X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/5d5c5d0d5b79ade9a973d55186ffda2638ba2b6e..bd504ef0e0b883cdd7917b73b3574eb9ce669905:/bsd/netinet/in_arp.c diff --git a/bsd/netinet/in_arp.c b/bsd/netinet/in_arp.c index 45dde50d7..7dd09e904 100644 --- a/bsd/netinet/in_arp.c +++ b/bsd/netinet/in_arp.c @@ -1,31 +1,29 @@ /* - * Copyright (c) 2004 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2004-2012 Apple Inc. All rights reserved. * - * @APPLE_LICENSE_OSREFERENCE_HEADER_START@ + * @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 - * compliance with the License. The rights granted to you under the - * License may not be used to create, or enable the creation or - * redistribution of, 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, - * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. - * Please see the License for the specific language governing rights and + * 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 + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * 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, + * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, + * 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_LICENSE_OSREFERENCE_HEADER_END@ + * + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * Copyright (c) 1982, 1989, 1993 @@ -72,22 +70,26 @@ #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 equal(a1, a2) (bcmp((caddr_t)(a1), (caddr_t)(a2), (a1)->sa_len) == 0) static const size_t MAX_HW_LEN = 10; 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 */ @@ -98,91 +100,475 @@ static int arpt_down = 20; /* once declared down, don't send for 20 sec */ 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 = (LL_BASE_REACHABLE / 1000); /* seconds */ + +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, + CTLFLAG_RW | CTLFLAG_LOCKED, &arpt_prune, 0, ""); + +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, + CTLFLAG_RW | CTLFLAG_LOCKED, &arpt_keep, 0, ""); + +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, + CTLFLAG_RW | CTLFLAG_LOCKED, &arpt_down, 0, ""); + +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, apple_hwcksum_tx, + CTLFLAG_RW | CTLFLAG_LOCKED, &apple_hwcksum_tx, 0, ""); + +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, apple_hwcksum_rx, + CTLFLAG_RW | CTLFLAG_LOCKED, &apple_hwcksum_rx, 0, ""); + +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, arp_llreach_base, + CTLFLAG_RW | CTLFLAG_LOCKED, &arp_llreach_base, LL_BASE_REACHABLE, + "default ARP link-layer reachability max lifetime (in seconds)"); 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 + */ struct mbuf *la_hold; /* last packet until resolved/timeout */ - long la_asked; /* last time we QUERIED for this addr */ + 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_persist; /* expirable, but stays around */ }; +/* + * 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_hold, la_asked, la_llreach, la_lastused + * + * - 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. + */ static LIST_HEAD(, llinfo_arp) llinfo_arp; static int arp_inuse, arp_allocated; -static int arp_maxtries = 5; +static u_int32_t arp_maxtries = 5; static int useloopback = 1; /* use loopback interface for local traffic */ static int arp_proxyall = 0; +static int arp_sendllconflict = 0; -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW | CTLFLAG_LOCKED, &arp_maxtries, 0, ""); -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW | CTLFLAG_LOCKED, &useloopback, 0, ""); -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW | CTLFLAG_LOCKED, &arp_proxyall, 0, ""); +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, sendllconflict, CTLFLAG_RW | CTLFLAG_LOCKED, + &arp_sendllconflict, 0, ""); -static int log_arp_warnings = 0; +static int log_arp_warnings = 0; /* Thread safe: no accumulated state */ -SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_warnings, CTLFLAG_RW, +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_warnings, + CTLFLAG_RW | CTLFLAG_LOCKED, &log_arp_warnings, 0, "log arp warning messages"); +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 errno_t arp_lookup_route(const struct in_addr *, int, + int, route_t *, unsigned int); +static void arptimer(void *); +static struct llinfo_arp *arp_llinfo_alloc(void); +static void arp_llinfo_free(void *); +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 __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); + extern u_int32_t ipv4_ll_arp_aware; +static int arpinit_done; + +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) +{ + if (arpinit_done) { + log(LOG_NOTICE, "arp_init called more than once (ignored)\n"); + return; + } + + 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; + + /* start timer */ + timeout(arptimer, (caddr_t)0, hz); +} + +static struct llinfo_arp * +arp_llinfo_alloc(void) +{ + return (zalloc(llinfo_arp_zone)); +} + +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 */ + } + + /* Just in case there's anything there, free it */ + if (la->la_hold != NULL) { + m_freem(la->la_hold); + la->la_hold = NULL; + } + + /* 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_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); + } +} + +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 (log_arp_warnings) { + char tmp[MAX_IPv4_STR_LEN]; + u_int64_t now = net_uptime(); + + log(LOG_DEBUG, "%s%d: ARP probe(s) needed for %s; " + "%s [lastused %lld, lastrcvd %lld] secs ago\n", + lr->lr_ifp->if_name, lr->lr_ifp->if_unit, 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) +{ + 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 != lo_ifp && + 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"; + } else { + 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"; + } + } + + if (log_arp_warnings && lr != NULL && why != NULL) { + char tmp[MAX_IPv4_STR_LEN]; + + log(LOG_DEBUG, "%s%d: %s%s for %s\n", ifp->if_name, + ifp->if_unit, type, why, inet_ntop(AF_INET, + &SIN(rt_key(rt))->sin_addr, tmp, sizeof (tmp))); + } + } +} + /* * Free an arp entry. */ static void -arptfree( - struct llinfo_arp *la) +arptfree(struct llinfo_arp *la) { struct rtentry *rt = la->la_rt; struct sockaddr_dl *sdl; - lck_mtx_assert(rt_mtx, LCK_MTX_ASSERT_OWNED); - if (rt == 0) - panic("arptfree"); + + lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED); + RT_LOCK_ASSERT_HELD(rt); + 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; - return; + RT_UNLOCK(rt); + } else if (la->la_persist) { + /* + * Instead of issuing RTM_DELETE, stop this route entry + * from holding an interface idle reference count; if + * the route is later reused, arp_validate() will revert + * this action. + */ + if (rt->rt_refcnt == 0) + rt_clear_idleref(rt); + RT_UNLOCK(rt); + } else { + /* + * 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); } - rtrequest_locked(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt), - 0, (struct rtentry **)0); } -/* - * Timeout routine. Age arp_tab entries periodically. - */ -/* ARGSUSED */ -static void -arptimer( - __unused void *ignored_arg) +void +in_arpdrain(void *ignored_arg) { - struct llinfo_arp *la = llinfo_arp.lh_first; - struct llinfo_arp *ola; - struct timeval timenow; +#pragma unused (ignored_arg) + struct llinfo_arp *la, *ola; + uint64_t timenow; - lck_mtx_lock(rt_mtx); - getmicrotime(&timenow); + lck_mtx_lock(rnh_lock); + la = llinfo_arp.lh_first; + timenow = net_uptime(); while ((ola = la) != 0) { struct rtentry *rt = la->la_rt; la = la->la_le.le_next; - if (rt->rt_expire && rt->rt_expire <= timenow.tv_sec) + 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); + if (rt->rt_expire && rt->rt_expire <= timenow) arptfree(ola); /* timer has expired, clear */ + else + RT_UNLOCK(rt); } - lck_mtx_unlock(rt_mtx); + lck_mtx_unlock(rnh_lock); +} + +void +arp_validate(struct rtentry *rt) +{ + struct llinfo_arp *la = rt->rt_llinfo; + + RT_LOCK_ASSERT_HELD(rt); + /* + * If this is a persistent ARP entry, make it count towards the + * interface idleness just like before arptfree() was called. + */ + if (la->la_persist) + rt_set_idleref(rt); +} + +/* + * Timeout routine. Age arp_tab entries periodically. + */ +/* ARGSUSED */ +static void +arptimer(void *ignored_arg) +{ +#pragma unused (ignored_arg) + in_arpdrain(NULL); timeout(arptimer, (caddr_t)0, arpt_prune * hz); } @@ -196,21 +582,20 @@ arp_rtrequest( __unused struct sockaddr *sa) { struct sockaddr *gate = rt->rt_gateway; - struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo; + struct llinfo_arp *la = 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; + uint64_t timenow; if (!arpinit_done) { - arpinit_done = 1; - LIST_INIT(&llinfo_arp); - timeout(arptimer, (caddr_t)0, hz); + panic("%s: ARP has not been initialized", __func__); + /* NOTREACHED */ } - lck_mtx_assert(rt_mtx, LCK_MTX_ASSERT_OWNED); + lck_mtx_assert(rnh_lock, LCK_MTX_ASSERT_OWNED); + RT_LOCK_ASSERT_HELD(rt); if (rt->rt_flags & RTF_GATEWAY) return; - getmicrotime(&timenow); + timenow = net_uptime(); switch (req) { case RTM_ADD: @@ -219,29 +604,40 @@ arp_rtrequest( * such as older version of routed or gated might provide, * restore cloning bit. */ - if ((rt->rt_flags & RTF_HOST) == 0 && + if ((rt->rt_flags & RTF_HOST) == 0 && rt_mask(rt) != NULL && SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 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), + (struct sockaddr *)&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); + 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); + } /*FALLTHROUGH*/ case RTM_RESOLVE: if (gate->sa_family != AF_LINK || gate->sa_len < sizeof(null_sdl)) { - if (log_arp_warnings) + if (log_arp_warnings) log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); break; } @@ -253,59 +649,101 @@ arp_rtrequest( * 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(); + if (la == NULL) { + if (log_arp_warnings) + log(LOG_DEBUG, "%s: malloc failed\n", __func__); break; } + 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; + arp_inuse++, arp_allocated++; Bzero(la, sizeof(*la)); la->la_rt = rt; rt->rt_flags |= RTF_LLINFO; LIST_INSERT_HEAD(&llinfo_arp, la, la_le); -#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; + 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); + 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; + /* 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))) { + /* + * The persistent bit implies that once the ARP + * entry has reached it expiration time, the idle + * reference count to the interface will be released, + * but the ARP entry itself stays in the routing table + * until it is explicitly removed. + */ + la->la_persist = 1; + rt->rt_flags |= RTF_STATIC; } -#endif + /* 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; + } + } else { + IFA_UNLOCK(rt->rt_ifa); } break; @@ -313,14 +751,27 @@ arp_rtrequest( if (la == 0) 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; + + /* + * 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) { + if (la->la_hold != NULL) { m_freem(la->la_hold); + la->la_hold = NULL; } - la->la_hold = NULL; - R_Free((caddr_t)la); } } @@ -332,7 +783,7 @@ 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; + const u_char * lladdr = (u_char *)(size_t)sdl->sdl_data; int maxbytes = buflen / 3; if (maxbytes > sdl->sdl_alen) { @@ -351,264 +802,293 @@ 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; + 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 && log_arp_warnings) { + char tmp[MAX_IPv4_STR_LEN]; + log(LOG_DEBUG, "arplookup link#%d %s failed: %s\n", + 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, 0); + 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); } +/* + * 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 llinfo_arp *llinfo = NULL; + uint64_t timenow; + int unreachable = 0; + 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; + 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; + 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); } - - ll_dest->sdl_alen = broadcast_len; - ll_dest->sdl_family = AF_LINK; - ll_dest->sdl_len = sizeof(struct sockaddr_dl); - - return 0; + goto release; } if (packet->m_flags & M_MCAST) { - return dlil_resolve_multi(ifp, (const struct sockaddr*)net_dest, - (struct sockaddr*)ll_dest, ll_dest_len); + 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; } - - lck_mtx_lock(rt_mtx); - + /* * 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) { + 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) { 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; + + /* In case result is 0 but no route, return an error */ + if (result == 0) + result = EHOSTUNREACH; + + if (log_arp_warnings && + route != NULL && route->rt_llinfo == NULL) + log(LOG_DEBUG, "arpresolve: can't allocate llinfo " + "for %s\n", 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); + if ((route->rt_expire == 0 || + route->rt_expire > timenow) && gateway != NULL && + gateway->sdl_family == AF_LINK && gateway->sdl_alen != 0 && + !(unreachable = !arp_llreach_reachable(llinfo))) { 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 */ + goto release; + } else if (unreachable) { + /* + * Discard existing answer in case we need to probe. + */ + gateway->sdl_alen = 0; } - + + if (ifp->if_flags & IFF_NOARP) { + result = ENOTSUP; + goto release; + } + /* * Route wasn't complete/valid. We need to arp. */ - if (ifp->if_flags & IFF_NOARP) { - lck_mtx_unlock(rt_mtx); - return ENOTSUP; - } - - llinfo = (struct llinfo_arp*)route->rt_llinfo; - if (packet) { - if (llinfo->la_hold) { + if (packet != NULL) { + if (llinfo->la_hold != NULL) m_freem(llinfo->la_hold); - } llinfo->la_hold = packet; } - - 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 == 0 || + route->rt_expire != timenow) { + rt_setexpire(route, timenow); 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 { + struct ifaddr *rt_ifa = route->rt_ifa; + struct sockaddr *sa; + u_int32_t rtflags; + + /* Become a regular mutex, just in case */ + RT_CONVERT_LOCK(route); + /* Update probe count, if applicable */ + if (llinfo->la_llreach != NULL) { + IFLR_LOCK_SPIN(llinfo->la_llreach); + llinfo->la_llreach->lr_probes++; + IFLR_UNLOCK(llinfo->la_llreach); + } + 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 timestamp */ + 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); + RT_LOCK(route); + result = EJUSTRETURN; + goto release; + } else { route->rt_flags |= RTF_REJECT; - route->rt_rmx.rmx_expire += arpt_down; + rt_setexpire(route, rt_expiry(route, + route->rt_expire, arpt_down)); llinfo->la_asked = 0; - llinfo->la_hold = 0; - lck_mtx_unlock(rt_mtx); - return EHOSTUNREACH; + /* + * Clear la_hold; don't free the packet since + * we're not returning EJUSTRETURN; the caller + * will handle the freeing. + */ + llinfo->la_hold = NULL; + result = EHOSTUNREACH; + goto release; } } } - lck_mtx_unlock(rt_mtx); - - return EJUSTRETURN; + + /* The packet is now held inside la_hold (can "packet" be NULL?) */ + result = EJUSTRETURN; + +release: + if (route != NULL) { + if (route == hint) { + RT_REMREF_LOCKED(route); + RT_UNLOCK(route); + } else { + RT_UNLOCK(route); + rtfree(route); + } + } + return (result); } errno_t @@ -620,58 +1100,140 @@ arp_ip_handle_input( const struct sockaddr_in *target_ip) { char ipv4str[MAX_IPv4_STR_LEN]; - struct sockaddr_dl *gateway; + 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 struct llinfo_arp *llinfo; - struct timeval timenow; errno_t error; - + int created_announcement = 0; + int bridged = 0, is_bridge = 0; + /* 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 == 0 && arpop == ARPOP_REQUEST) + goto done; + + if (ifp->if_bridge) + bridged = 1; + if (ifp->if_type == IFT_BRIDGE) + is_bridge = 1; + /* * 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(ifnet_lladdr(ia->ia_ifp), ifnet_lladdr(ifp), ifp->if_addrlen) && \ + 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; + 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), ifnet_lladdr(ifp), sender_hw->sdl_alen)) { + goto done; } - + /* Check for a conflict */ - if (sender_ip->sin_addr.s_addr == best_ia->ia_addr.sin_addr.s_addr) { + 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; + 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%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))); - + /* 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; @@ -687,70 +1249,143 @@ arp_ip_handle_input( 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); - + 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); - + 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 == 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) { + if (arpop != ARPOP_REQUEST) { + goto respond; + } + if (arp_sendllconflict + && send_conflicting_probes != 0 + && (ifp->if_eflags & IFEF_ARPLL) != 0 + && IN_LINKLOCAL(ntohl(target_ip->sin_addr.s_addr)) + && sender_ip->sin_addr.s_addr == 0) { /* * 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 (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) + RT_LOCK_ASSERT_HELD(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)) { + 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. */ - log(LOG_INFO, + if (log_arp_warnings) { + 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, + 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); - + } + /* 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, - (struct sockaddr_dl*)TAILQ_FIRST(&ifp->if_addrhead)->ifa_addr, + SDL(ifa->ifa_addr), (const struct sockaddr*)sender_ip, sender_hw, (const struct sockaddr*)target_ip); - } + IFA_REMREF(ifa); + ifa = NULL; + } + } + 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) != 0) { + 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 (!bridged && route->rt_ifp != ifp) { + if (!IN_LINKLOCAL(ntohl(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, @@ -763,122 +1398,216 @@ arp_ip_handle_input( } 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 && + 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; 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 (route->rt_expire && 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); + 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); + else if (route->rt_expire == 0) { + if (log_arp_warnings) { + 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); + } 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) { + uint64_t timenow; + + timenow = net_uptime(); + rt_setexpire(route, + rt_expiry(route, timenow, arpt_keep)); + } route->rt_flags &= ~RTF_REJECT; - + + /* cache the gateway (sender HW) address */ + arp_llreach_alloc(route, ifp, LLADDR(gateway), gateway->sdl_alen, + (arpop == ARPOP_REPLY)); + /* update the llinfo, send a queued packet if there is one */ - llinfo = (struct llinfo_arp*)route->rt_llinfo; + llinfo = route->rt_llinfo; 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_hold = NULL; + + 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; + /* 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); - + + 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); }