mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-24 11:29:10 +00:00
d1dd20be6e
that covers updates to the contents. Note this is separate from holding a reference and/or locking the routing table itself. Other/related changes: o rtredirect loses the final parameter by which an rtentry reference may be returned; this was never used and added unwarranted complexity for locking. o minor style cleanups to routing code (e.g. ansi-fy function decls) o remove the logic to bump the refcnt on the parent of cloned routes, we assume the parent will remain as long as the clone; doing this avoids a circularity in locking during delete o convert some timeouts to MPSAFE callouts Notes: 1. rt_mtx in struct rtentry is guarded by #ifdef _KERNEL as user-level applications cannot/do-no know about mutex's. Doing this requires that the mutex be the last element in the structure. A better solution is to introduce an externalized version of struct rtentry but this is a major task because of the intertwining of rtentry and other data structures that are visible to user applications. 2. There are known LOR's that are expected to go away with forthcoming work to eliminate many held references. If not these will be resolved prior to release. 3. ATM changes are untested. Sponsored by: FreeBSD Foundation Obtained from: BSD/OS (partly)
992 lines
28 KiB
C
992 lines
28 KiB
C
/*
|
|
* 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 8.1 (Berkeley) 6/10/93
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/*
|
|
* Ethernet address resolution protocol.
|
|
* TODO:
|
|
* add "inuse/lock" bit (or ref. count) along with valid bit
|
|
*/
|
|
|
|
#include "opt_inet.h"
|
|
#include "opt_bdg.h"
|
|
#include "opt_mac.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/queue.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/mac.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/syslog.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/if_dl.h>
|
|
#include <net/if_types.h>
|
|
#include <net/route.h>
|
|
#include <net/netisr.h>
|
|
#include <net/if_llc.h>
|
|
#ifdef BRIDGE
|
|
#include <net/ethernet.h>
|
|
#include <net/bridge.h>
|
|
#endif
|
|
|
|
#include <netinet/in.h>
|
|
#include <netinet/in_var.h>
|
|
#include <netinet/if_ether.h>
|
|
|
|
#include <net/if_arc.h>
|
|
#include <net/iso88025.h>
|
|
|
|
#define SIN(s) ((struct sockaddr_in *)s)
|
|
#define SDL(s) ((struct sockaddr_dl *)s)
|
|
|
|
SYSCTL_DECL(_net_link_ether);
|
|
SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, "");
|
|
|
|
/* timer values */
|
|
static int arpt_prune = (5*60*1); /* walk list every 5 minutes */
|
|
static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
|
|
static int arpt_down = 20; /* once declared down, don't send for 20 sec */
|
|
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW,
|
|
&arpt_prune, 0, "");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW,
|
|
&arpt_keep, 0, "");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW,
|
|
&arpt_down, 0, "");
|
|
|
|
#define rt_expire rt_rmx.rmx_expire
|
|
|
|
struct llinfo_arp {
|
|
LIST_ENTRY(llinfo_arp) la_le;
|
|
struct rtentry *la_rt;
|
|
struct mbuf *la_hold; /* last packet until resolved/timeout */
|
|
u_short la_preempt; /* countdown for pre-expiry arps */
|
|
u_short la_asked; /* #times we QUERIED following expiration */
|
|
#define la_timer la_rt->rt_rmx.rmx_expire /* deletion time in seconds */
|
|
};
|
|
|
|
static LIST_HEAD(, llinfo_arp) llinfo_arp;
|
|
|
|
static struct ifqueue arpintrq;
|
|
static int arp_allocated;
|
|
static int arpinit_done;
|
|
|
|
static int arp_maxtries = 5;
|
|
static int useloopback = 1; /* use loopback interface for local traffic */
|
|
static int arp_proxyall = 0;
|
|
static struct callout arp_callout;
|
|
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
|
|
&arp_maxtries, 0, "");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
|
|
&useloopback, 0, "");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
|
|
&arp_proxyall, 0, "");
|
|
|
|
static void arp_init(void);
|
|
static void arp_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
|
|
static void arprequest(struct ifnet *,
|
|
struct in_addr *, struct in_addr *, u_char *);
|
|
static void arpintr(struct mbuf *);
|
|
static void arptfree(struct llinfo_arp *);
|
|
static void arptimer(void *);
|
|
static struct llinfo_arp
|
|
*arplookup(u_long, int, int);
|
|
#ifdef INET
|
|
static void in_arpinput(struct mbuf *);
|
|
#endif
|
|
|
|
/*
|
|
* Timeout routine. Age arp_tab entries periodically.
|
|
*/
|
|
/* ARGSUSED */
|
|
static void
|
|
arptimer(ignored_arg)
|
|
void *ignored_arg;
|
|
{
|
|
struct llinfo_arp *la, *ola;
|
|
|
|
RADIX_NODE_HEAD_LOCK(rt_tables[AF_INET]);
|
|
la = LIST_FIRST(&llinfo_arp);
|
|
while (la != NULL) {
|
|
struct rtentry *rt = la->la_rt;
|
|
ola = la;
|
|
la = LIST_NEXT(la, la_le);
|
|
if (rt->rt_expire && rt->rt_expire <= time_second)
|
|
arptfree(ola); /* timer has expired, clear */
|
|
}
|
|
RADIX_NODE_HEAD_UNLOCK(rt_tables[AF_INET]);
|
|
|
|
callout_reset(&arp_callout, arpt_prune * hz, arptimer, NULL);
|
|
}
|
|
|
|
/*
|
|
* Parallel to llc_rtrequest.
|
|
*/
|
|
static void
|
|
arp_rtrequest(req, rt, info)
|
|
int req;
|
|
register struct rtentry *rt;
|
|
struct rt_addrinfo *info;
|
|
{
|
|
register struct sockaddr *gate;
|
|
register struct llinfo_arp *la;
|
|
static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
|
|
|
|
RT_LOCK_ASSERT(rt);
|
|
|
|
if (!arpinit_done) {
|
|
arpinit_done = 1;
|
|
callout_reset(&arp_callout, hz, arptimer, NULL);
|
|
}
|
|
if (rt->rt_flags & RTF_GATEWAY)
|
|
return;
|
|
gate = rt->rt_gateway;
|
|
la = (struct llinfo_arp *)rt->rt_llinfo;
|
|
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;
|
|
rt->rt_expire = time_second;
|
|
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, "%s: bad gateway %s%s\n", __func__,
|
|
inet_ntoa(SIN(rt_key(rt))->sin_addr),
|
|
(gate->sa_family != AF_LINK) ?
|
|
" (!AF_LINK)": "");
|
|
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_Zalloc(la, struct llinfo_arp *, sizeof(*la));
|
|
rt->rt_llinfo = (caddr_t)la;
|
|
if (la == 0) {
|
|
log(LOG_DEBUG, "%s: malloc failed\n", __func__);
|
|
break;
|
|
}
|
|
arp_allocated++;
|
|
la->la_rt = rt;
|
|
rt->rt_flags |= RTF_LLINFO;
|
|
RADIX_NODE_HEAD_LOCK_ASSERT(rt_tables[AF_INET]);
|
|
LIST_INSERT_HEAD(&llinfo_arp, la, la_le);
|
|
|
|
#ifdef INET
|
|
/*
|
|
* This keeps the multicast addresses from showing up
|
|
* in `arp -a' listings as unresolved. It's not actually
|
|
* functional. Then the same for broadcast.
|
|
*/
|
|
if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr)) &&
|
|
rt->rt_ifp->if_type != IFT_ARCNET) {
|
|
ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr,
|
|
LLADDR(SDL(gate)));
|
|
SDL(gate)->sdl_alen = 6;
|
|
rt->rt_expire = 0;
|
|
}
|
|
if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) {
|
|
memcpy(LLADDR(SDL(gate)), rt->rt_ifp->if_broadcastaddr,
|
|
rt->rt_ifp->if_addrlen);
|
|
SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen;
|
|
rt->rt_expire = 0;
|
|
}
|
|
#endif
|
|
|
|
if (SIN(rt_key(rt))->sin_addr.s_addr ==
|
|
(IA_SIN(rt->rt_ifa))->sin_addr.s_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(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)),
|
|
SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen);
|
|
if (useloopback)
|
|
rt->rt_ifp = loif;
|
|
|
|
}
|
|
break;
|
|
|
|
case RTM_DELETE:
|
|
if (la == 0)
|
|
break;
|
|
RADIX_NODE_HEAD_LOCK_ASSERT(rt_tables[AF_INET]);
|
|
LIST_REMOVE(la, la_le);
|
|
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_char *enaddr;
|
|
{
|
|
register struct mbuf *m;
|
|
register struct ether_header *eh;
|
|
register struct arc_header *arh;
|
|
register struct arphdr *ah;
|
|
struct sockaddr sa;
|
|
static u_char llcx[] = { 0x82, 0x40, LLC_SNAP_LSAP, LLC_SNAP_LSAP,
|
|
LLC_UI, 0x00, 0x00, 0x00, 0x08, 0x06 };
|
|
u_short ar_hrd;
|
|
|
|
if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
|
|
return;
|
|
m->m_pkthdr.rcvif = (struct ifnet *)0;
|
|
#ifdef MAC
|
|
mac_create_mbuf_linklayer(ifp, m);
|
|
#endif
|
|
switch (ifp->if_type) {
|
|
case IFT_ARCNET:
|
|
ar_hrd = htons(ARPHRD_ARCNET);
|
|
|
|
m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
|
|
m->m_pkthdr.len = m->m_len;
|
|
MH_ALIGN(m, m->m_len);
|
|
|
|
arh = (struct arc_header *)sa.sa_data;
|
|
arh->arc_dhost = *ifp->if_broadcastaddr;
|
|
arh->arc_type = ARCTYPE_ARP;
|
|
|
|
ah = mtod(m, struct arphdr *);
|
|
break;
|
|
|
|
case IFT_ISO88025:
|
|
ar_hrd = htons(ARPHRD_IEEE802);
|
|
|
|
m->m_len = sizeof(llcx) +
|
|
arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
|
|
m->m_pkthdr.len = m->m_len;
|
|
MH_ALIGN(m, m->m_len);
|
|
|
|
(void)memcpy(mtod(m, caddr_t), llcx, sizeof(llcx));
|
|
(void)memcpy(sa.sa_data, ifp->if_broadcastaddr, 6);
|
|
(void)memcpy(sa.sa_data + 6, enaddr, 6);
|
|
sa.sa_data[6] |= TR_RII;
|
|
sa.sa_data[12] = TR_AC;
|
|
sa.sa_data[13] = TR_LLC_FRAME;
|
|
|
|
ah = (struct arphdr *)(mtod(m, char *) + sizeof(llcx));
|
|
break;
|
|
case IFT_FDDI:
|
|
case IFT_ETHER:
|
|
/*
|
|
* This may not be correct for types not explicitly
|
|
* listed, but this is our best guess
|
|
*/
|
|
default:
|
|
ar_hrd = htons(ARPHRD_ETHER);
|
|
|
|
m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
|
|
m->m_pkthdr.len = m->m_len;
|
|
MH_ALIGN(m, m->m_len);
|
|
|
|
eh = (struct ether_header *)sa.sa_data;
|
|
/* if_output will not swap */
|
|
eh->ether_type = htons(ETHERTYPE_ARP);
|
|
(void)memcpy(eh->ether_dhost, ifp->if_broadcastaddr,
|
|
sizeof(eh->ether_dhost));
|
|
|
|
ah = mtod(m, struct arphdr *);
|
|
break;
|
|
}
|
|
|
|
ah->ar_hrd = ar_hrd;
|
|
ah->ar_pro = htons(ETHERTYPE_IP);
|
|
ah->ar_hln = ifp->if_addrlen; /* hardware address length */
|
|
ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
|
|
ah->ar_op = htons(ARPOP_REQUEST);
|
|
(void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
|
|
memset(ar_tha(ah), 0, ah->ar_hln);
|
|
(void)memcpy(ar_spa(ah), sip, ah->ar_pln);
|
|
(void)memcpy(ar_tpa(ah), tip, ah->ar_pln);
|
|
|
|
sa.sa_family = AF_UNSPEC;
|
|
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(ifp, rt, m, dst, desten, rt0)
|
|
register struct ifnet *ifp;
|
|
register struct rtentry *rt;
|
|
struct mbuf *m;
|
|
register struct sockaddr *dst;
|
|
register u_char *desten;
|
|
struct rtentry *rt0;
|
|
{
|
|
struct llinfo_arp *la = 0;
|
|
struct sockaddr_dl *sdl;
|
|
|
|
if (m->m_flags & M_BCAST) { /* broadcast */
|
|
(void)memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen);
|
|
return (1);
|
|
}
|
|
if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {/* multicast */
|
|
ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
|
|
return(1);
|
|
}
|
|
if (rt)
|
|
la = (struct llinfo_arp *)rt->rt_llinfo;
|
|
if (la == 0) {
|
|
la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0);
|
|
if (la)
|
|
rt = la->la_rt;
|
|
}
|
|
if (la == 0 || rt == 0) {
|
|
log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n",
|
|
inet_ntoa(SIN(dst)->sin_addr), la ? "la" : "",
|
|
rt ? "rt" : "");
|
|
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) {
|
|
/*
|
|
* If entry has an expiry time and it is approaching,
|
|
* see if we need to send an ARP request within this
|
|
* arpt_down interval.
|
|
*/
|
|
if ((rt->rt_expire != 0) &&
|
|
(time_second + la->la_preempt > rt->rt_expire)) {
|
|
arprequest(ifp,
|
|
&SIN(rt->rt_ifa->ifa_addr)->sin_addr,
|
|
&SIN(dst)->sin_addr,
|
|
IF_LLADDR(ifp));
|
|
la->la_preempt--;
|
|
}
|
|
|
|
bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
|
|
return 1;
|
|
}
|
|
/*
|
|
* If ARP is disabled or static on this interface, stop.
|
|
* XXX
|
|
* Probably should not allocate empty llinfo struct if we are
|
|
* not going to be sending out an arp request.
|
|
*/
|
|
if (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) {
|
|
m_freem(m);
|
|
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;
|
|
if (rt->rt_expire) {
|
|
RT_LOCK(rt);
|
|
rt->rt_flags &= ~RTF_REJECT;
|
|
if (la->la_asked == 0 || rt->rt_expire != time_second) {
|
|
rt->rt_expire = time_second;
|
|
if (la->la_asked++ < arp_maxtries) {
|
|
arprequest(ifp,
|
|
&SIN(rt->rt_ifa->ifa_addr)->sin_addr,
|
|
&SIN(dst)->sin_addr,
|
|
IF_LLADDR(ifp));
|
|
} else {
|
|
rt->rt_flags |= RTF_REJECT;
|
|
rt->rt_expire += arpt_down;
|
|
la->la_asked = 0;
|
|
la->la_preempt = arp_maxtries;
|
|
}
|
|
|
|
}
|
|
RT_UNLOCK(rt);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Common length and type checks are done here,
|
|
* then the protocol-specific routine is called.
|
|
*/
|
|
static void
|
|
arpintr(struct mbuf *m)
|
|
{
|
|
struct arphdr *ar;
|
|
|
|
if (!arpinit_done) {
|
|
/* NB: this race should not matter */
|
|
arpinit_done = 1;
|
|
callout_reset(&arp_callout, hz, arptimer, NULL);
|
|
}
|
|
if (m->m_len < sizeof(struct arphdr) &&
|
|
((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
|
|
log(LOG_ERR, "arp: runt packet -- m_pullup failed\n");
|
|
return;
|
|
}
|
|
ar = mtod(m, struct arphdr *);
|
|
|
|
if (ntohs(ar->ar_hrd) != ARPHRD_ETHER &&
|
|
ntohs(ar->ar_hrd) != ARPHRD_IEEE802 &&
|
|
ntohs(ar->ar_hrd) != ARPHRD_ARCNET) {
|
|
log(LOG_ERR, "arp: unknown hardware address format (0x%2D)\n",
|
|
(unsigned char *)&ar->ar_hrd, "");
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
if (m->m_pkthdr.len < arphdr_len(ar) &&
|
|
(m = m_pullup(m, arphdr_len(ar))) == NULL) {
|
|
log(LOG_ERR, "arp: runt packet\n");
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
switch (ntohs(ar->ar_pro)) {
|
|
#ifdef INET
|
|
case ETHERTYPE_IP:
|
|
in_arpinput(m);
|
|
return;
|
|
#endif
|
|
}
|
|
m_freem(m);
|
|
}
|
|
|
|
#ifdef INET
|
|
/*
|
|
* ARP for Internet protocols on 10 Mb/s Ethernet.
|
|
* Algorithm is that given in RFC 826.
|
|
* In addition, a sanity check is performed on the sender
|
|
* protocol address, to catch impersonators.
|
|
* We no longer handle negotiations for use of trailer protocol:
|
|
* Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
|
|
* along with IP replies if we wanted trailers sent to us,
|
|
* and also sent them in response to IP replies.
|
|
* This allowed either end to announce the desire to receive
|
|
* trailer packets.
|
|
* We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
|
|
* but formerly didn't normally send requests.
|
|
*/
|
|
static int log_arp_wrong_iface = 1;
|
|
static int log_arp_movements = 1;
|
|
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
|
|
&log_arp_wrong_iface, 0,
|
|
"log arp packets arriving on the wrong interface");
|
|
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
|
|
&log_arp_movements, 0,
|
|
"log arp replies from MACs different than the one in the cache");
|
|
|
|
|
|
static void
|
|
in_arpinput(m)
|
|
struct mbuf *m;
|
|
{
|
|
register struct arphdr *ah;
|
|
register struct ifnet *ifp = m->m_pkthdr.rcvif;
|
|
struct ether_header *eh;
|
|
struct arc_header *arh;
|
|
struct iso88025_header *th = (struct iso88025_header *)0;
|
|
struct iso88025_sockaddr_dl_data *trld;
|
|
register struct llinfo_arp *la = 0;
|
|
register struct rtentry *rt;
|
|
struct ifaddr *ifa;
|
|
struct in_ifaddr *ia;
|
|
struct sockaddr_dl *sdl;
|
|
struct sockaddr sa;
|
|
struct in_addr isaddr, itaddr, myaddr;
|
|
int op, rif_len;
|
|
int req_len;
|
|
|
|
req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
|
|
if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
|
|
log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n");
|
|
return;
|
|
}
|
|
|
|
ah = mtod(m, struct arphdr *);
|
|
op = ntohs(ah->ar_op);
|
|
(void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
|
|
(void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
|
|
#ifdef BRIDGE
|
|
#define BRIDGE_TEST (do_bridge)
|
|
#else
|
|
#define BRIDGE_TEST (0) /* cc will optimise the test away */
|
|
#endif
|
|
/*
|
|
* For a bridge, we want to check the address irrespective
|
|
* of the receive interface. (This will change slightly
|
|
* when we have clusters of interfaces).
|
|
*/
|
|
LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash)
|
|
if ((BRIDGE_TEST || (ia->ia_ifp == ifp)) &&
|
|
itaddr.s_addr == ia->ia_addr.sin_addr.s_addr)
|
|
goto match;
|
|
LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
|
|
if ((BRIDGE_TEST || (ia->ia_ifp == ifp)) &&
|
|
isaddr.s_addr == ia->ia_addr.sin_addr.s_addr)
|
|
goto match;
|
|
/*
|
|
* No match, use the first inet address on the receive interface
|
|
* as a dummy address for the rest of the function.
|
|
*/
|
|
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
|
|
if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) {
|
|
ia = ifatoia(ifa);
|
|
goto match;
|
|
}
|
|
/*
|
|
* If bridging, fall back to using any inet address.
|
|
*/
|
|
if (!BRIDGE_TEST ||
|
|
(ia = TAILQ_FIRST(&in_ifaddrhead)) == NULL) {
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
match:
|
|
myaddr = ia->ia_addr.sin_addr;
|
|
if (!bcmp(ar_sha(ah), IF_LLADDR(ifp), ifp->if_addrlen)) {
|
|
m_freem(m); /* it's from me, ignore it. */
|
|
return;
|
|
}
|
|
if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
|
|
log(LOG_ERR,
|
|
"arp: link address is broadcast for IP address %s!\n",
|
|
inet_ntoa(isaddr));
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
if (isaddr.s_addr == myaddr.s_addr) {
|
|
log(LOG_ERR,
|
|
"arp: %*D is using my IP address %s!\n",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
inet_ntoa(isaddr));
|
|
itaddr = myaddr;
|
|
goto reply;
|
|
}
|
|
if (ifp->if_flags & IFF_STATICARP)
|
|
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))) {
|
|
/* the following is not an error when doing bridging */
|
|
if (!BRIDGE_TEST && rt->rt_ifp != ifp) {
|
|
if (log_arp_wrong_iface)
|
|
log(LOG_ERR, "arp: %s is on %s%d but got reply from %*D on %s%d\n",
|
|
inet_ntoa(isaddr),
|
|
rt->rt_ifp->if_name, rt->rt_ifp->if_unit,
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
ifp->if_name, ifp->if_unit);
|
|
goto reply;
|
|
}
|
|
if (sdl->sdl_alen &&
|
|
bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) {
|
|
if (rt->rt_expire) {
|
|
if (log_arp_movements)
|
|
log(LOG_INFO, "arp: %s moved from %*D to %*D on %s%d\n",
|
|
inet_ntoa(isaddr),
|
|
ifp->if_addrlen, (u_char *)LLADDR(sdl), ":",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
ifp->if_name, ifp->if_unit);
|
|
} else {
|
|
log(LOG_ERR,
|
|
"arp: %*D attempts to modify permanent entry for %s on %s%d\n",
|
|
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
|
|
inet_ntoa(isaddr), ifp->if_name, ifp->if_unit);
|
|
goto reply;
|
|
}
|
|
}
|
|
/*
|
|
* 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 %*D: new addr len %d, was %d",
|
|
ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
|
|
ah->ar_hln, sdl->sdl_alen);
|
|
}
|
|
if (ifp->if_addrlen != ah->ar_hln) {
|
|
log(LOG_WARNING,
|
|
"arp from %*D: addr len: new %d, i/f %d (ignored)",
|
|
ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
|
|
ah->ar_hln, ifp->if_addrlen);
|
|
goto reply;
|
|
}
|
|
(void)memcpy(LLADDR(sdl), ar_sha(ah),
|
|
sdl->sdl_alen = ah->ar_hln);
|
|
/*
|
|
* If we receive an arp from a token-ring station over
|
|
* a token-ring nic then try to save the source
|
|
* routing info.
|
|
*/
|
|
if (ifp->if_type == IFT_ISO88025) {
|
|
th = (struct iso88025_header *)m->m_pkthdr.header;
|
|
trld = SDL_ISO88025(sdl);
|
|
rif_len = TR_RCF_RIFLEN(th->rcf);
|
|
if ((th->iso88025_shost[0] & TR_RII) &&
|
|
(rif_len > 2)) {
|
|
trld->trld_rcf = th->rcf;
|
|
trld->trld_rcf ^= htons(TR_RCF_DIR);
|
|
memcpy(trld->trld_route, th->rd, rif_len - 2);
|
|
trld->trld_rcf &= ~htons(TR_RCF_BCST_MASK);
|
|
/*
|
|
* Set up source routing information for
|
|
* reply packet (XXX)
|
|
*/
|
|
m->m_data -= rif_len;
|
|
m->m_len += rif_len;
|
|
m->m_pkthdr.len += rif_len;
|
|
} else {
|
|
th->iso88025_shost[0] &= ~TR_RII;
|
|
trld->trld_rcf = 0;
|
|
}
|
|
m->m_data -= 8;
|
|
m->m_len += 8;
|
|
m->m_pkthdr.len += 8;
|
|
th->rcf = trld->trld_rcf;
|
|
}
|
|
RT_LOCK(rt);
|
|
if (rt->rt_expire)
|
|
rt->rt_expire = time_second + arpt_keep;
|
|
rt->rt_flags &= ~RTF_REJECT;
|
|
RT_UNLOCK(rt);
|
|
la->la_asked = 0;
|
|
la->la_preempt = arp_maxtries;
|
|
if (la->la_hold) {
|
|
(*ifp->if_output)(ifp, la->la_hold,
|
|
rt_key(rt), rt);
|
|
la->la_hold = 0;
|
|
}
|
|
}
|
|
reply:
|
|
if (op != ARPOP_REQUEST) {
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
if (itaddr.s_addr == myaddr.s_addr) {
|
|
/* I am the target */
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln);
|
|
} else {
|
|
la = arplookup(itaddr.s_addr, 0, SIN_PROXY);
|
|
if (la == NULL) {
|
|
struct sockaddr_in sin;
|
|
|
|
if (!arp_proxyall) {
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
|
|
bzero(&sin, sizeof sin);
|
|
sin.sin_family = AF_INET;
|
|
sin.sin_len = sizeof sin;
|
|
sin.sin_addr = itaddr;
|
|
|
|
rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
|
|
if (!rt) {
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
/*
|
|
* Don't send proxies for nodes on the same interface
|
|
* as this one came out of, or we'll get into a fight
|
|
* over who claims what Ether address.
|
|
*/
|
|
if (rt->rt_ifp == ifp) {
|
|
rtfree(rt);
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
(void)memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln);
|
|
rtfree(rt);
|
|
|
|
/*
|
|
* Also check that the node which sent the ARP packet
|
|
* is on the the interface we expect it to be on. This
|
|
* avoids ARP chaos if an interface is connected to the
|
|
* wrong network.
|
|
*/
|
|
sin.sin_addr = isaddr;
|
|
|
|
rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
|
|
if (!rt) {
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
if (rt->rt_ifp != ifp) {
|
|
log(LOG_INFO, "arp_proxy: ignoring request"
|
|
" from %s via %s%d, expecting %s%d\n",
|
|
inet_ntoa(isaddr), ifp->if_name,
|
|
ifp->if_unit, rt->rt_ifp->if_name,
|
|
rt->rt_ifp->if_unit);
|
|
rtfree(rt);
|
|
m_freem(m);
|
|
return;
|
|
}
|
|
rtfree(rt);
|
|
|
|
#ifdef DEBUG_PROXY
|
|
printf("arp: proxying for %s\n",
|
|
inet_ntoa(itaddr));
|
|
#endif
|
|
} else {
|
|
rt = la->la_rt;
|
|
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
|
|
sdl = SDL(rt->rt_gateway);
|
|
(void)memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln);
|
|
}
|
|
}
|
|
|
|
(void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
|
|
(void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
|
|
ah->ar_op = htons(ARPOP_REPLY);
|
|
ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
|
|
switch (ifp->if_type) {
|
|
case IFT_ARCNET:
|
|
arh = (struct arc_header *)sa.sa_data;
|
|
arh->arc_dhost = *ar_tha(ah);
|
|
arh->arc_type = ARCTYPE_ARP;
|
|
break;
|
|
|
|
case IFT_ISO88025:
|
|
/* Re-arrange the source/dest address */
|
|
memcpy(th->iso88025_dhost, th->iso88025_shost,
|
|
sizeof(th->iso88025_dhost));
|
|
memcpy(th->iso88025_shost, IF_LLADDR(ifp),
|
|
sizeof(th->iso88025_shost));
|
|
/* Set the source routing bit if neccesary */
|
|
if (th->iso88025_dhost[0] & TR_RII) {
|
|
th->iso88025_dhost[0] &= ~TR_RII;
|
|
if (TR_RCF_RIFLEN(th->rcf) > 2)
|
|
th->iso88025_shost[0] |= TR_RII;
|
|
}
|
|
/* Copy the addresses, ac and fc into sa_data */
|
|
memcpy(sa.sa_data, th->iso88025_dhost,
|
|
sizeof(th->iso88025_dhost) * 2);
|
|
sa.sa_data[(sizeof(th->iso88025_dhost) * 2)] = TR_AC;
|
|
sa.sa_data[(sizeof(th->iso88025_dhost) * 2) + 1] = TR_LLC_FRAME;
|
|
break;
|
|
case IFT_ETHER:
|
|
case IFT_FDDI:
|
|
/*
|
|
* May not be correct for types not explictly
|
|
* listed, but it is our best guess.
|
|
*/
|
|
default:
|
|
eh = (struct ether_header *)sa.sa_data;
|
|
(void)memcpy(eh->ether_dhost, ar_tha(ah),
|
|
sizeof(eh->ether_dhost));
|
|
eh->ether_type = htons(ETHERTYPE_ARP);
|
|
break;
|
|
}
|
|
sa.sa_family = AF_UNSPEC;
|
|
sa.sa_len = sizeof(sa);
|
|
(*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 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_preempt = la->la_asked = 0;
|
|
RT_LOCK(rt); /* XXX needed or move higher? */
|
|
rt->rt_flags &= ~RTF_REJECT;
|
|
RT_UNLOCK(rt);
|
|
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)
|
|
u_long addr;
|
|
int create, proxy;
|
|
{
|
|
register struct rtentry *rt;
|
|
struct sockaddr_inarp sin;
|
|
const char *why = 0;
|
|
|
|
bzero(&sin, sizeof(sin));
|
|
sin.sin_len = sizeof(sin);
|
|
sin.sin_family = AF_INET;
|
|
sin.sin_addr.s_addr = addr;
|
|
if (proxy)
|
|
sin.sin_other = SIN_PROXY;
|
|
rt = rtalloc1((struct sockaddr *)&sin, create, 0UL);
|
|
if (rt == 0)
|
|
return (0);
|
|
|
|
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";
|
|
|
|
if (why) {
|
|
#define ISDYNCLONE(_rt) \
|
|
(((_rt)->rt_flags & (RTF_STATIC | RTF_WASCLONED)) == RTF_WASCLONED)
|
|
if (create)
|
|
log(LOG_DEBUG, "arplookup %s failed: %s\n",
|
|
inet_ntoa(sin.sin_addr), why);
|
|
/*
|
|
* If there are no references to this Layer 2 route,
|
|
* and it is a cloned route, and not static, and
|
|
* arplookup() is creating the route, then purge
|
|
* it from the routing table as it is probably bogus.
|
|
*/
|
|
RT_UNLOCK(rt);
|
|
if (rt->rt_refcnt == 1 && ISDYNCLONE(rt)) {
|
|
rtrequest(RTM_DELETE,
|
|
(struct sockaddr *)rt_key(rt),
|
|
rt->rt_gateway, rt_mask(rt),
|
|
rt->rt_flags, 0);
|
|
}
|
|
RTFREE(rt);
|
|
return (0);
|
|
#undef ISDYNCLONE
|
|
} else {
|
|
rt->rt_refcnt--;
|
|
RT_UNLOCK(rt);
|
|
return ((struct llinfo_arp *)rt->rt_llinfo);
|
|
}
|
|
}
|
|
|
|
void
|
|
arp_ifinit(ifp, ifa)
|
|
struct ifnet *ifp;
|
|
struct ifaddr *ifa;
|
|
{
|
|
if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
|
|
arprequest(ifp, &IA_SIN(ifa)->sin_addr,
|
|
&IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp));
|
|
ifa->ifa_rtrequest = arp_rtrequest;
|
|
ifa->ifa_flags |= RTF_CLONING;
|
|
}
|
|
|
|
static void
|
|
arp_init(void)
|
|
{
|
|
|
|
arpintrq.ifq_maxlen = 50;
|
|
mtx_init(&arpintrq.ifq_mtx, "arp_inq", NULL, MTX_DEF);
|
|
LIST_INIT(&llinfo_arp);
|
|
callout_init(&arp_callout, CALLOUT_MPSAFE);
|
|
netisr_register(NETISR_ARP, arpintr, &arpintrq);
|
|
}
|
|
SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);
|