1710 lines
42 KiB
C
1710 lines
42 KiB
C
/* $NetBSD: if_arp.c,v 1.158 2014/06/03 01:24:32 ozaki-r Exp $ */
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/*-
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* Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Public Access Networks Corporation ("Panix"). It was developed under
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* contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Copyright (c) 1982, 1986, 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)if_ether.c 8.2 (Berkeley) 9/26/94
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*/
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/*
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* Ethernet address resolution protocol.
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* TODO:
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* add "inuse/lock" bit (or ref. count) along with valid bit
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.158 2014/06/03 01:24:32 ozaki-r Exp $");
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#include "opt_ddb.h"
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#include "opt_inet.h"
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#ifdef INET
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#include "bridge.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/callout.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/socket.h>
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#include <sys/time.h>
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#include <sys/timetc.h>
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#include <sys/kernel.h>
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#include <sys/errno.h>
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#include <sys/ioctl.h>
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#include <sys/syslog.h>
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#include <sys/proc.h>
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#include <sys/protosw.h>
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#include <sys/domain.h>
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#include <sys/sysctl.h>
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#include <sys/socketvar.h>
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#include <sys/percpu.h>
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#include <net/ethertypes.h>
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#include <net/if.h>
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#include <net/if_dl.h>
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#include <net/if_token.h>
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#include <net/if_types.h>
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#include <net/if_ether.h>
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#include <net/route.h>
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#include <net/net_stats.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/in_var.h>
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#include <netinet/ip.h>
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#include <netinet/if_inarp.h>
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#include "arcnet.h"
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#if NARCNET > 0
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#include <net/if_arc.h>
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#endif
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#include "fddi.h"
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#if NFDDI > 0
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#include <net/if_fddi.h>
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#endif
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#include "token.h"
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#include "carp.h"
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#if NCARP > 0
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#include <netinet/ip_carp.h>
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#endif
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#define SIN(s) ((struct sockaddr_in *)s)
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#define SRP(s) ((struct sockaddr_inarp *)s)
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/*
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* ARP trailer negotiation. Trailer protocol is not IP specific,
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* but ARP request/response use IP addresses.
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*/
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#define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL
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/* timer values */
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int arpt_prune = (5*60*1); /* walk list every 5 minutes */
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int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
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int arpt_down = 20; /* once declared down, don't send for 20 secs */
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int arpt_refresh = (5*60); /* time left before refreshing */
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#define rt_expire rt_rmx.rmx_expire
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#define rt_pksent rt_rmx.rmx_pksent
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static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *,
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const struct sockaddr *);
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static void arptfree(struct llinfo_arp *);
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static void arptimer(void *);
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static struct llinfo_arp *arplookup1(struct mbuf *, const struct in_addr *,
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int, int, struct rtentry *);
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static struct llinfo_arp *arplookup(struct mbuf *, const struct in_addr *,
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int, int);
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static void in_arpinput(struct mbuf *);
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static void arp_drainstub(void);
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LIST_HEAD(, llinfo_arp) llinfo_arp;
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struct ifqueue arpintrq = {
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.ifq_head = NULL,
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.ifq_tail = NULL,
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.ifq_len = 0,
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.ifq_maxlen = 50,
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.ifq_drops = 0,
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};
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int arp_inuse, arp_allocated;
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int arp_maxtries = 5;
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int useloopback = 1; /* use loopback interface for local traffic */
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int arpinit_done = 0;
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static percpu_t *arpstat_percpu;
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#define ARP_STAT_GETREF() _NET_STAT_GETREF(arpstat_percpu)
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#define ARP_STAT_PUTREF() _NET_STAT_PUTREF(arpstat_percpu)
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#define ARP_STATINC(x) _NET_STATINC(arpstat_percpu, x)
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#define ARP_STATADD(x, v) _NET_STATADD(arpstat_percpu, x, v)
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struct callout arptimer_ch;
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/* revarp state */
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struct in_addr myip, srv_ip;
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int myip_initialized = 0;
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int revarp_in_progress = 0;
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struct ifnet *myip_ifp = NULL;
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#ifdef DDB
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static void db_print_sa(const struct sockaddr *);
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static void db_print_ifa(struct ifaddr *);
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static void db_print_llinfo(void *);
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static int db_show_rtentry(struct rtentry *, void *);
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#endif
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static int arp_drainwanted;
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static int log_movements = 1;
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static int log_permanent_modify = 1;
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static int log_wrong_iface = 1;
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/*
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* this should be elsewhere.
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*/
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static char *
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lla_snprintf(u_int8_t *, int);
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static char *
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lla_snprintf(u_int8_t *adrp, int len)
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{
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#define NUMBUFS 3
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static char buf[NUMBUFS][16*3];
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static int bnum = 0;
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int i;
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char *p;
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p = buf[bnum];
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*p++ = hexdigits[(*adrp)>>4];
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*p++ = hexdigits[(*adrp++)&0xf];
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for (i=1; i<len && i<16; i++) {
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*p++ = ':';
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*p++ = hexdigits[(*adrp)>>4];
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*p++ = hexdigits[(*adrp++)&0xf];
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}
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*p = 0;
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p = buf[bnum];
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bnum = (bnum + 1) % NUMBUFS;
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return p;
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}
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DOMAIN_DEFINE(arpdomain); /* forward declare and add to link set */
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static void
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arp_fasttimo(void)
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{
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if (arp_drainwanted) {
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arp_drain();
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arp_drainwanted = 0;
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}
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}
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const struct protosw arpsw[] = {
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{ .pr_type = 0,
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.pr_domain = &arpdomain,
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.pr_protocol = 0,
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.pr_flags = 0,
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.pr_input = 0,
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.pr_output = 0,
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.pr_ctlinput = 0,
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.pr_ctloutput = 0,
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.pr_usrreqs = 0,
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.pr_init = arp_init,
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.pr_fasttimo = arp_fasttimo,
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.pr_slowtimo = 0,
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.pr_drain = arp_drainstub,
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}
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};
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struct domain arpdomain = {
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.dom_family = PF_ARP,
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.dom_name = "arp",
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.dom_protosw = arpsw,
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.dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)],
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};
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/*
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* ARP table locking.
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*
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* to prevent lossage vs. the arp_drain routine (which may be called at
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* any time, including in a device driver context), we do two things:
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*
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* 1) manipulation of la->la_hold is done at splnet() (for all of
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* about two instructions).
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*
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* 2) manipulation of the arp table's linked list is done under the
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* protection of the ARP_LOCK; if arp_drain() or arptimer is called
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* while the arp table is locked, we punt and try again later.
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*/
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static int arp_locked;
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static inline int arp_lock_try(int);
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static inline void arp_unlock(void);
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static inline int
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arp_lock_try(int recurse)
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{
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int s;
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/*
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* Use splvm() -- we're blocking things that would cause
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* mbuf allocation.
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*/
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s = splvm();
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if (!recurse && arp_locked) {
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splx(s);
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return 0;
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}
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arp_locked++;
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splx(s);
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return 1;
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}
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static inline void
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arp_unlock(void)
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{
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int s;
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s = splvm();
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arp_locked--;
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splx(s);
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}
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#ifdef DIAGNOSTIC
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#define ARP_LOCK(recurse) \
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do { \
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if (arp_lock_try(recurse) == 0) { \
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printf("%s:%d: arp already locked\n", __FILE__, __LINE__); \
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panic("arp_lock"); \
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} \
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} while (/*CONSTCOND*/ 0)
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#define ARP_LOCK_CHECK() \
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do { \
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if (arp_locked == 0) { \
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printf("%s:%d: arp lock not held\n", __FILE__, __LINE__); \
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panic("arp lock check"); \
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} \
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} while (/*CONSTCOND*/ 0)
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#else
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#define ARP_LOCK(x) (void) arp_lock_try(x)
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#define ARP_LOCK_CHECK() /* nothing */
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#endif
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#define ARP_UNLOCK() arp_unlock()
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static void sysctl_net_inet_arp_setup(struct sysctllog **);
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void
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arp_init(void)
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{
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sysctl_net_inet_arp_setup(NULL);
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arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS);
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}
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static void
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arp_drainstub(void)
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{
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arp_drainwanted = 1;
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}
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/*
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* ARP protocol drain routine. Called when memory is in short supply.
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* Called at splvm(); don't acquire softnet_lock as can be called from
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* hardware interrupt handlers.
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*/
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void
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arp_drain(void)
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{
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struct llinfo_arp *la, *nla;
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int count = 0;
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struct mbuf *mold;
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KERNEL_LOCK(1, NULL);
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if (arp_lock_try(0) == 0) {
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KERNEL_UNLOCK_ONE(NULL);
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return;
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}
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for (la = LIST_FIRST(&llinfo_arp); la != NULL; la = nla) {
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nla = LIST_NEXT(la, la_list);
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mold = la->la_hold;
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la->la_hold = 0;
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if (mold) {
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m_freem(mold);
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count++;
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}
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}
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ARP_UNLOCK();
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ARP_STATADD(ARP_STAT_DFRDROPPED, count);
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KERNEL_UNLOCK_ONE(NULL);
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}
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/*
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* Timeout routine. Age arp_tab entries periodically.
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*/
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/* ARGSUSED */
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static void
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arptimer(void *arg)
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{
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struct llinfo_arp *la, *nla;
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mutex_enter(softnet_lock);
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KERNEL_LOCK(1, NULL);
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if (arp_lock_try(0) == 0) {
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/* get it later.. */
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KERNEL_UNLOCK_ONE(NULL);
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mutex_exit(softnet_lock);
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return;
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}
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callout_reset(&arptimer_ch, arpt_prune * hz, arptimer, NULL);
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for (la = LIST_FIRST(&llinfo_arp); la != NULL; la = nla) {
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struct rtentry *rt = la->la_rt;
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nla = LIST_NEXT(la, la_list);
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if (rt->rt_expire == 0)
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continue;
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if ((rt->rt_expire - time_second) < arpt_refresh &&
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rt->rt_pksent > (time_second - arpt_keep)) {
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/*
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* If the entry has been used during since last
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* refresh, try to renew it before deleting.
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*/
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arprequest(rt->rt_ifp,
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&satocsin(rt->rt_ifa->ifa_addr)->sin_addr,
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&satocsin(rt_getkey(rt))->sin_addr,
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CLLADDR(rt->rt_ifp->if_sadl));
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} else if (rt->rt_expire <= time_second)
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arptfree(la); /* timer has expired; clear */
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}
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ARP_UNLOCK();
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KERNEL_UNLOCK_ONE(NULL);
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mutex_exit(softnet_lock);
|
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}
|
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|
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/*
|
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* We set the gateway for RTF_CLONING routes to a "prototype"
|
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* link-layer sockaddr whose interface type (if_type) and interface
|
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* index (if_index) fields are prepared.
|
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*/
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static struct sockaddr *
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arp_setgate(struct rtentry *rt, struct sockaddr *gate,
|
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const struct sockaddr *netmask)
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{
|
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const struct ifnet *ifp = rt->rt_ifp;
|
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uint8_t namelen = strlen(ifp->if_xname);
|
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uint8_t addrlen = ifp->if_addrlen;
|
||
|
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/*
|
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* XXX: If this is a manually added route to interface
|
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* such as older version of routed or gated might provide,
|
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* restore cloning bit.
|
||
*/
|
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if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL &&
|
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satocsin(netmask)->sin_addr.s_addr != 0xffffffff)
|
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rt->rt_flags |= RTF_CLONING;
|
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if (rt->rt_flags & RTF_CLONING) {
|
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union {
|
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struct sockaddr sa;
|
||
struct sockaddr_storage ss;
|
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struct sockaddr_dl sdl;
|
||
} u;
|
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/*
|
||
* Case 1: This route should come from a route to iface.
|
||
*/
|
||
sockaddr_dl_init(&u.sdl, sizeof(u.ss),
|
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ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen);
|
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rt_setgate(rt, &u.sa);
|
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gate = rt->rt_gateway;
|
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}
|
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return gate;
|
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}
|
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|
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/*
|
||
* Parallel to llc_rtrequest.
|
||
*/
|
||
void
|
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arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info)
|
||
{
|
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struct sockaddr *gate = rt->rt_gateway;
|
||
struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo;
|
||
size_t allocsize;
|
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struct mbuf *mold;
|
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int s;
|
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struct in_ifaddr *ia;
|
||
struct ifaddr *ifa;
|
||
struct ifnet *ifp = rt->rt_ifp;
|
||
|
||
if (!arpinit_done) {
|
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arpinit_done = 1;
|
||
/*
|
||
* We generate expiration times from time_second
|
||
* so avoid accidentally creating permanent routes.
|
||
*/
|
||
if (time_second == 0) {
|
||
struct timespec ts;
|
||
ts.tv_sec = 1;
|
||
ts.tv_nsec = 0;
|
||
tc_setclock(&ts);
|
||
}
|
||
callout_init(&arptimer_ch, CALLOUT_MPSAFE);
|
||
callout_reset(&arptimer_ch, hz, arptimer, NULL);
|
||
}
|
||
|
||
if (req == RTM_LLINFO_UPD) {
|
||
struct in_addr *in;
|
||
|
||
if ((ifa = info->rti_ifa) == NULL)
|
||
return;
|
||
|
||
in = &ifatoia(ifa)->ia_addr.sin_addr;
|
||
|
||
arprequest(ifa->ifa_ifp, in, in,
|
||
CLLADDR(ifa->ifa_ifp->if_sadl));
|
||
return;
|
||
}
|
||
|
||
if ((rt->rt_flags & RTF_GATEWAY) != 0) {
|
||
if (req != RTM_ADD)
|
||
return;
|
||
|
||
/*
|
||
* linklayers with particular link MTU limitation.
|
||
*/
|
||
switch(ifp->if_type) {
|
||
#if NFDDI > 0
|
||
case IFT_FDDI:
|
||
if (ifp->if_mtu > FDDIIPMTU)
|
||
rt->rt_rmx.rmx_mtu = FDDIIPMTU;
|
||
break;
|
||
#endif
|
||
#if NARC > 0
|
||
case IFT_ARCNET:
|
||
{
|
||
int arcipifmtu;
|
||
|
||
if (ifp->if_flags & IFF_LINK0)
|
||
arcipifmtu = arc_ipmtu;
|
||
else
|
||
arcipifmtu = ARCMTU;
|
||
if (ifp->if_mtu > arcipifmtu)
|
||
rt->rt_rmx.rmx_mtu = arcipifmtu;
|
||
break;
|
||
}
|
||
#endif
|
||
}
|
||
return;
|
||
}
|
||
|
||
ARP_LOCK(1); /* we may already be locked here. */
|
||
|
||
switch (req) {
|
||
case RTM_SETGATE:
|
||
gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]);
|
||
break;
|
||
case RTM_ADD:
|
||
gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]);
|
||
if (rt->rt_flags & RTF_CLONING) {
|
||
/*
|
||
* Give this route an expiration time, even though
|
||
* it's a "permanent" route, so that routes cloned
|
||
* from it do not need their expiration time set.
|
||
*/
|
||
rt->rt_expire = time_second;
|
||
/*
|
||
* linklayers with particular link MTU limitation.
|
||
*/
|
||
switch (ifp->if_type) {
|
||
#if NFDDI > 0
|
||
case IFT_FDDI:
|
||
if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 &&
|
||
(rt->rt_rmx.rmx_mtu > FDDIIPMTU ||
|
||
(rt->rt_rmx.rmx_mtu == 0 &&
|
||
ifp->if_mtu > FDDIIPMTU)))
|
||
rt->rt_rmx.rmx_mtu = FDDIIPMTU;
|
||
break;
|
||
#endif
|
||
#if NARC > 0
|
||
case IFT_ARCNET:
|
||
{
|
||
int arcipifmtu;
|
||
if (ifp->if_flags & IFF_LINK0)
|
||
arcipifmtu = arc_ipmtu;
|
||
else
|
||
arcipifmtu = ARCMTU;
|
||
|
||
if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 &&
|
||
(rt->rt_rmx.rmx_mtu > arcipifmtu ||
|
||
(rt->rt_rmx.rmx_mtu == 0 &&
|
||
ifp->if_mtu > arcipifmtu)))
|
||
rt->rt_rmx.rmx_mtu = arcipifmtu;
|
||
break;
|
||
}
|
||
#endif
|
||
}
|
||
break;
|
||
}
|
||
/* Announce a new entry if requested. */
|
||
if (rt->rt_flags & RTF_ANNOUNCE) {
|
||
arprequest(ifp,
|
||
&satocsin(rt_getkey(rt))->sin_addr,
|
||
&satocsin(rt_getkey(rt))->sin_addr,
|
||
CLLADDR(satocsdl(gate)));
|
||
}
|
||
/*FALLTHROUGH*/
|
||
case RTM_RESOLVE:
|
||
if (gate->sa_family != AF_LINK ||
|
||
gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) {
|
||
log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n");
|
||
break;
|
||
}
|
||
satosdl(gate)->sdl_type = ifp->if_type;
|
||
satosdl(gate)->sdl_index = ifp->if_index;
|
||
if (la != NULL)
|
||
break; /* This happens on a route change */
|
||
/*
|
||
* Case 2: This route may come from cloning, or a manual route
|
||
* add with a LL address.
|
||
*/
|
||
switch (ifp->if_type) {
|
||
#if NTOKEN > 0
|
||
case IFT_ISO88025:
|
||
allocsize = sizeof(*la) + sizeof(struct token_rif);
|
||
break;
|
||
#endif /* NTOKEN > 0 */
|
||
default:
|
||
allocsize = sizeof(*la);
|
||
}
|
||
R_Malloc(la, struct llinfo_arp *, allocsize);
|
||
rt->rt_llinfo = (void *)la;
|
||
if (la == NULL) {
|
||
log(LOG_DEBUG, "arp_rtrequest: malloc failed\n");
|
||
break;
|
||
}
|
||
arp_inuse++, arp_allocated++;
|
||
memset(la, 0, allocsize);
|
||
la->la_rt = rt;
|
||
rt->rt_flags |= RTF_LLINFO;
|
||
LIST_INSERT_HEAD(&llinfo_arp, la, la_list);
|
||
|
||
INADDR_TO_IA(satocsin(rt_getkey(rt))->sin_addr, ia);
|
||
while (ia && ia->ia_ifp != ifp)
|
||
NEXT_IA_WITH_SAME_ADDR(ia);
|
||
if (ia) {
|
||
/*
|
||
* This test used to be
|
||
* if (lo0ifp->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.
|
||
*
|
||
* In 4.4BSD, the above "if" statement checked
|
||
* rt->rt_ifa against rt_getkey(rt). It was changed
|
||
* to the current form so that we can provide a
|
||
* better support for multiple IPv4 addresses on a
|
||
* interface.
|
||
*/
|
||
rt->rt_expire = 0;
|
||
if (sockaddr_dl_init(satosdl(gate), gate->sa_len,
|
||
ifp->if_index, ifp->if_type, NULL, 0,
|
||
CLLADDR(ifp->if_sadl), ifp->if_addrlen) == NULL) {
|
||
panic("%s(%s): sockaddr_dl_init cannot fail",
|
||
__func__, ifp->if_xname);
|
||
}
|
||
if (useloopback)
|
||
ifp = rt->rt_ifp = lo0ifp;
|
||
/*
|
||
* make sure to set rt->rt_ifa to the interface
|
||
* address we are using, otherwise we will have trouble
|
||
* with source address selection.
|
||
*/
|
||
ifa = &ia->ia_ifa;
|
||
if (ifa != rt->rt_ifa)
|
||
rt_replace_ifa(rt, ifa);
|
||
}
|
||
break;
|
||
|
||
case RTM_DELETE:
|
||
if (la == NULL)
|
||
break;
|
||
arp_inuse--;
|
||
LIST_REMOVE(la, la_list);
|
||
rt->rt_llinfo = NULL;
|
||
rt->rt_flags &= ~RTF_LLINFO;
|
||
|
||
s = splnet();
|
||
mold = la->la_hold;
|
||
la->la_hold = 0;
|
||
splx(s);
|
||
|
||
if (mold)
|
||
m_freem(mold);
|
||
|
||
Free((void *)la);
|
||
}
|
||
ARP_UNLOCK();
|
||
}
|
||
|
||
/*
|
||
* Broadcast an ARP request. Caller specifies:
|
||
* - arp header source ip address
|
||
* - arp header target ip address
|
||
* - arp header source ethernet address
|
||
*/
|
||
void
|
||
arprequest(struct ifnet *ifp,
|
||
const struct in_addr *sip, const struct in_addr *tip,
|
||
const u_int8_t *enaddr)
|
||
{
|
||
struct mbuf *m;
|
||
struct arphdr *ah;
|
||
struct sockaddr sa;
|
||
uint64_t *arps;
|
||
|
||
if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
|
||
return;
|
||
MCLAIM(m, &arpdomain.dom_mowner);
|
||
switch (ifp->if_type) {
|
||
case IFT_IEEE1394:
|
||
m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) +
|
||
ifp->if_addrlen;
|
||
break;
|
||
default:
|
||
m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) +
|
||
2 * ifp->if_addrlen;
|
||
break;
|
||
}
|
||
m->m_pkthdr.len = m->m_len;
|
||
MH_ALIGN(m, m->m_len);
|
||
ah = mtod(m, struct arphdr *);
|
||
memset(ah, 0, m->m_len);
|
||
switch (ifp->if_type) {
|
||
case IFT_IEEE1394: /* RFC2734 */
|
||
/* fill it now for ar_tpa computation */
|
||
ah->ar_hrd = htons(ARPHRD_IEEE1394);
|
||
break;
|
||
default:
|
||
/* ifp->if_output will fill ar_hrd */
|
||
break;
|
||
}
|
||
ah->ar_pro = htons(ETHERTYPE_IP);
|
||
ah->ar_hln = ifp->if_addrlen; /* hardware address length */
|
||
ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
|
||
ah->ar_op = htons(ARPOP_REQUEST);
|
||
memcpy(ar_sha(ah), enaddr, ah->ar_hln);
|
||
memcpy(ar_spa(ah), sip, ah->ar_pln);
|
||
memcpy(ar_tpa(ah), tip, ah->ar_pln);
|
||
sa.sa_family = AF_ARP;
|
||
sa.sa_len = 2;
|
||
m->m_flags |= M_BCAST;
|
||
arps = ARP_STAT_GETREF();
|
||
arps[ARP_STAT_SNDTOTAL]++;
|
||
arps[ARP_STAT_SENDREQUEST]++;
|
||
ARP_STAT_PUTREF();
|
||
(*ifp->if_output)(ifp, m, &sa, NULL);
|
||
}
|
||
|
||
/*
|
||
* 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 ifnet *ifp, struct rtentry *rt, struct mbuf *m,
|
||
const struct sockaddr *dst, u_char *desten)
|
||
{
|
||
struct llinfo_arp *la;
|
||
const struct sockaddr_dl *sdl;
|
||
struct mbuf *mold;
|
||
int s;
|
||
|
||
if ((la = arplookup1(m, &satocsin(dst)->sin_addr, 1, 0, rt)) != NULL)
|
||
rt = la->la_rt;
|
||
|
||
if (la == NULL || rt == NULL) {
|
||
ARP_STATINC(ARP_STAT_ALLOCFAIL);
|
||
log(LOG_DEBUG,
|
||
"arpresolve: can't allocate llinfo on %s for %s\n",
|
||
ifp->if_xname, in_fmtaddr(satocsin(dst)->sin_addr));
|
||
m_freem(m);
|
||
return 0;
|
||
}
|
||
sdl = satocsdl(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 > time_second) &&
|
||
sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
|
||
memcpy(desten, CLLADDR(sdl),
|
||
min(sdl->sdl_alen, ifp->if_addrlen));
|
||
rt->rt_pksent = time_second; /* Time for last pkt sent */
|
||
return 1;
|
||
}
|
||
/*
|
||
* There is an arptab entry, but no ethernet address
|
||
* response yet. Replace the held mbuf with this
|
||
* latest one.
|
||
*/
|
||
|
||
ARP_STATINC(ARP_STAT_DFRTOTAL);
|
||
s = splnet();
|
||
mold = la->la_hold;
|
||
la->la_hold = m;
|
||
splx(s);
|
||
|
||
if (mold) {
|
||
ARP_STATINC(ARP_STAT_DFRDROPPED);
|
||
m_freem(mold);
|
||
}
|
||
|
||
/*
|
||
* Re-send the ARP request when appropriate.
|
||
*/
|
||
#ifdef DIAGNOSTIC
|
||
if (rt->rt_expire == 0) {
|
||
/* This should never happen. (Should it? -gwr) */
|
||
printf("arpresolve: unresolved and rt_expire == 0\n");
|
||
/* Set expiration time to now (expired). */
|
||
rt->rt_expire = time_second;
|
||
}
|
||
#endif
|
||
if (rt->rt_expire) {
|
||
rt->rt_flags &= ~RTF_REJECT;
|
||
if (la->la_asked == 0 || rt->rt_expire != time_second) {
|
||
rt->rt_expire = time_second;
|
||
if (la->la_asked++ < arp_maxtries) {
|
||
arprequest(ifp,
|
||
&satocsin(rt->rt_ifa->ifa_addr)->sin_addr,
|
||
&satocsin(dst)->sin_addr,
|
||
#if NCARP > 0
|
||
(rt->rt_ifp->if_type == IFT_CARP) ?
|
||
CLLADDR(rt->rt_ifp->if_sadl):
|
||
#endif
|
||
CLLADDR(ifp->if_sadl));
|
||
} 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;
|
||
int arplen;
|
||
|
||
mutex_enter(softnet_lock);
|
||
KERNEL_LOCK(1, NULL);
|
||
while (arpintrq.ifq_head) {
|
||
s = splnet();
|
||
IF_DEQUEUE(&arpintrq, m);
|
||
splx(s);
|
||
if (m == 0 || (m->m_flags & M_PKTHDR) == 0)
|
||
panic("arpintr");
|
||
|
||
MCLAIM(m, &arpdomain.dom_mowner);
|
||
ARP_STATINC(ARP_STAT_RCVTOTAL);
|
||
|
||
/*
|
||
* First, make sure we have at least struct arphdr.
|
||
*/
|
||
if (m->m_len < sizeof(struct arphdr) ||
|
||
(ar = mtod(m, struct arphdr *)) == NULL)
|
||
goto badlen;
|
||
|
||
switch (m->m_pkthdr.rcvif->if_type) {
|
||
case IFT_IEEE1394:
|
||
arplen = sizeof(struct arphdr) +
|
||
ar->ar_hln + 2 * ar->ar_pln;
|
||
break;
|
||
default:
|
||
arplen = sizeof(struct arphdr) +
|
||
2 * ar->ar_hln + 2 * ar->ar_pln;
|
||
break;
|
||
}
|
||
|
||
if (/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */
|
||
m->m_len >= arplen)
|
||
switch (ntohs(ar->ar_pro)) {
|
||
case ETHERTYPE_IP:
|
||
case ETHERTYPE_IPTRAILERS:
|
||
in_arpinput(m);
|
||
continue;
|
||
default:
|
||
ARP_STATINC(ARP_STAT_RCVBADPROTO);
|
||
}
|
||
else {
|
||
badlen:
|
||
ARP_STATINC(ARP_STAT_RCVBADLEN);
|
||
}
|
||
m_freem(m);
|
||
}
|
||
KERNEL_UNLOCK_ONE(NULL);
|
||
mutex_exit(softnet_lock);
|
||
}
|
||
|
||
/*
|
||
* 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 arphdr *ah;
|
||
struct ifnet *ifp = m->m_pkthdr.rcvif;
|
||
struct llinfo_arp *la = NULL;
|
||
struct rtentry *rt;
|
||
struct in_ifaddr *ia;
|
||
#if NBRIDGE > 0
|
||
struct in_ifaddr *bridge_ia = NULL;
|
||
#endif
|
||
#if NCARP > 0
|
||
u_int32_t count = 0, index = 0;
|
||
#endif
|
||
struct sockaddr_dl *sdl;
|
||
struct sockaddr sa;
|
||
struct in_addr isaddr, itaddr, myaddr;
|
||
int op;
|
||
struct mbuf *mold;
|
||
void *tha;
|
||
int s;
|
||
uint64_t *arps;
|
||
|
||
if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT)))
|
||
goto out;
|
||
ah = mtod(m, struct arphdr *);
|
||
op = ntohs(ah->ar_op);
|
||
|
||
/*
|
||
* Fix up ah->ar_hrd if necessary, before using ar_tha() or
|
||
* ar_tpa().
|
||
*/
|
||
switch (ifp->if_type) {
|
||
case IFT_IEEE1394:
|
||
if (ntohs(ah->ar_hrd) == ARPHRD_IEEE1394)
|
||
;
|
||
else {
|
||
/* XXX this is to make sure we compute ar_tha right */
|
||
/* XXX check ar_hrd more strictly? */
|
||
ah->ar_hrd = htons(ARPHRD_IEEE1394);
|
||
}
|
||
break;
|
||
default:
|
||
/* XXX check ar_hrd? */
|
||
break;
|
||
}
|
||
|
||
memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
|
||
memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
|
||
|
||
if (m->m_flags & (M_BCAST|M_MCAST))
|
||
ARP_STATINC(ARP_STAT_RCVMCAST);
|
||
|
||
/*
|
||
* If the target IP address is zero, ignore the packet.
|
||
* This prevents the code below from tring to answer
|
||
* when we are using IP address zero (booting).
|
||
*/
|
||
if (in_nullhost(itaddr)) {
|
||
ARP_STATINC(ARP_STAT_RCVZEROTPA);
|
||
goto out;
|
||
}
|
||
|
||
|
||
/*
|
||
* Search for a matching interface address
|
||
* or any address on the interface to use
|
||
* as a dummy address in the rest of this function
|
||
*/
|
||
|
||
INADDR_TO_IA(itaddr, ia);
|
||
while (ia != NULL) {
|
||
#if NCARP > 0
|
||
if (ia->ia_ifp->if_type == IFT_CARP &&
|
||
((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) ==
|
||
(IFF_UP|IFF_RUNNING))) {
|
||
index++;
|
||
if (ia->ia_ifp == m->m_pkthdr.rcvif &&
|
||
carp_iamatch(ia, ar_sha(ah),
|
||
&count, index)) {
|
||
break;
|
||
}
|
||
} else
|
||
#endif
|
||
if (ia->ia_ifp == m->m_pkthdr.rcvif)
|
||
break;
|
||
#if NBRIDGE > 0
|
||
/*
|
||
* If the interface we received the packet on
|
||
* is part of a bridge, check to see if we need
|
||
* to "bridge" the packet to ourselves at this
|
||
* layer. Note we still prefer a perfect match,
|
||
* but allow this weaker match if necessary.
|
||
*/
|
||
if (m->m_pkthdr.rcvif->if_bridge != NULL &&
|
||
m->m_pkthdr.rcvif->if_bridge == ia->ia_ifp->if_bridge)
|
||
bridge_ia = ia;
|
||
#endif /* NBRIDGE > 0 */
|
||
|
||
NEXT_IA_WITH_SAME_ADDR(ia);
|
||
}
|
||
|
||
#if NBRIDGE > 0
|
||
if (ia == NULL && bridge_ia != NULL) {
|
||
ia = bridge_ia;
|
||
ifp = bridge_ia->ia_ifp;
|
||
}
|
||
#endif
|
||
|
||
if (ia == NULL) {
|
||
INADDR_TO_IA(isaddr, ia);
|
||
while ((ia != NULL) && ia->ia_ifp != m->m_pkthdr.rcvif)
|
||
NEXT_IA_WITH_SAME_ADDR(ia);
|
||
|
||
if (ia == NULL) {
|
||
IFP_TO_IA(ifp, ia);
|
||
if (ia == NULL) {
|
||
ARP_STATINC(ARP_STAT_RCVNOINT);
|
||
goto out;
|
||
}
|
||
}
|
||
}
|
||
|
||
myaddr = ia->ia_addr.sin_addr;
|
||
|
||
/* XXX checks for bridge case? */
|
||
if (!memcmp(ar_sha(ah), CLLADDR(ifp->if_sadl), ifp->if_addrlen)) {
|
||
ARP_STATINC(ARP_STAT_RCVLOCALSHA);
|
||
goto out; /* it's from me, ignore it. */
|
||
}
|
||
|
||
/* XXX checks for bridge case? */
|
||
if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
|
||
ARP_STATINC(ARP_STAT_RCVBCASTSHA);
|
||
log(LOG_ERR,
|
||
"%s: arp: link address is broadcast for IP address %s!\n",
|
||
ifp->if_xname, in_fmtaddr(isaddr));
|
||
goto out;
|
||
}
|
||
|
||
/*
|
||
* If the source IP address is zero, this is an RFC 5227 ARP probe
|
||
*/
|
||
if (in_nullhost(isaddr)) {
|
||
ARP_STATINC(ARP_STAT_RCVZEROSPA);
|
||
goto reply;
|
||
}
|
||
|
||
if (in_hosteq(isaddr, myaddr)) {
|
||
ARP_STATINC(ARP_STAT_RCVLOCALSPA);
|
||
log(LOG_ERR,
|
||
"duplicate IP address %s sent from link address %s\n",
|
||
in_fmtaddr(isaddr), lla_snprintf(ar_sha(ah), ah->ar_hln));
|
||
itaddr = myaddr;
|
||
goto reply;
|
||
}
|
||
la = arplookup(m, &isaddr, in_hosteq(itaddr, myaddr), 0);
|
||
if (la != NULL && (rt = la->la_rt) && (sdl = satosdl(rt->rt_gateway))) {
|
||
if (sdl->sdl_alen &&
|
||
memcmp(ar_sha(ah), CLLADDR(sdl), sdl->sdl_alen)) {
|
||
if (rt->rt_flags & RTF_STATIC) {
|
||
ARP_STATINC(ARP_STAT_RCVOVERPERM);
|
||
if (!log_permanent_modify)
|
||
goto out;
|
||
log(LOG_INFO,
|
||
"%s tried to overwrite permanent arp info"
|
||
" for %s\n",
|
||
lla_snprintf(ar_sha(ah), ah->ar_hln),
|
||
in_fmtaddr(isaddr));
|
||
goto out;
|
||
} else if (rt->rt_ifp != ifp) {
|
||
ARP_STATINC(ARP_STAT_RCVOVERINT);
|
||
if (!log_wrong_iface)
|
||
goto out;
|
||
log(LOG_INFO,
|
||
"%s on %s tried to overwrite "
|
||
"arp info for %s on %s\n",
|
||
lla_snprintf(ar_sha(ah), ah->ar_hln),
|
||
ifp->if_xname, in_fmtaddr(isaddr),
|
||
rt->rt_ifp->if_xname);
|
||
goto out;
|
||
} else {
|
||
ARP_STATINC(ARP_STAT_RCVOVER);
|
||
if (log_movements)
|
||
log(LOG_INFO, "arp info overwritten "
|
||
"for %s by %s\n",
|
||
in_fmtaddr(isaddr),
|
||
lla_snprintf(ar_sha(ah),
|
||
ah->ar_hln));
|
||
}
|
||
}
|
||
/*
|
||
* sanity check for the address length.
|
||
* XXX this does not work for protocols with variable address
|
||
* length. -is
|
||
*/
|
||
if (sdl->sdl_alen &&
|
||
sdl->sdl_alen != ah->ar_hln) {
|
||
ARP_STATINC(ARP_STAT_RCVLENCHG);
|
||
log(LOG_WARNING,
|
||
"arp from %s: new addr len %d, was %d\n",
|
||
in_fmtaddr(isaddr), ah->ar_hln, sdl->sdl_alen);
|
||
}
|
||
if (ifp->if_addrlen != ah->ar_hln) {
|
||
ARP_STATINC(ARP_STAT_RCVBADLEN);
|
||
log(LOG_WARNING,
|
||
"arp from %s: addr len: new %d, i/f %d (ignored)\n",
|
||
in_fmtaddr(isaddr), ah->ar_hln,
|
||
ifp->if_addrlen);
|
||
goto reply;
|
||
}
|
||
#if NTOKEN > 0
|
||
/*
|
||
* XXX uses m_data and assumes the complete answer including
|
||
* XXX token-ring headers is in the same buf
|
||
*/
|
||
if (ifp->if_type == IFT_ISO88025) {
|
||
struct token_header *trh;
|
||
|
||
trh = (struct token_header *)M_TRHSTART(m);
|
||
if (trh->token_shost[0] & TOKEN_RI_PRESENT) {
|
||
struct token_rif *rif;
|
||
size_t riflen;
|
||
|
||
rif = TOKEN_RIF(trh);
|
||
riflen = (ntohs(rif->tr_rcf) &
|
||
TOKEN_RCF_LEN_MASK) >> 8;
|
||
|
||
if (riflen > 2 &&
|
||
riflen < sizeof(struct token_rif) &&
|
||
(riflen & 1) == 0) {
|
||
rif->tr_rcf ^= htons(TOKEN_RCF_DIRECTION);
|
||
rif->tr_rcf &= htons(~TOKEN_RCF_BROADCAST_MASK);
|
||
memcpy(TOKEN_RIF(la), rif, riflen);
|
||
}
|
||
}
|
||
}
|
||
#endif /* NTOKEN > 0 */
|
||
(void)sockaddr_dl_setaddr(sdl, sdl->sdl_len, ar_sha(ah),
|
||
ah->ar_hln);
|
||
if (rt->rt_expire)
|
||
rt->rt_expire = time_second + arpt_keep;
|
||
rt->rt_flags &= ~RTF_REJECT;
|
||
la->la_asked = 0;
|
||
|
||
s = splnet();
|
||
mold = la->la_hold;
|
||
la->la_hold = 0;
|
||
splx(s);
|
||
|
||
if (mold) {
|
||
ARP_STATINC(ARP_STAT_DFRSENT);
|
||
(*ifp->if_output)(ifp, mold, rt_getkey(rt), rt);
|
||
}
|
||
}
|
||
reply:
|
||
if (op != ARPOP_REQUEST) {
|
||
if (op == ARPOP_REPLY)
|
||
ARP_STATINC(ARP_STAT_RCVREPLY);
|
||
out:
|
||
m_freem(m);
|
||
return;
|
||
}
|
||
ARP_STATINC(ARP_STAT_RCVREQUEST);
|
||
if (in_hosteq(itaddr, myaddr)) {
|
||
/* I am the target */
|
||
tha = ar_tha(ah);
|
||
if (tha)
|
||
memcpy(tha, ar_sha(ah), ah->ar_hln);
|
||
memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln);
|
||
} else {
|
||
la = arplookup(m, &itaddr, 0, SIN_PROXY);
|
||
if (la == NULL)
|
||
goto out;
|
||
rt = la->la_rt;
|
||
if (rt->rt_ifp->if_type == IFT_CARP &&
|
||
m->m_pkthdr.rcvif->if_type != IFT_CARP)
|
||
goto out;
|
||
tha = ar_tha(ah);
|
||
if (tha)
|
||
memcpy(tha, ar_sha(ah), ah->ar_hln);
|
||
sdl = satosdl(rt->rt_gateway);
|
||
memcpy(ar_sha(ah), CLLADDR(sdl), ah->ar_hln);
|
||
}
|
||
|
||
memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
|
||
memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
|
||
ah->ar_op = htons(ARPOP_REPLY);
|
||
ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
|
||
switch (ifp->if_type) {
|
||
case IFT_IEEE1394:
|
||
/*
|
||
* ieee1394 arp reply is broadcast
|
||
*/
|
||
m->m_flags &= ~M_MCAST;
|
||
m->m_flags |= M_BCAST;
|
||
m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln;
|
||
break;
|
||
|
||
default:
|
||
m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */
|
||
m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);
|
||
break;
|
||
}
|
||
m->m_pkthdr.len = m->m_len;
|
||
sa.sa_family = AF_ARP;
|
||
sa.sa_len = 2;
|
||
arps = ARP_STAT_GETREF();
|
||
arps[ARP_STAT_SNDTOTAL]++;
|
||
arps[ARP_STAT_SNDREPLY]++;
|
||
ARP_STAT_PUTREF();
|
||
(*ifp->if_output)(ifp, m, &sa, NULL);
|
||
return;
|
||
}
|
||
|
||
/*
|
||
* Free an arp entry.
|
||
*/
|
||
static void arptfree(struct llinfo_arp *la)
|
||
{
|
||
struct rtentry *rt = la->la_rt;
|
||
struct sockaddr_dl *sdl;
|
||
|
||
ARP_LOCK_CHECK();
|
||
|
||
if (rt == NULL)
|
||
panic("arptfree");
|
||
if (rt->rt_refcnt > 0 && (sdl = satosdl(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_getkey(rt), NULL, rt_mask(rt), 0, NULL);
|
||
}
|
||
|
||
static struct llinfo_arp *
|
||
arplookup(struct mbuf *m, const struct in_addr *addr, int create, int proxy)
|
||
{
|
||
return arplookup1(m, addr, create, proxy, NULL);
|
||
}
|
||
|
||
/*
|
||
* Lookup or enter a new address in arptab.
|
||
*/
|
||
static struct llinfo_arp *
|
||
arplookup1(struct mbuf *m, const struct in_addr *addr, int create, int proxy,
|
||
struct rtentry *rt0)
|
||
{
|
||
struct arphdr *ah;
|
||
struct ifnet *ifp = m->m_pkthdr.rcvif;
|
||
struct rtentry *rt;
|
||
struct sockaddr_inarp sin;
|
||
const char *why = NULL;
|
||
|
||
ah = mtod(m, struct arphdr *);
|
||
if (rt0 == NULL) {
|
||
memset(&sin, 0, sizeof(sin));
|
||
sin.sin_len = sizeof(sin);
|
||
sin.sin_family = AF_INET;
|
||
sin.sin_addr = *addr;
|
||
sin.sin_other = proxy ? SIN_PROXY : 0;
|
||
rt = rtalloc1(sintosa(&sin), create);
|
||
if (rt == NULL)
|
||
return NULL;
|
||
rt->rt_refcnt--;
|
||
} else
|
||
rt = rt0;
|
||
|
||
#define IS_LLINFO(__rt) \
|
||
(((__rt)->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) == RTF_LLINFO && \
|
||
(__rt)->rt_gateway->sa_family == AF_LINK)
|
||
|
||
|
||
if (IS_LLINFO(rt))
|
||
return (struct llinfo_arp *)rt->rt_llinfo;
|
||
|
||
if (create) {
|
||
if (rt->rt_flags & RTF_GATEWAY)
|
||
why = "host is not on local network";
|
||
else if ((rt->rt_flags & RTF_LLINFO) == 0) {
|
||
ARP_STATINC(ARP_STAT_ALLOCFAIL);
|
||
why = "could not allocate llinfo";
|
||
} else
|
||
why = "gateway route is not ours";
|
||
log(LOG_DEBUG, "arplookup: unable to enter address"
|
||
" for %s@%s on %s (%s)\n",
|
||
in_fmtaddr(*addr), lla_snprintf(ar_sha(ah), ah->ar_hln),
|
||
(ifp) ? ifp->if_xname : "null", why);
|
||
if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_CLONED) != 0) {
|
||
rtrequest(RTM_DELETE, rt_getkey(rt),
|
||
rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
|
||
}
|
||
}
|
||
return NULL;
|
||
}
|
||
|
||
int
|
||
arpioctl(u_long cmd, void *data)
|
||
{
|
||
|
||
return EOPNOTSUPP;
|
||
}
|
||
|
||
void
|
||
arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
|
||
{
|
||
struct in_addr *ip;
|
||
|
||
/*
|
||
* Warn the user if another station has this IP address,
|
||
* but only if the interface IP address is not zero.
|
||
*/
|
||
ip = &IA_SIN(ifa)->sin_addr;
|
||
if (!in_nullhost(*ip))
|
||
arprequest(ifp, ip, ip, CLLADDR(ifp->if_sadl));
|
||
|
||
ifa->ifa_rtrequest = arp_rtrequest;
|
||
ifa->ifa_flags |= RTF_CLONING;
|
||
}
|
||
|
||
/*
|
||
* Called from 10 Mb/s Ethernet interrupt handlers
|
||
* when ether packet type ETHERTYPE_REVARP
|
||
* is received. Common length and type checks are done here,
|
||
* then the protocol-specific routine is called.
|
||
*/
|
||
void
|
||
revarpinput(struct mbuf *m)
|
||
{
|
||
struct arphdr *ar;
|
||
|
||
if (m->m_len < sizeof(struct arphdr))
|
||
goto out;
|
||
ar = mtod(m, struct arphdr *);
|
||
#if 0 /* XXX I don't think we need this... and it will prevent other LL */
|
||
if (ntohs(ar->ar_hrd) != ARPHRD_ETHER)
|
||
goto out;
|
||
#endif
|
||
if (m->m_len < sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln))
|
||
goto out;
|
||
switch (ntohs(ar->ar_pro)) {
|
||
case ETHERTYPE_IP:
|
||
case ETHERTYPE_IPTRAILERS:
|
||
in_revarpinput(m);
|
||
return;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
out:
|
||
m_freem(m);
|
||
}
|
||
|
||
/*
|
||
* RARP for Internet protocols on 10 Mb/s Ethernet.
|
||
* Algorithm is that given in RFC 903.
|
||
* We are only using for bootstrap purposes to get an ip address for one of
|
||
* our interfaces. Thus we support no user-interface.
|
||
*
|
||
* Since the contents of the RARP reply are specific to the interface that
|
||
* sent the request, this code must ensure that they are properly associated.
|
||
*
|
||
* Note: also supports ARP via RARP packets, per the RFC.
|
||
*/
|
||
void
|
||
in_revarpinput(struct mbuf *m)
|
||
{
|
||
struct ifnet *ifp;
|
||
struct arphdr *ah;
|
||
void *tha;
|
||
int op;
|
||
|
||
ah = mtod(m, struct arphdr *);
|
||
op = ntohs(ah->ar_op);
|
||
|
||
switch (m->m_pkthdr.rcvif->if_type) {
|
||
case IFT_IEEE1394:
|
||
/* ARP without target hardware address is not supported */
|
||
goto out;
|
||
default:
|
||
break;
|
||
}
|
||
|
||
switch (op) {
|
||
case ARPOP_REQUEST:
|
||
case ARPOP_REPLY: /* per RFC */
|
||
in_arpinput(m);
|
||
return;
|
||
case ARPOP_REVREPLY:
|
||
break;
|
||
case ARPOP_REVREQUEST: /* handled by rarpd(8) */
|
||
default:
|
||
goto out;
|
||
}
|
||
if (!revarp_in_progress)
|
||
goto out;
|
||
ifp = m->m_pkthdr.rcvif;
|
||
if (ifp != myip_ifp) /* !same interface */
|
||
goto out;
|
||
if (myip_initialized)
|
||
goto wake;
|
||
tha = ar_tha(ah);
|
||
if (tha == NULL)
|
||
goto out;
|
||
if (memcmp(tha, CLLADDR(ifp->if_sadl), ifp->if_sadl->sdl_alen))
|
||
goto out;
|
||
memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip));
|
||
memcpy(&myip, ar_tpa(ah), sizeof(myip));
|
||
myip_initialized = 1;
|
||
wake: /* Do wakeup every time in case it was missed. */
|
||
wakeup((void *)&myip);
|
||
|
||
out:
|
||
m_freem(m);
|
||
}
|
||
|
||
/*
|
||
* Send a RARP request for the ip address of the specified interface.
|
||
* The request should be RFC 903-compliant.
|
||
*/
|
||
void
|
||
revarprequest(struct ifnet *ifp)
|
||
{
|
||
struct sockaddr sa;
|
||
struct mbuf *m;
|
||
struct arphdr *ah;
|
||
void *tha;
|
||
|
||
if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
|
||
return;
|
||
MCLAIM(m, &arpdomain.dom_mowner);
|
||
m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) +
|
||
2*ifp->if_addrlen;
|
||
m->m_pkthdr.len = m->m_len;
|
||
MH_ALIGN(m, m->m_len);
|
||
ah = mtod(m, struct arphdr *);
|
||
memset(ah, 0, m->m_len);
|
||
ah->ar_pro = htons(ETHERTYPE_IP);
|
||
ah->ar_hln = ifp->if_addrlen; /* hardware address length */
|
||
ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
|
||
ah->ar_op = htons(ARPOP_REVREQUEST);
|
||
|
||
memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln);
|
||
tha = ar_tha(ah);
|
||
if (tha == NULL) {
|
||
m_free(m);
|
||
return;
|
||
}
|
||
memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln);
|
||
|
||
sa.sa_family = AF_ARP;
|
||
sa.sa_len = 2;
|
||
m->m_flags |= M_BCAST;
|
||
|
||
KERNEL_LOCK(1, NULL);
|
||
(*ifp->if_output)(ifp, m, &sa, NULL);
|
||
KERNEL_UNLOCK_ONE(NULL);
|
||
}
|
||
|
||
/*
|
||
* RARP for the ip address of the specified interface, but also
|
||
* save the ip address of the server that sent the answer.
|
||
* Timeout if no response is received.
|
||
*/
|
||
int
|
||
revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in,
|
||
struct in_addr *clnt_in)
|
||
{
|
||
int result, count = 20;
|
||
|
||
myip_initialized = 0;
|
||
myip_ifp = ifp;
|
||
|
||
revarp_in_progress = 1;
|
||
while (count--) {
|
||
revarprequest(ifp);
|
||
result = tsleep((void *)&myip, PSOCK, "revarp", hz/2);
|
||
if (result != EWOULDBLOCK)
|
||
break;
|
||
}
|
||
revarp_in_progress = 0;
|
||
|
||
if (!myip_initialized)
|
||
return ENETUNREACH;
|
||
|
||
memcpy(serv_in, &srv_ip, sizeof(*serv_in));
|
||
memcpy(clnt_in, &myip, sizeof(*clnt_in));
|
||
return 0;
|
||
}
|
||
|
||
|
||
|
||
#ifdef DDB
|
||
|
||
#include <machine/db_machdep.h>
|
||
#include <ddb/db_interface.h>
|
||
#include <ddb/db_output.h>
|
||
|
||
static void
|
||
db_print_sa(const struct sockaddr *sa)
|
||
{
|
||
int len;
|
||
const u_char *p;
|
||
|
||
if (sa == NULL) {
|
||
db_printf("[NULL]");
|
||
return;
|
||
}
|
||
|
||
p = (const u_char *)sa;
|
||
len = sa->sa_len;
|
||
db_printf("[");
|
||
while (len > 0) {
|
||
db_printf("%d", *p);
|
||
p++; len--;
|
||
if (len) db_printf(",");
|
||
}
|
||
db_printf("]\n");
|
||
}
|
||
|
||
static void
|
||
db_print_ifa(struct ifaddr *ifa)
|
||
{
|
||
if (ifa == NULL)
|
||
return;
|
||
db_printf(" ifa_addr=");
|
||
db_print_sa(ifa->ifa_addr);
|
||
db_printf(" ifa_dsta=");
|
||
db_print_sa(ifa->ifa_dstaddr);
|
||
db_printf(" ifa_mask=");
|
||
db_print_sa(ifa->ifa_netmask);
|
||
db_printf(" flags=0x%x,refcnt=%d,metric=%d\n",
|
||
ifa->ifa_flags,
|
||
ifa->ifa_refcnt,
|
||
ifa->ifa_metric);
|
||
}
|
||
|
||
static void
|
||
db_print_llinfo(void *li)
|
||
{
|
||
struct llinfo_arp *la;
|
||
|
||
if (li == NULL)
|
||
return;
|
||
la = (struct llinfo_arp *)li;
|
||
db_printf(" la_rt=%p la_hold=%p, la_asked=0x%lx\n",
|
||
la->la_rt, la->la_hold, la->la_asked);
|
||
}
|
||
|
||
/*
|
||
* Function to pass to rt_walktree().
|
||
* Return non-zero error to abort walk.
|
||
*/
|
||
static int
|
||
db_show_rtentry(struct rtentry *rt, void *w)
|
||
{
|
||
db_printf("rtentry=%p", rt);
|
||
|
||
db_printf(" flags=0x%x refcnt=%d use=%"PRId64" expire=%"PRId64"\n",
|
||
rt->rt_flags, rt->rt_refcnt,
|
||
rt->rt_use, (uint64_t)rt->rt_expire);
|
||
|
||
db_printf(" key="); db_print_sa(rt_getkey(rt));
|
||
db_printf(" mask="); db_print_sa(rt_mask(rt));
|
||
db_printf(" gw="); db_print_sa(rt->rt_gateway);
|
||
|
||
db_printf(" ifp=%p ", rt->rt_ifp);
|
||
if (rt->rt_ifp)
|
||
db_printf("(%s)", rt->rt_ifp->if_xname);
|
||
else
|
||
db_printf("(NULL)");
|
||
|
||
db_printf(" ifa=%p\n", rt->rt_ifa);
|
||
db_print_ifa(rt->rt_ifa);
|
||
|
||
db_printf(" gwroute=%p llinfo=%p\n",
|
||
rt->rt_gwroute, rt->rt_llinfo);
|
||
db_print_llinfo(rt->rt_llinfo);
|
||
|
||
return 0;
|
||
}
|
||
|
||
/*
|
||
* Function to print all the route trees.
|
||
* Use this from ddb: "show arptab"
|
||
*/
|
||
void
|
||
db_show_arptab(db_expr_t addr, bool have_addr,
|
||
db_expr_t count, const char *modif)
|
||
{
|
||
rt_walktree(AF_INET, db_show_rtentry, NULL);
|
||
}
|
||
#endif
|
||
|
||
static int
|
||
sysctl_net_inet_arp_stats(SYSCTLFN_ARGS)
|
||
{
|
||
|
||
return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS);
|
||
}
|
||
|
||
static void
|
||
sysctl_net_inet_arp_setup(struct sysctllog **clog)
|
||
{
|
||
const struct sysctlnode *node;
|
||
|
||
sysctl_createv(clog, 0, NULL, NULL,
|
||
CTLFLAG_PERMANENT,
|
||
CTLTYPE_NODE, "inet", NULL,
|
||
NULL, 0, NULL, 0,
|
||
CTL_NET, PF_INET, CTL_EOL);
|
||
sysctl_createv(clog, 0, NULL, &node,
|
||
CTLFLAG_PERMANENT,
|
||
CTLTYPE_NODE, "arp",
|
||
SYSCTL_DESCR("Address Resolution Protocol"),
|
||
NULL, 0, NULL, 0,
|
||
CTL_NET, PF_INET, CTL_CREATE, CTL_EOL);
|
||
|
||
sysctl_createv(clog, 0, NULL, NULL,
|
||
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
|
||
CTLTYPE_INT, "prune",
|
||
SYSCTL_DESCR("ARP cache pruning interval in seconds"),
|
||
NULL, 0, &arpt_prune, 0,
|
||
CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
|
||
|
||
sysctl_createv(clog, 0, NULL, NULL,
|
||
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
|
||
CTLTYPE_INT, "keep",
|
||
SYSCTL_DESCR("Valid ARP entry lifetime in seconds"),
|
||
NULL, 0, &arpt_keep, 0,
|
||
CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
|
||
|
||
sysctl_createv(clog, 0, NULL, NULL,
|
||
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
|
||
CTLTYPE_INT, "down",
|
||
SYSCTL_DESCR("Failed ARP entry lifetime in seconds"),
|
||
NULL, 0, &arpt_down, 0,
|
||
CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
|
||
|
||
sysctl_createv(clog, 0, NULL, NULL,
|
||
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
|
||
CTLTYPE_INT, "refresh",
|
||
SYSCTL_DESCR("ARP entry refresh interval"),
|
||
NULL, 0, &arpt_refresh, 0,
|
||
CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
|
||
|
||
sysctl_createv(clog, 0, NULL, NULL,
|
||
CTLFLAG_PERMANENT,
|
||
CTLTYPE_STRUCT, "stats",
|
||
SYSCTL_DESCR("ARP statistics"),
|
||
sysctl_net_inet_arp_stats, 0, NULL, 0,
|
||
CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
|
||
|
||
sysctl_createv(clog, 0, NULL, NULL,
|
||
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
|
||
CTLTYPE_INT, "log_movements",
|
||
SYSCTL_DESCR("log ARP replies from MACs different than"
|
||
" the one in the cache"),
|
||
NULL, 0, &log_movements, 0,
|
||
CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
|
||
|
||
sysctl_createv(clog, 0, NULL, NULL,
|
||
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
|
||
CTLTYPE_INT, "log_permanent_modify",
|
||
SYSCTL_DESCR("log ARP replies from MACs different than"
|
||
" the one in the permanent arp entry"),
|
||
NULL, 0, &log_permanent_modify, 0,
|
||
CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
|
||
|
||
sysctl_createv(clog, 0, NULL, NULL,
|
||
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
|
||
CTLTYPE_INT, "log_wrong_iface",
|
||
SYSCTL_DESCR("log ARP packets arriving on the wrong"
|
||
" interface"),
|
||
NULL, 0, &log_wrong_iface, 0,
|
||
CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
|
||
}
|
||
|
||
#endif /* INET */
|