2575fbb827
and arp were being used. They basically would pass in the mutex to the callout_init. Because they used this method to the callout system, it was possible to "stop" the callout. When flushing the table and you stopped the running callout, the callout_stop code would return 1 indicating that it was going to stop the callout (that was about to run on the callout_wheel blocked by the function calling the stop). Now when 1 was returned, it would lower the reference count one extra time for the stopped timer, then a few lines later delete the memory. Of course the callout_wheel was stuck in the lock code and would then crash since it was accessing freed memory. By using callout_init(c, 1) we always get a 0 back and the reference counting bug does not rear its head. We do have to make a few adjustments to the callouts themselves though to make sure it does the proper thing if rescheduled as well as gets the lock. Commented upon by hiren and sbruno See Phabricator D1777 for more details. Commented upon by hiren and sbruno Reviewed by: adrian, jhb and bz Sponsored by: Netflix Inc.
966 lines
27 KiB
C
966 lines
27 KiB
C
/*-
|
|
* 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
|
|
* 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
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
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* 4. 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 8.1 (Berkeley) 6/10/93
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*/
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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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|
__FBSDID("$FreeBSD$");
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|
|
|
#include "opt_inet.h"
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|
|
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#include <sys/param.h>
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#include <sys/kernel.h>
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|
#include <sys/queue.h>
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|
#include <sys/sysctl.h>
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#include <sys/systm.h>
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|
#include <sys/mbuf.h>
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|
#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <sys/socket.h>
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#include <sys/syslog.h>
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|
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|
#include <net/if.h>
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|
#include <net/if_var.h>
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#include <net/if_dl.h>
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#include <net/if_types.h>
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#include <net/netisr.h>
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#include <net/if_llc.h>
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#include <net/ethernet.h>
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#include <net/route.h>
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#include <net/vnet.h>
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|
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#include <netinet/in.h>
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#include <netinet/in_var.h>
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#include <net/if_llatbl.h>
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#include <netinet/if_ether.h>
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#ifdef INET
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#include <netinet/ip_carp.h>
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#endif
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|
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#include <net/if_arc.h>
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#include <net/iso88025.h>
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|
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#include <security/mac/mac_framework.h>
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|
#define SIN(s) ((const struct sockaddr_in *)(s))
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#define SDL(s) ((struct sockaddr_dl *)s)
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|
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SYSCTL_DECL(_net_link_ether);
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static SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, "");
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static SYSCTL_NODE(_net_link_ether, PF_ARP, arp, CTLFLAG_RW, 0, "");
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|
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|
/* timer values */
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static VNET_DEFINE(int, arpt_keep) = (20*60); /* once resolved, good for 20
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* minutes */
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static VNET_DEFINE(int, arp_maxtries) = 5;
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static VNET_DEFINE(int, arp_proxyall) = 0;
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static VNET_DEFINE(int, arpt_down) = 20; /* keep incomplete entries for
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* 20 seconds */
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VNET_PCPUSTAT_DEFINE(struct arpstat, arpstat); /* ARP statistics, see if_arp.h */
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VNET_PCPUSTAT_SYSINIT(arpstat);
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|
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|
#ifdef VIMAGE
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VNET_PCPUSTAT_SYSUNINIT(arpstat);
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#endif /* VIMAGE */
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|
|
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static VNET_DEFINE(int, arp_maxhold) = 1;
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#define V_arpt_keep VNET(arpt_keep)
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#define V_arpt_down VNET(arpt_down)
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#define V_arp_maxtries VNET(arp_maxtries)
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#define V_arp_proxyall VNET(arp_proxyall)
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#define V_arp_maxhold VNET(arp_maxhold)
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|
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_VNET | CTLFLAG_RW,
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&VNET_NAME(arpt_keep), 0,
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"ARP entry lifetime in seconds");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_VNET | CTLFLAG_RW,
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&VNET_NAME(arp_maxtries), 0,
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"ARP resolution attempts before returning error");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_VNET | CTLFLAG_RW,
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&VNET_NAME(arp_proxyall), 0,
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"Enable proxy ARP for all suitable requests");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, wait, CTLFLAG_VNET | CTLFLAG_RW,
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&VNET_NAME(arpt_down), 0,
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"Incomplete ARP entry lifetime in seconds");
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SYSCTL_VNET_PCPUSTAT(_net_link_ether_arp, OID_AUTO, stats, struct arpstat,
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arpstat, "ARP statistics (struct arpstat, net/if_arp.h)");
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SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxhold, CTLFLAG_VNET | CTLFLAG_RW,
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&VNET_NAME(arp_maxhold), 0,
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"Number of packets to hold per ARP entry");
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|
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|
static void arp_init(void);
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static void arpintr(struct mbuf *);
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static void arptimer(void *);
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#ifdef INET
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static void in_arpinput(struct mbuf *);
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|
#endif
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|
static const struct netisr_handler arp_nh = {
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|
.nh_name = "arp",
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.nh_handler = arpintr,
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.nh_proto = NETISR_ARP,
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.nh_policy = NETISR_POLICY_SOURCE,
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};
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|
#ifdef AF_INET
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/*
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* called by in_scrubprefix() to remove entry from the table when
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* the interface goes away
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*/
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void
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arp_ifscrub(struct ifnet *ifp, uint32_t addr)
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{
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struct sockaddr_in addr4;
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bzero((void *)&addr4, sizeof(addr4));
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addr4.sin_len = sizeof(addr4);
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addr4.sin_family = AF_INET;
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addr4.sin_addr.s_addr = addr;
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IF_AFDATA_RLOCK(ifp);
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lla_lookup(LLTABLE(ifp), (LLE_DELETE | LLE_IFADDR),
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(struct sockaddr *)&addr4);
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IF_AFDATA_RUNLOCK(ifp);
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}
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#endif
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/*
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* Timeout routine. Age arp_tab entries periodically.
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*/
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static void
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arptimer(void *arg)
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{
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struct llentry *lle = (struct llentry *)arg;
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struct ifnet *ifp;
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|
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|
if (lle->la_flags & LLE_STATIC) {
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return;
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|
}
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|
LLE_WLOCK(lle);
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|
if (callout_pending(&lle->la_timer)) {
|
|
/*
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|
* Here we are a bit odd here in the treatment of
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* active/pending. If the pending bit is set, it got
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|
* rescheduled before I ran. The active
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|
* bit we ignore, since if it was stopped
|
|
* in ll_tablefree() and was currently running
|
|
* it would have return 0 so the code would
|
|
* not have deleted it since the callout could
|
|
* not be stopped so we want to go through
|
|
* with the delete here now. If the callout
|
|
* was restarted, the pending bit will be back on and
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|
* we just want to bail since the callout_reset would
|
|
* return 1 and our reference would have been removed
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|
* by arpresolve() below.
|
|
*/
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LLE_WUNLOCK(lle);
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return;
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|
}
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ifp = lle->lle_tbl->llt_ifp;
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CURVNET_SET(ifp->if_vnet);
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|
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|
if ((lle->la_flags & LLE_DELETED) == 0) {
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int evt;
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|
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|
if (lle->la_flags & LLE_VALID)
|
|
evt = LLENTRY_EXPIRED;
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|
else
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|
evt = LLENTRY_TIMEDOUT;
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|
EVENTHANDLER_INVOKE(lle_event, lle, evt);
|
|
}
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|
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|
callout_stop(&lle->la_timer);
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|
|
|
/* XXX: LOR avoidance. We still have ref on lle. */
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LLE_WUNLOCK(lle);
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IF_AFDATA_LOCK(ifp);
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LLE_WLOCK(lle);
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|
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/* Guard against race with other llentry_free(). */
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if (lle->la_flags & LLE_LINKED) {
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size_t pkts_dropped;
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|
LLE_REMREF(lle);
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pkts_dropped = llentry_free(lle);
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ARPSTAT_ADD(dropped, pkts_dropped);
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} else
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LLE_FREE_LOCKED(lle);
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|
|
|
IF_AFDATA_UNLOCK(ifp);
|
|
|
|
ARPSTAT_INC(timeouts);
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|
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|
CURVNET_RESTORE();
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|
}
|
|
|
|
/*
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|
* Broadcast an ARP request. Caller specifies:
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* - arp header source ip address
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* - arp header target ip address
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* - arp header source ethernet address
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|
*/
|
|
void
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|
arprequest(struct ifnet *ifp, const struct in_addr *sip,
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|
const struct in_addr *tip, u_char *enaddr)
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|
{
|
|
struct mbuf *m;
|
|
struct arphdr *ah;
|
|
struct sockaddr sa;
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|
u_char *carpaddr = NULL;
|
|
|
|
if (sip == NULL) {
|
|
/*
|
|
* The caller did not supply a source address, try to find
|
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* a compatible one among those assigned to this interface.
|
|
*/
|
|
struct ifaddr *ifa;
|
|
|
|
IF_ADDR_RLOCK(ifp);
|
|
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
|
|
if (ifa->ifa_addr->sa_family != AF_INET)
|
|
continue;
|
|
|
|
if (ifa->ifa_carp) {
|
|
if ((*carp_iamatch_p)(ifa, &carpaddr) == 0)
|
|
continue;
|
|
sip = &IA_SIN(ifa)->sin_addr;
|
|
} else {
|
|
carpaddr = NULL;
|
|
sip = &IA_SIN(ifa)->sin_addr;
|
|
}
|
|
|
|
if (0 == ((sip->s_addr ^ tip->s_addr) &
|
|
IA_MASKSIN(ifa)->sin_addr.s_addr))
|
|
break; /* found it. */
|
|
}
|
|
IF_ADDR_RUNLOCK(ifp);
|
|
if (sip == NULL) {
|
|
printf("%s: cannot find matching address\n", __func__);
|
|
return;
|
|
}
|
|
}
|
|
if (enaddr == NULL)
|
|
enaddr = carpaddr ? carpaddr : (u_char *)IF_LLADDR(ifp);
|
|
|
|
if ((m = m_gethdr(M_NOWAIT, MT_DATA)) == NULL)
|
|
return;
|
|
m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) +
|
|
2 * ifp->if_addrlen;
|
|
m->m_pkthdr.len = m->m_len;
|
|
M_ALIGN(m, m->m_len);
|
|
ah = mtod(m, struct arphdr *);
|
|
bzero((caddr_t)ah, m->m_len);
|
|
#ifdef MAC
|
|
mac_netinet_arp_send(ifp, m);
|
|
#endif
|
|
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);
|
|
bcopy(enaddr, ar_sha(ah), ah->ar_hln);
|
|
bcopy(sip, ar_spa(ah), ah->ar_pln);
|
|
bcopy(tip, ar_tpa(ah), ah->ar_pln);
|
|
sa.sa_family = AF_ARP;
|
|
sa.sa_len = 2;
|
|
m->m_flags |= M_BCAST;
|
|
m_clrprotoflags(m); /* Avoid confusing lower layers. */
|
|
(*ifp->if_output)(ifp, m, &sa, NULL);
|
|
ARPSTAT_INC(txrequests);
|
|
}
|
|
|
|
/*
|
|
* Resolve an IP address into an ethernet address.
|
|
* On input:
|
|
* ifp is the interface we use
|
|
* is_gw != if @dst represents gateway to some destination
|
|
* m is the mbuf. May be NULL if we don't have a packet.
|
|
* dst is the next hop,
|
|
* desten is where we want the address.
|
|
* flags returns lle entry flags.
|
|
*
|
|
* On success, desten and flags are filled in and the function returns 0;
|
|
* If the packet must be held pending resolution, we return EWOULDBLOCK
|
|
* On other errors, we return the corresponding error code.
|
|
* Note that m_freem() handles NULL.
|
|
*/
|
|
int
|
|
arpresolve(struct ifnet *ifp, int is_gw, struct mbuf *m,
|
|
const struct sockaddr *dst, u_char *desten, uint32_t *pflags)
|
|
{
|
|
struct llentry *la = 0;
|
|
u_int flags = 0;
|
|
struct mbuf *curr = NULL;
|
|
struct mbuf *next = NULL;
|
|
int error, renew;
|
|
|
|
if (pflags != NULL)
|
|
*pflags = 0;
|
|
|
|
if (m != NULL) {
|
|
if (m->m_flags & M_BCAST) {
|
|
/* broadcast */
|
|
(void)memcpy(desten,
|
|
ifp->if_broadcastaddr, ifp->if_addrlen);
|
|
return (0);
|
|
}
|
|
if (m->m_flags & M_MCAST) {
|
|
/* multicast */
|
|
ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
|
|
return (0);
|
|
}
|
|
}
|
|
retry:
|
|
IF_AFDATA_RLOCK(ifp);
|
|
la = lla_lookup(LLTABLE(ifp), flags, dst);
|
|
IF_AFDATA_RUNLOCK(ifp);
|
|
if ((la == NULL) && ((flags & LLE_EXCLUSIVE) == 0)
|
|
&& ((ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0)) {
|
|
flags |= (LLE_CREATE | LLE_EXCLUSIVE);
|
|
IF_AFDATA_WLOCK(ifp);
|
|
la = lla_lookup(LLTABLE(ifp), flags, dst);
|
|
IF_AFDATA_WUNLOCK(ifp);
|
|
}
|
|
if (la == NULL) {
|
|
if (flags & LLE_CREATE)
|
|
log(LOG_DEBUG,
|
|
"arpresolve: can't allocate llinfo for %s on %s\n",
|
|
inet_ntoa(SIN(dst)->sin_addr), ifp->if_xname);
|
|
m_freem(m);
|
|
return (EINVAL);
|
|
}
|
|
|
|
if ((la->la_flags & LLE_VALID) &&
|
|
((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) {
|
|
bcopy(&la->ll_addr, desten, ifp->if_addrlen);
|
|
/*
|
|
* If entry has an expiry time and it is approaching,
|
|
* see if we need to send an ARP request within this
|
|
* arpt_down interval.
|
|
*/
|
|
if (!(la->la_flags & LLE_STATIC) &&
|
|
time_uptime + la->la_preempt > la->la_expire) {
|
|
arprequest(ifp, NULL, &SIN(dst)->sin_addr, NULL);
|
|
la->la_preempt--;
|
|
}
|
|
|
|
if (pflags != NULL)
|
|
*pflags = la->la_flags;
|
|
error = 0;
|
|
goto done;
|
|
}
|
|
|
|
if (la->la_flags & LLE_STATIC) { /* should not happen! */
|
|
log(LOG_DEBUG, "arpresolve: ouch, empty static llinfo for %s\n",
|
|
inet_ntoa(SIN(dst)->sin_addr));
|
|
m_freem(m);
|
|
error = EINVAL;
|
|
goto done;
|
|
}
|
|
|
|
renew = (la->la_asked == 0 || la->la_expire != time_uptime);
|
|
if ((renew || m != NULL) && (flags & LLE_EXCLUSIVE) == 0) {
|
|
flags |= LLE_EXCLUSIVE;
|
|
LLE_RUNLOCK(la);
|
|
goto retry;
|
|
}
|
|
/*
|
|
* There is an arptab entry, but no ethernet address
|
|
* response yet. Add the mbuf to the list, dropping
|
|
* the oldest packet if we have exceeded the system
|
|
* setting.
|
|
*/
|
|
if (m != NULL) {
|
|
if (la->la_numheld >= V_arp_maxhold) {
|
|
if (la->la_hold != NULL) {
|
|
next = la->la_hold->m_nextpkt;
|
|
m_freem(la->la_hold);
|
|
la->la_hold = next;
|
|
la->la_numheld--;
|
|
ARPSTAT_INC(dropped);
|
|
}
|
|
}
|
|
if (la->la_hold != NULL) {
|
|
curr = la->la_hold;
|
|
while (curr->m_nextpkt != NULL)
|
|
curr = curr->m_nextpkt;
|
|
curr->m_nextpkt = m;
|
|
} else
|
|
la->la_hold = m;
|
|
la->la_numheld++;
|
|
if (renew == 0 && (flags & LLE_EXCLUSIVE)) {
|
|
flags &= ~LLE_EXCLUSIVE;
|
|
LLE_DOWNGRADE(la);
|
|
}
|
|
|
|
}
|
|
/*
|
|
* Return EWOULDBLOCK if we have tried less than arp_maxtries. It
|
|
* will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH
|
|
* if we have already sent arp_maxtries ARP requests. Retransmit the
|
|
* ARP request, but not faster than one request per second.
|
|
*/
|
|
if (la->la_asked < V_arp_maxtries)
|
|
error = EWOULDBLOCK; /* First request. */
|
|
else
|
|
error = is_gw != 0 ? EHOSTUNREACH : EHOSTDOWN;
|
|
|
|
if (renew) {
|
|
int canceled;
|
|
|
|
LLE_ADDREF(la);
|
|
la->la_expire = time_uptime;
|
|
canceled = callout_reset(&la->la_timer, hz * V_arpt_down,
|
|
arptimer, la);
|
|
if (canceled)
|
|
LLE_REMREF(la);
|
|
la->la_asked++;
|
|
LLE_WUNLOCK(la);
|
|
arprequest(ifp, NULL, &SIN(dst)->sin_addr, NULL);
|
|
return (error);
|
|
}
|
|
done:
|
|
if (flags & LLE_EXCLUSIVE)
|
|
LLE_WUNLOCK(la);
|
|
else
|
|
LLE_RUNLOCK(la);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Common length and type checks are done here,
|
|
* then the protocol-specific routine is called.
|
|
*/
|
|
static void
|
|
arpintr(struct mbuf *m)
|
|
{
|
|
struct arphdr *ar;
|
|
|
|
if (m->m_len < sizeof(struct arphdr) &&
|
|
((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
|
|
log(LOG_NOTICE, "arp: runt packet -- m_pullup failed\n");
|
|
return;
|
|
}
|
|
ar = mtod(m, struct arphdr *);
|
|
|
|
if (ntohs(ar->ar_hrd) != ARPHRD_ETHER &&
|
|
ntohs(ar->ar_hrd) != ARPHRD_IEEE802 &&
|
|
ntohs(ar->ar_hrd) != ARPHRD_ARCNET &&
|
|
ntohs(ar->ar_hrd) != ARPHRD_IEEE1394 &&
|
|
ntohs(ar->ar_hrd) != ARPHRD_INFINIBAND) {
|
|
log(LOG_NOTICE, "arp: unknown hardware address format (0x%2D)"
|
|
" (from %*D to %*D)\n", (unsigned char *)&ar->ar_hrd, "",
|
|
ETHER_ADDR_LEN, (u_char *)ar_sha(ar), ":",
|
|
ETHER_ADDR_LEN, (u_char *)ar_tha(ar), ":");
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
if (m->m_len < arphdr_len(ar)) {
|
|
if ((m = m_pullup(m, arphdr_len(ar))) == NULL) {
|
|
log(LOG_NOTICE, "arp: runt packet\n");
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
ar = mtod(m, struct arphdr *);
|
|
}
|
|
|
|
ARPSTAT_INC(received);
|
|
switch (ntohs(ar->ar_pro)) {
|
|
#ifdef INET
|
|
case ETHERTYPE_IP:
|
|
in_arpinput(m);
|
|
return;
|
|
#endif
|
|
}
|
|
m_freem(m);
|
|
}
|
|
|
|
#ifdef INET
|
|
/*
|
|
* 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 int log_arp_wrong_iface = 1;
|
|
static int log_arp_movements = 1;
|
|
static int log_arp_permanent_modify = 1;
|
|
static int allow_multicast = 0;
|
|
static struct timeval arp_lastlog;
|
|
static int arp_curpps;
|
|
static int arp_maxpps = 1;
|
|
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
|
|
&log_arp_wrong_iface, 0,
|
|
"log arp packets arriving on the wrong interface");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
|
|
&log_arp_movements, 0,
|
|
"log arp replies from MACs different than the one in the cache");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW,
|
|
&log_arp_permanent_modify, 0,
|
|
"log arp replies from MACs different than the one in the permanent arp entry");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, allow_multicast, CTLFLAG_RW,
|
|
&allow_multicast, 0, "accept multicast addresses");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_log_per_second,
|
|
CTLFLAG_RW, &arp_maxpps, 0,
|
|
"Maximum number of remotely triggered ARP messages that can be "
|
|
"logged per second");
|
|
|
|
#define ARP_LOG(pri, ...) do { \
|
|
if (ppsratecheck(&arp_lastlog, &arp_curpps, arp_maxpps)) \
|
|
log((pri), "arp: " __VA_ARGS__); \
|
|
} while (0)
|
|
|
|
static void
|
|
in_arpinput(struct mbuf *m)
|
|
{
|
|
struct arphdr *ah;
|
|
struct ifnet *ifp = m->m_pkthdr.rcvif;
|
|
struct llentry *la = NULL;
|
|
struct rtentry *rt;
|
|
struct ifaddr *ifa;
|
|
struct in_ifaddr *ia;
|
|
struct sockaddr sa;
|
|
struct in_addr isaddr, itaddr, myaddr;
|
|
u_int8_t *enaddr = NULL;
|
|
int op, flags;
|
|
int req_len;
|
|
int bridged = 0, is_bridge = 0;
|
|
int carped;
|
|
struct sockaddr_in sin;
|
|
sin.sin_len = sizeof(struct sockaddr_in);
|
|
sin.sin_family = AF_INET;
|
|
sin.sin_addr.s_addr = 0;
|
|
|
|
if (ifp->if_bridge)
|
|
bridged = 1;
|
|
if (ifp->if_type == IFT_BRIDGE)
|
|
is_bridge = 1;
|
|
|
|
req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
|
|
if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
|
|
ARP_LOG(LOG_NOTICE, "runt packet -- m_pullup failed\n");
|
|
return;
|
|
}
|
|
|
|
ah = mtod(m, struct arphdr *);
|
|
/*
|
|
* ARP is only for IPv4 so we can reject packets with
|
|
* a protocol length not equal to an IPv4 address.
|
|
*/
|
|
if (ah->ar_pln != sizeof(struct in_addr)) {
|
|
ARP_LOG(LOG_NOTICE, "requested protocol length != %zu\n",
|
|
sizeof(struct in_addr));
|
|
goto drop;
|
|
}
|
|
|
|
if (allow_multicast == 0 && ETHER_IS_MULTICAST(ar_sha(ah))) {
|
|
ARP_LOG(LOG_NOTICE, "%*D is multicast\n",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":");
|
|
goto drop;
|
|
}
|
|
|
|
op = ntohs(ah->ar_op);
|
|
(void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
|
|
(void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
|
|
|
|
if (op == ARPOP_REPLY)
|
|
ARPSTAT_INC(rxreplies);
|
|
|
|
/*
|
|
* For a bridge, we want to check the address irrespective
|
|
* of the receive interface. (This will change slightly
|
|
* when we have clusters of interfaces).
|
|
*/
|
|
IN_IFADDR_RLOCK();
|
|
LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
|
|
if (((bridged && ia->ia_ifp->if_bridge == ifp->if_bridge) ||
|
|
ia->ia_ifp == ifp) &&
|
|
itaddr.s_addr == ia->ia_addr.sin_addr.s_addr &&
|
|
(ia->ia_ifa.ifa_carp == NULL ||
|
|
(*carp_iamatch_p)(&ia->ia_ifa, &enaddr))) {
|
|
ifa_ref(&ia->ia_ifa);
|
|
IN_IFADDR_RUNLOCK();
|
|
goto match;
|
|
}
|
|
}
|
|
LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
|
|
if (((bridged && ia->ia_ifp->if_bridge == ifp->if_bridge) ||
|
|
ia->ia_ifp == ifp) &&
|
|
isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
|
|
ifa_ref(&ia->ia_ifa);
|
|
IN_IFADDR_RUNLOCK();
|
|
goto match;
|
|
}
|
|
|
|
#define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia) \
|
|
(ia->ia_ifp->if_bridge == ifp->if_softc && \
|
|
!bcmp(IF_LLADDR(ia->ia_ifp), IF_LLADDR(ifp), ifp->if_addrlen) && \
|
|
addr == ia->ia_addr.sin_addr.s_addr)
|
|
/*
|
|
* Check the case when bridge shares its MAC address with
|
|
* some of its children, so packets are claimed by bridge
|
|
* itself (bridge_input() does it first), but they are really
|
|
* meant to be destined to the bridge member.
|
|
*/
|
|
if (is_bridge) {
|
|
LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
|
|
if (BDG_MEMBER_MATCHES_ARP(itaddr.s_addr, ifp, ia)) {
|
|
ifa_ref(&ia->ia_ifa);
|
|
ifp = ia->ia_ifp;
|
|
IN_IFADDR_RUNLOCK();
|
|
goto match;
|
|
}
|
|
}
|
|
}
|
|
#undef BDG_MEMBER_MATCHES_ARP
|
|
IN_IFADDR_RUNLOCK();
|
|
|
|
/*
|
|
* No match, use the first inet address on the receive interface
|
|
* as a dummy address for the rest of the function.
|
|
*/
|
|
IF_ADDR_RLOCK(ifp);
|
|
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
|
|
if (ifa->ifa_addr->sa_family == AF_INET &&
|
|
(ifa->ifa_carp == NULL ||
|
|
(*carp_iamatch_p)(ifa, &enaddr))) {
|
|
ia = ifatoia(ifa);
|
|
ifa_ref(ifa);
|
|
IF_ADDR_RUNLOCK(ifp);
|
|
goto match;
|
|
}
|
|
IF_ADDR_RUNLOCK(ifp);
|
|
|
|
/*
|
|
* If bridging, fall back to using any inet address.
|
|
*/
|
|
IN_IFADDR_RLOCK();
|
|
if (!bridged || (ia = TAILQ_FIRST(&V_in_ifaddrhead)) == NULL) {
|
|
IN_IFADDR_RUNLOCK();
|
|
goto drop;
|
|
}
|
|
ifa_ref(&ia->ia_ifa);
|
|
IN_IFADDR_RUNLOCK();
|
|
match:
|
|
if (!enaddr)
|
|
enaddr = (u_int8_t *)IF_LLADDR(ifp);
|
|
carped = (ia->ia_ifa.ifa_carp != NULL);
|
|
myaddr = ia->ia_addr.sin_addr;
|
|
ifa_free(&ia->ia_ifa);
|
|
if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen))
|
|
goto drop; /* it's from me, ignore it. */
|
|
if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
|
|
ARP_LOG(LOG_NOTICE, "link address is broadcast for IP address "
|
|
"%s!\n", inet_ntoa(isaddr));
|
|
goto drop;
|
|
}
|
|
/*
|
|
* Warn if another host is using the same IP address, but only if the
|
|
* IP address isn't 0.0.0.0, which is used for DHCP only, in which
|
|
* case we suppress the warning to avoid false positive complaints of
|
|
* potential misconfiguration.
|
|
*/
|
|
if (!bridged && !carped && isaddr.s_addr == myaddr.s_addr &&
|
|
myaddr.s_addr != 0) {
|
|
ARP_LOG(LOG_ERR, "%*D is using my IP address %s on %s!\n",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
inet_ntoa(isaddr), ifp->if_xname);
|
|
itaddr = myaddr;
|
|
ARPSTAT_INC(dupips);
|
|
goto reply;
|
|
}
|
|
if (ifp->if_flags & IFF_STATICARP)
|
|
goto reply;
|
|
|
|
bzero(&sin, sizeof(sin));
|
|
sin.sin_len = sizeof(struct sockaddr_in);
|
|
sin.sin_family = AF_INET;
|
|
sin.sin_addr = isaddr;
|
|
flags = (itaddr.s_addr == myaddr.s_addr) ? LLE_CREATE : 0;
|
|
flags |= LLE_EXCLUSIVE;
|
|
IF_AFDATA_LOCK(ifp);
|
|
la = lla_lookup(LLTABLE(ifp), flags, (struct sockaddr *)&sin);
|
|
IF_AFDATA_UNLOCK(ifp);
|
|
if (la != NULL) {
|
|
/* the following is not an error when doing bridging */
|
|
if (!bridged && la->lle_tbl->llt_ifp != ifp) {
|
|
if (log_arp_wrong_iface)
|
|
ARP_LOG(LOG_WARNING, "%s is on %s "
|
|
"but got reply from %*D on %s\n",
|
|
inet_ntoa(isaddr),
|
|
la->lle_tbl->llt_ifp->if_xname,
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
ifp->if_xname);
|
|
LLE_WUNLOCK(la);
|
|
goto reply;
|
|
}
|
|
if ((la->la_flags & LLE_VALID) &&
|
|
bcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) {
|
|
if (la->la_flags & LLE_STATIC) {
|
|
LLE_WUNLOCK(la);
|
|
if (log_arp_permanent_modify)
|
|
ARP_LOG(LOG_ERR,
|
|
"%*D attempts to modify "
|
|
"permanent entry for %s on %s\n",
|
|
ifp->if_addrlen,
|
|
(u_char *)ar_sha(ah), ":",
|
|
inet_ntoa(isaddr), ifp->if_xname);
|
|
goto reply;
|
|
}
|
|
if (log_arp_movements) {
|
|
ARP_LOG(LOG_INFO, "%s moved from %*D "
|
|
"to %*D on %s\n",
|
|
inet_ntoa(isaddr),
|
|
ifp->if_addrlen,
|
|
(u_char *)&la->ll_addr, ":",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
ifp->if_xname);
|
|
}
|
|
}
|
|
|
|
if (ifp->if_addrlen != ah->ar_hln) {
|
|
LLE_WUNLOCK(la);
|
|
ARP_LOG(LOG_WARNING, "from %*D: addr len: new %d, "
|
|
"i/f %d (ignored)\n", ifp->if_addrlen,
|
|
(u_char *) ar_sha(ah), ":", ah->ar_hln,
|
|
ifp->if_addrlen);
|
|
goto drop;
|
|
}
|
|
(void)memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
|
|
la->la_flags |= LLE_VALID;
|
|
|
|
EVENTHANDLER_INVOKE(lle_event, la, LLENTRY_RESOLVED);
|
|
|
|
if (!(la->la_flags & LLE_STATIC)) {
|
|
int canceled;
|
|
|
|
LLE_ADDREF(la);
|
|
la->la_expire = time_uptime + V_arpt_keep;
|
|
canceled = callout_reset(&la->la_timer,
|
|
hz * V_arpt_keep, arptimer, la);
|
|
if (canceled)
|
|
LLE_REMREF(la);
|
|
}
|
|
la->la_asked = 0;
|
|
la->la_preempt = V_arp_maxtries;
|
|
/*
|
|
* The packets are all freed within the call to the output
|
|
* routine.
|
|
*
|
|
* NB: The lock MUST be released before the call to the
|
|
* output routine.
|
|
*/
|
|
if (la->la_hold != NULL) {
|
|
struct mbuf *m_hold, *m_hold_next;
|
|
|
|
m_hold = la->la_hold;
|
|
la->la_hold = NULL;
|
|
la->la_numheld = 0;
|
|
memcpy(&sa, L3_ADDR(la), sizeof(sa));
|
|
LLE_WUNLOCK(la);
|
|
for (; m_hold != NULL; m_hold = m_hold_next) {
|
|
m_hold_next = m_hold->m_nextpkt;
|
|
m_hold->m_nextpkt = NULL;
|
|
/* Avoid confusing lower layers. */
|
|
m_clrprotoflags(m_hold);
|
|
(*ifp->if_output)(ifp, m_hold, &sa, NULL);
|
|
}
|
|
} else
|
|
LLE_WUNLOCK(la);
|
|
}
|
|
reply:
|
|
if (op != ARPOP_REQUEST)
|
|
goto drop;
|
|
ARPSTAT_INC(rxrequests);
|
|
|
|
if (itaddr.s_addr == myaddr.s_addr) {
|
|
/* Shortcut.. the receiving interface is the target. */
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
|
|
} else {
|
|
struct llentry *lle = NULL;
|
|
|
|
sin.sin_addr = itaddr;
|
|
IF_AFDATA_RLOCK(ifp);
|
|
lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin);
|
|
IF_AFDATA_RUNLOCK(ifp);
|
|
|
|
if ((lle != NULL) && (lle->la_flags & LLE_PUB)) {
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln);
|
|
LLE_RUNLOCK(lle);
|
|
} else {
|
|
|
|
if (lle != NULL)
|
|
LLE_RUNLOCK(lle);
|
|
|
|
if (!V_arp_proxyall)
|
|
goto drop;
|
|
|
|
sin.sin_addr = itaddr;
|
|
/* XXX MRT use table 0 for arp reply */
|
|
rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
|
|
if (!rt)
|
|
goto drop;
|
|
|
|
/*
|
|
* 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 || rt->rt_ifp == ifp) {
|
|
RTFREE_LOCKED(rt);
|
|
goto drop;
|
|
}
|
|
RTFREE_LOCKED(rt);
|
|
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
|
|
|
|
/*
|
|
* Also check that the node which sent the ARP packet
|
|
* is on the interface we expect it to be on. This
|
|
* avoids ARP chaos if an interface is connected to the
|
|
* wrong network.
|
|
*/
|
|
sin.sin_addr = isaddr;
|
|
|
|
/* XXX MRT use table 0 for arp checks */
|
|
rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
|
|
if (!rt)
|
|
goto drop;
|
|
if (rt->rt_ifp != ifp) {
|
|
ARP_LOG(LOG_INFO, "proxy: ignoring request"
|
|
" from %s via %s, expecting %s\n",
|
|
inet_ntoa(isaddr), ifp->if_xname,
|
|
rt->rt_ifp->if_xname);
|
|
RTFREE_LOCKED(rt);
|
|
goto drop;
|
|
}
|
|
RTFREE_LOCKED(rt);
|
|
|
|
#ifdef DEBUG_PROXY
|
|
printf("arp: proxying for %s\n", inet_ntoa(itaddr));
|
|
#endif
|
|
}
|
|
}
|
|
|
|
if (itaddr.s_addr == myaddr.s_addr &&
|
|
IN_LINKLOCAL(ntohl(itaddr.s_addr))) {
|
|
/* RFC 3927 link-local IPv4; always reply by broadcast. */
|
|
#ifdef DEBUG_LINKLOCAL
|
|
printf("arp: sending reply for link-local addr %s\n",
|
|
inet_ntoa(itaddr));
|
|
#endif
|
|
m->m_flags |= M_BCAST;
|
|
m->m_flags &= ~M_MCAST;
|
|
} else {
|
|
/* default behaviour; never reply by broadcast. */
|
|
m->m_flags &= ~(M_BCAST|M_MCAST);
|
|
}
|
|
(void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
|
|
(void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
|
|
ah->ar_op = htons(ARPOP_REPLY);
|
|
ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
|
|
m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);
|
|
m->m_pkthdr.len = m->m_len;
|
|
m->m_pkthdr.rcvif = NULL;
|
|
sa.sa_family = AF_ARP;
|
|
sa.sa_len = 2;
|
|
m_clrprotoflags(m); /* Avoid confusing lower layers. */
|
|
(*ifp->if_output)(ifp, m, &sa, NULL);
|
|
ARPSTAT_INC(txreplies);
|
|
return;
|
|
|
|
drop:
|
|
m_freem(m);
|
|
}
|
|
#endif
|
|
|
|
void
|
|
arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
|
|
{
|
|
struct llentry *lle;
|
|
|
|
if (ifa->ifa_carp != NULL)
|
|
return;
|
|
|
|
if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) {
|
|
arprequest(ifp, &IA_SIN(ifa)->sin_addr,
|
|
&IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp));
|
|
/*
|
|
* interface address is considered static entry
|
|
* because the output of the arp utility shows
|
|
* that L2 entry as permanent
|
|
*/
|
|
IF_AFDATA_LOCK(ifp);
|
|
lle = lla_lookup(LLTABLE(ifp), (LLE_CREATE | LLE_IFADDR | LLE_STATIC),
|
|
(struct sockaddr *)IA_SIN(ifa));
|
|
IF_AFDATA_UNLOCK(ifp);
|
|
if (lle == NULL)
|
|
log(LOG_INFO, "arp_ifinit: cannot create arp "
|
|
"entry for interface address\n");
|
|
else
|
|
LLE_RUNLOCK(lle);
|
|
}
|
|
ifa->ifa_rtrequest = NULL;
|
|
}
|
|
|
|
void
|
|
arp_ifinit2(struct ifnet *ifp, struct ifaddr *ifa, u_char *enaddr)
|
|
{
|
|
if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
|
|
arprequest(ifp, &IA_SIN(ifa)->sin_addr,
|
|
&IA_SIN(ifa)->sin_addr, enaddr);
|
|
ifa->ifa_rtrequest = NULL;
|
|
}
|
|
|
|
static void
|
|
arp_init(void)
|
|
{
|
|
|
|
netisr_register(&arp_nh);
|
|
}
|
|
SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);
|