/
if_ether.c
1231 lines (1110 loc) · 33.8 KB
/
if_ether.c
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/*
* Copyright (c) 2004, 2005 The DragonFly Project. All rights reserved.
*
* This code is derived from software contributed to The DragonFly Project
* by Jeffrey M. Hsu.
*
* 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 DragonFly Project 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 COPYRIGHT HOLDERS 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
* COPYRIGHT HOLDERS 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 8.1 (Berkeley) 6/10/93
* $FreeBSD: src/sys/netinet/if_ether.c,v 1.64.2.23 2003/04/11 07:23:15 fjoe Exp $
* $DragonFly: src/sys/netinet/if_ether.c,v 1.59 2008/11/22 11:03:35 sephe Exp $
*/
/*
* Ethernet address resolution protocol.
* TODO:
* add "inuse/lock" bit (or ref. count) along with valid bit
*/
#include "opt_inet.h"
#include "opt_carp.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/queue.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/lock.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>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/if_ether.h>
#include <sys/thread2.h>
#include <sys/msgport2.h>
#include <net/netmsg2.h>
#include <sys/mplock2.h>
#ifdef CARP
#include <netinet/ip_carp.h>
#endif
#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 */
struct lwkt_port *la_msgport; /* last packet's msgport */
u_short la_preempt; /* countdown for pre-expiry arps */
u_short la_asked; /* #times we QUERIED following expiration */
};
static LIST_HEAD(, llinfo_arp) llinfo_arp_list[MAXCPU];
static int arp_maxtries = 5;
static int useloopback = 1; /* use loopback interface for local traffic */
static int arp_proxyall = 0;
static int arp_refresh = 60; /* refresh arp cache ~60 (not impl yet) */
static int arp_restricted_match = 0;
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
&arp_maxtries, 0, "ARP resolution attempts before returning error");
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
&useloopback, 0, "Use the loopback interface for local traffic");
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
&arp_proxyall, 0, "Enable proxy ARP for all suitable requests");
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, restricted_match, CTLFLAG_RW,
&arp_restricted_match, 0, "Only match against the sender");
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, refresh, CTLFLAG_RW,
&arp_refresh, 0, "Preemptively refresh the ARP");
static void arp_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
static void arprequest(struct ifnet *, const struct in_addr *,
const struct in_addr *, const u_char *);
static void arprequest_async(struct ifnet *, const struct in_addr *,
const struct in_addr *, const u_char *);
static void arpintr(netmsg_t msg);
static void arptfree(struct llinfo_arp *);
static void arptimer(void *);
static struct llinfo_arp *
arplookup(in_addr_t, boolean_t, boolean_t, boolean_t);
#ifdef INET
static void in_arpinput(struct mbuf *);
#endif
static struct callout arptimer_ch[MAXCPU];
/*
* Timeout routine. Age arp_tab entries periodically.
*/
/* ARGSUSED */
static void
arptimer(void *ignored_arg)
{
struct llinfo_arp *la, *nla;
crit_enter();
LIST_FOREACH_MUTABLE(la, &llinfo_arp_list[mycpuid], la_le, nla) {
if (la->la_rt->rt_expire && la->la_rt->rt_expire <= time_second)
arptfree(la);
}
callout_reset(&arptimer_ch[mycpuid], arpt_prune * hz, arptimer, NULL);
crit_exit();
}
/*
* Parallel to llc_rtrequest.
*
* Called after a route is successfully added to the tree to fix-up the
* route and initiate arp operations if required.
*/
static void
arp_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
{
struct sockaddr *gate = rt->rt_gateway;
struct llinfo_arp *la = rt->rt_llinfo;
struct sockaddr_dl null_sdl = { sizeof null_sdl, AF_LINK };
static boolean_t arpinit_done[MAXCPU];
if (!arpinit_done[mycpuid]) {
arpinit_done[mycpuid] = TRUE;
callout_init(&arptimer_ch[mycpuid]);
callout_reset(&arptimer_ch[mycpuid], hz, arptimer, NULL);
}
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) &&
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,
RTL_DONTREPORT);
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_async(rt->rt_ifp,
&SIN(rt_key(rt))->sin_addr,
&SIN(rt_key(rt))->sin_addr,
LLADDR(SDL(gate)));
}
/*FALLTHROUGH*/
case RTM_RESOLVE:
if (gate->sa_family != AF_LINK ||
gate->sa_len < sizeof(struct sockaddr_dl)) {
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 != NULL)
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 = la;
if (la == NULL) {
log(LOG_DEBUG, "arp_rtrequest: malloc failed\n");
break;
}
bzero(la, sizeof *la);
la->la_rt = rt;
rt->rt_flags |= RTF_LLINFO;
LIST_INSERT_HEAD(&llinfo_arp_list[mycpuid], 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))) {
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
/*
* This fixes up the routing interface for local addresses.
* The route is adjusted to point at lo0 and the expiration
* timer is disabled.
*
* NOTE: This prevents locally targetted traffic from going
* out the hardware interface, which is inefficient
* and might not work if the hardware cannot listen
* to its own transmitted packets. Setting
* net.link.ether.inet.useloopback to 0 will force
* packets for local addresses out the hardware (and
* it is expected to receive its own packet).
*
* XXX We should just be able to test RTF_LOCAL here instead
* of having to compare IPs.
*/
if (SIN(rt_key(rt))->sin_addr.s_addr ==
(IA_SIN(rt->rt_ifa))->sin_addr.s_addr) {
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 == NULL)
break;
LIST_REMOVE(la, la_le);
rt->rt_llinfo = NULL;
rt->rt_flags &= ~RTF_LLINFO;
if (la->la_hold != NULL)
m_freem(la->la_hold);
Free(la);
break;
}
}
static struct mbuf *
arpreq_alloc(struct ifnet *ifp, const struct in_addr *sip,
const struct in_addr *tip, const u_char *enaddr)
{
struct mbuf *m;
struct arphdr *ah;
u_short ar_hrd;
if ((m = m_gethdr(MB_DONTWAIT, MT_DATA)) == NULL)
return NULL;
m->m_pkthdr.rcvif = NULL;
switch (ifp->if_type) {
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);
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);
memcpy(ar_sha(ah), enaddr, ah->ar_hln);
memset(ar_tha(ah), 0, ah->ar_hln);
memcpy(ar_spa(ah), sip, ah->ar_pln);
memcpy(ar_tpa(ah), tip, ah->ar_pln);
return m;
}
static void
arpreq_send(struct ifnet *ifp, struct mbuf *m)
{
struct sockaddr sa;
struct ether_header *eh;
switch (ifp->if_type) {
case IFT_ETHER:
/*
* This may not be correct for types not explicitly
* listed, but this is our best guess
*/
default:
eh = (struct ether_header *)sa.sa_data;
/* if_output() will not swap */
eh->ether_type = htons(ETHERTYPE_ARP);
memcpy(eh->ether_dhost, ifp->if_broadcastaddr, ifp->if_addrlen);
break;
}
sa.sa_family = AF_UNSPEC;
sa.sa_len = sizeof(sa);
ifp->if_output(ifp, m, &sa, NULL);
}
static void
arpreq_send_handler(netmsg_t msg)
{
struct mbuf *m = msg->packet.nm_packet;
struct ifnet *ifp = msg->lmsg.u.ms_resultp;
arpreq_send(ifp, m);
/* nmsg was embedded in the mbuf, do not reply! */
}
/*
* Broadcast an ARP request. Caller specifies:
* - arp header source ip address
* - arp header target ip address
* - arp header source ethernet address
*
* NOTE: Caller MUST NOT hold ifp's serializer
*/
static void
arprequest(struct ifnet *ifp, const struct in_addr *sip,
const struct in_addr *tip, const u_char *enaddr)
{
struct mbuf *m;
if (enaddr == NULL) {
if (ifp->if_bridge) {
enaddr = IF_LLADDR(ether_bridge_interface(ifp));
} else {
enaddr = IF_LLADDR(ifp);
}
}
m = arpreq_alloc(ifp, sip, tip, enaddr);
if (m == NULL)
return;
arpreq_send(ifp, m);
}
/*
* Same as arprequest(), except:
* - Caller is allowed to hold ifp's serializer
* - Network output is done in protocol thead
*/
static void
arprequest_async(struct ifnet *ifp, const struct in_addr *sip,
const struct in_addr *tip, const u_char *enaddr)
{
struct mbuf *m;
struct netmsg_packet *pmsg;
if (enaddr == NULL) {
if (ifp->if_bridge) {
enaddr = IF_LLADDR(ether_bridge_interface(ifp));
} else {
enaddr = IF_LLADDR(ifp);
}
}
m = arpreq_alloc(ifp, sip, tip, enaddr);
if (m == NULL)
return;
pmsg = &m->m_hdr.mh_netmsg;
netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport,
0, arpreq_send_handler);
pmsg->nm_packet = m;
pmsg->base.lmsg.u.ms_resultp = ifp;
lwkt_sendmsg(cpu_portfn(mycpuid), &pmsg->base.lmsg);
}
/*
* 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(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
struct sockaddr *dst, u_char *desten)
{
struct rtentry *rt;
struct llinfo_arp *la = NULL;
struct sockaddr_dl *sdl;
if (m->m_flags & M_BCAST) { /* broadcast */
memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen);
return (1);
}
if (m->m_flags & M_MCAST) {/* multicast */
ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
return (1);
}
if (rt0 != NULL) {
if (rt_llroute(dst, rt0, &rt) != 0) {
m_freem(m);
return 0;
}
la = rt->rt_llinfo;
}
if (la == NULL) {
la = arplookup(SIN(dst)->sin_addr.s_addr,
TRUE, RTL_REPORTMSG, FALSE);
if (la != NULL)
rt = la->la_rt;
}
if (la == NULL || rt == NULL) {
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,
NULL);
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 != NULL)
m_freem(la->la_hold);
la->la_hold = m;
la->la_msgport = cur_netport();
if (rt->rt_expire || ((rt->rt_flags & RTF_STATIC) && !sdl->sdl_alen)) {
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,
NULL);
} else {
rt->rt_flags |= RTF_REJECT;
rt->rt_expire += arpt_down;
la->la_asked = 0;
la->la_preempt = arp_maxtries;
}
}
}
return (0);
}
/*
* Common length and type checks are done here,
* then the protocol-specific routine is called.
*/
static void
arpintr(netmsg_t msg)
{
struct mbuf *m = msg->packet.nm_packet;
struct arphdr *ar;
u_short ar_hrd;
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 *);
ar_hrd = ntohs(ar->ar_hrd);
if (ar_hrd != ARPHRD_ETHER && ar_hrd != ARPHRD_IEEE802) {
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)) {
if ((m = m_pullup(m, arphdr_len(ar))) == NULL) {
log(LOG_ERR, "arp: runt packet\n");
return;
}
ar = mtod(m, struct arphdr *);
}
switch (ntohs(ar->ar_pro)) {
#ifdef INET
case ETHERTYPE_IP:
in_arpinput(m);
return;
#endif
}
m_freem(m);
/* msg was embedded in the mbuf, do not reply! */
}
#ifdef INET
/*
* ARP for Internet protocols on 10 Mb/s Ethernet.
* Algorithm is that given in RFC 826.
* In addition, a sanity check is performed on the sender
* protocol address, to catch impersonators.
* We no longer handle negotiations for use of trailer protocol:
* Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
* along with IP replies if we wanted trailers sent to us,
* and also sent them in response to IP replies.
* This allowed either end to announce the desire to receive
* trailer packets.
* We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
* but formerly didn't normally send requests.
*/
static int log_arp_wrong_iface = 1;
static int log_arp_movements = 1;
static int log_arp_permanent_modify = 1;
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
&log_arp_wrong_iface, 0,
"Log arp packets arriving on the wrong interface");
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
&log_arp_movements, 0,
"Log arp replies from MACs different than the one in the cache");
SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW,
&log_arp_permanent_modify, 0,
"Log arp replies from MACs different than the one "
"in the permanent arp entry");
static void
arp_hold_output(netmsg_t msg)
{
struct mbuf *m = msg->packet.nm_packet;
struct rtentry *rt;
struct ifnet *ifp;
rt = msg->lmsg.u.ms_resultp;
ifp = m->m_pkthdr.rcvif;
m->m_pkthdr.rcvif = NULL;
ifp->if_output(ifp, m, rt_key(rt), rt);
/* Drop the reference count bumped by the sender */
RTFREE(rt);
/* nmsg was embedded in the mbuf, do not reply! */
}
static void
arp_update_oncpu(struct mbuf *m, in_addr_t saddr, boolean_t create,
boolean_t generate_report, boolean_t dologging)
{
struct arphdr *ah = mtod(m, struct arphdr *);
struct ifnet *ifp = m->m_pkthdr.rcvif;
struct llinfo_arp *la;
struct sockaddr_dl *sdl;
struct rtentry *rt;
la = arplookup(saddr, create, generate_report, FALSE);
if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) {
struct in_addr isaddr = { saddr };
/*
* Normally arps coming in on the wrong interface are ignored,
* but if we are bridging and the two interfaces belong to
* the same bridge, or one is a member of the bridge which
* is the other, then it isn't an error.
*/
if (rt->rt_ifp != ifp) {
/*
* (1) ifp and rt_ifp both members of same bridge
* (2) rt_ifp member of bridge ifp
* (3) ifp member of bridge rt_ifp
*
* Always replace rt_ifp with the bridge ifc.
*/
struct ifnet *nifp;
if (ifp->if_bridge &&
rt->rt_ifp->if_bridge == ifp->if_bridge) {
nifp = ether_bridge_interface(ifp);
} else if (rt->rt_ifp->if_bridge &&
ether_bridge_interface(rt->rt_ifp) == ifp) {
nifp = ifp;
} else if (ifp->if_bridge &&
ether_bridge_interface(ifp) == rt->rt_ifp) {
nifp = rt->rt_ifp;
} else {
nifp = NULL;
}
if ((log_arp_wrong_iface == 1 && nifp == NULL) ||
log_arp_wrong_iface == 2) {
log(LOG_ERR,
"arp: %s is on %s "
"but got reply from %*D on %s\n",
inet_ntoa(isaddr),
rt->rt_ifp->if_xname,
ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
ifp->if_xname);
}
if (nifp == NULL)
return;
/*
* nifp is our man! Replace rt_ifp and adjust
* the sdl.
*/
ifp = rt->rt_ifp = nifp;
sdl->sdl_type = ifp->if_type;
sdl->sdl_index = ifp->if_index;
}
if (sdl->sdl_alen &&
bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) {
if (rt->rt_expire != 0) {
if (dologging && log_arp_movements) {
log(LOG_INFO,
"arp: %s moved from %*D to %*D on %s\n",
inet_ntoa(isaddr),
ifp->if_addrlen, (u_char *)LLADDR(sdl),
":", ifp->if_addrlen,
(u_char *)ar_sha(ah), ":",
ifp->if_xname);
}
} else {
if (dologging && log_arp_permanent_modify) {
log(LOG_ERR,
"arp: %*D attempts to modify "
"permanent entry for %s on %s\n",
ifp->if_addrlen, (u_char *)ar_sha(ah),
":", inet_ntoa(isaddr), ifp->if_xname);
}
return;
}
}
/*
* sanity check for the address length.
* XXX this does not work for protocols with variable address
* length. -is
*/
if (dologging && 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) {
if (dologging) {
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);
}
return;
}
memcpy(LLADDR(sdl), ar_sha(ah), sdl->sdl_alen = ah->ar_hln);
if (rt->rt_expire != 0) {
rt->rt_expire = time_second + arpt_keep;
}
rt->rt_flags &= ~RTF_REJECT;
la->la_asked = 0;
la->la_preempt = arp_maxtries;
/*
* This particular cpu might have been holding an mbuf
* pending ARP resolution. If so, transmit the mbuf now.
*/
if (la->la_hold != NULL) {
struct mbuf *m = la->la_hold;
struct lwkt_port *port = la->la_msgport;
struct netmsg_packet *pmsg;
la->la_hold = NULL;
la->la_msgport = NULL;
m_adj(m, sizeof(struct ether_header));
/*
* Make sure that this rtentry will not be freed
* before the packet is processed on the target
* msgport. The reference count will be dropped
* in the handler associated with this packet.
*/
rt->rt_refcnt++;
pmsg = &m->m_hdr.mh_netmsg;
netmsg_init(&pmsg->base, NULL,
&netisr_apanic_rport,
MSGF_PRIORITY, arp_hold_output);
pmsg->nm_packet = m;
/* Record necessary information */
m->m_pkthdr.rcvif = ifp;
pmsg->base.lmsg.u.ms_resultp = rt;
lwkt_sendmsg(port, &pmsg->base.lmsg);
}
}
}
#ifdef SMP
struct netmsg_arp_update {
struct netmsg_base base;
struct mbuf *m;
in_addr_t saddr;
boolean_t create;
};
static void arp_update_msghandler(netmsg_t msg);
#endif
/*
* Called from arpintr() - this routine is run from a single cpu.
*/
static void
in_arpinput(struct mbuf *m)
{
struct arphdr *ah;
struct ifnet *ifp = m->m_pkthdr.rcvif;
struct ether_header *eh;
struct rtentry *rt;
struct ifaddr_container *ifac;
struct in_ifaddr_container *iac;
struct in_ifaddr *ia = NULL;
struct sockaddr sa;
struct in_addr isaddr, itaddr, myaddr;
#ifdef SMP
struct netmsg_arp_update msg;
#endif
uint8_t *enaddr = NULL;
int op;
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);
memcpy(&isaddr, ar_spa(ah), sizeof isaddr);
memcpy(&itaddr, ar_tpa(ah), sizeof itaddr);
myaddr.s_addr = INADDR_ANY;
#ifdef CARP
if (ifp->if_carp != NULL) {
carp_gettok();
if (ifp->if_carp != NULL &&
carp_iamatch(ifp->if_carp, &itaddr, &isaddr, &enaddr)) {
carp_reltok();
myaddr = itaddr;
goto match;
}
carp_reltok();
}
#endif
/*
* Check both target and sender IP addresses:
*
* If we receive the packet on the interface owning the address,
* then accept the address.
*
* For a bridge, we accept the address if the receive interface and
* the interface owning the address are on the same bridge, and
* use the bridge MAC as the is-at response. The bridge will be
* responsible for handling the packet.
*
* (1) Check target IP against our local IPs
*/
LIST_FOREACH(iac, INADDR_HASH(itaddr.s_addr), ia_hash) {
ia = iac->ia;
/* Skip all ia's which don't match */
if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr)
continue;
#ifdef CARP
if (ia->ia_ifp->if_type == IFT_CARP)
continue;
#endif
if (ifp->if_bridge && ia->ia_ifp &&
ifp->if_bridge == ia->ia_ifp->if_bridge) {
ifp = ether_bridge_interface(ifp);
goto match;
}
if (ia->ia_ifp && ia->ia_ifp->if_bridge &&
ether_bridge_interface(ia->ia_ifp) == ifp) {
goto match;
}
if (ifp->if_bridge && ether_bridge_interface(ifp) ==
ia->ia_ifp) {
goto match;
}
if (ia->ia_ifp == ifp)
goto match;
}
/*
* (2) Check sender IP against our local IPs
*/
LIST_FOREACH(iac, INADDR_HASH(isaddr.s_addr), ia_hash) {
ia = iac->ia;
/* Skip all ia's which don't match */
if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr)
continue;
#ifdef CARP
if (ia->ia_ifp->if_type == IFT_CARP)
continue;
#endif
if (ifp->if_bridge && ia->ia_ifp &&
ifp->if_bridge == ia->ia_ifp->if_bridge) {
ifp = ether_bridge_interface(ifp);
goto match;
}
if (ia->ia_ifp && ia->ia_ifp->if_bridge &&
ether_bridge_interface(ia->ia_ifp) == ifp) {
goto match;
}
if (ifp->if_bridge && ether_bridge_interface(ifp) ==
ia->ia_ifp) {
goto match;
}
if (ia->ia_ifp == ifp)
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(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
struct ifaddr *ifa = ifac->ifa;
if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) {
ia = ifatoia(ifa);
goto match;
}
}
/*
* If we got here, we didn't find any suitable interface,
* so drop the packet.
*/
m_freem(m);
return;
match:
if (!enaddr)
enaddr = (uint8_t *)IF_LLADDR(ifp);
if (myaddr.s_addr == INADDR_ANY)
myaddr = ia->ia_addr.sin_addr;
if (!bcmp(ar_sha(ah), enaddr, 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 && myaddr.s_addr != 0) {
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;
}