/* $NetBSD: if_arp.c,v 1.56 1999/03/22 22:30:42 bad Exp $ */
/*-
* Copyright (c) 1998 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Public Access Networks Corporation ("Panix"). It was developed under
* contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 1982, 1986, 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)if_ether.c 8.2 (Berkeley) 9/26/94
*/
/*
* Ethernet address resolution protocol.
* TODO:
* add "inuse/lock" bit (or ref. count) along with valid bit
*/
#include "opt_ddb.h"
#include "opt_inet.h"
#ifdef INET
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/syslog.h>
#include <sys/proc.h>
#include <net/ethertypes.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_token.h>
#include <net/if_types.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/if_inarp.h>
#include "loop.h"
#include "token.h"
#define SIN(s) ((struct sockaddr_in *)s)
#define SDL(s) ((struct sockaddr_dl *)s)
#define SRP(s) ((struct sockaddr_inarp *)s)
/*
* ARP trailer negotiation. Trailer protocol is not IP specific,
* but ARP request/response use IP addresses.
*/
#define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL
/* timer values */
int arpt_prune = (5*60*1); /* walk list every 5 minutes */
int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
int arpt_down = 20; /* once declared down, don't send for 20 secs */
#define rt_expire rt_rmx.rmx_expire
static void arprequest __P((struct ifnet *,
struct in_addr *, struct in_addr *, u_int8_t *));
static void arptfree __P((struct llinfo_arp *));
static void arptimer __P((void *));
static struct llinfo_arp *arplookup __P((struct in_addr *, int, int));
static void in_arpinput __P((struct mbuf *));
extern struct ifnet loif[NLOOP];
LIST_HEAD(, llinfo_arp) llinfo_arp;
struct ifqueue arpintrq = {0, 0, 0, 50};
int arp_inuse, arp_allocated, arp_intimer;
int arp_maxtries = 5;
int useloopback = 1; /* use loopback interface for local traffic */
int arpinit_done = 0;
/* revarp state */
static struct in_addr myip, srv_ip;
static int myip_initialized = 0;
static int revarp_in_progress = 0;
static struct ifnet *myip_ifp = NULL;
#ifdef DDB
static void db_print_sa __P((struct sockaddr *));
static void db_print_ifa __P((struct ifaddr *));
static void db_print_llinfo __P((caddr_t));
static int db_show_radix_node __P((struct radix_node *, void *));
#endif
/*
* this should be elsewhere.
*/
static char *
lla_snprintf __P((u_int8_t *, int));
static char *
lla_snprintf(adrp, len)
u_int8_t *adrp;
int len;
{
static char buf[16*3];
static const char hexdigits[] = {
'0','1','2','3','4','5','6','7',
'8','9','a','b','c','d','e','f'
};
int i;
char *p;
p = buf;
*p++ = hexdigits[(*adrp)>>4];
*p++ = hexdigits[(*adrp++)&0xf];
for (i=1; i<len && i<16; i++) {
*p++ = ':';
*p++ = hexdigits[(*adrp)>>4];
*p++ = hexdigits[(*adrp++)&0xf];
}
*p = 0;
return buf;
}
/*
* Timeout routine. Age arp_tab entries periodically.
*/
/* ARGSUSED */
static void
arptimer(arg)
void *arg;
{
int s;
register struct llinfo_arp *la, *nla;
s = splsoftnet();
timeout(arptimer, NULL, arpt_prune * hz);
for (la = llinfo_arp.lh_first; la != 0; la = nla) {
register struct rtentry *rt = la->la_rt;
nla = la->la_list.le_next;
if (rt->rt_expire && rt->rt_expire <= time.tv_sec)
arptfree(la); /* timer has expired; clear */
}
splx(s);
}
/*
* Parallel to llc_rtrequest.
*/
void
arp_rtrequest(req, rt, sa)
int req;
register struct rtentry *rt;
struct sockaddr *sa;
{
register struct sockaddr *gate = rt->rt_gateway;
register struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo;
static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
size_t allocsize;
if (!arpinit_done) {
arpinit_done = 1;
/*
* We generate expiration times from time.tv_sec
* so avoid accidently creating permanent routes.
*/
if (time.tv_sec == 0) {
time.tv_sec++;
}
timeout(arptimer, (caddr_t)0, hz);
}
if (rt->rt_flags & RTF_GATEWAY)
return;
switch (req) {
case RTM_ADD:
/*
* XXX: If this is a manually added route to interface
* such as older version of routed or gated might provide,
* restore cloning bit.
*/
if ((rt->rt_flags & RTF_HOST) == 0 &&
SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
rt->rt_flags |= RTF_CLONING;
if (rt->rt_flags & RTF_CLONING) {
/*
* Case 1: This route should come from a route to iface.
*/
rt_setgate(rt, rt_key(rt),
(struct sockaddr *)&null_sdl);
gate = rt->rt_gateway;
SDL(gate)->sdl_type = rt->rt_ifp->if_type;
SDL(gate)->sdl_index = rt->rt_ifp->if_index;
/*
* 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.tv_sec;
break;
}
/* Announce a new entry if requested. */
if (rt->rt_flags & RTF_ANNOUNCE)
arprequest(rt->rt_ifp,
&SIN(rt_key(rt))->sin_addr,
&SIN(rt_key(rt))->sin_addr,
(u_char *)LLADDR(SDL(gate)));
/*FALLTHROUGH*/
case RTM_RESOLVE:
if (gate->sa_family != AF_LINK ||
gate->sa_len < sizeof(null_sdl)) {
log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n");
break;
}
SDL(gate)->sdl_type = rt->rt_ifp->if_type;
SDL(gate)->sdl_index = rt->rt_ifp->if_index;
if (la != 0)
break; /* This happens on a route change */
/*
* Case 2: This route may come from cloning, or a manual route
* add with a LL address.
*/
switch (SDL(gate)->sdl_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 = (caddr_t)la;
if (la == 0) {
log(LOG_DEBUG, "arp_rtrequest: malloc failed\n");
break;
}
arp_inuse++, arp_allocated++;
Bzero(la, allocsize);
la->la_rt = rt;
rt->rt_flags |= RTF_LLINFO;
LIST_INSERT_HEAD(&llinfo_arp, la, la_list);
if (in_hosteq(SIN(rt_key(rt))->sin_addr,
(IA_SIN(rt->rt_ifa))->sin_addr)) {
/*
* This test used to be
* if (loif.if_flags & IFF_UP)
* It allowed local traffic to be forced through
* the hardware by configuring the loopback down.
* However, it causes problems during network
* configuration for boards that can't receive
* packets they send. It is now necessary to clear
* "useloopback" and remove the route to force
* traffic out to the hardware.
*/
rt->rt_expire = 0;
Bcopy(LLADDR(rt->rt_ifp->if_sadl),
LLADDR(SDL(gate)),
SDL(gate)->sdl_alen =
rt->rt_ifp->if_data.ifi_addrlen);
if (useloopback)
rt->rt_ifp = &loif[0];
}
break;
case RTM_DELETE:
if (la == 0)
break;
arp_inuse--;
LIST_REMOVE(la, la_list);
rt->rt_llinfo = 0;
rt->rt_flags &= ~RTF_LLINFO;
if (la->la_hold)
m_freem(la->la_hold);
Free((caddr_t)la);
}
}
/*
* Broadcast an ARP request. Caller specifies:
* - arp header source ip address
* - arp header target ip address
* - arp header source ethernet address
*/
static void
arprequest(ifp, sip, tip, enaddr)
register struct ifnet *ifp;
register struct in_addr *sip, *tip;
register u_int8_t *enaddr;
{
register struct mbuf *m;
struct arphdr *ah;
struct sockaddr sa;
if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
return;
m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) +
2*ifp->if_data.ifi_addrlen;
m->m_pkthdr.len = m->m_len;
MH_ALIGN(m, m->m_len);
ah = mtod(m, struct arphdr *);
bzero((caddr_t)ah, m->m_len);
ah->ar_pro = htons(ETHERTYPE_IP);
ah->ar_hln = ifp->if_data.ifi_addrlen; /* hardware address length */
ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
ah->ar_op = htons(ARPOP_REQUEST);
bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln);
bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln);
bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln);
sa.sa_family = AF_ARP;
sa.sa_len = 2;
m->m_flags |= M_BCAST;
(*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
}
/*
* Resolve an IP address into an ethernet address. If success,
* desten is filled in. If there is no entry in arptab,
* set one up and broadcast a request for the IP address.
* Hold onto this mbuf and resend it once the address
* is finally resolved. A return value of 1 indicates
* that desten has been filled in and the packet should be sent
* normally; a 0 return indicates that the packet has been
* taken over here, either now or for later transmission.
*/
int
arpresolve(ifp, rt, m, dst, desten)
register struct ifnet *ifp;
register struct rtentry *rt;
struct mbuf *m;
register struct sockaddr *dst;
register u_char *desten;
{
register struct llinfo_arp *la;
struct sockaddr_dl *sdl;
if (rt)
la = (struct llinfo_arp *)rt->rt_llinfo;
else {
if ((la = arplookup(&SIN(dst)->sin_addr, 1, 0)) != NULL)
rt = la->la_rt;
}
if (la == 0 || rt == 0) {
log(LOG_DEBUG, "arpresolve: can't allocate llinfo\n");
m_freem(m);
return (0);
}
sdl = SDL(rt->rt_gateway);
/*
* Check the address family and length is valid, the address
* is resolved; otherwise, try to resolve.
*/
if ((rt->rt_expire == 0 || rt->rt_expire > time.tv_sec) &&
sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
bcopy(LLADDR(sdl), desten,
min(sdl->sdl_alen, ifp->if_data.ifi_addrlen));
return 1;
}
/*
* There is an arptab entry, but no ethernet address
* response yet. Replace the held mbuf with this
* latest one.
*/
if (la->la_hold)
m_freem(la->la_hold);
la->la_hold = m;
/*
* 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.tv_sec;
}
#endif
if (rt->rt_expire) {
rt->rt_flags &= ~RTF_REJECT;
if (la->la_asked == 0 || rt->rt_expire != time.tv_sec) {
rt->rt_expire = time.tv_sec;
if (la->la_asked++ < arp_maxtries)
arprequest(ifp,
&SIN(rt->rt_ifa->ifa_addr)->sin_addr,
&SIN(dst)->sin_addr,
LLADDR(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()
{
register struct mbuf *m;
register struct arphdr *ar;
int s;
while (arpintrq.ifq_head) {
s = splimp();
IF_DEQUEUE(&arpintrq, m);
splx(s);
if (m == 0 || (m->m_flags & M_PKTHDR) == 0)
panic("arpintr");
if (m->m_len >= sizeof(struct arphdr) &&
(ar = mtod(m, struct arphdr *)) &&
/* XXX ntohs(ar->ar_hrd) == ARPHRD_ETHER && */
m->m_len >=
sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln))
switch (ntohs(ar->ar_pro)) {
case ETHERTYPE_IP:
case ETHERTYPE_IPTRAILERS:
in_arpinput(m);
continue;
}
m_freem(m);
}
}
/*
* 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(m)
struct mbuf *m;
{
struct arphdr *ah;
register struct ifnet *ifp = m->m_pkthdr.rcvif;
register struct llinfo_arp *la = 0;
register struct rtentry *rt;
struct in_ifaddr *ia;
struct sockaddr_dl *sdl;
struct sockaddr sa;
struct in_addr isaddr, itaddr, myaddr;
int op;
ah = mtod(m, struct arphdr *);
op = ntohs(ah->ar_op);
bcopy((caddr_t)ar_spa(ah), (caddr_t)&isaddr, sizeof (isaddr));
bcopy((caddr_t)ar_tpa(ah), (caddr_t)&itaddr, sizeof (itaddr));
/*
* 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))
goto out;
/*
* If the source IP address is zero, this is most likely a
* confused host trying to use IP address zero. (Windoze?)
* XXX: Should we bother trying to reply to these?
*/
if (in_nullhost(isaddr))
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) && ia->ia_ifp != m->m_pkthdr.rcvif)
NEXT_IA_WITH_SAME_ADDR(ia);
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)
goto out;
}
}
myaddr = ia->ia_addr.sin_addr;
if (!bcmp((caddr_t)ar_sha(ah), LLADDR(ifp->if_sadl),
ifp->if_data.ifi_addrlen))
goto out; /* it's from me, ignore it. */
if (!bcmp((caddr_t)ar_sha(ah), (caddr_t)ifp->if_broadcastaddr,
ifp->if_data.ifi_addrlen)) {
log(LOG_ERR,
"%s: arp: link address is broadcast for IP address %s!\n",
ifp->if_xname, in_fmtaddr(isaddr));
goto out;
}
if (in_hosteq(isaddr, myaddr)) {
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(&isaddr, in_hosteq(itaddr, myaddr), 0);
if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) {
if (sdl->sdl_alen &&
bcmp((caddr_t)ar_sha(ah), LLADDR(sdl), sdl->sdl_alen))
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) {
log(LOG_WARNING,
"arp from %s: new addr len %d, was %d",
in_fmtaddr(isaddr), ah->ar_hln, sdl->sdl_alen);
}
if (ifp->if_data.ifi_addrlen != ah->ar_hln) {
log(LOG_WARNING,
"arp from %s: addr len: new %d, i/f %d (ignored)",
in_fmtaddr(isaddr), ah->ar_hln,
ifp->if_data.ifi_addrlen);
goto reply;
}
#if NTOKEN > 0
/*
* XXX uses m_pktdat and assumes the complete answer including
* XXX token-ring headers is in the same buf
*/
if (ifp->if_type == IFT_ISO88025 &&
m->m_pktdat[8] & TOKEN_RI_PRESENT) {
struct token_rif *rif;
size_t riflen;
rif = TOKEN_RIF((struct token_header *) m->m_pktdat);
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);
bcopy(rif, TOKEN_RIF(la), riflen);
}
}
#endif /* NTOKEN > 0 */
bcopy((caddr_t)ar_sha(ah), LLADDR(sdl),
sdl->sdl_alen = ah->ar_hln);
if (rt->rt_expire)
rt->rt_expire = time.tv_sec + arpt_keep;
rt->rt_flags &= ~RTF_REJECT;
la->la_asked = 0;
if (la->la_hold) {
(*ifp->if_output)(ifp, la->la_hold,
rt_key(rt), rt);
la->la_hold = 0;
}
}
reply:
if (op != ARPOP_REQUEST) {
out:
m_freem(m);
return;
}
if (in_hosteq(itaddr, myaddr)) {
/* I am the target */
bcopy((caddr_t)ar_sha(ah), (caddr_t)ar_tha(ah), ah->ar_hln);
bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_sha(ah), ah->ar_hln);
} else {
la = arplookup(&itaddr, 0, SIN_PROXY);
if (la == 0)
goto out;
rt = la->la_rt;
bcopy((caddr_t)ar_sha(ah), (caddr_t)ar_tha(ah), ah->ar_hln);
sdl = SDL(rt->rt_gateway);
bcopy(LLADDR(sdl), (caddr_t)ar_sha(ah), ah->ar_hln);
}
bcopy((caddr_t)ar_spa(ah), (caddr_t)ar_tpa(ah), ah->ar_pln);
bcopy((caddr_t)&itaddr, (caddr_t)ar_spa(ah), ah->ar_pln);
ah->ar_op = htons(ARPOP_REPLY);
ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */
sa.sa_family = AF_ARP;
sa.sa_len = 2;
(*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
return;
}
/*
* Free an arp entry.
*/
static void
arptfree(la)
register struct llinfo_arp *la;
{
register struct rtentry *rt = la->la_rt;
register struct sockaddr_dl *sdl;
if (rt == 0)
panic("arptfree");
if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) &&
sdl->sdl_family == AF_LINK) {
sdl->sdl_alen = 0;
la->la_asked = 0;
rt->rt_flags &= ~RTF_REJECT;
return;
}
rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt),
0, (struct rtentry **)0);
}
/*
* Lookup or enter a new address in arptab.
*/
static struct llinfo_arp *
arplookup(addr, create, proxy)
struct in_addr *addr;
int create, proxy;
{
register struct rtentry *rt;
static struct sockaddr_inarp sin;
const char *why = 0;
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 == 0)
return (0);
rt->rt_refcnt--;
if (rt->rt_flags & RTF_GATEWAY)
why = "host is not on local network";
else if ((rt->rt_flags & RTF_LLINFO) == 0)
why = "could not allocate llinfo";
else if (rt->rt_gateway->sa_family != AF_LINK)
why = "gateway route is not ours";
else
return ((struct llinfo_arp *)rt->rt_llinfo);
if (create)
log(LOG_DEBUG, "arplookup: unable to enter address"
" for %s (%s)\n",
in_fmtaddr(*addr), why);
return (0);
}
int
arpioctl(cmd, data)
u_long cmd;
caddr_t data;
{
return (EOPNOTSUPP);
}
void
arp_ifinit(ifp, ifa)
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, LLADDR(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(m)
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(m)
struct mbuf *m;
{
struct ifnet *ifp;
struct arphdr *ah;
int op;
ah = mtod(m, struct arphdr *);
op = ntohs(ah->ar_op);
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;
if (bcmp(ar_tha(ah), LLADDR(ifp->if_sadl), ifp->if_sadl->sdl_alen))
goto out;
bcopy((caddr_t)ar_spa(ah), (caddr_t)&srv_ip, sizeof(srv_ip));
bcopy((caddr_t)ar_tpa(ah), (caddr_t)&myip, sizeof(myip));
myip_initialized = 1;
wake: /* Do wakeup every time in case it was missed. */
wakeup((caddr_t)&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(ifp)
struct ifnet *ifp;
{
struct sockaddr sa;
struct mbuf *m;
struct arphdr *ah;
if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
return;
m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) +
2*ifp->if_data.ifi_addrlen;
m->m_pkthdr.len = m->m_len;
MH_ALIGN(m, m->m_len);
ah = mtod(m, struct arphdr *);
bzero((caddr_t)ah, m->m_len);
ah->ar_pro = htons(ETHERTYPE_IP);
ah->ar_hln = ifp->if_data.ifi_addrlen; /* hardware address length */
ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
ah->ar_op = htons(ARPOP_REVREQUEST);
bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_sha(ah), ah->ar_hln);
bcopy(LLADDR(ifp->if_sadl), (caddr_t)ar_tha(ah), ah->ar_hln);
sa.sa_family = AF_ARP;
sa.sa_len = 2;
m->m_flags |= M_BCAST;
(*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
}
/*
* 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(ifp, serv_in, clnt_in)
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((caddr_t)&myip, PSOCK, "revarp", hz/2);
if (result != EWOULDBLOCK)
break;
}
revarp_in_progress = 0;
if (!myip_initialized)
return ENETUNREACH;
bcopy((caddr_t)&srv_ip, serv_in, sizeof(*serv_in));
bcopy((caddr_t)&myip, clnt_in, 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(sa)
struct sockaddr *sa;
{
int len;
u_char *p;
if (sa == 0) {
db_printf("[NULL]");
return;
}
p = (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(ifa)
struct ifaddr *ifa;
{
if (ifa == 0)
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(li)
caddr_t li;
{
struct llinfo_arp *la;
if (li == 0)
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 rn_walktree().
* Return non-zero error to abort walk.
*/
static int
db_show_radix_node(rn, w)
struct radix_node *rn;
void *w;
{
struct rtentry *rt = (struct rtentry *)rn;
db_printf("rtentry=%p", rt);
db_printf(" flags=0x%x refcnt=%d use=%ld expire=%ld\n",
rt->rt_flags, rt->rt_refcnt,
rt->rt_use, rt->rt_expire);
db_printf(" key="); db_print_sa(rt_key(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(" genmask="); db_print_sa(rt->rt_genmask);
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: "call db_show_arptab"
*/
int
db_show_arptab()
{
struct radix_node_head *rnh;
rnh = rt_tables[AF_INET];
db_printf("Route tree for AF_INET\n");
if (rnh == NULL) {
db_printf(" (not initialized)\n");
return (0);
}
rn_walktree(rnh, db_show_radix_node, NULL);
return (0);
}
#endif
#endif /* INET */