/* $OpenBSD: if_ether.c,v 1.68 2007/03/25 16:43:22 claudio Exp $ */
/* $NetBSD: if_ether.c,v 1.31 1996/05/11 12:59:58 mycroft Exp $ */
/*
* 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)if_ether.c 8.1 (Berkeley) 6/10/93
*/
/*
* Ethernet address resolution protocol.
* TODO:
* add "inuse/lock" bit (or ref. count) along with valid bit
*/
#ifdef INET
#include "carp.h"
#include "bridge.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/proc.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/if_fddi.h>
#include <net/if_types.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/if_ether.h>
#if NCARP > 0
#include <netinet/ip_carp.h>
#endif
#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
void arptfree(struct llinfo_arp *);
void arptimer(void *);
struct llinfo_arp *arplookup(u_int32_t, int, int);
void in_arpinput(struct mbuf *);
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 */
struct in_addr myip, srv_ip;
int myip_initialized = 0;
int revarp_in_progress = 0;
struct ifnet *myip_ifp = NULL;
#ifdef DDB
#include <uvm/uvm_extern.h>
void db_print_sa(struct sockaddr *);
void db_print_ifa(struct ifaddr *);
void db_print_llinfo(caddr_t);
int db_show_radix_node(struct radix_node *, void *);
#endif
/*
* Timeout routine. Age arp_tab entries periodically.
*/
/* ARGSUSED */
void
arptimer(arg)
void *arg;
{
struct timeout *to = (struct timeout *)arg;
int s;
struct llinfo_arp *la, *nla;
s = splsoftnet();
timeout_add(to, arpt_prune * hz);
for (la = LIST_FIRST(&llinfo_arp); la != LIST_END(&llinfo_arp);
la = nla) {
struct rtentry *rt = la->la_rt;
nla = LIST_NEXT(la, la_list);
if (rt->rt_expire && rt->rt_expire <= time_second)
arptfree(la); /* timer has expired; clear */
}
splx(s);
}
/*
* Parallel to llc_rtrequest.
*/
void
arp_rtrequest(req, rt, info)
int req;
struct rtentry *rt;
struct rt_addrinfo *info;
{
struct sockaddr *gate = rt->rt_gateway;
struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo;
static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
struct in_ifaddr *ia;
struct ifaddr *ifa;
if (!arpinit_done) {
static struct timeout arptimer_to;
arpinit_done = 1;
/*
* We generate expiration times from time.tv_sec
* so avoid accidently creating permanent routes.
*/
if (time_second == 0) {
time_second++;
}
timeout_set(&arptimer_to, arptimer, &arptimer_to);
timeout_add(&arptimer_to, hz);
}
if (rt->rt_flags & RTF_GATEWAY) {
if (req != RTM_ADD)
return;
/*
* linklayers with particular link MTU limitation. it is a bit
* awkward to have FDDI handling here, we should split ARP from
* netinet/if_ether.c like NetBSD does.
*/
switch (rt->rt_ifp->if_type) {
case IFT_FDDI:
if (rt->rt_ifp->if_mtu > FDDIIPMTU)
rt->rt_rmx.rmx_mtu = FDDIIPMTU;
break;
}
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, 0);
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_second;
/*
* linklayers with particular link MTU limitation.
*/
switch (rt->rt_ifp->if_type) {
case IFT_FDDI:
if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 &&
(rt->rt_rmx.rmx_mtu > FDDIIPMTU ||
(rt->rt_rmx.rmx_mtu == 0 &&
rt->rt_ifp->if_mtu > FDDIIPMTU)))
rt->rt_rmx.rmx_mtu = FDDIIPMTU;
break;
}
break;
}
/* Announce a new entry if requested. */
if (rt->rt_flags & RTF_ANNOUNCE)
arprequest(rt->rt_ifp,
&SIN(rt_key(rt))->sin_addr.s_addr,
&SIN(rt_key(rt))->sin_addr.s_addr,
(u_char *)LLADDR(SDL(gate)));
/*FALLTHROUGH*/
case RTM_RESOLVE:
if (gate->sa_family != AF_LINK ||
gate->sa_len < sizeof(null_sdl)) {
log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n");
break;
}
SDL(gate)->sdl_type = rt->rt_ifp->if_type;
SDL(gate)->sdl_index = rt->rt_ifp->if_index;
if (la != 0)
break; /* This happens on a route change */
/*
* Case 2: This route may come from cloning, or a manual route
* add with a LL address.
*/
R_Malloc(la, struct llinfo_arp *, sizeof(*la));
rt->rt_llinfo = (caddr_t)la;
if (la == 0) {
log(LOG_DEBUG, "arp_rtrequest: malloc failed\n");
break;
}
arp_inuse++, arp_allocated++;
Bzero(la, sizeof(*la));
la->la_rt = rt;
rt->rt_flags |= RTF_LLINFO;
LIST_INSERT_HEAD(&llinfo_arp, la, la_list);
TAILQ_FOREACH(ia, &in_ifaddr, ia_list) {
if (ia->ia_ifp == rt->rt_ifp &&
SIN(rt_key(rt))->sin_addr.s_addr ==
(IA_SIN(ia))->sin_addr.s_addr)
break;
}
if (ia) {
/*
* This test used to be
* if (lo0ifp->if_flags & IFF_UP)
* It allowed local traffic to be forced through
* the hardware by configuring the loopback down.
* However, it causes problems during network
* configuration for boards that can't receive
* packets they send. It is now necessary to clear
* "useloopback" and remove the route to force
* traffic out to the hardware.
*
* In 4.4BSD, the above "if" statement checked
* rt->rt_ifa against rt_key(rt). It was changed
* to the current form so that we can provide a
* better support for multiple IPv4 addresses on a
* interface.
*/
rt->rt_expire = 0;
Bcopy(((struct arpcom *)rt->rt_ifp)->ac_enaddr,
LLADDR(SDL(gate)),
SDL(gate)->sdl_alen = ETHER_ADDR_LEN);
if (useloopback)
rt->rt_ifp = lo0ifp;
/*
* make sure to set rt->rt_ifa to the interface
* address we are using, otherwise we will have trouble
* with source address selection.
*/
ifa = &ia->ia_ifa;
if (ifa != rt->rt_ifa) {
IFAFREE(rt->rt_ifa);
ifa->ifa_refcnt++;
rt->rt_ifa = ifa;
}
}
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
*/
void
arprequest(ifp, sip, tip, enaddr)
struct ifnet *ifp;
u_int32_t *sip, *tip;
u_int8_t *enaddr;
{
struct mbuf *m;
struct ether_header *eh;
struct ether_arp *ea;
struct sockaddr sa;
if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
return;
m->m_len = sizeof(*ea);
m->m_pkthdr.len = sizeof(*ea);
MH_ALIGN(m, sizeof(*ea));
ea = mtod(m, struct ether_arp *);
eh = (struct ether_header *)sa.sa_data;
bzero((caddr_t)ea, sizeof (*ea));
bcopy((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
sizeof(eh->ether_dhost));
eh->ether_type = htons(ETHERTYPE_ARP); /* if_output will not swap */
ea->arp_hrd = htons(ARPHRD_ETHER);
ea->arp_pro = htons(ETHERTYPE_IP);
ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */
ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */
ea->arp_op = htons(ARPOP_REQUEST);
bcopy((caddr_t)enaddr, (caddr_t)eh->ether_shost,
sizeof(eh->ether_shost));
bcopy((caddr_t)enaddr, (caddr_t)ea->arp_sha, sizeof(ea->arp_sha));
bcopy((caddr_t)sip, (caddr_t)ea->arp_spa, sizeof(ea->arp_spa));
bcopy((caddr_t)tip, (caddr_t)ea->arp_tpa, sizeof(ea->arp_tpa));
sa.sa_family = pseudo_AF_HDRCMPLT;
sa.sa_len = sizeof(sa);
(*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(ac, rt, m, dst, desten)
struct arpcom *ac;
struct rtentry *rt;
struct mbuf *m;
struct sockaddr *dst;
u_char *desten;
{
struct llinfo_arp *la;
struct sockaddr_dl *sdl;
if (m->m_flags & M_BCAST) { /* broadcast */
bcopy((caddr_t)etherbroadcastaddr, (caddr_t)desten,
sizeof(etherbroadcastaddr));
return (1);
}
if (m->m_flags & M_MCAST) { /* multicast */
ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
return (1);
}
if (rt) {
la = (struct llinfo_arp *)rt->rt_llinfo;
if (la == NULL)
log(LOG_DEBUG, "arpresolve: %s: route without link "
"local address\n", inet_ntoa(SIN(dst)->sin_addr));
} else {
if ((la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0)) != NULL)
rt = la->la_rt;
else
log(LOG_DEBUG,
"arpresolve: %s: can't allocate llinfo\n",
inet_ntoa(SIN(dst)->sin_addr));
}
if (la == 0 || rt == 0) {
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_second) &&
sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
return 1;
}
if (((struct ifnet *)ac)->if_flags & IFF_NOARP)
return 0;
/*
* 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_second;
}
#endif
if (rt->rt_expire) {
rt->rt_flags &= ~RTF_REJECT;
if (la->la_asked == 0 || rt->rt_expire != time_second) {
rt->rt_expire = time_second;
if (la->la_asked++ < arp_maxtries)
arprequest(&ac->ac_if,
&(SIN(rt->rt_ifa->ifa_addr)->sin_addr.s_addr),
&(SIN(dst)->sin_addr.s_addr),
#if NCARP > 0
(rt->rt_ifp->if_type == IFT_CARP) ?
((struct arpcom *) rt->rt_ifp->if_softc
)->ac_enaddr :
#endif
ac->ac_enaddr);
else {
rt->rt_flags |= RTF_REJECT;
rt->rt_expire += arpt_down;
la->la_asked = 0;
}
}
}
return (0);
}
/*
* Common length and type checks are done here,
* then the protocol-specific routine is called.
*/
void
arpintr()
{
struct mbuf *m;
struct arphdr *ar;
int s, len;
while (arpintrq.ifq_head) {
s = splnet();
IF_DEQUEUE(&arpintrq, m);
splx(s);
if (m == 0 || (m->m_flags & M_PKTHDR) == 0)
panic("arpintr");
len = sizeof(struct arphdr);
if (m->m_len < len && (m = m_pullup(m, len)) == NULL)
continue;
ar = mtod(m, struct arphdr *);
if (ntohs(ar->ar_hrd) != ARPHRD_ETHER) {
m_freem(m);
continue;
}
len += 2 * (ar->ar_hln + ar->ar_pln);
if (m->m_len < len && (m = m_pullup(m, len)) == NULL)
continue;
switch (ntohs(ar->ar_pro)) {
case ETHERTYPE_IP:
case ETHERTYPE_IPTRAILERS:
in_arpinput(m);
continue;
}
m_freem(m);
}
}
/*
* ARP for Internet protocols on 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.
*/
void
in_arpinput(m)
struct mbuf *m;
{
struct ether_arp *ea;
struct arpcom *ac = (struct arpcom *)m->m_pkthdr.rcvif;
struct ether_header *eh;
struct llinfo_arp *la = 0;
struct rtentry *rt;
struct in_ifaddr *ia;
#if NBRIDGE > 0
struct in_ifaddr *bridge_ia = NULL;
#endif
#if NCARP > 0
u_int32_t count = 0, index = 0;
#endif
struct sockaddr_dl *sdl;
struct sockaddr sa;
struct in_addr isaddr, itaddr, myaddr;
u_int8_t *enaddr = NULL;
int op;
ea = mtod(m, struct ether_arp *);
op = ntohs(ea->arp_op);
if ((op != ARPOP_REQUEST) && (op != ARPOP_REPLY))
goto out;
#if notyet
if ((op == ARPOP_REPLY) && (m->m_flags & (M_BCAST|M_MCAST))) {
log(LOG_ERR,
"arp: received reply to broadcast or multicast address\n");
goto out;
}
#endif
bcopy((caddr_t)ea->arp_tpa, (caddr_t)&itaddr, sizeof(itaddr));
bcopy((caddr_t)ea->arp_spa, (caddr_t)&isaddr, sizeof(isaddr));
TAILQ_FOREACH(ia, &in_ifaddr, ia_list) {
if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr)
continue;
#if NCARP > 0
if (ia->ia_ifp->if_type == IFT_CARP &&
((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) ==
(IFF_UP|IFF_RUNNING))) {
index++;
if (ia->ia_ifp == m->m_pkthdr.rcvif &&
carp_iamatch(ia, ea->arp_sha,
&count, index))
break;
} else
#endif
if (ia->ia_ifp == m->m_pkthdr.rcvif)
break;
#if NBRIDGE > 0
/*
* If the interface we received the packet on
* is part of a bridge, check to see if we need
* to "bridge" the packet to ourselves at this
* layer. Note we still prefer a perfect match,
* but allow this weaker match if necessary.
*/
if (m->m_pkthdr.rcvif->if_bridge != NULL) {
if (m->m_pkthdr.rcvif->if_bridge ==
ia->ia_ifp->if_bridge)
bridge_ia = ia;
#if NCARP > 0
else if (ia->ia_ifp->if_carpdev != NULL &&
m->m_pkthdr.rcvif->if_bridge ==
ia->ia_ifp->if_carpdev->if_bridge &&
carp_iamatch(ia, ea->arp_sha,
&count, index))
bridge_ia = ia;
#endif
}
#endif
}
#if NBRIDGE > 0
if (ia == NULL && bridge_ia != NULL) {
ia = bridge_ia;
ac = (struct arpcom *)bridge_ia->ia_ifp;
}
#endif
if (ia == NULL) {
TAILQ_FOREACH(ia, &in_ifaddr, ia_list) {
if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr)
continue;
if (ia->ia_ifp == m->m_pkthdr.rcvif)
break;
}
}
if (ia == NULL && m->m_pkthdr.rcvif->if_type != IFT_CARP) {
struct ifaddr *ifa;
TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrlist, ifa_list) {
if (ifa->ifa_addr->sa_family == AF_INET)
break;
}
if (ifa)
ia = (struct in_ifaddr *)ifa;
}
if (ia == NULL)
goto out;
if (!enaddr)
enaddr = ac->ac_enaddr;
myaddr = ia->ia_addr.sin_addr;
if (!bcmp((caddr_t)ea->arp_sha, enaddr, sizeof (ea->arp_sha)))
goto out; /* it's from me, ignore it. */
if (ETHER_IS_MULTICAST (&ea->arp_sha[0]))
if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)etherbroadcastaddr,
sizeof (ea->arp_sha))) {
log(LOG_ERR, "arp: ether address is broadcast for "
"IP address %s!\n", inet_ntoa(isaddr));
goto out;
}
if (myaddr.s_addr && isaddr.s_addr == myaddr.s_addr) {
log(LOG_ERR,
"duplicate IP address %s sent from ethernet address %s\n",
inet_ntoa(isaddr), ether_sprintf(ea->arp_sha));
itaddr = myaddr;
goto reply;
}
la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0);
if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) {
if (sdl->sdl_alen) {
if (bcmp(ea->arp_sha, LLADDR(sdl), sdl->sdl_alen)) {
if (rt->rt_flags & RTF_PERMANENT_ARP) {
log(LOG_WARNING,
"arp: attempt to overwrite permanent "
"entry for %s by %s on %s\n",
inet_ntoa(isaddr),
ether_sprintf(ea->arp_sha),
ac->ac_if.if_xname);
goto out;
} else if (rt->rt_ifp != &ac->ac_if) {
log(LOG_WARNING,
"arp: attempt to overwrite entry for %s "
"on %s by %s on %s\n",
inet_ntoa(isaddr), rt->rt_ifp->if_xname,
ether_sprintf(ea->arp_sha),
ac->ac_if.if_xname);
goto out;
} else {
log(LOG_INFO,
"arp info overwritten for %s by %s on %s\n",
inet_ntoa(isaddr),
ether_sprintf(ea->arp_sha),
ac->ac_if.if_xname);
rt->rt_expire = 1; /* no longer static */
}
}
} else if (rt->rt_ifp != &ac->ac_if && !(ac->ac_if.if_bridge &&
(rt->rt_ifp->if_bridge == ac->ac_if.if_bridge)) &&
!(rt->rt_ifp->if_type == IFT_CARP &&
rt->rt_ifp->if_carpdev == &ac->ac_if) &&
!(ac->ac_if.if_type == IFT_CARP &&
ac->ac_if.if_carpdev == rt->rt_ifp)) {
log(LOG_WARNING,
"arp: attempt to add entry for %s "
"on %s by %s on %s\n",
inet_ntoa(isaddr), rt->rt_ifp->if_xname,
ether_sprintf(ea->arp_sha),
ac->ac_if.if_xname);
goto out;
}
bcopy(ea->arp_sha, LLADDR(sdl),
sdl->sdl_alen = sizeof(ea->arp_sha));
if (rt->rt_expire)
rt->rt_expire = time_second + arpt_keep;
rt->rt_flags &= ~RTF_REJECT;
la->la_asked = 0;
if (la->la_hold) {
(*ac->ac_if.if_output)(&ac->ac_if, la->la_hold,
rt_key(rt), rt);
la->la_hold = 0;
}
}
reply:
if (op != ARPOP_REQUEST) {
out:
m_freem(m);
return;
}
if (itaddr.s_addr == myaddr.s_addr) {
/* I am the target */
bcopy(ea->arp_sha, ea->arp_tha, sizeof(ea->arp_sha));
bcopy(enaddr, ea->arp_sha, sizeof(ea->arp_sha));
} else {
la = arplookup(itaddr.s_addr, 0, SIN_PROXY);
if (la == 0)
goto out;
rt = la->la_rt;
if (rt->rt_ifp->if_type == IFT_CARP &&
m->m_pkthdr.rcvif->if_type != IFT_CARP)
goto out;
bcopy(ea->arp_sha, ea->arp_tha, sizeof(ea->arp_sha));
sdl = SDL(rt->rt_gateway);
bcopy(LLADDR(sdl), ea->arp_sha, sizeof(ea->arp_sha));
}
bcopy(ea->arp_spa, ea->arp_tpa, sizeof(ea->arp_spa));
bcopy(&itaddr, ea->arp_spa, sizeof(ea->arp_spa));
ea->arp_op = htons(ARPOP_REPLY);
ea->arp_pro = htons(ETHERTYPE_IP); /* let's be sure! */
eh = (struct ether_header *)sa.sa_data;
bcopy(ea->arp_tha, eh->ether_dhost, sizeof(eh->ether_dhost));
#if NCARP > 0
if (ac->ac_if.if_type == IFT_CARP && ac->ac_if.if_flags & IFF_LINK1)
bcopy(((struct arpcom *)ac->ac_if.if_carpdev)->ac_enaddr,
eh->ether_shost, sizeof(eh->ether_shost));
else
#endif
bcopy(enaddr, eh->ether_shost, sizeof(eh->ether_shost));
eh->ether_type = htons(ETHERTYPE_ARP);
sa.sa_family = pseudo_AF_HDRCMPLT;
sa.sa_len = sizeof(sa);
(*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0);
return;
}
/*
* Free an arp entry.
*/
void
arptfree(la)
struct llinfo_arp *la;
{
struct rtentry *rt = la->la_rt;
struct sockaddr_dl *sdl;
if (rt == 0)
panic("arptfree");
if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) &&
sdl->sdl_family == AF_LINK) {
sdl->sdl_alen = 0;
la->la_asked = 0;
rt->rt_flags &= ~RTF_REJECT;
return;
}
rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt),
0, (struct rtentry **)0, 0);
}
/*
* Lookup or enter a new address in arptab.
*/
struct llinfo_arp *
arplookup(addr, create, proxy)
u_int32_t addr;
int create, proxy;
{
struct rtentry *rt;
static struct sockaddr_inarp sin;
sin.sin_len = sizeof(sin);
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = addr;
sin.sin_other = proxy ? SIN_PROXY : 0;
rt = rtalloc1(sintosa(&sin), create, 0);
if (rt == 0)
return (0);
rt->rt_refcnt--;
if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
rt->rt_gateway->sa_family != AF_LINK) {
if (create) {
if (rt->rt_refcnt <= 0 &&
(rt->rt_flags & RTF_CLONED) != 0) {
rtrequest(RTM_DELETE,
(struct sockaddr *)rt_key(rt),
rt->rt_gateway, rt_mask(rt), rt->rt_flags,
0, 0);
}
}
return (0);
}
return ((struct llinfo_arp *)rt->rt_llinfo);
}
int
arpioctl(cmd, data)
u_long cmd;
caddr_t data;
{
return (EOPNOTSUPP);
}
void
arp_ifinit(ac, ifa)
struct arpcom *ac;
struct ifaddr *ifa;
{
/* Warn the user if another station has this IP address. */
arprequest(&ac->ac_if,
&(IA_SIN(ifa)->sin_addr.s_addr),
&(IA_SIN(ifa)->sin_addr.s_addr),
ac->ac_enaddr);
ifa->ifa_rtrequest = arp_rtrequest;
ifa->ifa_flags |= RTF_CLONING;
}
/*
* 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(m)
struct mbuf *m;
{
struct arphdr *ar;
if (m->m_len < sizeof(struct arphdr))
goto out;
ar = mtod(m, struct arphdr *);
if (ntohs(ar->ar_hrd) != ARPHRD_ETHER)
goto out;
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 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 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 */
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->arp_tha, ((struct arpcom *)ifp)->ac_enaddr,
sizeof(ar->arp_tha)))
goto out;
bcopy((caddr_t)ar->arp_spa, (caddr_t)&srv_ip, sizeof(srv_ip));
bcopy((caddr_t)ar->arp_tpa, (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 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);
MH_ALIGN(m, sizeof(*ea));
ea = mtod(m, struct ether_arp *);
eh = (struct ether_header *)sa.sa_data;
bzero((caddr_t)ea, sizeof(*ea));
bcopy((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
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);
bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
sizeof(ea->arp_tha));
bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->arp_sha,
sizeof(ea->arp_sha));
bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->arp_tha,
sizeof(ea->arp_tha));
sa.sa_family = pseudo_AF_HDRCMPLT;
sa.sa_len = sizeof(sa);
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;
if (myip_initialized)
return EIO;
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;
}
/* For compatibility: only saves interface address. */
int
revarpwhoami(in, ifp)
struct in_addr *in;
struct ifnet *ifp;
{
struct in_addr server;
return (revarpwhoarewe(ifp, &server, in));
}
#ifdef DDB
#include <machine/db_machdep.h>
#include <ddb/db_interface.h>
#include <ddb/db_output.h>
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");
}
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);
}
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.
*/
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_gettable(AF_INET, 0);
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 */
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