/* * Copyright (c) 2004-2008 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 * 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_OSREFERENCE_LICENSE_HEADER_END@ */ /* * Copyright (c) 1982, 1989, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * */ #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 static const size_t MAX_HW_LEN = 10; SYSCTL_DECL(_net_link_ether); 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 */ static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ static int arpt_down = 20; /* once declared down, don't send for 20 sec */ /* 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, ""); 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 */ }; static LIST_HEAD(, llinfo_arp) llinfo_arp; static int arp_inuse, arp_allocated; static int 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, &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, ""); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, sendllconflict, CTLFLAG_RW, &arp_sendllconflict, 0, ""); static int log_arp_warnings = 0; SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_warnings, CTLFLAG_RW, &log_arp_warnings, 0, "log arp warning messages"); static int keep_announcements = 1; SYSCTL_INT(_net_link_ether_inet, OID_AUTO, keep_announcements, CTLFLAG_RW, &keep_announcements, 0, "keep arp announcements"); static int send_conflicting_probes = 1; SYSCTL_INT(_net_link_ether_inet, OID_AUTO, send_conflicting_probes, CTLFLAG_RW, &send_conflicting_probes, 0, "send conflicting link-local arp probes"); extern u_int32_t ipv4_ll_arp_aware; /* * Free an arp entry. */ static void 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"); 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; } 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(void *ignored_arg) { #pragma unused (ignored_arg) struct llinfo_arp *la, *ola; struct timeval timenow; lck_mtx_lock(rt_mtx); la = llinfo_arp.lh_first; getmicrotime(&timenow); 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) arptfree(ola); /* timer has expired, clear */ } lck_mtx_unlock(rt_mtx); timeout(arptimer, (caddr_t)0, arpt_prune * hz); } /* * Parallel to llc_rtrequest. */ static void arp_rtrequest( int req, struct rtentry *rt, __unused struct sockaddr *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; 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); if (rt->rt_flags & RTF_GATEWAY) return; getmicrotime(&timenow); 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) 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; /* In case we're called before 1.0 sec. has elapsed */ rt->rt_expire = MAX(timenow.tv_sec, 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*/ 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"); break; } SDL(gate)->sdl_type = rt->rt_ifp->if_type; SDL(gate)->sdl_index = rt->rt_ifp->if_index; if (la != 0) 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"); break; } 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. */ 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); gate_ll->sdl_alen = broadcast_len; gate_ll->sdl_family = AF_LINK; gate_ll->sdl_len = sizeof(struct sockaddr_dl); /* In case we're called before 1.0 sec. has elapsed */ rt->rt_expire = MAX(timenow.tv_sec, 1); } #endif 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 = lo_ifp; } break; case RTM_DELETE: if (la == 0) break; arp_inuse--; LIST_REMOVE(la, la_le); rt->rt_llinfo = NULL; rt->rt_flags &= ~RTF_LLINFO; if (la->la_hold) { m_freem(la->la_hold); } la->la_hold = NULL; R_Free((caddr_t)la); } } /* * 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) { char * buf = orig_buf; int i; const u_char * lladdr = (u_char *)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]); buf += 2; *buf = (i == maxbytes - 1) ? '\0' : ':'; buf++; } return (orig_buf); } /* * 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. */ static errno_t 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 = NULL; errno_t error = 0; // Caller is responsible for taking the routing lock lck_mtx_assert(rt_mtx, LCK_MTX_ASSERT_OWNED); sin.sin_addr.s_addr = addr->s_addr; sin.sin_other = proxy ? SIN_PROXY : 0; *route = rtalloc1_scoped_locked((struct sockaddr*)&sin, create, 0, ifscope); if (*route == NULL) return ENETUNREACH; rtunref(*route); if ((*route)->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) { why = "could not allocate llinfo"; *route = NULL; error = ENOMEM; } else if ((*route)->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 link#%d %s failed: %s\n", ifscope, 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) { struct timeval timenow; route_t route = hint; *out_route = NULL; /* 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_scoped_locked(net_dest, 1, 0, route->rt_ifp->if_index); if (hint) { rtunref(hint); } else { /* No route to host */ lck_mtx_unlock(rt_mtx); return EHOSTUNREACH; } } if (route->rt_flags & RTF_GATEWAY) { /* * We need the gateway route. If it is NULL or down, * look it up. */ 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_scoped_locked( route->rt_gateway, 1, 0, route->rt_ifp->if_index); 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; } } lck_mtx_unlock(rt_mtx); } *out_route = route; return 0; } 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) { route_t route = NULL; errno_t result = 0; struct sockaddr_dl *gateway; struct llinfo_arp *llinfo; struct timeval timenow; if (net_dest->sin_family != AF_INET) return EAFNOSUPPORT; if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) 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 (result != 0) return result; } if (packet->m_flags & M_BCAST) { u_long 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); /* * 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, ifp->if_index); 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; } /* * 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) { bcopy(gateway, ll_dest, MIN(gateway->sdl_len, ll_dest_len)); lck_mtx_unlock(rt_mtx); return 0; } /* * 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) { m_freem(llinfo->la_hold); } llinfo->la_hold = packet; } if (route->rt_rmx.rmx_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 { route->rt_flags |= RTF_REJECT; route->rt_rmx.rmx_expire += arpt_down; llinfo->la_asked = 0; llinfo->la_hold = NULL; lck_mtx_unlock(rt_mtx); return EHOSTUNREACH; } } } lck_mtx_unlock(rt_mtx); return EJUSTRETURN; } 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) { char ipv4str[MAX_IPv4_STR_LEN]; struct sockaddr_dl *gateway; struct in_ifaddr *ia; struct in_ifaddr *best_ia = NULL; route_t route = NULL; char buf[3 * MAX_HW_LEN]; // enough for MAX_HW_LEN byte hw address struct llinfo_arp *llinfo; errno_t error; int created_announcement = 0; /* Do not respond to requests for 0.0.0.0 */ if (target_ip->sin_addr.s_addr == 0 && arpop == ARPOP_REQUEST) { return 0; } /* * Determine if this ARP is for us */ 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) { 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; } } } /* 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; } /* 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; } /* Check for a conflict */ if (sender_ip->sin_addr.s_addr == best_ia->ia_addr.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))); /* 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); 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); 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[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, and the sender isn't 0.0.0.0, go ahead and create one. */ error = arp_lookup_route(&sender_ip->sin_addr, (target_ip->sin_addr.s_addr == best_ia->ia_addr.sin_addr.s_addr && sender_ip->sin_addr.s_addr != 0), 0, &route, ifp->if_index); if (error || route == 0 || route->rt_gateway == 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, ifp->if_index); if (error == 0 && route && route->rt_gateway) { 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 (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, "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); } } 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) { error = arp_lookup_route(&sender_ip->sin_addr, 1, 0, &route, ifp->if_index); if (error == 0 && route != NULL && route->rt_gateway != NULL) { created_announcement = 1; } } if (created_announcement == 0) { goto respond; } } else { goto respond; } } gateway = SDL(route->rt_gateway); if (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, 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); goto respond; } else { /* Don't change a permanent address */ if (route->rt_rmx.rmx_expire == 0) { goto respond; } /* * Don't change the cloned route away from the parent's interface * if the address did resolve. */ if (gateway->sdl_alen != 0 && route->rt_parent && route->rt_parent->rt_ifp == route->rt_ifp) { goto respond; } /* 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; } } if (gateway->sdl_alen && bcmp(LLADDR(gateway), CONST_LLADDR(sender_hw), gateway->sdl_alen)) { if (route->rt_rmx.rmx_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); } else if (route->rt_rmx.rmx_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 */ if (route->rt_rmx.rmx_expire) { struct timeval timenow; getmicrotime(&timenow); route->rt_rmx.rmx_expire = timenow.tv_sec + 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; 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); } respond: if (arpop != ARPOP_REQUEST) { lck_mtx_unlock(rt_mtx); return 0; } /* 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, ifp->if_index); 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_scoped_locked( (const struct sockaddr *)target_ip, 0, 0, ifp->if_index); if (!route) { lck_mtx_unlock(rt_mtx); return 0; } /* * Don't proxy for hosts already on the same interface. */ if (route->rt_ifp == ifp) { rtfree_locked(route); lck_mtx_unlock(rt_mtx); return 0; } } } 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; } void arp_ifinit( struct ifnet *ifp, struct ifaddr *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); }