982 lines
26 KiB
C
982 lines
26 KiB
C
/* $OpenBSD: if_ether.c,v 1.267 2023/12/18 13:30:44 bluhm Exp $ */
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/* $NetBSD: if_ether.c,v 1.31 1996/05/11 12:59:58 mycroft Exp $ */
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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 8.1 (Berkeley) 6/10/93
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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 "carp.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/mbuf.h>
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#include <sys/socket.h>
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#include <sys/timeout.h>
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#include <sys/kernel.h>
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#include <sys/syslog.h>
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#include <sys/queue.h>
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#include <sys/pool.h>
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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/route.h>
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#include <net/if_types.h>
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#include <net/netisr.h>
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#include <netinet/in.h>
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#include <netinet/in_var.h>
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#include <netinet/if_ether.h>
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#include <netinet/ip_var.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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/*
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* Locks used to protect struct members in this file:
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* a atomic operations
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* I immutable after creation
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* K kernel lock
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* m arp mutex, needed when net lock is shared
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* N net lock
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*/
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struct llinfo_arp {
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LIST_ENTRY(llinfo_arp) la_list; /* [mN] global arp_list */
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struct rtentry *la_rt; /* [I] backpointer to rtentry */
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struct mbuf_queue la_mq; /* packet hold queue */
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time_t la_refreshed; /* when was refresh sent */
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int la_asked; /* number of queries sent */
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};
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#define LA_HOLD_QUEUE 10
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#define LA_HOLD_TOTAL 100
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/* timer values */
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int arpt_prune = (5 * 60); /* [I] walk list every 5 minutes */
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int arpt_keep = (20 * 60); /* [a] once resolved, cache for 20 minutes */
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int arpt_down = 20; /* [a] once declared down, don't send for 20 secs */
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struct mbuf *arppullup(struct mbuf *m);
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void arpinvalidate(struct rtentry *);
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void arptfree(struct rtentry *);
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void arptimer(void *);
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struct rtentry *arplookup(struct in_addr *, int, int, unsigned int);
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void in_arpinput(struct ifnet *, struct mbuf *);
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void in_revarpinput(struct ifnet *, struct mbuf *);
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int arpcache(struct ifnet *, struct ether_arp *, struct rtentry *);
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void arpreply(struct ifnet *, struct mbuf *, struct in_addr *, uint8_t *,
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unsigned int);
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struct niqueue arpinq = NIQUEUE_INITIALIZER(50, NETISR_ARP);
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/* llinfo_arp live time, rt_llinfo and RTF_LLINFO are protected by arp_mtx */
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struct mutex arp_mtx = MUTEX_INITIALIZER(IPL_SOFTNET);
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LIST_HEAD(, llinfo_arp) arp_list =
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LIST_HEAD_INITIALIZER(arp_list); /* [mN] list of llinfo_arp structures */
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struct pool arp_pool; /* [I] pool for llinfo_arp structures */
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int arp_maxtries = 5; /* [I] arp requests before set to rejected */
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unsigned int la_hold_total; /* [a] packets currently in the arp queue */
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#ifdef NFSCLIENT
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/* revarp state */
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struct in_addr revarp_myip, revarp_srvip;
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int revarp_finished;
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unsigned int revarp_ifidx;
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#endif /* NFSCLIENT */
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/*
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* Timeout routine. Age arp_tab entries periodically.
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*/
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void
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arptimer(void *arg)
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{
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struct timeout *to = arg;
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struct llinfo_arp *la, *nla;
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time_t uptime;
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NET_LOCK();
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uptime = getuptime();
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timeout_add_sec(to, arpt_prune);
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/* Net lock is exclusive, no arp mutex needed for arp_list here. */
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LIST_FOREACH_SAFE(la, &arp_list, la_list, nla) {
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struct rtentry *rt = la->la_rt;
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if (rt->rt_expire && rt->rt_expire < uptime)
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arptfree(rt); /* timer has expired; clear */
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}
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NET_UNLOCK();
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}
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void
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arpinit(void)
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{
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static struct timeout arptimer_to;
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pool_init(&arp_pool, sizeof(struct llinfo_arp), 0,
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IPL_SOFTNET, 0, "arp", NULL);
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timeout_set_flags(&arptimer_to, arptimer, &arptimer_to,
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KCLOCK_NONE, TIMEOUT_PROC | TIMEOUT_MPSAFE);
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timeout_add_sec(&arptimer_to, arpt_prune);
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}
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void
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arp_rtrequest(struct ifnet *ifp, int req, struct rtentry *rt)
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{
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struct sockaddr *gate = rt->rt_gateway;
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struct llinfo_arp *la;
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time_t uptime;
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NET_ASSERT_LOCKED();
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if (ISSET(rt->rt_flags,
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RTF_GATEWAY|RTF_BROADCAST|RTF_MULTICAST|RTF_MPLS))
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return;
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uptime = getuptime();
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switch (req) {
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case RTM_ADD:
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if (rt->rt_flags & RTF_CLONING) {
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rt->rt_expire = 0;
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break;
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}
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if ((rt->rt_flags & RTF_LOCAL) && rt->rt_llinfo == NULL)
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rt->rt_expire = 0;
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/*
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* Announce a new entry if requested or warn the user
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* if another station has this IP address.
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*/
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if (rt->rt_flags & (RTF_ANNOUNCE|RTF_LOCAL))
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arprequest(ifp,
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&satosin(rt_key(rt))->sin_addr.s_addr,
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&satosin(rt_key(rt))->sin_addr.s_addr,
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(u_char *)LLADDR(satosdl(gate)));
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/*FALLTHROUGH*/
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case RTM_RESOLVE:
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if (gate->sa_family != AF_LINK ||
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gate->sa_len < sizeof(struct sockaddr_dl)) {
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log(LOG_DEBUG, "%s: bad gateway value: %s\n", __func__,
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ifp->if_xname);
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break;
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}
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satosdl(gate)->sdl_type = ifp->if_type;
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satosdl(gate)->sdl_index = ifp->if_index;
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/*
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* Case 2: This route may come from cloning, or a manual route
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* add with a LL address.
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*/
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la = pool_get(&arp_pool, PR_NOWAIT | PR_ZERO);
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if (la == NULL) {
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log(LOG_DEBUG, "%s: pool get failed\n", __func__);
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break;
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}
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mtx_enter(&arp_mtx);
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if (rt->rt_llinfo != NULL) {
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/* we lost the race, another thread has entered it */
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mtx_leave(&arp_mtx);
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pool_put(&arp_pool, la);
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break;
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}
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mq_init(&la->la_mq, LA_HOLD_QUEUE, IPL_SOFTNET);
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rt->rt_llinfo = (caddr_t)la;
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la->la_rt = rt;
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rt->rt_flags |= RTF_LLINFO;
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LIST_INSERT_HEAD(&arp_list, la, la_list);
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if ((rt->rt_flags & RTF_LOCAL) == 0)
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rt->rt_expire = uptime;
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mtx_leave(&arp_mtx);
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break;
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case RTM_DELETE:
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mtx_enter(&arp_mtx);
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la = (struct llinfo_arp *)rt->rt_llinfo;
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if (la == NULL) {
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/* we lost the race, another thread has removed it */
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mtx_leave(&arp_mtx);
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break;
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}
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LIST_REMOVE(la, la_list);
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rt->rt_llinfo = NULL;
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rt->rt_flags &= ~RTF_LLINFO;
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atomic_sub_int(&la_hold_total, mq_purge(&la->la_mq));
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mtx_leave(&arp_mtx);
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pool_put(&arp_pool, la);
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break;
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case RTM_INVALIDATE:
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if (!ISSET(rt->rt_flags, RTF_LOCAL))
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arpinvalidate(rt);
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break;
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}
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}
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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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*/
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void
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arprequest(struct ifnet *ifp, u_int32_t *sip, u_int32_t *tip, u_int8_t *enaddr)
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{
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struct mbuf *m;
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struct ether_header *eh;
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struct ether_arp *ea;
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struct sockaddr sa;
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if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
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return;
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m->m_len = sizeof(*ea);
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m->m_pkthdr.len = sizeof(*ea);
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m->m_pkthdr.ph_rtableid = ifp->if_rdomain;
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m->m_pkthdr.pf.prio = ifp->if_llprio;
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m_align(m, sizeof(*ea));
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ea = mtod(m, struct ether_arp *);
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eh = (struct ether_header *)sa.sa_data;
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memset(ea, 0, sizeof(*ea));
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memcpy(eh->ether_dhost, etherbroadcastaddr, sizeof(eh->ether_dhost));
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eh->ether_type = htons(ETHERTYPE_ARP); /* if_output will not swap */
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ea->arp_hrd = htons(ARPHRD_ETHER);
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ea->arp_pro = htons(ETHERTYPE_IP);
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ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */
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ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */
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ea->arp_op = htons(ARPOP_REQUEST);
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memcpy(eh->ether_shost, enaddr, sizeof(eh->ether_shost));
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memcpy(ea->arp_sha, enaddr, sizeof(ea->arp_sha));
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memcpy(ea->arp_spa, sip, sizeof(ea->arp_spa));
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memcpy(ea->arp_tpa, tip, sizeof(ea->arp_tpa));
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sa.sa_family = pseudo_AF_HDRCMPLT;
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sa.sa_len = sizeof(sa);
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m->m_flags |= M_BCAST;
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ifp->if_output(ifp, m, &sa, NULL);
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}
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void
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arpreply(struct ifnet *ifp, struct mbuf *m, struct in_addr *sip, uint8_t *eaddr,
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unsigned int rdomain)
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{
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struct ether_header *eh;
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struct ether_arp *ea;
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struct sockaddr sa;
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m_resethdr(m);
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m->m_pkthdr.ph_rtableid = rdomain;
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ea = mtod(m, struct ether_arp *);
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ea->arp_op = htons(ARPOP_REPLY);
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ea->arp_pro = htons(ETHERTYPE_IP); /* let's be sure! */
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/* We're replying to a request. */
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memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha));
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memcpy(ea->arp_tpa, ea->arp_spa, sizeof(ea->arp_spa));
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memcpy(ea->arp_sha, eaddr, sizeof(ea->arp_sha));
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memcpy(ea->arp_spa, sip, sizeof(ea->arp_spa));
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eh = (struct ether_header *)sa.sa_data;
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memcpy(eh->ether_dhost, ea->arp_tha, sizeof(eh->ether_dhost));
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memcpy(eh->ether_shost, eaddr, sizeof(eh->ether_shost));
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eh->ether_type = htons(ETHERTYPE_ARP);
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sa.sa_family = pseudo_AF_HDRCMPLT;
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sa.sa_len = sizeof(sa);
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ifp->if_output(ifp, m, &sa, NULL);
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}
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/*
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* Resolve an IP address into an ethernet address. If success,
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* desten is filled in. If there is no entry in arptab,
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* set one up and broadcast a request for the IP address.
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* Hold onto this mbuf and resend it once the address
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* is finally resolved. A return value of 0 indicates
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* that desten has been filled in and the packet should be sent
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* normally; A return value of EAGAIN indicates that the packet
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* has been taken over here, either now or for later transmission.
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* Any other return value indicates an error.
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*/
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int
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arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
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struct sockaddr *dst, u_char *desten)
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{
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struct arpcom *ac = (struct arpcom *)ifp;
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struct llinfo_arp *la;
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struct sockaddr_dl *sdl;
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struct rtentry *rt = NULL;
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char addr[INET_ADDRSTRLEN];
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time_t uptime;
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int refresh = 0, reject = 0;
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if (m->m_flags & M_BCAST) { /* broadcast */
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memcpy(desten, etherbroadcastaddr, sizeof(etherbroadcastaddr));
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return (0);
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}
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if (m->m_flags & M_MCAST) { /* multicast */
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ETHER_MAP_IP_MULTICAST(&satosin(dst)->sin_addr, desten);
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return (0);
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}
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uptime = getuptime();
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rt = rt_getll(rt0);
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if (ISSET(rt->rt_flags, RTF_REJECT) &&
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(rt->rt_expire == 0 || rt->rt_expire > uptime)) {
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m_freem(m);
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return (rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
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}
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if (!ISSET(rt->rt_flags, RTF_LLINFO)) {
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log(LOG_DEBUG, "%s: %s: route contains no arp information\n",
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__func__, inet_ntop(AF_INET, &satosin(rt_key(rt))->sin_addr,
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addr, sizeof(addr)));
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goto bad;
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}
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sdl = satosdl(rt->rt_gateway);
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if (sdl->sdl_alen > 0 && sdl->sdl_alen != ETHER_ADDR_LEN) {
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log(LOG_DEBUG, "%s: %s: incorrect arp information\n", __func__,
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inet_ntop(AF_INET, &satosin(dst)->sin_addr,
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addr, sizeof(addr)));
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goto bad;
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}
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/*
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* Check the address family and length is valid, the address
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* is resolved; otherwise, try to resolve.
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*/
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if ((rt->rt_expire == 0 || rt->rt_expire > uptime) &&
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sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
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memcpy(desten, LLADDR(sdl), sdl->sdl_alen);
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/* refresh ARP entry when timeout gets close */
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if (rt->rt_expire != 0 &&
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rt->rt_expire - arpt_keep / 8 < uptime) {
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mtx_enter(&arp_mtx);
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la = (struct llinfo_arp *)rt->rt_llinfo;
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if (la != NULL) {
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if (la->la_refreshed + 30 < uptime) {
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la->la_refreshed = uptime;
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refresh = 1;
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}
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}
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mtx_leave(&arp_mtx);
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}
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if (refresh) {
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arprequest(ifp,
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&satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr,
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&satosin(dst)->sin_addr.s_addr,
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ac->ac_enaddr);
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}
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return (0);
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}
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if (ifp->if_flags & (IFF_NOARP|IFF_STATICARP))
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goto bad;
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mtx_enter(&arp_mtx);
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la = (struct llinfo_arp *)rt->rt_llinfo;
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if (la == NULL) {
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mtx_leave(&arp_mtx);
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goto bad;
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}
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/*
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* There is an arptab entry, but no ethernet address
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* response yet. Insert mbuf in hold queue if below limit.
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* If above the limit free the queue without queuing the new packet.
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*/
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if (atomic_inc_int_nv(&la_hold_total) <= LA_HOLD_TOTAL) {
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if (mq_push(&la->la_mq, m) != 0)
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atomic_dec_int(&la_hold_total);
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} else {
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atomic_sub_int(&la_hold_total, mq_purge(&la->la_mq) + 1);
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m_freem(m);
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}
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/*
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* Re-send the ARP request when appropriate.
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*/
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#ifdef DIAGNOSTIC
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if (rt->rt_expire == 0) {
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/* This should never happen. (Should it? -gwr) */
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printf("%s: unresolved and rt_expire == 0\n", __func__);
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/* Set expiration time to now (expired). */
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rt->rt_expire = uptime;
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}
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#endif
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if (rt->rt_expire) {
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reject = ~RTF_REJECT;
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if (la->la_asked == 0 || rt->rt_expire != uptime) {
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rt->rt_expire = uptime;
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if (la->la_asked++ < arp_maxtries)
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refresh = 1;
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else {
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reject = RTF_REJECT;
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rt->rt_expire += arpt_down;
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la->la_asked = 0;
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la->la_refreshed = 0;
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atomic_sub_int(&la_hold_total,
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mq_purge(&la->la_mq));
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}
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}
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}
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mtx_leave(&arp_mtx);
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if (reject == RTF_REJECT && !ISSET(rt->rt_flags, RTF_REJECT)) {
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KERNEL_LOCK();
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SET(rt->rt_flags, RTF_REJECT);
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KERNEL_UNLOCK();
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}
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|
if (reject == ~RTF_REJECT && ISSET(rt->rt_flags, RTF_REJECT)) {
|
|
KERNEL_LOCK();
|
|
CLR(rt->rt_flags, RTF_REJECT);
|
|
KERNEL_UNLOCK();
|
|
}
|
|
if (refresh)
|
|
arprequest(ifp, &satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr,
|
|
&satosin(dst)->sin_addr.s_addr, ac->ac_enaddr);
|
|
return (EAGAIN);
|
|
|
|
bad:
|
|
m_freem(m);
|
|
return (EINVAL);
|
|
}
|
|
|
|
struct mbuf *
|
|
arppullup(struct mbuf *m)
|
|
{
|
|
struct arphdr *ar;
|
|
int len;
|
|
|
|
#ifdef DIAGNOSTIC
|
|
if ((m->m_flags & M_PKTHDR) == 0)
|
|
panic("arp without packet header");
|
|
#endif
|
|
|
|
len = sizeof(struct arphdr);
|
|
if (m->m_len < len && (m = m_pullup(m, len)) == NULL)
|
|
return NULL;
|
|
|
|
ar = mtod(m, struct arphdr *);
|
|
if (ntohs(ar->ar_hrd) != ARPHRD_ETHER ||
|
|
ntohs(ar->ar_pro) != ETHERTYPE_IP ||
|
|
ar->ar_hln != ETHER_ADDR_LEN ||
|
|
ar->ar_pln != sizeof(struct in_addr)) {
|
|
m_freem(m);
|
|
return NULL;
|
|
}
|
|
|
|
len += 2 * (ar->ar_hln + ar->ar_pln);
|
|
if (m->m_len < len && (m = m_pullup(m, len)) == NULL)
|
|
return NULL;
|
|
|
|
return m;
|
|
}
|
|
|
|
/*
|
|
* Common length and type checks are done here,
|
|
* then the protocol-specific routine is called.
|
|
*/
|
|
void
|
|
arpinput(struct ifnet *ifp, struct mbuf *m)
|
|
{
|
|
if ((m = arppullup(m)) == NULL)
|
|
return;
|
|
niq_enqueue(&arpinq, m);
|
|
}
|
|
|
|
void
|
|
arpintr(void)
|
|
{
|
|
struct mbuf_list ml;
|
|
struct mbuf *m;
|
|
struct ifnet *ifp;
|
|
|
|
niq_delist(&arpinq, &ml);
|
|
|
|
while ((m = ml_dequeue(&ml)) != NULL) {
|
|
ifp = if_get(m->m_pkthdr.ph_ifidx);
|
|
|
|
if (ifp != NULL)
|
|
in_arpinput(ifp, m);
|
|
else
|
|
m_freem(m);
|
|
|
|
if_put(ifp);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* ARP for Internet protocols on Ethernet, RFC 826.
|
|
* In addition, a sanity check is performed on the sender
|
|
* protocol address, to catch impersonators.
|
|
*/
|
|
void
|
|
in_arpinput(struct ifnet *ifp, struct mbuf *m)
|
|
{
|
|
struct ether_arp *ea;
|
|
struct rtentry *rt = NULL;
|
|
struct sockaddr_in sin;
|
|
struct in_addr isaddr, itaddr;
|
|
char addr[INET_ADDRSTRLEN];
|
|
int op, target = 0;
|
|
unsigned int rdomain;
|
|
|
|
rdomain = rtable_l2(m->m_pkthdr.ph_rtableid);
|
|
|
|
ea = mtod(m, struct ether_arp *);
|
|
op = ntohs(ea->arp_op);
|
|
if ((op != ARPOP_REQUEST) && (op != ARPOP_REPLY))
|
|
goto out;
|
|
|
|
memcpy(&itaddr, ea->arp_tpa, sizeof(itaddr));
|
|
memcpy(&isaddr, ea->arp_spa, sizeof(isaddr));
|
|
memset(&sin, 0, sizeof(sin));
|
|
sin.sin_len = sizeof(sin);
|
|
sin.sin_family = AF_INET;
|
|
|
|
if (ETHER_IS_MULTICAST(ea->arp_sha) &&
|
|
ETHER_IS_BROADCAST(ea->arp_sha)) {
|
|
inet_ntop(AF_INET, &isaddr, addr, sizeof(addr));
|
|
log(LOG_ERR, "arp: ether address is broadcast for IP address "
|
|
"%s!\n", addr);
|
|
goto out;
|
|
}
|
|
|
|
if (!memcmp(ea->arp_sha, LLADDR(ifp->if_sadl), sizeof(ea->arp_sha)))
|
|
goto out; /* it's from me, ignore it. */
|
|
|
|
/* Check target against our interface addresses. */
|
|
sin.sin_addr = itaddr;
|
|
rt = rtalloc(sintosa(&sin), 0, rdomain);
|
|
if (rtisvalid(rt) && ISSET(rt->rt_flags, RTF_LOCAL) &&
|
|
rt->rt_ifidx == ifp->if_index)
|
|
target = 1;
|
|
rtfree(rt);
|
|
rt = NULL;
|
|
|
|
#if NCARP > 0
|
|
if (target && op == ARPOP_REQUEST && ifp->if_type == IFT_CARP &&
|
|
!carp_iamatch(ifp))
|
|
goto out;
|
|
#endif
|
|
|
|
/* Do we have an ARP cache for the sender? Create if we are target. */
|
|
rt = arplookup(&isaddr, target, 0, rdomain);
|
|
|
|
/* Check sender against our interface addresses. */
|
|
if (rtisvalid(rt) && ISSET(rt->rt_flags, RTF_LOCAL) &&
|
|
rt->rt_ifidx == ifp->if_index && isaddr.s_addr != INADDR_ANY) {
|
|
inet_ntop(AF_INET, &isaddr, addr, sizeof(addr));
|
|
log(LOG_ERR, "duplicate IP address %s sent from ethernet "
|
|
"address %s\n", addr, ether_sprintf(ea->arp_sha));
|
|
itaddr = isaddr;
|
|
} else if (rt != NULL) {
|
|
if (arpcache(ifp, ea, rt))
|
|
goto out;
|
|
}
|
|
|
|
if (op == ARPOP_REQUEST) {
|
|
uint8_t *eaddr;
|
|
|
|
if (target) {
|
|
/* We already have all info for the reply */
|
|
eaddr = LLADDR(ifp->if_sadl);
|
|
} else {
|
|
rtfree(rt);
|
|
rt = arplookup(&itaddr, 0, SIN_PROXY, rdomain);
|
|
/*
|
|
* Protect from possible duplicates, only owner
|
|
* should respond
|
|
*/
|
|
if ((rt == NULL) || (rt->rt_ifidx != ifp->if_index))
|
|
goto out;
|
|
eaddr = LLADDR(satosdl(rt->rt_gateway));
|
|
}
|
|
arpreply(ifp, m, &itaddr, eaddr, rdomain);
|
|
rtfree(rt);
|
|
return;
|
|
}
|
|
|
|
out:
|
|
rtfree(rt);
|
|
m_freem(m);
|
|
}
|
|
|
|
int
|
|
arpcache(struct ifnet *ifp, struct ether_arp *ea, struct rtentry *rt)
|
|
{
|
|
struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo;
|
|
struct sockaddr_dl *sdl = satosdl(rt->rt_gateway);
|
|
struct in_addr *spa = (struct in_addr *)ea->arp_spa;
|
|
char addr[INET_ADDRSTRLEN];
|
|
struct ifnet *rifp;
|
|
time_t uptime;
|
|
int changed = 0;
|
|
|
|
NET_ASSERT_LOCKED_EXCLUSIVE();
|
|
KASSERT(sdl != NULL);
|
|
|
|
/*
|
|
* This can happen if the entry has been deleted by another CPU
|
|
* after we found it.
|
|
*/
|
|
if (la == NULL)
|
|
return (0);
|
|
|
|
uptime = getuptime();
|
|
if (sdl->sdl_alen > 0) {
|
|
if (memcmp(ea->arp_sha, LLADDR(sdl), sdl->sdl_alen)) {
|
|
if (ISSET(rt->rt_flags, RTF_PERMANENT_ARP|RTF_LOCAL)) {
|
|
inet_ntop(AF_INET, spa, addr, sizeof(addr));
|
|
log(LOG_WARNING, "arp: attempt to overwrite "
|
|
"permanent entry for %s by %s on %s\n", addr,
|
|
ether_sprintf(ea->arp_sha), ifp->if_xname);
|
|
return (-1);
|
|
} else if (rt->rt_ifidx != ifp->if_index) {
|
|
#if NCARP > 0
|
|
if (ifp->if_type != IFT_CARP)
|
|
#endif
|
|
{
|
|
rifp = if_get(rt->rt_ifidx);
|
|
if (rifp == NULL)
|
|
return (-1);
|
|
inet_ntop(AF_INET, spa, addr,
|
|
sizeof(addr));
|
|
log(LOG_WARNING, "arp: attempt to "
|
|
"overwrite entry for %s on %s by "
|
|
"%s on %s\n", addr, rifp->if_xname,
|
|
ether_sprintf(ea->arp_sha),
|
|
ifp->if_xname);
|
|
if_put(rifp);
|
|
}
|
|
return (-1);
|
|
} else {
|
|
inet_ntop(AF_INET, spa, addr, sizeof(addr));
|
|
log(LOG_INFO, "arp info overwritten for %s by "
|
|
"%s on %s\n", addr,
|
|
ether_sprintf(ea->arp_sha), ifp->if_xname);
|
|
rt->rt_expire = 1;/* no longer static */
|
|
}
|
|
changed = 1;
|
|
}
|
|
} else if (!if_isconnected(ifp, rt->rt_ifidx)) {
|
|
rifp = if_get(rt->rt_ifidx);
|
|
if (rifp == NULL)
|
|
return (-1);
|
|
inet_ntop(AF_INET, spa, addr, sizeof(addr));
|
|
log(LOG_WARNING, "arp: attempt to add entry for %s on %s by %s"
|
|
" on %s\n", addr, rifp->if_xname,
|
|
ether_sprintf(ea->arp_sha), ifp->if_xname);
|
|
if_put(rifp);
|
|
return (-1);
|
|
}
|
|
sdl->sdl_alen = sizeof(ea->arp_sha);
|
|
memcpy(LLADDR(sdl), ea->arp_sha, sizeof(ea->arp_sha));
|
|
if (rt->rt_expire)
|
|
rt->rt_expire = uptime + arpt_keep;
|
|
rt->rt_flags &= ~RTF_REJECT;
|
|
|
|
/* Notify userland that an ARP resolution has been done. */
|
|
if (la->la_asked || changed) {
|
|
rtm_send(rt, RTM_RESOLVE, 0, ifp->if_rdomain);
|
|
}
|
|
|
|
la->la_asked = 0;
|
|
la->la_refreshed = 0;
|
|
if_output_mq(ifp, &la->la_mq, &la_hold_total, rt_key(rt), rt);
|
|
|
|
return (0);
|
|
}
|
|
|
|
void
|
|
arpinvalidate(struct rtentry *rt)
|
|
{
|
|
struct llinfo_arp *la;
|
|
struct sockaddr_dl *sdl = satosdl(rt->rt_gateway);
|
|
|
|
mtx_enter(&arp_mtx);
|
|
la = (struct llinfo_arp *)rt->rt_llinfo;
|
|
if (la == NULL) {
|
|
mtx_leave(&arp_mtx);
|
|
return;
|
|
}
|
|
atomic_sub_int(&la_hold_total, mq_purge(&la->la_mq));
|
|
sdl->sdl_alen = 0;
|
|
la->la_asked = 0;
|
|
mtx_leave(&arp_mtx);
|
|
}
|
|
|
|
/*
|
|
* Free an arp entry.
|
|
*/
|
|
void
|
|
arptfree(struct rtentry *rt)
|
|
{
|
|
struct ifnet *ifp;
|
|
|
|
KASSERT(!ISSET(rt->rt_flags, RTF_LOCAL));
|
|
arpinvalidate(rt);
|
|
|
|
ifp = if_get(rt->rt_ifidx);
|
|
if (ifp == NULL)
|
|
return;
|
|
if (!ISSET(rt->rt_flags, RTF_STATIC|RTF_CACHED))
|
|
rtdeletemsg(rt, ifp, ifp->if_rdomain);
|
|
if_put(ifp);
|
|
}
|
|
|
|
/*
|
|
* Lookup or enter a new address in arptab.
|
|
*/
|
|
struct rtentry *
|
|
arplookup(struct in_addr *inp, int create, int proxy, u_int tableid)
|
|
{
|
|
struct rtentry *rt;
|
|
struct sockaddr_inarp sin;
|
|
int flags;
|
|
|
|
memset(&sin, 0, sizeof(sin));
|
|
sin.sin_len = sizeof(sin);
|
|
sin.sin_family = AF_INET;
|
|
sin.sin_addr.s_addr = inp->s_addr;
|
|
sin.sin_other = proxy ? SIN_PROXY : 0;
|
|
flags = (create) ? RT_RESOLVE : 0;
|
|
|
|
rt = rtalloc((struct sockaddr *)&sin, flags, tableid);
|
|
if (!rtisvalid(rt) || ISSET(rt->rt_flags, RTF_GATEWAY) ||
|
|
!ISSET(rt->rt_flags, RTF_LLINFO) ||
|
|
rt->rt_gateway->sa_family != AF_LINK) {
|
|
rtfree(rt);
|
|
return (NULL);
|
|
}
|
|
|
|
if (proxy && !ISSET(rt->rt_flags, RTF_ANNOUNCE)) {
|
|
while ((rt = rtable_iterate(rt)) != NULL) {
|
|
if (ISSET(rt->rt_flags, RTF_ANNOUNCE)) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
return (rt);
|
|
}
|
|
|
|
/*
|
|
* Check whether we do proxy ARP for this address and we point to ourselves.
|
|
*/
|
|
int
|
|
arpproxy(struct in_addr in, unsigned int rtableid)
|
|
{
|
|
struct sockaddr_dl *sdl;
|
|
struct rtentry *rt;
|
|
struct ifnet *ifp;
|
|
int found = 0;
|
|
|
|
rt = arplookup(&in, 0, SIN_PROXY, rtableid);
|
|
if (!rtisvalid(rt)) {
|
|
rtfree(rt);
|
|
return (0);
|
|
}
|
|
|
|
/* Check that arp information are correct. */
|
|
sdl = satosdl(rt->rt_gateway);
|
|
if (sdl->sdl_alen != ETHER_ADDR_LEN) {
|
|
rtfree(rt);
|
|
return (0);
|
|
}
|
|
|
|
ifp = if_get(rt->rt_ifidx);
|
|
if (ifp == NULL) {
|
|
rtfree(rt);
|
|
return (0);
|
|
}
|
|
|
|
if (!memcmp(LLADDR(sdl), LLADDR(ifp->if_sadl), sdl->sdl_alen))
|
|
found = 1;
|
|
|
|
if_put(ifp);
|
|
rtfree(rt);
|
|
return (found);
|
|
}
|
|
|
|
/*
|
|
* Called from 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 ifnet *ifp, struct mbuf *m)
|
|
{
|
|
if ((m = arppullup(m)) == NULL)
|
|
return;
|
|
in_revarpinput(ifp, m);
|
|
}
|
|
|
|
/*
|
|
* RARP for Internet protocols on 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 ifnet *ifp, struct mbuf *m)
|
|
{
|
|
struct ether_arp *ar;
|
|
int op;
|
|
|
|
ar = mtod(m, struct ether_arp *);
|
|
op = ntohs(ar->arp_op);
|
|
switch (op) {
|
|
case ARPOP_REQUEST:
|
|
case ARPOP_REPLY: /* per RFC */
|
|
niq_enqueue(&arpinq, m);
|
|
return;
|
|
case ARPOP_REVREPLY:
|
|
break;
|
|
case ARPOP_REVREQUEST: /* handled by rarpd(8) */
|
|
default:
|
|
goto out;
|
|
}
|
|
#ifdef NFSCLIENT
|
|
if (revarp_ifidx == 0)
|
|
goto out;
|
|
if (revarp_ifidx != m->m_pkthdr.ph_ifidx) /* !same interface */
|
|
goto out;
|
|
if (revarp_finished)
|
|
goto wake;
|
|
if (memcmp(ar->arp_tha, LLADDR(ifp->if_sadl), sizeof(ar->arp_tha)))
|
|
goto out;
|
|
memcpy(&revarp_srvip, ar->arp_spa, sizeof(revarp_srvip));
|
|
memcpy(&revarp_myip, ar->arp_tpa, sizeof(revarp_myip));
|
|
revarp_finished = 1;
|
|
wake: /* Do wakeup every time in case it was missed. */
|
|
wakeup((caddr_t)&revarp_myip);
|
|
#endif /* NFSCLIENT */
|
|
|
|
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 ether_header *eh;
|
|
struct ether_arp *ea;
|
|
struct arpcom *ac = (struct arpcom *)ifp;
|
|
|
|
if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
|
|
return;
|
|
m->m_len = sizeof(*ea);
|
|
m->m_pkthdr.len = sizeof(*ea);
|
|
m->m_pkthdr.ph_rtableid = ifp->if_rdomain;
|
|
m->m_pkthdr.pf.prio = ifp->if_llprio;
|
|
m_align(m, sizeof(*ea));
|
|
ea = mtod(m, struct ether_arp *);
|
|
eh = (struct ether_header *)sa.sa_data;
|
|
memset(ea, 0, sizeof(*ea));
|
|
memcpy(eh->ether_dhost, etherbroadcastaddr, sizeof(eh->ether_dhost));
|
|
eh->ether_type = htons(ETHERTYPE_REVARP);
|
|
ea->arp_hrd = htons(ARPHRD_ETHER);
|
|
ea->arp_pro = htons(ETHERTYPE_IP);
|
|
ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */
|
|
ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */
|
|
ea->arp_op = htons(ARPOP_REVREQUEST);
|
|
memcpy(eh->ether_shost, ac->ac_enaddr, sizeof(ea->arp_tha));
|
|
memcpy(ea->arp_sha, ac->ac_enaddr, sizeof(ea->arp_sha));
|
|
memcpy(ea->arp_tha, ac->ac_enaddr, sizeof(ea->arp_tha));
|
|
sa.sa_family = pseudo_AF_HDRCMPLT;
|
|
sa.sa_len = sizeof(sa);
|
|
m->m_flags |= M_BCAST;
|
|
ifp->if_output(ifp, m, &sa, NULL);
|
|
}
|
|
|
|
#ifdef NFSCLIENT
|
|
/*
|
|
* 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;
|
|
|
|
if (revarp_finished)
|
|
return EIO;
|
|
|
|
revarp_ifidx = ifp->if_index;
|
|
while (count--) {
|
|
revarprequest(ifp);
|
|
result = tsleep_nsec(&revarp_myip, PSOCK, "revarp",
|
|
MSEC_TO_NSEC(500));
|
|
if (result != EWOULDBLOCK)
|
|
break;
|
|
}
|
|
revarp_ifidx = 0;
|
|
if (!revarp_finished)
|
|
return ENETUNREACH;
|
|
|
|
memcpy(serv_in, &revarp_srvip, sizeof(*serv_in));
|
|
memcpy(clnt_in, &revarp_myip, sizeof(*clnt_in));
|
|
return 0;
|
|
}
|
|
|
|
/* For compatibility: only saves interface address. */
|
|
int
|
|
revarpwhoami(struct in_addr *in, struct ifnet *ifp)
|
|
{
|
|
struct in_addr server;
|
|
return (revarpwhoarewe(ifp, &server, in));
|
|
}
|
|
#endif /* NFSCLIENT */
|