/*
- * Copyright (c) 2004-2009 Apple Inc. All rights reserved.
+ * Copyright (c) 2004-2012 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/sysctl.h>
+#include <sys/mcache.h>
+#include <sys/protosw.h>
#include <string.h>
#include <net/if_arp.h>
#include <net/if_dl.h>
#include <net/dlil.h>
#include <net/if_types.h>
+#include <net/if_llreach.h>
#include <net/route.h>
#include <netinet/if_ether.h>
#include <netinet/in_var.h>
#include <kern/zalloc.h>
-#define SA(p) ((struct sockaddr *)(p))
-#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;
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 rt_lock
*/
struct mbuf *la_hold; /* last packet until resolved/timeout */
- int32_t 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 */
};
/*
*
* - Routing lock (rnh_lock)
*
- * la_hold, la_asked
+ * la_hold, la_asked, la_llreach, la_lastused
*
* - Routing entry lock (rt_lock)
*
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,
+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;
-SYSCTL_INT(_net_link_ether_inet, OID_AUTO, keep_announcements, CTLFLAG_RW,
+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;
-SYSCTL_INT(_net_link_ether_inet, OID_AUTO, send_conflicting_probes, CTLFLAG_RW,
+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 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;
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;
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.
*/
la->la_asked = 0;
rt->rt_flags &= ~RTF_REJECT;
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
}
}
-/*
- * Timeout routine. Age arp_tab entries periodically.
- */
-/* ARGSUSED */
-static void
-arptimer(void *ignored_arg)
+void
+in_arpdrain(void *ignored_arg)
{
#pragma unused (ignored_arg)
struct llinfo_arp *la, *ola;
- struct timeval timenow;
+ uint64_t timenow;
lck_mtx_lock(rnh_lock);
la = llinfo_arp.lh_first;
- getmicrotime(&timenow);
+ timenow = net_uptime();
while ((ola = la) != 0) {
struct rtentry *rt = la->la_rt;
la = la->la_le.le_next;
RT_LOCK(rt);
- if (rt->rt_expire && rt->rt_expire <= timenow.tv_sec)
+ 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(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);
}
struct sockaddr *gate = rt->rt_gateway;
struct llinfo_arp *la = rt->rt_llinfo;
static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK, 0, 0, 0, 0, 0, {0}};
- struct timeval timenow;
+ uint64_t timenow;
if (!arpinit_done) {
panic("%s: ARP has not been initialized", __func__);
if (rt->rt_flags & RTF_GATEWAY)
return;
- getmicrotime(&timenow);
+ timenow = net_uptime();
switch (req) {
case RTM_ADD:
* 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) {
* In case we're called before 1.0 sec.
* has elapsed.
*/
- rt->rt_expire = MAX(timenow.tv_sec, 1);
+ rt_setexpire(rt, MAX(timenow, 1));
}
break;
}
/* Announce a new entry if requested. */
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));
+ SDL(gate), rt_key(rt), NULL, rt_key(rt), 0);
RT_LOCK(rt);
}
/*FALLTHROUGH*/
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++;
/*
* 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))) {
RT_UNLOCK(rt);
dlil_resolve_multi(rt->rt_ifp, rt_key(rt), gate,
sizeof(struct sockaddr_dl));
RT_LOCK(rt);
- rt->rt_expire = 0;
+ rt_setexpire(rt, 0);
}
else if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) {
struct sockaddr_dl *gate_ll = SDL(gate);
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);
+ 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;
}
+ /* 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 = lo_ifp;
+ 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;
LIST_REMOVE(la, la_le);
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 != NULL)
+ if (la->la_hold != NULL) {
m_freem(la->la_hold);
- la->la_hold = NULL;
+ la->la_hold = NULL;
+ }
}
}
sin.sin_addr.s_addr = addr->s_addr;
sin.sin_other = proxy ? SIN_PROXY : 0;
+ /*
+ * 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);
return (0);
}
-/*
- * 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.
- *
- * If the returned route is non-NULL, the caller is responsible for
- * releasing the reference and unlocking the route.
- */
-#define senderr(e) { error = (e); goto bad; }
-__private_extern__ errno_t
-arp_route_to_gateway_route(const struct sockaddr *net_dest, route_t hint0,
- route_t *out_route)
-{
- struct timeval timenow;
- route_t rt = hint0, hint = hint0;
- errno_t error = 0;
-
- *out_route = NULL;
-
- /*
- * Next hop determination. Because we may involve the gateway route
- * in addition to the original route, locking is rather complicated.
- * The general concept is that regardless of whether the route points
- * to the original route or to the gateway route, this routine takes
- * an extra reference on such a route. This extra reference will be
- * released at the end.
- *
- * Care must be taken to ensure that the "hint0" route never gets freed
- * via rtfree(), since the caller may have stored it inside a struct
- * route with a reference held for that placeholder.
- */
- if (rt != NULL) {
- unsigned int ifindex;
-
- RT_LOCK_SPIN(rt);
- ifindex = rt->rt_ifp->if_index;
- RT_ADDREF_LOCKED(rt);
- if (!(rt->rt_flags & RTF_UP)) {
- RT_REMREF_LOCKED(rt);
- RT_UNLOCK(rt);
- /* route is down, find a new one */
- hint = rt = rtalloc1_scoped((struct sockaddr *)
- (size_t)net_dest, 1, 0, ifindex);
- if (hint != NULL) {
- RT_LOCK_SPIN(rt);
- ifindex = rt->rt_ifp->if_index;
- } else {
- senderr(EHOSTUNREACH);
- }
- }
-
- /*
- * We have a reference to "rt" by now; it will either
- * be released or freed at the end of this routine.
- */
- RT_LOCK_ASSERT_HELD(rt);
- if (rt->rt_flags & RTF_GATEWAY) {
- struct rtentry *gwrt = rt->rt_gwroute;
- struct sockaddr_in gw;
-
- /* If there's no gateway rt, look it up */
- if (gwrt == NULL) {
- gw = *((struct sockaddr_in *)rt->rt_gateway);
- RT_UNLOCK(rt);
- goto lookup;
- }
- /* Become a regular mutex */
- RT_CONVERT_LOCK(rt);
-
- /*
- * Take gwrt's lock while holding route's lock;
- * this is okay since gwrt never points back
- * to "rt", so no lock ordering issues.
- */
- RT_LOCK_SPIN(gwrt);
- if (!(gwrt->rt_flags & RTF_UP)) {
- struct rtentry *ogwrt;
-
- rt->rt_gwroute = NULL;
- RT_UNLOCK(gwrt);
- gw = *((struct sockaddr_in *)rt->rt_gateway);
- RT_UNLOCK(rt);
- rtfree(gwrt);
-lookup:
- gwrt = rtalloc1_scoped(
- (struct sockaddr *)&gw, 1, 0, ifindex);
-
- RT_LOCK(rt);
- /*
- * Bail out if the route is down, no route
- * to gateway, circular route, or if the
- * gateway portion of "rt" has changed.
- */
- if (!(rt->rt_flags & RTF_UP) ||
- gwrt == NULL || gwrt == rt ||
- !equal(SA(&gw), rt->rt_gateway)) {
- if (gwrt == rt) {
- RT_REMREF_LOCKED(gwrt);
- gwrt = NULL;
- }
- RT_UNLOCK(rt);
- if (gwrt != NULL)
- rtfree(gwrt);
- senderr(EHOSTUNREACH);
- }
-
- /* Remove any existing gwrt */
- ogwrt = rt->rt_gwroute;
- if ((rt->rt_gwroute = gwrt) != NULL)
- RT_ADDREF(gwrt);
-
- /* Clean up "rt" now while we can */
- if (rt == hint0) {
- RT_REMREF_LOCKED(rt);
- RT_UNLOCK(rt);
- } else {
- RT_UNLOCK(rt);
- rtfree(rt);
- }
- rt = gwrt;
- /* Now free the replaced gwrt */
- if (ogwrt != NULL)
- rtfree(ogwrt);
- /* If still no route to gateway, bail out */
- if (rt == NULL)
- senderr(EHOSTUNREACH);
- } else {
- RT_ADDREF_LOCKED(gwrt);
- RT_UNLOCK(gwrt);
- /* Clean up "rt" now while we can */
- if (rt == hint0) {
- RT_REMREF_LOCKED(rt);
- RT_UNLOCK(rt);
- } else {
- RT_UNLOCK(rt);
- rtfree(rt);
- }
- rt = gwrt;
- }
-
- /* rt == gwrt; if it is now down, give up */
- RT_LOCK_SPIN(rt);
- if (!(rt->rt_flags & RTF_UP)) {
- RT_UNLOCK(rt);
- senderr(EHOSTUNREACH);
- }
- }
-
- if (rt->rt_flags & RTF_REJECT) {
- getmicrotime(&timenow);
- if (rt->rt_rmx.rmx_expire == 0 ||
- timenow.tv_sec < rt->rt_rmx.rmx_expire) {
- RT_UNLOCK(rt);
- senderr(rt == hint ? EHOSTDOWN : EHOSTUNREACH);
- }
- }
-
- /* Become a regular mutex */
- RT_CONVERT_LOCK(rt);
-
- /* Caller is responsible for cleaning up "rt" */
- *out_route = rt;
- }
- return (0);
-
-bad:
- /* Clean up route (either it is "rt" or "gwrt") */
- if (rt != NULL) {
- RT_LOCK_SPIN(rt);
- if (rt == hint0) {
- RT_REMREF_LOCKED(rt);
- RT_UNLOCK(rt);
- } else {
- RT_UNLOCK(rt);
- rtfree(rt);
- }
- }
- return (error);
-}
-#undef senderr
-
/*
* 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
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);
* Callee holds a reference on the route and returns
* with the route entry locked, upon success.
*/
- result = arp_route_to_gateway_route((const struct sockaddr*)
+ result = route_to_gwroute((const struct sockaddr *)
net_dest, hint, &route);
if (result != 0)
return (result);
RT_LOCK_ASSERT_HELD(route);
}
- if (result || route == NULL || route->rt_llinfo == NULL) {
+ if (result || route == NULL || (llinfo = route->rt_llinfo) == NULL) {
char tmp[MAX_IPv4_STR_LEN];
/* In case result is 0 but no route, return an error */
* 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));
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) {
/*
* Route wasn't complete/valid. We need to arp.
*/
- llinfo = route->rt_llinfo;
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;
+ route->rt_expire != timenow) {
+ rt_setexpire(route, timenow);
if (llinfo->la_asked++ < arp_maxtries) {
struct ifaddr *rt_ifa = route->rt_ifa;
- ifaref(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,
- rt_ifa->ifa_addr, NULL,
- (const struct sockaddr*)net_dest);
- ifafree(rt_ifa);
+ 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;
+ /*
+ * 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;
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;
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)
goto done;
-
- if (ifp->if_bridge)
+
+ 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
+ * For a bridge, we want to check the address irrespective
* of the receive interface.
*/
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_ifp == ifp)) &&
ia->ia_addr.sin_addr.s_addr == target_ip->sin_addr.s_addr) {
- best_ia = ia;
- ifaref(&best_ia->ia_ifa);
- lck_rw_done(in_ifaddr_rwlock);
- goto match;
+ 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_ifp == ifp)) &&
ia->ia_addr.sin_addr.s_addr == sender_ip->sin_addr.s_addr) {
- best_ia = ia;
- ifaref(&best_ia->ia_ifa);
- lck_rw_done(in_ifaddr_rwlock);
- goto match;
+ 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);
}
-#define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia) \
- (ia->ia_ifp->if_bridge == ifp->if_softc && \
+#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)
/*
* meant to be destined to the bridge member.
*/
if (is_bridge) {
- TAILQ_FOREACH(ia, INADDR_HASH(target_ip->sin_addr.s_addr), ia_hash) {
- if (BDG_MEMBER_MATCHES_ARP(target_ip->sin_addr.s_addr, ifp, ia)) {
+ 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;
- ifaref(&best_ia->ia_ifa);
+ 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);
}
}
lck_rw_done(in_ifaddr_rwlock);
*/
ifnet_lock_shared(ifp);
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
- if (ifa->ifa_addr->sa_family != AF_INET)
+ IFA_LOCK_SPIN(ifa);
+ if (ifa->ifa_addr->sa_family != AF_INET) {
+ IFA_UNLOCK(ifa);
continue;
+ }
best_ia = (struct in_ifaddr *)ifa;
- ifaref(&best_ia->ia_ifa);
+ best_ia_sin = best_ia->ia_addr;
+ IFA_ADDREF_LOCKED(ifa);
+ IFA_UNLOCK(ifa);
ifnet_lock_done(ifp);
goto match;
}
match:
/* If the packet is from this interface, ignore the packet */
- if (!bcmp(CONST_LLADDR(sender_hw), ifnet_lladdr(ifp), sender_hw->sdl_len)) {
+ if (!bcmp(CONST_LLADDR(sender_hw), ifnet_lladdr(ifp), sender_hw->sdl_alen)) {
goto done;
}
/* Check for a conflict */
- if (!bridged && 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)),
* 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 &&
+ (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)
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);
* 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 = TAILQ_FIRST(&ifp->if_addrhead);
- if (ifa != NULL)
- ifaref(ifa);
+ ifa = ifp->if_lladdr;
+ IFA_ADDREF(ifa);
ifnet_lock_done(ifp);
dlil_send_arp_internal(ifp, ARPOP_REQUEST,
- ifa != NULL ? SDL(ifa->ifa_addr) : NULL,
+ SDL(ifa->ifa_addr),
(const struct sockaddr*)sender_ip, sender_hw,
(const struct sockaddr*)target_ip);
- if (ifa != NULL) {
- ifafree(ifa);
- ifa = NULL;
- }
- }
+ IFA_REMREF(ifa);
+ ifa = NULL;
+ }
}
goto respond;
} else if (keep_announcements != 0
}
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 (!bridged && route->rt_ifp != ifp) {
if (!IN_LINKLOCAL(ntohl(sender_ip->sin_addr.s_addr)) || (ifp->if_eflags & IFEF_ARPLL) == 0) {
}
else {
/* Don't change a permanent address */
- if (route->rt_rmx.rmx_expire == 0) {
+ if (route->rt_expire == 0) {
goto respond;
}
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);
}
if (gateway->sdl_alen && bcmp(LLADDR(gateway), CONST_LLADDR(sender_hw), gateway->sdl_alen)) {
- if (route->rt_rmx.rmx_expire && log_arp_warnings) {
+ 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,
sdl_addr_to_hex(sender_hw, buf2, sizeof(buf2)),
ifp->if_name, ifp->if_unit);
}
- else if (route->rt_rmx.rmx_expire == 0) {
+ 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",
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;
+ if (route->rt_expire) {
+ uint64_t timenow;
- getmicrotime(&timenow);
- route->rt_rmx.rmx_expire = timenow.tv_sec + arpt_keep;
+ 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 = route->rt_llinfo;
llinfo->la_asked = 0;
if (llinfo->la_hold) {
struct mbuf *m0;
m0 = llinfo->la_hold;
- llinfo->la_hold = 0;
+ llinfo->la_hold = NULL;
RT_UNLOCK(route);
- dlil_output(ifp, PF_INET, m0, (caddr_t)route, rt_key(route), 0);
+ dlil_output(ifp, PF_INET, m0, (caddr_t)route, rt_key(route), 0, NULL);
RT_REMREF(route);
route = NULL;
}
respond:
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;
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) {
+ 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
goto done;
}
}
+ /* Mark use timestamp */
+ if (route->rt_llinfo != NULL)
+ arp_llreach_use(route->rt_llinfo);
RT_REMREF_LOCKED(route);
RT_UNLOCK(route);
}
dlil_send_arp(ifp, ARPOP_REPLY,
target_hw, (const struct sockaddr*)target_ip,
- sender_hw, (const struct sockaddr*)sender_ip);
+ sender_hw, (const struct sockaddr*)sender_ip, 0);
done:
if (best_ia != NULL)
- ifafree(&best_ia->ia_ifa);
+ 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);
}