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-rw-r--r--cpukit/libnetworking/netinet/if_ether.c642
1 files changed, 642 insertions, 0 deletions
diff --git a/cpukit/libnetworking/netinet/if_ether.c b/cpukit/libnetworking/netinet/if_ether.c
new file mode 100644
index 0000000000..2742c3b678
--- /dev/null
+++ b/cpukit/libnetworking/netinet/if_ether.c
@@ -0,0 +1,642 @@
+/*
+ * Copyright (c) 1982, 1986, 1988, 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.
+ * 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.
+ *
+ * @(#)if_ether.c 8.1 (Berkeley) 6/10/93
+ * $FreeBSD: src/sys/netinet/if_ether.c,v 1.136 2005/03/13 11:23:22 glebius Exp $
+ */
+
+/*
+ * $Id$
+ */
+
+/*
+ * Ethernet address resolution protocol.
+ * TODO:
+ * add "inuse/lock" bit (or ref. count) along with valid bit
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "opt_inet.h"
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/queue.h>
+#include <sys/sysctl.h>
+#include <sys/systm.h>
+#include <sys/mbuf.h>
+#include <sys/malloc.h>
+#include <sys/socket.h>
+#include <sys/syslog.h>
+
+#include <net/if.h>
+#include <net/if_dl.h>
+#include <net/if_types.h>
+#include <net/route.h>
+#include <net/netisr.h>
+
+#include <netinet/in.h>
+#include <netinet/in_var.h>
+#include <netinet/if_ether.h>
+
+#define SIN(s) ((struct sockaddr_in *)s)
+#define SDL(s) ((struct sockaddr_dl *)s)
+
+SYSCTL_DECL(_net_link_ether);
+SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 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 */
+
+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, "");
+
+#define rt_expire rt_rmx.rmx_expire
+
+struct llinfo_arp {
+ LIST_ENTRY(llinfo_arp) la_le;
+ struct rtentry *la_rt;
+ struct mbuf *la_hold; /* last packet until resolved/timeout */
+ long la_asked; /* last time we QUERIED for this addr */
+#define la_timer la_rt->rt_rmx.rmx_expire /* deletion time in seconds */
+};
+
+static LIST_HEAD(, llinfo_arp) llinfo_arp;
+
+struct ifqueue arpintrq = {0, 0, 0, 50, 0};
+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;
+
+SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
+ &arp_maxtries, 0, "");
+SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
+ &useloopback, 0, "");
+SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
+ &arp_proxyall, 0, "");
+
+static void arp_rtrequest(int, struct rtentry *, struct sockaddr *);
+static void arprequest(struct arpcom *, struct in_addr *, struct in_addr *, u_char *);
+void arpintr(void);
+static void arptfree(struct llinfo_arp *);
+static void arptimer(void *);
+static struct llinfo_arp
+ *arplookup(u_long, int, int);
+#ifdef INET
+static void in_arpinput(struct mbuf *);
+#endif
+
+/*
+ * Timeout routine. Age arp_tab entries periodically.
+ */
+/* ARGSUSED */
+static void
+arptimer(void *ignored_arg)
+{
+ int s = splnet();
+ struct llinfo_arp *la, *ola;
+
+ la = llinfo_arp.lh_first;
+ timeout(arptimer, (caddr_t)0, arpt_prune * hz);
+ while ((ola = la) != 0) {
+ register struct rtentry *rt = la->la_rt;
+ la = la->la_le.le_next;
+ if (rt->rt_expire && rt->rt_expire <= rtems_bsdnet_seconds_since_boot())
+ arptfree(ola); /* timer has expired, clear */
+ }
+ splx(s);
+}
+
+/*
+ * Parallel to llc_rtrequest.
+ */
+static void
+arp_rtrequest(int req, struct rtentry *rt, struct sockaddr *sa)
+{
+ struct sockaddr *gate;
+ struct llinfo_arp *la;
+ static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK, 0, 0, 0, 0, 0, { 0 } };
+ static int arpinit_done;
+
+ if (!arpinit_done) {
+ arpinit_done = 1;
+ LIST_INIT(&llinfo_arp);
+ timeout(arptimer, (caddr_t)0, hz);
+ }
+ if (rt->rt_flags & RTF_GATEWAY)
+ return;
+ gate = rt->rt_gateway;
+ la = (struct llinfo_arp *)rt->rt_llinfo;
+ 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 &&
+ 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 = rtems_bsdnet_seconds_since_boot();
+ break;
+ }
+ /* Announce a new entry if requested. */
+ if (rt->rt_flags & RTF_ANNOUNCE)
+ arprequest((struct arpcom *)rt->rt_ifp,
+ &SIN(rt_key(rt))->sin_addr,
+ &SIN(rt_key(rt))->sin_addr,
+ (u_char *)LLADDR(SDL(gate)));
+ /*FALLTHROUGH*/
+ case RTM_RESOLVE:
+ if (gate->sa_family != AF_LINK ||
+ gate->sa_len < sizeof(null_sdl)) {
+ 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) {
+ 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);
+
+ /*
+ * 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))) {
+ ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr,
+ LLADDR(SDL(gate)));
+ SDL(gate)->sdl_alen = 6;
+ rt->rt_expire = 0;
+ }
+ if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) {
+ memcpy(LLADDR(SDL(gate)), etherbroadcastaddr, 6);
+ SDL(gate)->sdl_alen = 6;
+ rt->rt_expire = 0;
+ }
+
+ 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;
+ Bcopy(((struct arpcom *)rt->rt_ifp)->ac_enaddr,
+ LLADDR(SDL(gate)), SDL(gate)->sdl_alen = 6);
+ if (useloopback)
+ rt->rt_ifp = loif;
+
+ }
+ break;
+
+ case RTM_DELETE:
+ if (la == 0)
+ break;
+ arp_inuse--;
+ LIST_REMOVE(la, la_le);
+ rt->rt_llinfo = 0;
+ rt->rt_flags &= ~RTF_LLINFO;
+ if (la->la_hold)
+ m_freem(la->la_hold);
+ Free((caddr_t)la);
+ }
+}
+
+/*
+ * Broadcast an ARP request. Caller specifies:
+ * - arp header source ip address
+ * - arp header target ip address
+ * - arp header source ethernet address
+ */
+static void
+arprequest(struct arpcom *ac, struct in_addr *sip, struct in_addr *tip, u_char *enaddr)
+{
+ struct mbuf *m;
+ struct ether_header *eh;
+ struct ether_arp *ea;
+ struct sockaddr sa;
+
+ if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
+ return;
+ m->m_len = sizeof(*ea);
+ m->m_pkthdr.len = sizeof(*ea);
+ MH_ALIGN(m, sizeof(*ea));
+ ea = mtod(m, struct ether_arp *);
+ eh = (struct ether_header *)sa.sa_data;
+ bzero((caddr_t)ea, sizeof (*ea));
+ (void)memcpy(eh->ether_dhost, etherbroadcastaddr, sizeof(eh->ether_dhost));
+ eh->ether_type = htons(ETHERTYPE_ARP); /* if_output will not swap */
+ ea->arp_hrd = htons(ARPHRD_ETHER);
+ ea->arp_pro = htons(ETHERTYPE_IP);
+ ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */
+ ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */
+ ea->arp_op = htons(ARPOP_REQUEST);
+ (void)memcpy(ea->arp_sha, enaddr, sizeof(ea->arp_sha));
+ (void)memcpy(ea->arp_spa, sip, sizeof(ea->arp_spa));
+ (void)memcpy(ea->arp_tpa, tip, sizeof(ea->arp_tpa));
+ sa.sa_family = AF_UNSPEC;
+ sa.sa_len = sizeof(sa);
+ (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0);
+}
+
+/*
+ * Resolve an IP address into an ethernet address. If success,
+ * desten is filled in. If there is no entry in arptab,
+ * set one up and broadcast a request for the IP address.
+ * Hold onto this mbuf and resend it once the address
+ * is finally resolved. A return value of 1 indicates
+ * that desten has been filled in and the packet should be sent
+ * normally; a 0 return indicates that the packet has been
+ * taken over here, either now or for later transmission.
+ */
+int
+arpresolve(
+ struct arpcom *ac,
+ struct rtentry *rt,
+ struct mbuf *m,
+ struct sockaddr *dst,
+ u_char *desten,
+ struct rtentry *rt0)
+{
+ struct llinfo_arp *la = 0;
+ struct sockaddr_dl *sdl;
+
+ if (m->m_flags & M_BCAST) { /* broadcast */
+ (void)memcpy(desten, etherbroadcastaddr, sizeof(etherbroadcastaddr));
+ return (1);
+ }
+ if (m->m_flags & M_MCAST) { /* multicast */
+ ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
+ return(1);
+ }
+ if (rt)
+ la = (struct llinfo_arp *)rt->rt_llinfo;
+ else {
+ la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0);
+ if (la)
+ rt = la->la_rt;
+ }
+ if (la == 0 || rt == 0) {
+ log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s\n",
+ inet_ntoa(SIN(dst)->sin_addr));
+ m_freem(m);
+ return (0);
+ }
+ sdl = SDL(rt->rt_gateway);
+ /*
+ * Check the address family and length is valid, the address
+ * is resolved; otherwise, try to resolve.
+ */
+ if ((rt->rt_expire == 0 || rt->rt_expire > rtems_bsdnet_seconds_since_boot()) &&
+ sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
+ bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
+ return 1;
+ }
+ /*
+ * There is an arptab entry, but no ethernet address
+ * response yet. Replace the held mbuf with this
+ * latest one.
+ */
+ if (la->la_hold)
+ m_freem(la->la_hold);
+ la->la_hold = m;
+ if (rt->rt_expire) {
+ rt->rt_flags &= ~RTF_REJECT;
+ if (la->la_asked == 0 || rt->rt_expire != rtems_bsdnet_seconds_since_boot()) {
+ rt->rt_expire = rtems_bsdnet_seconds_since_boot();
+ if (la->la_asked++ < arp_maxtries)
+ arprequest(ac,
+ &(SIN(rt->rt_ifa->ifa_addr)->sin_addr),
+ &(SIN(dst)->sin_addr),
+ ac->ac_enaddr);
+ else {
+ rt->rt_flags |= RTF_REJECT;
+ rt->rt_expire += arpt_down;
+ la->la_asked = 0;
+ }
+
+ }
+ }
+ return (0);
+}
+
+/*
+ * Common length and type checks are done here,
+ * then the protocol-specific routine is called.
+ */
+void
+arpintr(void)
+{
+ struct mbuf *m;
+ struct arphdr *ar;
+ int s;
+
+ while (arpintrq.ifq_head) {
+ s = splimp();
+ IF_DEQUEUE(&arpintrq, m);
+ splx(s);
+ if (m == 0 || (m->m_flags & M_PKTHDR) == 0)
+ panic("arpintr");
+ if (m->m_len >= sizeof(struct arphdr) &&
+ (ar = mtod(m, struct arphdr *)) &&
+ ntohs(ar->ar_hrd) == ARPHRD_ETHER &&
+ m->m_len >=
+ sizeof(struct arphdr) + 2 * ar->ar_hln + 2 * ar->ar_pln)
+
+ switch (ntohs(ar->ar_pro)) {
+
+ case ETHERTYPE_IP:
+ in_arpinput(m);
+ continue;
+ }
+ m_freem(m);
+ }
+}
+
+NETISR_SET(NETISR_ARP, arpintr);
+
+/*
+ * ARP for Internet protocols on 10 Mb/s Ethernet.
+ * Algorithm is that given in RFC 826.
+ * In addition, a sanity check is performed on the sender
+ * protocol address, to catch impersonators.
+ * We no longer handle negotiations for use of trailer protocol:
+ * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
+ * along with IP replies if we wanted trailers sent to us,
+ * and also sent them in response to IP replies.
+ * This allowed either end to announce the desire to receive
+ * trailer packets.
+ * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
+ * but formerly didn't normally send requests.
+ */
+static void
+in_arpinput(struct mbuf *m)
+{
+ struct ether_arp *ea;
+ struct arpcom *ac = (struct arpcom *)m->m_pkthdr.rcvif;
+ struct ether_header *eh;
+ struct llinfo_arp *la = 0;
+ struct rtentry *rt;
+ struct in_ifaddr *ia;
+ struct in_ifaddr *maybe_ia = 0;
+ struct sockaddr_dl *sdl;
+ struct sockaddr sa;
+ struct in_addr isaddr, itaddr, myaddr;
+ int op;
+
+ ea = mtod(m, struct ether_arp *);
+ op = ntohs(ea->arp_op);
+ (void)memcpy(&isaddr, ea->arp_spa, sizeof (isaddr));
+ (void)memcpy(&itaddr, ea->arp_tpa, sizeof (itaddr));
+ for (ia = in_ifaddr; ia; ia = ia->ia_next)
+ if (ia->ia_ifp == &ac->ac_if) {
+ maybe_ia = ia;
+ if ((itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) ||
+ (isaddr.s_addr == ia->ia_addr.sin_addr.s_addr))
+ break;
+ }
+ if (maybe_ia == 0) {
+ m_freem(m);
+ return;
+ }
+ myaddr = ia ? ia->ia_addr.sin_addr : maybe_ia->ia_addr.sin_addr;
+ if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)ac->ac_enaddr,
+ sizeof (ea->arp_sha))) {
+ m_freem(m); /* it's from me, ignore it. */
+ return;
+ }
+ if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)etherbroadcastaddr,
+ sizeof (ea->arp_sha))) {
+ log(LOG_ERR,
+ "arp: ether address is broadcast for IP address %s!\n",
+ inet_ntoa(isaddr));
+ m_freem(m);
+ return;
+ }
+ if (isaddr.s_addr == myaddr.s_addr) {
+ log(LOG_ERR,
+ "arp: %6D is using my IP address %s!\n",
+ ea->arp_sha, ":", inet_ntoa(isaddr));
+ itaddr = myaddr;
+ goto reply;
+ }
+ la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0);
+ if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) {
+ if (sdl->sdl_alen &&
+ bcmp((caddr_t)ea->arp_sha, LLADDR(sdl), sdl->sdl_alen))
+ log(LOG_INFO, "arp: %s moved from %6D to %6D\n",
+ inet_ntoa(isaddr), (u_char *)LLADDR(sdl), ":",
+ ea->arp_sha, ":");
+ (void)memcpy(LLADDR(sdl), ea->arp_sha, sizeof(ea->arp_sha));
+ sdl->sdl_alen = sizeof(ea->arp_sha);
+ if (rt->rt_expire)
+ rt->rt_expire = rtems_bsdnet_seconds_since_boot() + arpt_keep;
+ rt->rt_flags &= ~RTF_REJECT;
+ la->la_asked = 0;
+ if (la->la_hold) {
+ (*ac->ac_if.if_output)(&ac->ac_if, la->la_hold,
+ rt_key(rt), rt);
+ la->la_hold = 0;
+ }
+ }
+reply:
+ if (op != ARPOP_REQUEST) {
+ m_freem(m);
+ return;
+ }
+ if (itaddr.s_addr == myaddr.s_addr) {
+ /* I am the target */
+ (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha));
+ (void)memcpy(ea->arp_sha, ac->ac_enaddr, sizeof(ea->arp_sha));
+ } else {
+ la = arplookup(itaddr.s_addr, 0, SIN_PROXY);
+ if (la == NULL) {
+ struct sockaddr_in sin;
+
+ if (!arp_proxyall) {
+ m_freem(m);
+ return;
+ }
+
+ bzero(&sin, sizeof sin);
+ sin.sin_family = AF_INET;
+ sin.sin_len = sizeof sin;
+ sin.sin_addr = itaddr;
+
+ rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
+ if (!rt) {
+ m_freem(m);
+ return;
+ }
+ /*
+ * Don't send proxies for nodes on the same interface
+ * as this one came out of, or we'll get into a fight
+ * over who claims what Ether address.
+ */
+ if (rt->rt_ifp == &ac->ac_if) {
+ rtfree(rt);
+ m_freem(m);
+ return;
+ }
+ (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha));
+ (void)memcpy(ea->arp_sha, ac->ac_enaddr, sizeof(ea->arp_sha));
+ rtfree(rt);
+#ifdef DEBUG_PROXY
+ printf("arp: proxying for %s\n",
+ inet_ntoa(itaddr));
+#endif
+ } else {
+ rt = la->la_rt;
+ (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha));
+ sdl = SDL(rt->rt_gateway);
+ (void)memcpy(ea->arp_sha, LLADDR(sdl), sizeof(ea->arp_sha));
+ }
+ }
+
+ (void)memcpy(ea->arp_tpa, ea->arp_spa, sizeof(ea->arp_spa));
+ (void)memcpy(ea->arp_spa, &itaddr, sizeof(ea->arp_spa));
+ ea->arp_op = htons(ARPOP_REPLY);
+ ea->arp_pro = htons(ETHERTYPE_IP); /* let's be sure! */
+ eh = (struct ether_header *)sa.sa_data;
+ (void)memcpy(eh->ether_dhost, ea->arp_tha, sizeof(eh->ether_dhost));
+ eh->ether_type = htons(ETHERTYPE_ARP);
+ sa.sa_family = AF_UNSPEC;
+ sa.sa_len = sizeof(sa);
+ (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0);
+ return;
+}
+
+/*
+ * Free an arp entry.
+ */
+static void
+arptfree(struct llinfo_arp *la)
+{
+ struct rtentry *rt = la->la_rt;
+ struct sockaddr_dl *sdl;
+ 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(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt),
+ 0, (struct rtentry **)0);
+}
+/*
+ * Lookup or enter a new address in arptab.
+ */
+static struct llinfo_arp *
+arplookup(u_long addr, int create, int proxy)
+{
+ struct rtentry *rt;
+ static struct sockaddr_inarp sin = {sizeof(sin), AF_INET, 0, { 0 }, { 0 }, 0, 0 };
+ const char *why = 0;
+
+ sin.sin_len = sizeof(sin);
+ sin.sin_family = AF_INET;
+ sin.sin_addr.s_addr = addr;
+ sin.sin_other = proxy ? SIN_PROXY : 0;
+ rt = rtalloc1((struct sockaddr *)&sin, create, 0UL);
+ if (rt == 0)
+ return (0);
+ rt->rt_refcnt--;
+
+ if (rt->rt_flags & RTF_GATEWAY)
+ why = "host is not on local network";
+ else if ((rt->rt_flags & RTF_LLINFO) == 0)
+ why = "could not allocate llinfo";
+ else if (rt->rt_gateway->sa_family != AF_LINK)
+ why = "gateway route is not ours";
+
+ if (why && create) {
+ log(LOG_DEBUG, "arplookup %s failed: %s\n",
+ inet_ntoa(sin.sin_addr), why);
+ return 0;
+ } else if (why) {
+ return 0;
+ }
+ return ((struct llinfo_arp *)rt->rt_llinfo);
+}
+
+void
+arp_ifinit(struct arpcom *ac, struct ifaddr *ifa)
+{
+ if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
+ arprequest(ac, &(IA_SIN(ifa)->sin_addr),
+ &(IA_SIN(ifa)->sin_addr), ac->ac_enaddr);
+ ifa->ifa_rtrequest = arp_rtrequest;
+ ifa->ifa_flags |= RTF_CLONING;
+}