VERIFY(la->la_llreach != NULL); + arp_llreach_use(la); + } + + /* + * Record is present and shared with one or more ARP + * entries, and a packet has recently been received + * from the remote host. Since it's shared by more + * than one IP addresses, we can't rely on the link- + * layer reachability alone; consider it reachable if + * this ARP entry has been used "recently." + */ + if (ifnet_llreach_reachable_delta(lr, la->la_lastused)) + return (1); + + why = "has alias(es) and hasn't been used in a while"; + } else { + why = "haven't heard from it in a while"; + } + + if (arp_verbose > 1) { + char tmp[MAX_IPv4_STR_LEN]; + u_int64_t now = net_uptime(); + + log(LOG_DEBUG, "%s: ARP probe(s) needed for %s; " + "%s [lastused %lld, lastrcvd %lld] secs ago\n", + if_name(lr->lr_ifp), inet_ntop(AF_INET, + &SIN(rt_key(la->la_rt))->sin_addr, tmp, sizeof (tmp)), why, + (la->la_lastused ? (int64_t)(now - la->la_lastused) : -1), + (lr->lr_lastrcvd ? (int64_t)(now - lr->lr_lastrcvd) : -1)); + + } + return (0); +} + +/* + * Obtain a link-layer source cache entry for the sender. + * + * NOTE: This is currently only for ARP/Ethernet. + */ +static void +arp_llreach_alloc(struct rtentry *rt, struct ifnet *ifp, void *addr, + unsigned int alen, boolean_t solicited, uint32_t *p_rt_event_code) +{ + VERIFY(rt->rt_expire == 0 || rt->rt_rmx.rmx_expire != 0); + VERIFY(rt->rt_expire != 0 || rt->rt_rmx.rmx_expire == 0); + + if (arp_llreach_base != 0 && rt->rt_expire != 0 && + !(rt->rt_ifp->if_flags & IFF_LOOPBACK) && + ifp->if_addrlen == IF_LLREACH_MAXLEN && /* Ethernet */ + alen == ifp->if_addrlen) { + struct llinfo_arp *la = rt->rt_llinfo; + struct if_llreach *lr; + const char *why = NULL, *type = ""; + + /* Become a regular mutex, just in case */ + RT_CONVERT_LOCK(rt); + + if ((lr = la->la_llreach) != NULL) { + type = (solicited ? "ARP reply" : "ARP announcement"); + /* + * If target has changed, create a new record; + * otherwise keep existing record. + */ + IFLR_LOCK(lr); + if (bcmp(addr, lr->lr_key.addr, alen) != 0) { + IFLR_UNLOCK(lr); + /* Purge any link-layer info caching */ + VERIFY(rt->rt_llinfo_purge != NULL); + rt->rt_llinfo_purge(rt); + lr = NULL; + why = " for different target HW address; " + "using new llreach record"; + *p_rt_event_code = ROUTE_LLENTRY_CHANGED; + } else { + /* + * If we were doing unicast probing, we need to + * deliver an event for neighbor cache resolution + */ + if (lr->lr_probes != 0) + *p_rt_event_code = ROUTE_LLENTRY_RESOLVED; + + lr->lr_probes = 0; /* reset probe count */ + IFLR_UNLOCK(lr); + if (solicited) { + why = " for same target HW address; " + "keeping existing llreach record"; + } + } + } + + if (lr == NULL) { + lr = la->la_llreach = ifnet_llreach_alloc(ifp, + ETHERTYPE_IP, addr, alen, arp_llreach_base); + if (lr != NULL) { + lr->lr_probes = 0; /* reset probe count */ + if (why == NULL) + why = "creating new llreach record"; + } + *p_rt_event_code = ROUTE_LLENTRY_RESOLVED; + } + + if (arp_verbose > 1 && lr != NULL && why != NULL) { + char tmp[MAX_IPv4_STR_LEN]; + + log(LOG_DEBUG, "%s: %s%s for %s\n", if_name(ifp), + type, why, inet_ntop(AF_INET, + &SIN(rt_key(rt))->sin_addr, tmp, sizeof (tmp))); + } + } +} + +struct arptf_arg { + boolean_t draining; + boolean_t probing; + uint32_t killed; + uint32_t aging; + uint32_t sticky; + uint32_t found; + uint32_t qlen; + uint32_t qsize; +}; /* * Free an arp entry. */ static void -arptfree( - struct llinfo_arp *la) +arptfree(struct llinfo_arp *la, void *arg) { + struct arptf_arg *ap = arg; struct rtentry *rt = la->la_rt; - struct sockaddr_dl *sdl; - lck_mtx_assert(rt_mtx, LCK_MTX_ASSERT_OWNED); - if (rt == 0) - panic("arptfree"); - if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) && - sdl->sdl_family == AF_LINK) { - sdl->sdl_alen = 0; - la->la_asked = 0; - rt->rt_flags &= ~RTF_REJECT; + uint64_t timenow; + + LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED); + + /* rnh_lock acquired by caller protects rt from going away */ + RT_LOCK(rt); + + VERIFY(rt->rt_expire == 0 || rt->rt_rmx.rmx_expire != 0); + VERIFY(rt->rt_expire != 0 || rt->rt_rmx.rmx_expire == 0); + + ap->found++; + timenow = net_uptime(); + + /* If we're probing, flush out held packets upon probe expiration */ + if (ap->probing && (la->la_flags & LLINFO_PROBING) && + la->la_probeexp <= timenow) { + struct sockaddr_dl *sdl = SDL(rt->rt_gateway); + if (sdl != NULL) + sdl->sdl_alen = 0; + (void) arp_llinfo_flushq(la); + /* + * Enqueue work item to invoke callback for this route entry + */ + route_event_enqueue_nwk_wq_entry(rt, NULL, + ROUTE_LLENTRY_UNREACH, NULL, TRUE); + } + + /* + * The following is mostly being used to arm the timer + * again and for logging. + * qlen is used to re-arm the timer. Therefore, pure probe + * requests can be considered as 0 length packets + * contributing only to length but not to the size. + */ + ap->qlen += qlen(&la->la_holdq); + ap->qlen += la->la_prbreq_cnt; + ap->qsize += qsize(&la->la_holdq); + + if (rt->rt_expire == 0 || (rt->rt_flags & RTF_STATIC)) { + ap->sticky++; + /* ARP entry is permanent? */ + if (rt->rt_expire == 0) { + RT_UNLOCK(rt); + return; + } + } + + /* ARP entry hasn't expired and we're not draining? */ + if (!ap->draining && rt->rt_expire > timenow) { + RT_UNLOCK(rt); + ap->aging++; return; } - rtrequest_locked(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt), - 0, (struct rtentry **)0); + + if (rt->rt_refcnt > 0) { + /* + * ARP entry has expired, with outstanding refcnt. + * If we're not draining, force ARP query to be + * generated next time this entry is used. + */ + if (!ap->draining && !ap->probing) { + struct sockaddr_dl *sdl = SDL(rt->rt_gateway); + if (sdl != NULL) + sdl->sdl_alen = 0; + la->la_asked = 0; + rt->rt_flags &= ~RTF_REJECT; + } + RT_UNLOCK(rt); + } else if (!(rt->rt_flags & RTF_STATIC) && !ap->probing) { + /* + * ARP entry has no outstanding refcnt, and we're either + * draining or it has expired; delete it from the routing + * table. Safe to drop rt_lock and use rt_key, since holding + * rnh_lock here prevents another thread from calling + * rt_setgate() on this route. + */ + RT_UNLOCK(rt); + rtrequest_locked(RTM_DELETE, rt_key(rt), NULL, + rt_mask(rt), 0, NULL); + arpstat.timeouts++; + ap->killed++; + } else { + /* ARP entry is static; let it linger */ + RT_UNLOCK(rt); + } +} + +void +in_arpdrain(void *arg) +{ +#pragma unused(arg) + struct llinfo_arp *la, *ola; + struct arptf_arg farg; + + if (arp_verbose) + log(LOG_DEBUG, "%s: draining ARP entries\n", __func__); + + lck_mtx_lock(rnh_lock); + la = llinfo_arp.lh_first; + bzero(&farg, sizeof (farg)); + farg.draining = TRUE; + while ((ola = la) != NULL) { + la = la->la_le.le_next; + arptfree(ola, &farg); + } + if (arp_verbose) { + log(LOG_DEBUG, "%s: found %u, aging %u, sticky %u, killed %u; " + "%u pkts held (%u bytes)\n", __func__, farg.found, + farg.aging, farg.sticky, farg.killed, farg.qlen, + farg.qsize); + } + lck_mtx_unlock(rnh_lock); } /* * Timeout routine. Age arp_tab entries periodically. */ -/* ARGSUSED */ static void -arptimer( - __unused void *ignored_arg) +arp_timeout(thread_call_param_t arg0, thread_call_param_t arg1) +{ +#pragma unused(arg0, arg1) + struct llinfo_arp *la, *ola; + struct timeval atv; + struct arptf_arg farg; + + lck_mtx_lock(rnh_lock); + la = llinfo_arp.lh_first; + bzero(&farg, sizeof (farg)); + while ((ola = la) != NULL) { + la = la->la_le.le_next; + arptfree(ola, &farg); + } + if (arp_verbose) { + log(LOG_DEBUG, "%s: found %u, aging %u, sticky %u, killed %u; " + "%u pkts held (%u bytes)\n", __func__, farg.found, + farg.aging, farg.sticky, farg.killed, farg.qlen, + farg.qsize); + } + atv.tv_usec = 0; + atv.tv_sec = MAX(arpt_prune, 5); + /* re-arm the timer if there's work to do */ + arp_timeout_run = 0; + if (farg.aging > 0) + arp_sched_timeout(&atv); + else if (arp_verbose) + log(LOG_DEBUG, "%s: not rescheduling timer\n", __func__); + lck_mtx_unlock(rnh_lock); +} + +static void +arp_sched_timeout(struct timeval *atv) +{ + LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED); + + if (!arp_timeout_run) { + struct timeval tv; + uint64_t deadline = 0; + + if (arp_timeout_tcall == NULL) { + arp_timeout_tcall = + thread_call_allocate(arp_timeout, NULL); + VERIFY(arp_timeout_tcall != NULL); + } + + if (atv == NULL) { + tv.tv_usec = 0; + tv.tv_sec = MAX(arpt_prune / 5, 1); + atv = &tv; + } + if (arp_verbose) { + log(LOG_DEBUG, "%s: timer scheduled in " + "T+%llus.%lluu\n", __func__, + (uint64_t)atv->tv_sec, (uint64_t)atv->tv_usec); + } + arp_timeout_run = 1; + + clock_deadline_for_periodic_event(atv->tv_sec * NSEC_PER_SEC, + mach_absolute_time(), &deadline); + (void) thread_call_enter_delayed(arp_timeout_tcall, deadline); + } +} + +/* + * Probe routine. + */ +static void +arp_probe(thread_call_param_t arg0, thread_call_param_t arg1) { +#pragma unused(arg0, arg1) struct llinfo_arp *la, *ola; - struct timeval timenow; + struct timeval atv; + struct arptf_arg farg; - lck_mtx_lock(rt_mtx); + lck_mtx_lock(rnh_lock); la = llinfo_arp.lh_first; - getmicrotime(&timenow); - while ((ola = la) != 0) { - struct rtentry *rt = la->la_rt; + bzero(&farg, sizeof (farg)); + farg.probing = TRUE; + while ((ola = la) != NULL) { la = la->la_le.le_next; - if (rt->rt_expire && rt->rt_expire <= timenow.tv_sec) - arptfree(ola); /* timer has expired, clear */ + arptfree(ola, &farg); + } + if (arp_verbose) { + log(LOG_DEBUG, "%s: found %u, aging %u, sticky %u, killed %u; " + "%u pkts held (%u bytes)\n", __func__, farg.found, + farg.aging, farg.sticky, farg.killed, farg.qlen, + farg.qsize); + } + atv.tv_usec = 0; + atv.tv_sec = MAX(arpt_probe, ARP_PROBE_TIME); + /* re-arm the probe if there's work to do */ + arp_probe_run = 0; + if (farg.qlen > 0) + arp_sched_probe(&atv); + else if (arp_verbose) + log(LOG_DEBUG, "%s: not rescheduling probe\n", __func__); + lck_mtx_unlock(rnh_lock); +} + +static void +arp_sched_probe(struct timeval *atv) +{ + LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED); + + if (!arp_probe_run) { + struct timeval tv; + uint64_t deadline = 0; + + if (arp_probe_tcall == NULL) { + arp_probe_tcall = + thread_call_allocate(arp_probe, NULL); + VERIFY(arp_probe_tcall != NULL); + } + + if (atv == NULL) { + tv.tv_usec = 0; + tv.tv_sec = MAX(arpt_probe, ARP_PROBE_TIME); + atv = &tv; + } + if (arp_verbose) { + log(LOG_DEBUG, "%s: probe scheduled in " + "T+%llus.%lluu\n", __func__, + (uint64_t)atv->tv_sec, (uint64_t)atv->tv_usec); + } + arp_probe_run = 1; + + clock_deadline_for_periodic_event(atv->tv_sec * NSEC_PER_SEC, + mach_absolute_time(), &deadline); + (void) thread_call_enter_delayed(arp_probe_tcall, deadline); } - lck_mtx_unlock(rt_mtx); - timeout(arptimer, (caddr_t)0, arpt_prune * hz); } /* - * Parallel to llc_rtrequest. + * ifa_rtrequest() callback */ static void -arp_rtrequest( - int req, - struct rtentry *rt, - __unused struct sockaddr *sa) +arp_rtrequest(int req, struct rtentry *rt, struct sockaddr *sa) { +#pragma unused(sa) struct sockaddr *gate = rt->rt_gateway; - struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo; - static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK, 0, 0, 0, 0, 0, {0}}; - static int arpinit_done; - struct timeval timenow; + struct llinfo_arp *la = rt->rt_llinfo; + static struct sockaddr_dl null_sdl = + { .sdl_len = sizeof (null_sdl), .sdl_family = AF_LINK }; + uint64_t timenow; + char buf[MAX_IPv4_STR_LEN]; - if (!arpinit_done) { - arpinit_done = 1; - LIST_INIT(&llinfo_arp); - timeout(arptimer, (caddr_t)0, hz); - } - lck_mtx_assert(rt_mtx, LCK_MTX_ASSERT_OWNED); + VERIFY(arpinit_done); + LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED); + RT_LOCK_ASSERT_HELD(rt); if (rt->rt_flags & RTF_GATEWAY) return; - getmicrotime(&timenow); - switch (req) { + timenow = net_uptime(); + switch (req) { case RTM_ADD: /* * XXX: If this is a manually added route to interface * such as older version of routed or gated might provide, * restore cloning bit. */ - if ((rt->rt_flags & RTF_HOST) == 0 && - SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) + if (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != NULL && + SIN(rt_mask(rt))->sin_addr.s_addr != INADDR_BROADCAST) rt->rt_flags |= RTF_CLONING; + if (rt->rt_flags & RTF_CLONING) { /* * Case 1: This route should come from a route to iface. */ - rt_setgate(rt, rt_key(rt), - (struct sockaddr *)&null_sdl); - gate = rt->rt_gateway; - SDL(gate)->sdl_type = rt->rt_ifp->if_type; - SDL(gate)->sdl_index = rt->rt_ifp->if_index; - rt->rt_expire = timenow.tv_sec; + if (rt_setgate(rt, rt_key(rt), SA(&null_sdl)) == 0) { + gate = rt->rt_gateway; + SDL(gate)->sdl_type = rt->rt_ifp->if_type; + SDL(gate)->sdl_index = rt->rt_ifp->if_index; + /* + * In case we're called before 1.0 sec. + * has elapsed. + */ + rt_setexpire(rt, MAX(timenow, 1)); + } break; } /* Announce a new entry if requested. */ - if (rt->rt_flags & RTF_ANNOUNCE) - dlil_send_arp(rt->rt_ifp, ARPOP_REQUEST, SDL(gate), rt_key(rt), (struct sockaddr_dl *)rt_key(rt), NULL); - /*FALLTHROUGH*/ + if (rt->rt_flags & RTF_ANNOUNCE) { + if (la != NULL) + arp_llreach_use(la); /* Mark use timestamp */ + RT_UNLOCK(rt); + dlil_send_arp(rt->rt_ifp, ARPOP_REQUEST, + SDL(gate), rt_key(rt), NULL, rt_key(rt), 0); + RT_LOCK(rt); + arpstat.txannounces++; + } + /* FALLTHRU */ case RTM_RESOLVE: if (gate->sa_family != AF_LINK || - gate->sa_len < sizeof(null_sdl)) { - if (log_arp_warnings) - log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); + gate->sa_len < sizeof (null_sdl)) { + arpstat.invalidreqs++; + log(LOG_ERR, "%s: route to %s has bad gateway address " + "(sa_family %u sa_len %u) on %s\n", + __func__, inet_ntop(AF_INET, + &SIN(rt_key(rt))->sin_addr.s_addr, buf, + sizeof (buf)), gate->sa_family, gate->sa_len, + if_name(rt->rt_ifp)); break; } SDL(gate)->sdl_type = rt->rt_ifp->if_type; SDL(gate)->sdl_index = rt->rt_ifp->if_index; - if (la != 0) + + if (la != NULL) break; /* This happens on a route change */ + /* * Case 2: This route may come from cloning, or a manual route * add with a LL address. */ - R_Malloc(la, struct llinfo_arp *, sizeof(*la)); - rt->rt_llinfo = (caddr_t)la; - if (la == 0) { - if ( log_arp_warnings) - log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); + rt->rt_llinfo = la = arp_llinfo_alloc(M_WAITOK); + if (la == NULL) { + arpstat.reqnobufs++; break; } - arp_inuse++, arp_allocated++; - Bzero(la, sizeof(*la)); - la->la_rt = rt; + rt->rt_llinfo_get_ri = arp_llinfo_get_ri; + rt->rt_llinfo_get_iflri = arp_llinfo_get_iflri; + rt->rt_llinfo_purge = arp_llinfo_purge; + rt->rt_llinfo_free = arp_llinfo_free; + rt->rt_llinfo_refresh = arp_llinfo_refresh; rt->rt_flags |= RTF_LLINFO; + la->la_rt = rt; LIST_INSERT_HEAD(&llinfo_arp, la, la_le); + arpstat.inuse++; + + /* We have at least one entry; arm the timer if not already */ + arp_sched_timeout(NULL); -#if INET /* * This keeps the multicast addresses from showing up * in `arp -a' listings as unresolved. It's not actually - * functional. Then the same for broadcast. + * functional. Then the same for broadcast. For IPv4 + * link-local address, keep the entry around even after + * it has expired. */ if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr))) { - dlil_resolve_multi(rt->rt_ifp, rt_key(rt), gate, sizeof(struct sockaddr_dl)); - rt->rt_expire = 0; - } - else if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) { - struct sockaddr_dl *gate_ll = SDL(gate); - size_t broadcast_len; - ifnet_llbroadcast_copy_bytes(rt->rt_ifp, LLADDR(gate_ll), - sizeof(gate_ll->sdl_data), - &broadcast_len); + RT_UNLOCK(rt); + dlil_resolve_multi(rt->rt_ifp, rt_key(rt), gate, + sizeof (struct sockaddr_dl)); + RT_LOCK(rt); + rt_setexpire(rt, 0); + } else if (in_broadcast(SIN(rt_key(rt))->sin_addr, + rt->rt_ifp)) { + struct sockaddr_dl *gate_ll = SDL(gate); + size_t broadcast_len; + ifnet_llbroadcast_copy_bytes(rt->rt_ifp, + LLADDR(gate_ll), sizeof (gate_ll->sdl_data), + &broadcast_len); gate_ll->sdl_alen = broadcast_len; gate_ll->sdl_family = AF_LINK; - gate_ll->sdl_len = sizeof(struct sockaddr_dl); - rt->rt_expire = timenow.tv_sec; + gate_ll->sdl_len = sizeof (struct sockaddr_dl); + /* In case we're called before 1.0 sec. has elapsed */ + rt_setexpire(rt, MAX(timenow, 1)); + } else if (IN_LINKLOCAL(ntohl(SIN(rt_key(rt))-> + sin_addr.s_addr))) { + rt->rt_flags |= RTF_STATIC; } -#endif + /* Set default maximum number of retries */ + la->la_maxtries = arp_maxtries; + + /* Become a regular mutex, just in case */ + RT_CONVERT_LOCK(rt); + IFA_LOCK_SPIN(rt->rt_ifa); if (SIN(rt_key(rt))->sin_addr.s_addr == (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) { - /* - * This test used to be - * if (loif.if_flags & IFF_UP) - * It allowed local traffic to be forced - * through the hardware by configuring the loopback down. - * However, it causes problems during network configuration - * for boards that can't receive packets they send. - * It is now necessary to clear "useloopback" and remove - * the route to force traffic out to the hardware. - */ - rt->rt_expire = 0; - ifnet_lladdr_copy_bytes(rt->rt_ifp, LLADDR(SDL(gate)), SDL(gate)->sdl_alen = 6); - if (useloopback) - rt->rt_ifp = loif; + IFA_UNLOCK(rt->rt_ifa); + /* + * This test used to be + * if (loif.if_flags & IFF_UP) + * It allowed local traffic to be forced through the + * hardware by configuring the loopback down. However, + * it causes problems during network configuration + * for boards that can't receive packets they send. + * It is now necessary to clear "useloopback" and + * remove the route to force traffic out to the + * hardware. + */ + rt_setexpire(rt, 0); + ifnet_lladdr_copy_bytes(rt->rt_ifp, LLADDR(SDL(gate)), + SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen); + if (useloopback) { + if (rt->rt_ifp != lo_ifp) { + /* + * Purge any link-layer info caching. + */ + if (rt->rt_llinfo_purge != NULL) + rt->rt_llinfo_purge(rt); + /* + * Adjust route ref count for the + * interfaces. + */ + if (rt->rt_if_ref_fn != NULL) { + rt->rt_if_ref_fn(lo_ifp, 1); + rt->rt_if_ref_fn(rt->rt_ifp, -1); + } + } + rt->rt_ifp = lo_ifp; + /* + * If rmx_mtu is not locked, update it + * to the MTU used by the new interface. + */ + if (!(rt->rt_rmx.rmx_locks & RTV_MTU)) + rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; + } + } else { + IFA_UNLOCK(rt->rt_ifa); } break; case RTM_DELETE: - if (la == 0) + if (la == NULL) break; - arp_inuse--; + /* + * Unchain it but defer the actual freeing until the route + * itself is to be freed. rt->rt_llinfo still points to + * llinfo_arp, and likewise, la->la_rt still points to this + * route entry, except that RTF_LLINFO is now cleared. + */ LIST_REMOVE(la, la_le); - rt->rt_llinfo = 0; + la->la_le.le_next = NULL; + la->la_le.le_prev = NULL; + arpstat.inuse--; + + /* + * Purge any link-layer info caching. + */ + if (rt->rt_llinfo_purge != NULL) + rt->rt_llinfo_purge(rt); + rt->rt_flags &= ~RTF_LLINFO; - if (la->la_hold) { - m_freem(la->la_hold); - } - la->la_hold = NULL; - R_Free((caddr_t)la); + (void) arp_llinfo_flushq(la); } } @@ -326,16 +1080,16 @@ arp_rtrequest( * convert hardware address to hex string for logging errors. */ static const char * -sdl_addr_to_hex(const struct sockaddr_dl *sdl, char * orig_buf, int buflen) +sdl_addr_to_hex(const struct sockaddr_dl *sdl, char *orig_buf, int buflen) { - char * buf = orig_buf; - int i; - const u_char * lladdr = sdl->sdl_data; - int maxbytes = buflen / 3; - + char *buf = orig_buf; + int i; + const u_char *lladdr = (u_char *)(size_t)sdl->sdl_data; + int maxbytes = buflen / 3; + if (maxbytes > sdl->sdl_alen) { maxbytes = sdl->sdl_alen; - } + } *buf = '\0'; for (i = 0; i < maxbytes; i++) { snprintf(buf, 3, "%02x", lladdr[i]); @@ -349,534 +1103,1092 @@ sdl_addr_to_hex(const struct sockaddr_dl *sdl, char * orig_buf, int buflen) /* * arp_lookup_route will lookup the route for a given address. * - * The routing lock must be held. The address must be for a - * host on a local network on this interface. + * The address must be for a host on a local network on this interface. + * If the returned route is non-NULL, the route is locked and the caller + * is responsible for unlocking it and releasing its reference. */ static errno_t -arp_lookup_route( - const struct in_addr *addr, - int create, - int proxy, - route_t *route) +arp_lookup_route(const struct in_addr *addr, int create, int proxy, + route_t *route, unsigned int ifscope) { - struct sockaddr_inarp sin = {sizeof(sin), AF_INET, 0, {0}, {0}, 0, 0}; - const char *why = 0; + struct sockaddr_inarp sin = + { sizeof (sin), AF_INET, 0, { 0 }, { 0 }, 0, 0 }; + const char *why = NULL; errno_t error = 0; - - // Caller is responsible for taking the routing lock - lck_mtx_assert(rt_mtx, LCK_MTX_ASSERT_OWNED); + route_t rt; + + *route = NULL; sin.sin_addr.s_addr = addr->s_addr; sin.sin_other = proxy ? SIN_PROXY : 0; - - *route = rtalloc1_locked((const struct sockaddr*)&sin, create, 0); - if (*route == NULL) - return ENETUNREACH; - - rtunref(*route); - - if ((*route)->rt_flags & RTF_GATEWAY) { + + /* + * If the destination is a link-local address, don't + * constrain the lookup (don't scope it). + */ + if (IN_LINKLOCAL(ntohl(addr->s_addr))) + ifscope = IFSCOPE_NONE; + + rt = rtalloc1_scoped((struct sockaddr *)&sin, create, 0, ifscope); + if (rt == NULL) + return (ENETUNREACH); + + RT_LOCK(rt); + + if (rt->rt_flags & RTF_GATEWAY) { why = "host is not on local network"; - - /* If there are no references to this route, purge it */ - if ((*route)->rt_refcnt <= 0 && ((*route)->rt_flags & RTF_WASCLONED) != 0) { - rtrequest_locked(RTM_DELETE, - (struct sockaddr *)rt_key(*route), - (*route)->rt_gateway, rt_mask(*route), - (*route)->rt_flags, 0); - } - *route = NULL; error = ENETUNREACH; - } - else if (((*route)->rt_flags & RTF_LLINFO) == 0) { + } else if (!(rt->rt_flags & RTF_LLINFO)) { why = "could not allocate llinfo"; - *route = NULL; error = ENOMEM; - } - else if ((*route)->rt_gateway->sa_family != AF_LINK) { + } else if (rt->rt_gateway->sa_family != AF_LINK) { why = "gateway route is not ours"; - *route = NULL; error = EPROTONOSUPPORT; } - - if (why && create && log_arp_warnings) { - char tmp[MAX_IPv4_STR_LEN]; - log(LOG_DEBUG, "arplookup %s failed: %s\n", - inet_ntop(AF_INET, addr, tmp, sizeof(tmp)), why); - } - - return error; -} - -__private_extern__ errno_t -arp_route_to_gateway_route( - const struct sockaddr *net_dest, - route_t hint, - route_t *out_route); -/* - * arp_route_to_gateway_route will find the gateway route for a given route. - * - * If the route is down, look the route up again. - * If the route goes through a gateway, get the route to the gateway. - * If the gateway route is down, look it up again. - * If the route is set to reject, verify it hasn't expired. - */ -__private_extern__ errno_t -arp_route_to_gateway_route( - const struct sockaddr *net_dest, - route_t hint, - route_t *out_route) -{ - route_t route = hint; - *out_route = NULL; - struct timeval timenow; - - /* If we got a hint from the higher layers, check it out */ - if (route) { - lck_mtx_lock(rt_mtx); - - if ((route->rt_flags & RTF_UP) == 0) { - /* route is down, find a new one */ - hint = route = rtalloc1_locked(net_dest, 1, 0); - if (hint) { - rtunref(hint); - } - else { - /* No route to host */ - lck_mtx_unlock(rt_mtx); - return EHOSTUNREACH; - } + if (error != 0) { + if (create && (arp_verbose || log_arp_warnings)) { + char tmp[MAX_IPv4_STR_LEN]; + log(LOG_DEBUG, "%s: link#%d %s failed: %s\n", + __func__, ifscope, inet_ntop(AF_INET, addr, tmp, + sizeof (tmp)), why); } - - if (route->rt_flags & RTF_GATEWAY) { + + /* + * If there are no references to this route, and it is + * a cloned route, and not static, and ARP had created + * the route, then purge it from the routing table as + * it is probably bogus. + */ + if (rt->rt_refcnt == 1 && + (rt->rt_flags & (RTF_WASCLONED | RTF_STATIC)) == + RTF_WASCLONED) { /* - * We need the gateway route. If it is NULL or down, - * look it up. + * Prevent another thread from modiying rt_key, + * rt_gateway via rt_setgate() after rt_lock is + * dropped by marking the route as defunct. */ - if (route->rt_gwroute == 0 || - (route->rt_gwroute->rt_flags & RTF_UP) == 0) { - if (route->rt_gwroute != 0) - rtfree_locked(route->rt_gwroute); - - route->rt_gwroute = rtalloc1_locked(route->rt_gateway, 1, 0); - if (route->rt_gwroute == 0) { - lck_mtx_unlock(rt_mtx); - return EHOSTUNREACH; - } - } - - route = route->rt_gwroute; - } - - if (route->rt_flags & RTF_REJECT) { - getmicrotime(&timenow); - if (route->rt_rmx.rmx_expire == 0 || - timenow.tv_sec < route->rt_rmx.rmx_expire) { - lck_mtx_unlock(rt_mtx); - return route == hint ? EHOSTDOWN : EHOSTUNREACH; - } + rt->rt_flags |= RTF_CONDEMNED; + RT_UNLOCK(rt); + rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, + rt_mask(rt), rt->rt_flags, NULL); + rtfree(rt); + } else { + RT_REMREF_LOCKED(rt); + RT_UNLOCK(rt); } - - lck_mtx_unlock(rt_mtx); + return (error); } - - *out_route = route; - return 0; + + /* + * Caller releases reference and does RT_UNLOCK(rt). + */ + *route = rt; + return (0); } +boolean_t +arp_is_entry_probing (route_t p_route) +{ + struct llinfo_arp *llinfo = p_route->rt_llinfo; + + if (llinfo != NULL && + llinfo->la_llreach != NULL && + llinfo->la_llreach->lr_probes != 0) + return (TRUE); + + return (FALSE); +} + +/* + * This is the ARP pre-output routine; care must be taken to ensure that + * the "hint" route never gets freed via rtfree(), since the caller may + * have stored it inside a struct route with a reference held for that + * placeholder. + */ errno_t -arp_lookup_ip( - ifnet_t ifp, - const struct sockaddr_in *net_dest, - struct sockaddr_dl *ll_dest, - size_t ll_dest_len, - route_t hint, - mbuf_t packet) +arp_lookup_ip(ifnet_t ifp, const struct sockaddr_in *net_dest, + struct sockaddr_dl *ll_dest, size_t ll_dest_len, route_t hint, + mbuf_t packet) { - route_t route = NULL; + route_t route = NULL; /* output route */ errno_t result = 0; - struct sockaddr_dl *gateway; - struct llinfo_arp *llinfo; - struct timeval timenow; - + struct sockaddr_dl *gateway; + struct llinfo_arp *llinfo = NULL; + boolean_t usable, probing = FALSE; + uint64_t timenow; + struct if_llreach *lr; + struct ifaddr *rt_ifa; + struct sockaddr *sa; + uint32_t rtflags; + struct sockaddr_dl sdl; + boolean_t send_probe_notif = FALSE; + + if (ifp == NULL || net_dest == NULL) + return (EINVAL); + if (net_dest->sin_family != AF_INET) - return EAFNOSUPPORT; - + return (EAFNOSUPPORT); + if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) - return ENETDOWN; - + return (ENETDOWN); + /* * If we were given a route, verify the route and grab the gateway */ - if (hint) { - result = arp_route_to_gateway_route((const struct sockaddr*)net_dest, - hint, &route); + if (hint != NULL) { + /* + * Callee holds a reference on the route and returns + * with the route entry locked, upon success. + */ + result = route_to_gwroute((const struct sockaddr *) + net_dest, hint, &route); if (result != 0) - return result; + return (result); + if (route != NULL) + RT_LOCK_ASSERT_HELD(route); } - - if (packet->m_flags & M_BCAST) { - u_long broadcast_len; + + if ((packet != NULL && (packet->m_flags & M_BCAST)) || + in_broadcast(net_dest->sin_addr, ifp)) { + size_t broadcast_len; bzero(ll_dest, ll_dest_len); - result = ifnet_llbroadcast_copy_bytes(ifp, LLADDR(ll_dest), ll_dest_len - - offsetof(struct sockaddr_dl, - sdl_data), &broadcast_len); - if (result != 0) { - return result; - } - - ll_dest->sdl_alen = broadcast_len; - ll_dest->sdl_family = AF_LINK; - ll_dest->sdl_len = sizeof(struct sockaddr_dl); - - return 0; - } - if (packet->m_flags & M_MCAST) { - return dlil_resolve_multi(ifp, (const struct sockaddr*)net_dest, - (struct sockaddr*)ll_dest, ll_dest_len); - } - - lck_mtx_lock(rt_mtx); - + result = ifnet_llbroadcast_copy_bytes(ifp, LLADDR(ll_dest), + ll_dest_len - offsetof(struct sockaddr_dl, sdl_data), + &broadcast_len); + if (result == 0) { + ll_dest->sdl_alen = broadcast_len; + ll_dest->sdl_family = AF_LINK; + ll_dest->sdl_len = sizeof (struct sockaddr_dl); + } + goto release; + } + if ((packet != NULL && (packet->m_flags & M_MCAST)) || + ((ifp->if_flags & IFF_MULTICAST) && + IN_MULTICAST(ntohl(net_dest->sin_addr.s_addr)))) { + if (route != NULL) + RT_UNLOCK(route); + result = dlil_resolve_multi(ifp, + (const struct sockaddr *)net_dest, + (struct sockaddr *)ll_dest, ll_dest_len); + if (route != NULL) + RT_LOCK(route); + goto release; + } + /* * If we didn't find a route, or the route doesn't have * link layer information, trigger the creation of the * route and link layer information. */ - if (route == NULL || route->rt_llinfo == NULL) - result = arp_lookup_route(&net_dest->sin_addr, 1, 0, &route); - - if (result || route == NULL || route->rt_llinfo == NULL) { - char tmp[MAX_IPv4_STR_LEN]; - lck_mtx_unlock(rt_mtx); - if (log_arp_warnings) - log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s\n", - inet_ntop(AF_INET, &net_dest->sin_addr, tmp, sizeof(tmp))); - return result; - } - + if (route == NULL || route->rt_llinfo == NULL) { + /* Clean up now while we can */ + if (route != NULL) { + if (route == hint) { + RT_REMREF_LOCKED(route); + RT_UNLOCK(route); + } else { + RT_UNLOCK(route); + rtfree(route); + } + } + /* + * Callee holds a reference on the route and returns + * with the route entry locked, upon success. + */ + result = arp_lookup_route(&net_dest->sin_addr, 1, 0, &route, + ifp->if_index); + if (result == 0) + RT_LOCK_ASSERT_HELD(route); + } + + if (result || route == NULL || (llinfo = route->rt_llinfo) == NULL) { + /* In case result is 0 but no route, return an error */ + if (result == 0) + result = EHOSTUNREACH; + + if (route != NULL && route->rt_llinfo == NULL) { + char tmp[MAX_IPv4_STR_LEN]; + log(LOG_ERR, "%s: can't allocate llinfo for %s\n", + __func__, inet_ntop(AF_INET, &net_dest->sin_addr, + tmp, sizeof (tmp))); + } + goto release; + } + /* * Now that we have the right route, is it filled in? */ gateway = SDL(route->rt_gateway); - getmicrotime(&timenow); - if ((route->rt_rmx.rmx_expire == 0 || route->rt_rmx.rmx_expire > timenow.tv_sec) && - gateway != NULL && gateway->sdl_family == AF_LINK && gateway->sdl_alen != 0) { + timenow = net_uptime(); + VERIFY(route->rt_expire == 0 || route->rt_rmx.rmx_expire != 0); + VERIFY(route->rt_expire != 0 || route->rt_rmx.rmx_expire == 0); + + usable = ((route->rt_expire == 0 || route->rt_expire > timenow) && + gateway != NULL && gateway->sdl_family == AF_LINK && + gateway->sdl_alen != 0); + + if (usable) { + boolean_t unreachable = !arp_llreach_reachable(llinfo); + + /* Entry is usable, so fill in info for caller */ bcopy(gateway, ll_dest, MIN(gateway->sdl_len, ll_dest_len)); - lck_mtx_unlock(rt_mtx); - return 0; + result = 0; + arp_llreach_use(llinfo); /* Mark use timestamp */ + + lr = llinfo->la_llreach; + if (lr == NULL) + goto release; + rt_ifa = route->rt_ifa; + + /* Become a regular mutex, just in case */ + RT_CONVERT_LOCK(route); + IFLR_LOCK_SPIN(lr); + + if ((unreachable || (llinfo->la_flags & LLINFO_PROBING)) && + lr->lr_probes < arp_unicast_lim) { + /* + * Thus mark the entry with la_probeexp deadline to + * trigger the probe timer to be scheduled (if not + * already). This gets cleared the moment we get + * an ARP reply. + */ + probing = TRUE; + if (lr->lr_probes == 0) { + llinfo->la_probeexp = (timenow + arpt_probe); + llinfo->la_flags |= LLINFO_PROBING; + /* + * Provide notification that ARP unicast + * probing has started. + * We only do it for the first unicast probe + * attempt. + */ + send_probe_notif = TRUE; + } + + /* + * Start the unicast probe and anticipate a reply; + * afterwards, return existing entry to caller and + * let it be used anyway. If peer is non-existent + * we'll broadcast ARP next time around. + */ + lr->lr_probes++; + bzero(&sdl, sizeof (sdl)); + sdl.sdl_alen = ifp->if_addrlen; + bcopy(&lr->lr_key.addr, LLADDR(&sdl), + ifp->if_addrlen); + IFLR_UNLOCK(lr); + IFA_LOCK_SPIN(rt_ifa); + IFA_ADDREF_LOCKED(rt_ifa); + sa = rt_ifa->ifa_addr; + IFA_UNLOCK(rt_ifa); + rtflags = route->rt_flags; + RT_UNLOCK(route); + dlil_send_arp(ifp, ARPOP_REQUEST, NULL, sa, + (const struct sockaddr_dl *)&sdl, + (const struct sockaddr *)net_dest, rtflags); + IFA_REMREF(rt_ifa); + RT_LOCK(route); + goto release; + } else { + IFLR_UNLOCK(lr); + if (!unreachable && + !(llinfo->la_flags & LLINFO_PROBING)) { + /* + * Normal case where peer is still reachable, + * we're not probing and if_addrlen is anything + * but IF_LLREACH_MAXLEN. + */ + goto release; + } + } } - - /* - * Route wasn't complete/valid. We need to arp. - */ + if (ifp->if_flags & IFF_NOARP) { - lck_mtx_unlock(rt_mtx); - return ENOTSUP; + result = ENOTSUP; + goto release; } - - llinfo = (struct llinfo_arp*)route->rt_llinfo; - if (packet) { - if (llinfo->la_hold) { - m_freem(llinfo->la_hold); - } - llinfo->la_hold = packet; + + /* + * Route wasn't complete/valid; we need to send out ARP request. + * If we've exceeded the limit of la_holdq, drop from the head + * of queue and add this packet to the tail. If we end up with + * RTF_REJECT below, we'll dequeue this from tail and have the + * caller free the packet instead. It's safe to do that since + * we still hold the route's rt_lock. + */ + if (packet != NULL) + arp_llinfo_addq(llinfo, packet); + else + llinfo->la_prbreq_cnt++; + /* + * Regardless of permanent vs. expirable entry, we need to + * avoid having packets sit in la_holdq forever; thus mark the + * entry with la_probeexp deadline to trigger the probe timer + * to be scheduled (if not already). This gets cleared the + * moment we get an ARP reply. + */ + probing = TRUE; + if ((qlen(&llinfo->la_holdq) + llinfo->la_prbreq_cnt) == 1) { + llinfo->la_probeexp = (timenow + arpt_probe); + llinfo->la_flags |= LLINFO_PROBING; } - - if (route->rt_rmx.rmx_expire) { + + if (route->rt_expire) { route->rt_flags &= ~RTF_REJECT; - if (llinfo->la_asked == 0 || route->rt_rmx.rmx_expire != timenow.tv_sec) { - route->rt_rmx.rmx_expire = timenow.tv_sec; - if (llinfo->la_asked++ < arp_maxtries) { - lck_mtx_unlock(rt_mtx); - dlil_send_arp(ifp, ARPOP_REQUEST, NULL, route->rt_ifa->ifa_addr, - NULL, (const struct sockaddr*)net_dest); - return EJUSTRETURN; - } - else { + if (llinfo->la_asked == 0 || route->rt_expire != timenow) { + rt_setexpire(route, timenow); + if (llinfo->la_asked++ < llinfo->la_maxtries) { + struct kev_msg ev_msg; + struct kev_in_arpfailure in_arpfailure; + boolean_t sendkev = FALSE; + + rt_ifa = route->rt_ifa; + lr = llinfo->la_llreach; + /* Become a regular mutex, just in case */ + RT_CONVERT_LOCK(route); + /* Update probe count, if applicable */ + if (lr != NULL) { + IFLR_LOCK_SPIN(lr); + lr->lr_probes++; + IFLR_UNLOCK(lr); + } + if (ifp->if_addrlen == IF_LLREACH_MAXLEN && + route->rt_flags & RTF_ROUTER && + llinfo->la_asked > 1) { + sendkev = TRUE; + llinfo->la_flags |= LLINFO_RTRFAIL_EVTSENT; + } + IFA_LOCK_SPIN(rt_ifa); + IFA_ADDREF_LOCKED(rt_ifa); + sa = rt_ifa->ifa_addr; + IFA_UNLOCK(rt_ifa); + arp_llreach_use(llinfo); /* Mark use tstamp */ + rtflags = route->rt_flags; + RT_UNLOCK(route); + dlil_send_arp(ifp, ARPOP_REQUEST, NULL, sa, + NULL, (const struct sockaddr *)net_dest, + rtflags); + IFA_REMREF(rt_ifa); + if (sendkev) { + bzero(&ev_msg, sizeof(ev_msg)); + bzero(&in_arpfailure, + sizeof(in_arpfailure)); + in_arpfailure.link_data.if_family = + ifp->if_family; + in_arpfailure.link_data.if_unit = + ifp->if_unit; + strlcpy(in_arpfailure.link_data.if_name, + ifp->if_name, IFNAMSIZ); + ev_msg.vendor_code = KEV_VENDOR_APPLE; + ev_msg.kev_class = KEV_NETWORK_CLASS; + ev_msg.kev_subclass = KEV_INET_SUBCLASS; + ev_msg.event_code = + KEV_INET_ARPRTRFAILURE; + ev_msg.dv[0].data_ptr = &in_arpfailure; + ev_msg.dv[0].data_length = + sizeof(struct + kev_in_arpfailure); + dlil_post_complete_msg(NULL, &ev_msg); + } + result = EJUSTRETURN; + RT_LOCK(route); + goto release; + } else { route->rt_flags |= RTF_REJECT; - route->rt_rmx.rmx_expire += arpt_down; + rt_setexpire(route, + route->rt_expire + arpt_down); llinfo->la_asked = 0; - llinfo->la_hold = 0; - lck_mtx_unlock(rt_mtx); - return EHOSTUNREACH; + /* + * Remove the packet that was just added above; + * don't free it since we're not returning + * EJUSTRETURN. The caller will handle the + * freeing. Since we haven't dropped rt_lock + * from the time of _addq() above, this packet + * must be at the tail. + */ + if (packet != NULL) { + struct mbuf *_m = + _getq_tail(&llinfo->la_holdq); + atomic_add_32(&arpstat.held, -1); + VERIFY(_m == packet); + } + result = EHOSTUNREACH; + + /* + * Enqueue work item to invoke callback for this route entry + */ + route_event_enqueue_nwk_wq_entry(route, NULL, + ROUTE_LLENTRY_UNREACH, NULL, TRUE); + goto release; } } } - lck_mtx_unlock(rt_mtx); - - return EJUSTRETURN; + + /* The packet is now held inside la_holdq */ + result = EJUSTRETURN; + +release: + if (result == EHOSTUNREACH) + atomic_add_32(&arpstat.dropped, 1); + + if (route != NULL) { + if (send_probe_notif) { + route_event_enqueue_nwk_wq_entry(route, NULL, + ROUTE_LLENTRY_PROBED, NULL, TRUE); + + if (route->rt_flags & RTF_ROUTER) { + struct radix_node_head *rnh = NULL; + struct route_event rt_ev; + route_event_init(&rt_ev, route, NULL, ROUTE_LLENTRY_PROBED); + /* + * We already have a reference on rt. The function + * frees it before returning. + */ + RT_UNLOCK(route); + lck_mtx_lock(rnh_lock); + rnh = rt_tables[AF_INET]; + + if (rnh != NULL) + (void) rnh->rnh_walktree(rnh, + route_event_walktree, (void *)&rt_ev); + lck_mtx_unlock(rnh_lock); + RT_LOCK(route); + } + } + + if (route == hint) { + RT_REMREF_LOCKED(route); + RT_UNLOCK(route); + } else { + RT_UNLOCK(route); + rtfree(route); + } + } + if (probing) { + /* Do this after we drop rt_lock to preserve ordering */ + lck_mtx_lock(rnh_lock); + arp_sched_probe(NULL); + lck_mtx_unlock(rnh_lock); + } + return (result); } errno_t -arp_ip_handle_input( - ifnet_t ifp, - u_short arpop, - const struct sockaddr_dl *sender_hw, - const struct sockaddr_in *sender_ip, - const struct sockaddr_in *target_ip) +arp_ip_handle_input(ifnet_t ifp, u_short arpop, + const struct sockaddr_dl *sender_hw, const struct sockaddr_in *sender_ip, + const struct sockaddr_in *target_ip) { - char ipv4str[MAX_IPv4_STR_LEN]; - struct sockaddr_dl *gateway; + char ipv4str[MAX_IPv4_STR_LEN]; + struct sockaddr_dl proxied; + struct sockaddr_dl *gateway, *target_hw = NULL; + struct ifaddr *ifa; struct in_ifaddr *ia; struct in_ifaddr *best_ia = NULL; + struct sockaddr_in best_ia_sin; route_t route = NULL; - char buf[3 * MAX_HW_LEN]; // enough for MAX_HW_LEN byte hw address + char buf[3 * MAX_HW_LEN]; /* enough for MAX_HW_LEN byte hw address */ struct llinfo_arp *llinfo; - struct timeval timenow; errno_t error; - + int created_announcement = 0; + int bridged = 0, is_bridge = 0; + uint32_t rt_evcode = 0; + + /* + * Here and other places within this routine where we don't hold + * rnh_lock, trade accuracy for speed for the common scenarios + * and avoid the use of atomic updates. + */ + arpstat.received++; + /* Do not respond to requests for 0.0.0.0 */ - if (target_ip->sin_addr.s_addr == 0 && arpop == ARPOP_REQUEST) { - return 0; - } - + if (target_ip->sin_addr.s_addr == INADDR_ANY && arpop == ARPOP_REQUEST) + goto done; + + if (ifp->if_bridge) + bridged = 1; + if (ifp->if_type == IFT_BRIDGE) + is_bridge = 1; + + if (arpop == ARPOP_REPLY) + arpstat.rxreplies++; + /* * Determine if this ARP is for us + * For a bridge, we want to check the address irrespective + * of the receive interface. */ - lck_mtx_lock(rt_mtx); - for (ia = in_ifaddrhead.tqh_first; ia; ia = ia->ia_link.tqe_next) { - /* do_bridge should be tested here for bridging */ - if (ia->ia_ifp == ifp) { + lck_rw_lock_shared(in_ifaddr_rwlock); + TAILQ_FOREACH(ia, INADDR_HASH(target_ip->sin_addr.s_addr), ia_hash) { + IFA_LOCK_SPIN(&ia->ia_ifa); + if (((bridged && ia->ia_ifp->if_bridge != NULL) || + (ia->ia_ifp == ifp)) && + ia->ia_addr.sin_addr.s_addr == target_ip->sin_addr.s_addr) { + best_ia = ia; + best_ia_sin = best_ia->ia_addr; + IFA_ADDREF_LOCKED(&ia->ia_ifa); + IFA_UNLOCK(&ia->ia_ifa); + lck_rw_done(in_ifaddr_rwlock); + goto match; + } + IFA_UNLOCK(&ia->ia_ifa); + } + + TAILQ_FOREACH(ia, INADDR_HASH(sender_ip->sin_addr.s_addr), ia_hash) { + IFA_LOCK_SPIN(&ia->ia_ifa); + if (((bridged && ia->ia_ifp->if_bridge != NULL) || + (ia->ia_ifp == ifp)) && + ia->ia_addr.sin_addr.s_addr == sender_ip->sin_addr.s_addr) { best_ia = ia; - if (target_ip->sin_addr.s_addr == ia->ia_addr.sin_addr.s_addr || - sender_ip->sin_addr.s_addr == ia->ia_addr.sin_addr.s_addr) { - break; + best_ia_sin = best_ia->ia_addr; + IFA_ADDREF_LOCKED(&ia->ia_ifa); + IFA_UNLOCK(&ia->ia_ifa); + lck_rw_done(in_ifaddr_rwlock); + goto match; + } + IFA_UNLOCK(&ia->ia_ifa); + } + +#define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia) \ + (ia->ia_ifp->if_bridge == ifp->if_softc && \ + bcmp(IF_LLADDR(ia->ia_ifp), IF_LLADDR(ifp), ifp->if_addrlen) == 0 && \ + addr == ia->ia_addr.sin_addr.s_addr) + /* + * Check the case when bridge shares its MAC address with + * some of its children, so packets are claimed by bridge + * itself (bridge_input() does it first), but they are really + * meant to be destined to the bridge member. + */ + if (is_bridge) { + TAILQ_FOREACH(ia, INADDR_HASH(target_ip->sin_addr.s_addr), + ia_hash) { + IFA_LOCK_SPIN(&ia->ia_ifa); + if (BDG_MEMBER_MATCHES_ARP(target_ip->sin_addr.s_addr, + ifp, ia)) { + ifp = ia->ia_ifp; + best_ia = ia; + best_ia_sin = best_ia->ia_addr; + IFA_ADDREF_LOCKED(&ia->ia_ifa); + IFA_UNLOCK(&ia->ia_ifa); + lck_rw_done(in_ifaddr_rwlock); + goto match; } + IFA_UNLOCK(&ia->ia_ifa); } } - - /* If we don't have an IP address on this interface, ignore the packet */ - if (best_ia == 0) { - lck_mtx_unlock(rt_mtx); - return 0; +#undef BDG_MEMBER_MATCHES_ARP + lck_rw_done(in_ifaddr_rwlock); + + /* + * No match, use the first inet address on the receive interface + * as a dummy address for the rest of the function; we may be + * proxying for another address. + */ + ifnet_lock_shared(ifp); + TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { + IFA_LOCK_SPIN(ifa); + if (ifa->ifa_addr->sa_family != AF_INET) { + IFA_UNLOCK(ifa); + continue; + } + best_ia = (struct in_ifaddr *)ifa; + best_ia_sin = best_ia->ia_addr; + IFA_ADDREF_LOCKED(ifa); + IFA_UNLOCK(ifa); + ifnet_lock_done(ifp); + goto match; } - + ifnet_lock_done(ifp); + + /* + * If we're not a bridge member, or if we are but there's no + * IPv4 address to use for the interface, drop the packet. + */ + if (!bridged || best_ia == NULL) + goto done; + +match: /* If the packet is from this interface, ignore the packet */ - if (!bcmp(CONST_LLADDR(sender_hw), ifnet_lladdr(ifp), sender_hw->sdl_len)) { - lck_mtx_unlock(rt_mtx); - return 0; - } - + if (bcmp(CONST_LLADDR(sender_hw), IF_LLADDR(ifp), + sender_hw->sdl_alen) == 0) + goto done; + /* Check for a conflict */ - if (sender_ip->sin_addr.s_addr == best_ia->ia_addr.sin_addr.s_addr) { - struct kev_msg ev_msg; + if (!bridged && + sender_ip->sin_addr.s_addr == best_ia_sin.sin_addr.s_addr) { + struct kev_msg ev_msg; struct kev_in_collision *in_collision; - u_char storage[sizeof(struct kev_in_collision) + MAX_HW_LEN]; - in_collision = (struct kev_in_collision*)storage; - log(LOG_ERR, "%s%d duplicate IP address %s sent from address %s\n", - ifp->if_name, ifp->if_unit, - inet_ntop(AF_INET, &sender_ip->sin_addr, ipv4str, sizeof(ipv4str)), - sdl_addr_to_hex(sender_hw, buf, sizeof(buf))); - + u_char storage[sizeof (struct kev_in_collision) + MAX_HW_LEN]; + + bzero(&ev_msg, sizeof (struct kev_msg)); + bzero(storage, (sizeof (struct kev_in_collision) + MAX_HW_LEN)); + in_collision = (struct kev_in_collision *)(void *)storage; + log(LOG_ERR, "%s duplicate IP address %s sent from " + "address %s\n", if_name(ifp), + inet_ntop(AF_INET, &sender_ip->sin_addr, ipv4str, + sizeof (ipv4str)), sdl_addr_to_hex(sender_hw, buf, + sizeof (buf))); + /* Send a kernel event so anyone can learn of the conflict */ in_collision->link_data.if_family = ifp->if_family; in_collision->link_data.if_unit = ifp->if_unit; - strncpy(&in_collision->link_data.if_name[0], ifp->if_name, IFNAMSIZ); + strlcpy(&in_collision->link_data.if_name[0], + ifp->if_name, IFNAMSIZ); in_collision->ia_ipaddr = sender_ip->sin_addr; - in_collision->hw_len = sender_hw->sdl_alen < MAX_HW_LEN ? sender_hw->sdl_alen : MAX_HW_LEN; - bcopy(CONST_LLADDR(sender_hw), (caddr_t)in_collision->hw_addr, in_collision->hw_len); + in_collision->hw_len = (sender_hw->sdl_alen < MAX_HW_LEN) ? + sender_hw->sdl_alen : MAX_HW_LEN; + bcopy(CONST_LLADDR(sender_hw), (caddr_t)in_collision->hw_addr, + in_collision->hw_len); ev_msg.vendor_code = KEV_VENDOR_APPLE; ev_msg.kev_class = KEV_NETWORK_CLASS; ev_msg.kev_subclass = KEV_INET_SUBCLASS; ev_msg.event_code = KEV_INET_ARPCOLLISION; ev_msg.dv[0].data_ptr = in_collision; - ev_msg.dv[0].data_length = sizeof(struct kev_in_collision) + in_collision->hw_len; + ev_msg.dv[0].data_length = + sizeof (struct kev_in_collision) + in_collision->hw_len; ev_msg.dv[1].data_length = 0; - kev_post_msg(&ev_msg); - + dlil_post_complete_msg(NULL, &ev_msg); + atomic_add_32(&arpstat.dupips, 1); goto respond; } - + /* * Look up the routing entry. If it doesn't exist and we are the - * target, go ahead and create one. + * target, and the sender isn't 0.0.0.0, go ahead and create one. + * Callee holds a reference on the route and returns with the route + * entry locked, upon success. */ - error = arp_lookup_route(&sender_ip->sin_addr, (target_ip->sin_addr.s_addr == - best_ia->ia_addr.sin_addr.s_addr), 0, &route); - - if (error || route == 0 || route->rt_gateway == 0) { - if (ipv4_ll_arp_aware != 0 && IN_LINKLOCAL(target_ip->sin_addr.s_addr) - && arpop == ARPOP_REQUEST && sender_ip->sin_addr.s_addr == 0) { + error = arp_lookup_route(&sender_ip->sin_addr, + (target_ip->sin_addr.s_addr == best_ia_sin.sin_addr.s_addr && + sender_ip->sin_addr.s_addr != 0), 0, &route, ifp->if_index); + + if (error == 0) + RT_LOCK_ASSERT_HELD(route); + + if (error || route == NULL || route->rt_gateway == NULL) { + if (arpop != ARPOP_REQUEST) + goto respond; + + if (arp_sendllconflict && send_conflicting_probes != 0 && + (ifp->if_eflags & IFEF_ARPLL) && + IN_LINKLOCAL(ntohl(target_ip->sin_addr.s_addr)) && + sender_ip->sin_addr.s_addr == INADDR_ANY) { /* - * Verify this ARP probe doesn't conflict with an IPv4LL we know of - * on another interface. + * Verify this ARP probe doesn't conflict with + * an IPv4LL we know of on another interface. */ - error = arp_lookup_route(&target_ip->sin_addr, 0, 0, &route); - if (error == 0 && route && route->rt_gateway) { - gateway = SDL(route->rt_gateway); - if (route->rt_ifp != ifp && - (gateway->sdl_alen != sender_hw->sdl_alen || - bcmp(CONST_LLADDR(gateway), CONST_LLADDR(sender_hw), - gateway->sdl_alen) != 0)) { - /* - * A node is probing for an IPv4LL we know exists on a - * different interface. We respond with a conflicting probe - * to force the new device to pick a different IPv4LL - * address. - */ - log(LOG_INFO, - "arp: %s on %s%d sent probe for %s, already on %s%d\n", - sdl_addr_to_hex(sender_hw, buf, sizeof(buf)), - ifp->if_name, ifp->if_unit, - inet_ntop(AF_INET, &target_ip->sin_addr, ipv4str, - sizeof(ipv4str)), - route->rt_ifp->if_name, route->rt_ifp->if_unit); - log(LOG_INFO, - "arp: sending conflicting probe to %s on %s%d\n", - sdl_addr_to_hex(sender_hw, buf, sizeof(buf)), - ifp->if_name, ifp->if_unit); - - /* - * Send a conservative unicast "ARP probe". - * This should force the other device to pick a new number. - * This will not force the device to pick a new number if the device - * has already assigned that number. - * This will not imply to the device that we own that address. - */ - dlil_send_arp_internal(ifp, ARPOP_REQUEST, - (struct sockaddr_dl*)TAILQ_FIRST(&ifp->if_addrhead)->ifa_addr, - (const struct sockaddr*)sender_ip, sender_hw, - (const struct sockaddr*)target_ip); - } + if (route != NULL) { + RT_REMREF_LOCKED(route); + RT_UNLOCK(route); + route = NULL; + } + /* + * Callee holds a reference on the route and returns + * with the route entry locked, upon success. + */ + error = arp_lookup_route(&target_ip->sin_addr, 0, 0, + &route, ifp->if_index); + + if (error != 0 || route == NULL || + route->rt_gateway == NULL) + goto respond; + + RT_LOCK_ASSERT_HELD(route); + + gateway = SDL(route->rt_gateway); + if (route->rt_ifp != ifp && gateway->sdl_alen != 0 && + (gateway->sdl_alen != sender_hw->sdl_alen || + bcmp(CONST_LLADDR(gateway), CONST_LLADDR(sender_hw), + gateway->sdl_alen) != 0)) { + /* + * A node is probing for an IPv4LL we know + * exists on a different interface. We respond + * with a conflicting probe to force the new + * device to pick a different IPv4LL address. + */ + if (arp_verbose || log_arp_warnings) { + log(LOG_INFO, "arp: %s on %s sent " + "probe for %s, already on %s\n", + sdl_addr_to_hex(sender_hw, buf, + sizeof (buf)), if_name(ifp), + inet_ntop(AF_INET, + &target_ip->sin_addr, ipv4str, + sizeof (ipv4str)), + if_name(route->rt_ifp)); + log(LOG_INFO, "arp: sending " + "conflicting probe to %s on %s\n", + sdl_addr_to_hex(sender_hw, buf, + sizeof (buf)), if_name(ifp)); + } + /* Mark use timestamp */ + if (route->rt_llinfo != NULL) + arp_llreach_use(route->rt_llinfo); + /* We're done with the route */ + RT_REMREF_LOCKED(route); + RT_UNLOCK(route); + route = NULL; + /* + * Send a conservative unicast "ARP probe". + * This should force the other device to pick + * a new number. This will not force the + * device to pick a new number if the device + * has already assigned that number. This will + * not imply to the device that we own that + * address. The link address is always + * present; it's never freed. + */ + ifnet_lock_shared(ifp); + ifa = ifp->if_lladdr; + IFA_ADDREF(ifa); + ifnet_lock_done(ifp); + dlil_send_arp_internal(ifp, ARPOP_REQUEST, + SDL(ifa->ifa_addr), + (const struct sockaddr *)sender_ip, + sender_hw, + (const struct sockaddr *)target_ip); + IFA_REMREF(ifa); + ifa = NULL; + atomic_add_32(&arpstat.txconflicts, 1); } + goto respond; + } else if (keep_announcements != 0 && + target_ip->sin_addr.s_addr == sender_ip->sin_addr.s_addr) { + /* + * Don't create entry if link-local address and + * link-local is disabled + */ + if (!IN_LINKLOCAL(ntohl(sender_ip->sin_addr.s_addr)) || + (ifp->if_eflags & IFEF_ARPLL)) { + if (route != NULL) { + RT_REMREF_LOCKED(route); + RT_UNLOCK(route); + route = NULL; + } + /* + * Callee holds a reference on the route and + * returns with the route entry locked, upon + * success. + */ + error = arp_lookup_route(&sender_ip->sin_addr, + 1, 0, &route, ifp->if_index); + + if (error == 0) + RT_LOCK_ASSERT_HELD(route); + + if (error == 0 && route != NULL && + route->rt_gateway != NULL) + created_announcement = 1; + } + if (created_announcement == 0) + goto respond; + } else { + goto respond; } - - goto respond; } - + + RT_LOCK_ASSERT_HELD(route); + VERIFY(route->rt_expire == 0 || route->rt_rmx.rmx_expire != 0); + VERIFY(route->rt_expire != 0 || route->rt_rmx.rmx_expire == 0); + gateway = SDL(route->rt_gateway); - if (route->rt_ifp != ifp) { - if (!IN_LINKLOCAL(sender_ip->sin_addr.s_addr) || (ifp->if_eflags & IFEF_ARPLL) == 0) { - if (log_arp_warnings) - log(LOG_ERR, "arp: %s is on %s%d but got reply from %s on %s%d\n", - inet_ntop(AF_INET, &sender_ip->sin_addr, ipv4str, - sizeof(ipv4str)), - route->rt_ifp->if_name, - route->rt_ifp->if_unit, - sdl_addr_to_hex(sender_hw, buf, sizeof(buf)), - ifp->if_name, ifp->if_unit); + if (!bridged && route->rt_ifp != ifp) { + if (!IN_LINKLOCAL(ntohl(sender_ip->sin_addr.s_addr)) || + !(ifp->if_eflags & IFEF_ARPLL)) { + if (arp_verbose || log_arp_warnings) + log(LOG_ERR, "arp: %s is on %s but got " + "reply from %s on %s\n", + inet_ntop(AF_INET, &sender_ip->sin_addr, + ipv4str, sizeof (ipv4str)), + if_name(route->rt_ifp), + sdl_addr_to_hex(sender_hw, buf, + sizeof (buf)), if_name(ifp)); goto respond; - } - else { + } else { /* Don't change a permanent address */ - if (route->rt_rmx.rmx_expire == 0) { + if (route->rt_expire == 0) goto respond; - } - + /* - * Don't change the cloned route away from the parent's interface - * if the address did resolve. + * We're about to check and/or change the route's ifp + * and ifa, so do the lock dance: drop rt_lock, hold + * rnh_lock and re-hold rt_lock to avoid violating the + * lock ordering. We have an extra reference on the + * route, so it won't go away while we do this. */ - if (gateway->sdl_alen != 0 && route->rt_parent && - route->rt_parent->rt_ifp == route->rt_ifp) { + RT_UNLOCK(route); + lck_mtx_lock(rnh_lock); + RT_LOCK(route); + /* + * Don't change the cloned route away from the + * parent's interface if the address did resolve + * or if the route is defunct. rt_ifp on both + * the parent and the clone can now be freely + * accessed now that we have acquired rnh_lock. + */ + gateway = SDL(route->rt_gateway); + if ((gateway->sdl_alen != 0 && + route->rt_parent != NULL && + route->rt_parent->rt_ifp == route->rt_ifp) || + (route->rt_flags & RTF_CONDEMNED)) { + RT_REMREF_LOCKED(route); + RT_UNLOCK(route); + route = NULL; + lck_mtx_unlock(rnh_lock); goto respond; } - + if (route->rt_ifp != ifp) { + /* + * Purge any link-layer info caching. + */ + if (route->rt_llinfo_purge != NULL) + route->rt_llinfo_purge(route); + + /* Adjust route ref count for the interfaces */ + if (route->rt_if_ref_fn != NULL) { + route->rt_if_ref_fn(ifp, 1); + route->rt_if_ref_fn(route->rt_ifp, -1); + } + } /* Change the interface when the existing route is on */ route->rt_ifp = ifp; + /* + * If rmx_mtu is not locked, update it + * to the MTU used by the new interface. + */ + if (!(route->rt_rmx.rmx_locks & RTV_MTU)) + route->rt_rmx.rmx_mtu = route->rt_ifp->if_mtu; + rtsetifa(route, &best_ia->ia_ifa); gateway->sdl_index = ifp->if_index; + RT_UNLOCK(route); + lck_mtx_unlock(rnh_lock); + RT_LOCK(route); + /* Don't bother if the route is down */ + if (!(route->rt_flags & RTF_UP)) + goto respond; + /* Refresh gateway pointer */ + gateway = SDL(route->rt_gateway); } + RT_LOCK_ASSERT_HELD(route); } - - if (gateway->sdl_alen && bcmp(LLADDR(gateway), CONST_LLADDR(sender_hw), gateway->sdl_alen)) { - if (route->rt_rmx.rmx_expire) { + + if (gateway->sdl_alen != 0 && bcmp(LLADDR(gateway), + CONST_LLADDR(sender_hw), gateway->sdl_alen) != 0) { + if (route->rt_expire != 0 && + (arp_verbose || log_arp_warnings)) { char buf2[3 * MAX_HW_LEN]; - log(LOG_INFO, "arp: %s moved from %s to %s on %s%d\n", - inet_ntop(AF_INET, &sender_ip->sin_addr, ipv4str, - sizeof(ipv4str)), - sdl_addr_to_hex(gateway, buf, sizeof(buf)), - sdl_addr_to_hex(sender_hw, buf2, sizeof(buf2)), ifp->if_name, - ifp->if_unit); - } - else { - log(LOG_ERR, - "arp: %s attempts to modify permanent entry for %s on %s%d\n", - sdl_addr_to_hex(sender_hw, buf, sizeof(buf)), - inet_ntop(AF_INET, &sender_ip->sin_addr, ipv4str, - sizeof(ipv4str)), - ifp->if_name, ifp->if_unit); + log(LOG_INFO, "arp: %s moved from %s to %s on %s\n", + inet_ntop(AF_INET, &sender_ip->sin_addr, ipv4str, + sizeof (ipv4str)), + sdl_addr_to_hex(gateway, buf, sizeof (buf)), + sdl_addr_to_hex(sender_hw, buf2, sizeof (buf2)), + if_name(ifp)); + } else if (route->rt_expire == 0) { + if (arp_verbose || log_arp_warnings) { + log(LOG_ERR, "arp: %s attempts to modify " + "permanent entry for %s on %s\n", + sdl_addr_to_hex(sender_hw, buf, + sizeof (buf)), + inet_ntop(AF_INET, &sender_ip->sin_addr, + ipv4str, sizeof (ipv4str)), + if_name(ifp)); + } goto respond; } } - + /* Copy the sender hardware address in to the route's gateway address */ gateway->sdl_alen = sender_hw->sdl_alen; bcopy(CONST_LLADDR(sender_hw), LLADDR(gateway), gateway->sdl_alen); - + /* Update the expire time for the route and clear the reject flag */ - getmicrotime(&timenow); - if (route->rt_rmx.rmx_expire) - route->rt_rmx.rmx_expire = timenow.tv_sec + arpt_keep; + if (route->rt_expire != 0) + rt_setexpire(route, net_uptime() + arpt_keep); route->rt_flags &= ~RTF_REJECT; - - /* update the llinfo, send a queued packet if there is one */ - llinfo = (struct llinfo_arp*)route->rt_llinfo; + + /* cache the gateway (sender HW) address */ + arp_llreach_alloc(route, ifp, LLADDR(gateway), gateway->sdl_alen, + (arpop == ARPOP_REPLY), &rt_evcode); + + llinfo = route->rt_llinfo; + /* send a notification that the route is back up */ + if (ifp->if_addrlen == IF_LLREACH_MAXLEN && + route->rt_flags & RTF_ROUTER && + llinfo->la_flags & LLINFO_RTRFAIL_EVTSENT) { + struct kev_msg ev_msg; + struct kev_in_arpalive in_arpalive; + + llinfo->la_flags &= ~LLINFO_RTRFAIL_EVTSENT; + RT_UNLOCK(route); + bzero(&ev_msg, sizeof(ev_msg)); + bzero(&in_arpalive, sizeof(in_arpalive)); + in_arpalive.link_data.if_family = ifp->if_family; + in_arpalive.link_data.if_unit = ifp->if_unit; + strlcpy(in_arpalive.link_data.if_name, ifp->if_name, IFNAMSIZ); + ev_msg.vendor_code = KEV_VENDOR_APPLE; + ev_msg.kev_class = KEV_NETWORK_CLASS; + ev_msg.kev_subclass = KEV_INET_SUBCLASS; + ev_msg.event_code = KEV_INET_ARPRTRALIVE; + ev_msg.dv[0].data_ptr = &in_arpalive; + ev_msg.dv[0].data_length = sizeof(struct kev_in_arpalive); + dlil_post_complete_msg(NULL, &ev_msg); + RT_LOCK(route); + } + /* Update the llinfo, send out all queued packets at once */ llinfo->la_asked = 0; - if (llinfo->la_hold) { - struct mbuf *m0; - m0 = llinfo->la_hold; - llinfo->la_hold = 0; - - /* Should we a reference on the route first? */ - lck_mtx_unlock(rt_mtx); - dlil_output(ifp, PF_INET, m0, (caddr_t)route, rt_key(route), 0); - lck_mtx_lock(rt_mtx); - } - + llinfo->la_flags &= ~LLINFO_PROBING; + llinfo->la_prbreq_cnt = 0; + + if (rt_evcode) { + /* + * Enqueue work item to invoke callback for this route entry + */ + route_event_enqueue_nwk_wq_entry(route, NULL, rt_evcode, NULL, TRUE); + + if (route->rt_flags & RTF_ROUTER) { + struct radix_node_head *rnh = NULL; + struct route_event rt_ev; + route_event_init(&rt_ev, route, NULL, rt_evcode); + /* + * We already have a reference on rt. The function + * frees it before returning. + */ + RT_UNLOCK(route); + lck_mtx_lock(rnh_lock); + rnh = rt_tables[AF_INET]; + + if (rnh != NULL) + (void) rnh->rnh_walktree(rnh, route_event_walktree, + (void *)&rt_ev); + lck_mtx_unlock(rnh_lock); + RT_LOCK(route); + } + } + + if (!qempty(&llinfo->la_holdq)) { + uint32_t held; + struct mbuf *m0 = + _getq_all(&llinfo->la_holdq, NULL, &held, NULL); + if (arp_verbose) { + log(LOG_DEBUG, "%s: sending %u held packets\n", + __func__, held); + } + atomic_add_32(&arpstat.held, -held); + VERIFY(qempty(&llinfo->la_holdq)); + RT_UNLOCK(route); + dlil_output(ifp, PF_INET, m0, (caddr_t)route, + rt_key(route), 0, NULL); + RT_REMREF(route); + route = NULL; + } + respond: - if (arpop != ARPOP_REQUEST) { - lck_mtx_unlock(rt_mtx); - return 0; + if (route != NULL) { + /* Mark use timestamp if we're going to send a reply */ + if (arpop == ARPOP_REQUEST && route->rt_llinfo != NULL) + arp_llreach_use(route->rt_llinfo); + RT_REMREF_LOCKED(route); + RT_UNLOCK(route); + route = NULL; } - + + if (arpop != ARPOP_REQUEST) + goto done; + + /* See comments at the beginning of this routine */ + arpstat.rxrequests++; + /* If we are not the target, check if we should proxy */ - if (target_ip->sin_addr.s_addr != best_ia->ia_addr.sin_addr.s_addr) { - - /* Find a proxy route */ - error = arp_lookup_route(&target_ip->sin_addr, 0, SIN_PROXY, &route); - if (error || route == NULL) { - - /* We don't have a route entry indicating we should use proxy */ - /* If we aren't supposed to proxy all, we are done */ - if (!arp_proxyall) { - lck_mtx_unlock(rt_mtx); - return 0; - } - - /* See if we have a route to the target ip before we proxy it */ - route = rtalloc1_locked((const struct sockaddr*)target_ip, 0, 0); - if (!route) { - lck_mtx_unlock(rt_mtx); - return 0; + if (target_ip->sin_addr.s_addr != best_ia_sin.sin_addr.s_addr) { + /* + * Find a proxy route; callee holds a reference on the + * route and returns with the route entry locked, upon + * success. + */ + error = arp_lookup_route(&target_ip->sin_addr, 0, SIN_PROXY, + &route, ifp->if_index); + + if (error == 0) { + RT_LOCK_ASSERT_HELD(route); + /* + * Return proxied ARP replies only on the interface + * or bridge cluster where this network resides. + * Otherwise we may conflict with the host we are + * proxying for. + */ + if (route->rt_ifp != ifp && + (route->rt_ifp->if_bridge != ifp->if_bridge || + ifp->if_bridge == NULL)) { + RT_REMREF_LOCKED(route); + RT_UNLOCK(route); + goto done; } - + proxied = *SDL(route->rt_gateway); + target_hw = &proxied; + } else { + /* + * We don't have a route entry indicating we should + * use proxy. If we aren't supposed to proxy all, + * we are done. + */ + if (!arp_proxyall) + goto done; + + /* + * See if we have a route to the target ip before + * we proxy it. + */ + route = rtalloc1_scoped((struct sockaddr *) + (size_t)target_ip, 0, 0, ifp->if_index); + if (!route) + goto done; + /* * Don't proxy for hosts already on the same interface. */ + RT_LOCK(route); if (route->rt_ifp == ifp) { - rtfree_locked(route); - lck_mtx_unlock(rt_mtx); - return 0; + RT_UNLOCK(route); + rtfree(route); + goto done; } } + /* Mark use timestamp */ + if (route->rt_llinfo != NULL) + arp_llreach_use(route->rt_llinfo); + RT_REMREF_LOCKED(route); + RT_UNLOCK(route); } - lck_mtx_unlock(rt_mtx); - - dlil_send_arp(ifp, ARPOP_REPLY, NULL, (const struct sockaddr*)target_ip, - sender_hw, (const struct sockaddr*)sender_ip); - - return 0; + + dlil_send_arp(ifp, ARPOP_REPLY, + target_hw, (const struct sockaddr *)target_ip, + sender_hw, (const struct sockaddr *)sender_ip, 0); + +done: + if (best_ia != NULL) + IFA_REMREF(&best_ia->ia_ifa); + return (0); } void -arp_ifinit( - struct ifnet *ifp, - struct ifaddr *ifa) +arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) { + struct sockaddr *sa; + + IFA_LOCK(ifa); ifa->ifa_rtrequest = arp_rtrequest; ifa->ifa_flags |= RTF_CLONING; - dlil_send_arp(ifp, ARPOP_REQUEST, NULL, ifa->ifa_addr, NULL, ifa->ifa_addr); + sa = ifa->ifa_addr; + IFA_UNLOCK(ifa); + dlil_send_arp(ifp, ARPOP_REQUEST, NULL, sa, NULL, sa, 0); +} + +static int +arp_getstat SYSCTL_HANDLER_ARGS +{ +#pragma unused(oidp, arg1, arg2) + if (req->oldptr == USER_ADDR_NULL) + req->oldlen = (size_t)sizeof (struct arpstat); + + return (SYSCTL_OUT(req, &arpstat, MIN(sizeof (arpstat), req->oldlen))); }