FreeBSD-5.3/sys/netipx/ipx_input.c
/*
* Copyright (c) 1995, Mike Mitchell
* Copyright (c) 1984, 1985, 1986, 1987, 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.
*
* @(#)ipx_input.c
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/netipx/ipx_input.c,v 1.34 2003/11/08 22:28:40 sam Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/random.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/route.h>
#include <net/netisr.h>
#include <netipx/ipx.h>
#include <netipx/spx.h>
#include <netipx/ipx_if.h>
#include <netipx/ipx_pcb.h>
#include <netipx/ipx_var.h>
int ipxcksum = 0;
SYSCTL_INT(_net_ipx_ipx, OID_AUTO, checksum, CTLFLAG_RW,
&ipxcksum, 0, "");
static int ipxprintfs = 0; /* printing forwarding information */
SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxprintfs, CTLFLAG_RW,
&ipxprintfs, 0, "");
static int ipxforwarding = 0;
SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxforwarding, CTLFLAG_RW,
&ipxforwarding, 0, "");
static int ipxnetbios = 0;
SYSCTL_INT(_net_ipx, OID_AUTO, ipxnetbios, CTLFLAG_RW,
&ipxnetbios, 0, "");
union ipx_net ipx_zeronet;
union ipx_host ipx_zerohost;
union ipx_net ipx_broadnet;
union ipx_host ipx_broadhost;
struct ipxstat ipxstat;
struct sockaddr_ipx ipx_netmask, ipx_hostmask;
static u_short allones[] = {-1, -1, -1};
struct ipxpcb ipxpcb;
struct ipxpcb ipxrawpcb;
static int ipxqmaxlen = IFQ_MAXLEN;
static struct ifqueue ipxintrq;
long ipx_pexseq;
static int ipx_do_route(struct ipx_addr *src, struct route *ro);
static void ipx_undo_route(struct route *ro);
static void ipx_forward(struct mbuf *m);
static void ipxintr(struct mbuf *m);
/*
* IPX initialization.
*/
void
ipx_init()
{
ipx_broadnet = *(union ipx_net *)allones;
ipx_broadhost = *(union ipx_host *)allones;
read_random(&ipx_pexseq, sizeof ipx_pexseq);
ipxpcb.ipxp_next = ipxpcb.ipxp_prev = &ipxpcb;
ipxrawpcb.ipxp_next = ipxrawpcb.ipxp_prev = &ipxrawpcb;
ipx_netmask.sipx_len = 6;
ipx_netmask.sipx_addr.x_net = ipx_broadnet;
ipx_hostmask.sipx_len = 12;
ipx_hostmask.sipx_addr.x_net = ipx_broadnet;
ipx_hostmask.sipx_addr.x_host = ipx_broadhost;
ipxintrq.ifq_maxlen = ipxqmaxlen;
mtx_init(&ipxintrq.ifq_mtx, "ipx_inq", NULL, MTX_DEF);
netisr_register(NETISR_IPX, ipxintr, &ipxintrq, 0);
}
/*
* IPX input routine. Pass to next level.
*/
static void
ipxintr(struct mbuf *m)
{
register struct ipx *ipx;
register struct ipxpcb *ipxp;
struct ipx_ifaddr *ia;
int len;
GIANT_REQUIRED;
/*
* If no IPX addresses have been set yet but the interfaces
* are receiving, can't do anything with incoming packets yet.
*/
if (ipx_ifaddr == NULL)
goto bad;
ipxstat.ipxs_total++;
if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
(m = m_pullup(m, sizeof(struct ipx))) == 0) {
ipxstat.ipxs_toosmall++;
return;
}
/*
* Give any raw listeners a crack at the packet
*/
for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
ipxp = ipxp->ipxp_next) {
struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
if (m1 != NULL)
ipx_input(m1, ipxp);
}
ipx = mtod(m, struct ipx *);
len = ntohs(ipx->ipx_len);
/*
* Check that the amount of data in the buffers
* is as at least much as the IPX header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_pkthdr.len < len) {
ipxstat.ipxs_tooshort++;
goto bad;
}
if (m->m_pkthdr.len > len) {
if (m->m_len == m->m_pkthdr.len) {
m->m_len = len;
m->m_pkthdr.len = len;
} else
m_adj(m, len - m->m_pkthdr.len);
}
if (ipxcksum && ipx->ipx_sum != 0xffff) {
if (ipx->ipx_sum != ipx_cksum(m, len)) {
ipxstat.ipxs_badsum++;
goto bad;
}
}
/*
* Propagated (Netbios) packets (type 20) has to be handled
* different. :-(
*/
if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
if (ipxnetbios) {
ipx_output_type20(m);
return;
} else
goto bad;
}
/*
* Is this a directed broadcast?
*/
if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.x_host)) {
if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
(!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_broadnet)) &&
(!ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet)) &&
(!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)) ) {
/*
* If it is a broadcast to the net where it was
* received from, treat it as ours.
*/
for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
ipx_neteq(ia->ia_addr.sipx_addr,
ipx->ipx_dna))
goto ours;
/*
* Look to see if I need to eat this packet.
* Algorithm is to forward all young packets
* and prematurely age any packets which will
* by physically broadcasted.
* Any very old packets eaten without forwarding
* would die anyway.
*
* Suggestion of Bill Nesheim, Cornell U.
*/
if (ipx->ipx_tc < IPX_MAXHOPS) {
ipx_forward(m);
return;
}
}
/*
* Is this our packet? If not, forward.
*/
} else {
for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
(ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)))
break;
if (ia == NULL) {
ipx_forward(m);
return;
}
}
ours:
/*
* Locate pcb for datagram.
*/
ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
/*
* Switch out to protocol's input routine.
*/
if (ipxp != NULL) {
ipxstat.ipxs_delivered++;
if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
switch (ipx->ipx_pt) {
case IPXPROTO_SPX:
spx_input(m, ipxp);
return;
}
ipx_input(m, ipxp);
} else
goto bad;
return;
bad:
m_freem(m);
}
void
ipx_ctlinput(cmd, arg_as_sa, dummy)
int cmd;
struct sockaddr *arg_as_sa; /* XXX should be swapped with dummy */
void *dummy;
{
caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
struct ipx_addr *ipx;
if (cmd < 0 || cmd >= PRC_NCMDS)
return;
switch (cmd) {
struct sockaddr_ipx *sipx;
case PRC_IFDOWN:
case PRC_HOSTDEAD:
case PRC_HOSTUNREACH:
sipx = (struct sockaddr_ipx *)arg;
if (sipx->sipx_family != AF_IPX)
return;
ipx = &sipx->sipx_addr;
break;
default:
if (ipxprintfs)
printf("ipx_ctlinput: cmd %d.\n", cmd);
break;
}
}
/*
* Forward a packet. If some error occurs drop the packet. IPX don't
* have a way to return errors to the sender.
*/
static struct route ipx_droute;
static struct route ipx_sroute;
static void
ipx_forward(m)
struct mbuf *m;
{
register struct ipx *ipx = mtod(m, struct ipx *);
register int error;
struct mbuf *mcopy = NULL;
int agedelta = 1;
int flags = IPX_FORWARDING;
int ok_there = 0;
int ok_back = 0;
if (ipxforwarding == 0) {
/* can't tell difference between net and host */
ipxstat.ipxs_cantforward++;
m_freem(m);
goto cleanup;
}
ipx->ipx_tc++;
if (ipx->ipx_tc > IPX_MAXHOPS) {
ipxstat.ipxs_cantforward++;
m_freem(m);
goto cleanup;
}
if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
ipxstat.ipxs_noroute++;
m_freem(m);
goto cleanup;
}
/*
* Here we think about forwarding broadcast packets,
* so we try to insure that it doesn't go back out
* on the interface it came in on. Also, if we
* are going to physically broadcast this, let us
* age the packet so we can eat it safely the second time around.
*/
if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
struct ifnet *ifp;
if (ia != NULL) {
/* I'm gonna hafta eat this packet */
agedelta += IPX_MAXHOPS - ipx->ipx_tc;
ipx->ipx_tc = IPX_MAXHOPS;
}
if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
/* error = ENETUNREACH; He'll never get it! */
ipxstat.ipxs_noroute++;
m_freem(m);
goto cleanup;
}
if (ipx_droute.ro_rt &&
(ifp = ipx_droute.ro_rt->rt_ifp) &&
ipx_sroute.ro_rt &&
(ifp != ipx_sroute.ro_rt->rt_ifp)) {
flags |= IPX_ALLOWBROADCAST;
} else {
ipxstat.ipxs_noroute++;
m_freem(m);
goto cleanup;
}
}
/*
* We don't need to recompute checksum because ipx_tc field
* is ignored by checksum calculation routine, however
* it may be desirable to reset checksum if ipxcksum == 0
*/
#if 0
if (!ipxcksum)
ipx->ipx_sum = 0xffff;
#endif
error = ipx_outputfl(m, &ipx_droute, flags);
if (error == 0) {
ipxstat.ipxs_forward++;
if (ipxprintfs) {
printf("forward: ");
ipx_printhost(&ipx->ipx_sna);
printf(" to ");
ipx_printhost(&ipx->ipx_dna);
printf(" hops %d\n", ipx->ipx_tc);
}
} else if (mcopy != NULL) {
ipx = mtod(mcopy, struct ipx *);
switch (error) {
case ENETUNREACH:
case EHOSTDOWN:
case EHOSTUNREACH:
case ENETDOWN:
case EPERM:
ipxstat.ipxs_noroute++;
break;
case EMSGSIZE:
ipxstat.ipxs_mtutoosmall++;
break;
case ENOBUFS:
ipxstat.ipxs_odropped++;
break;
}
mcopy = NULL;
m_freem(m);
}
cleanup:
if (ok_there)
ipx_undo_route(&ipx_droute);
if (ok_back)
ipx_undo_route(&ipx_sroute);
if (mcopy != NULL)
m_freem(mcopy);
}
static int
ipx_do_route(src, ro)
struct ipx_addr *src;
struct route *ro;
{
struct sockaddr_ipx *dst;
bzero((caddr_t)ro, sizeof(*ro));
dst = (struct sockaddr_ipx *)&ro->ro_dst;
dst->sipx_len = sizeof(*dst);
dst->sipx_family = AF_IPX;
dst->sipx_addr = *src;
dst->sipx_addr.x_port = 0;
rtalloc(ro);
if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
return (0);
}
ro->ro_rt->rt_use++;
return (1);
}
static void
ipx_undo_route(ro)
register struct route *ro;
{
if (ro->ro_rt != NULL) {
RTFREE(ro->ro_rt);
}
}
void
ipx_watch_output(m, ifp)
struct mbuf *m;
struct ifnet *ifp;
{
register struct ipxpcb *ipxp;
register struct ifaddr *ifa;
register struct ipx_ifaddr *ia;
/*
* Give any raw listeners a crack at the packet
*/
for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
ipxp = ipxp->ipxp_next) {
struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
if (m0 != NULL) {
register struct ipx *ipx;
M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
if (m0 == NULL)
continue;
ipx = mtod(m0, struct ipx *);
ipx->ipx_sna.x_net = ipx_zeronet;
for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
if (ifp == ia->ia_ifp)
break;
if (ia == NULL)
ipx->ipx_sna.x_host = ipx_zerohost;
else
ipx->ipx_sna.x_host =
ia->ia_addr.sipx_addr.x_host;
if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family == AF_IPX) {
ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
break;
}
}
ipx->ipx_len = ntohl(m0->m_pkthdr.len);
ipx_input(m0, ipxp);
}
}
}