freebsd-nq/sys/netipx/ipx_input.c
John Hay e819bbbca4 Accept odd length ipx packets. (Win95 and some dialup servers use it.)
Original idea submitted by:	Atsushi Murai <amurai@spec.co.jp>
1996-08-18 08:38:15 +00:00

527 lines
13 KiB
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
*
* $Id: ipx_input.c,v 1.8 1996/03/11 15:13:48 davidg Exp $
*/
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/route.h>
#include <net/netisr.h>
#include <net/raw_cb.h>
#include <netipx/ipx.h>
#include <netipx/spx.h>
#include <netipx/ipx_if.h>
#include <netipx/ipx_pcb.h>
#include <netipx/ipx_var.h>
#include <netipx/ipx_error.h>
#ifndef IPXPRINTFS
#define IPXPRINTFS 1 /* printing forwarding information */
#endif
int ipxcksum = 0;
SYSCTL_INT(_net_ipx_ipx, OID_AUTO, checksum, CTLFLAG_RW,
&ipxcksum, 0, "");
int ipxprintfs = IPXPRINTFS;
int ipxdonosocks = 0;
SYSCTL_INT(_net_ipx_ipx, OID_AUTO, donosocks, CTLFLAG_RW,
&ipxdonosocks, 0, "");
int ipxforwarding = 0;
SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxforwarding, CTLFLAG_RW,
&ipxforwarding, 0, "");
union ipx_host ipx_thishost;
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;
int ipxintr_getpck = 0;
int ipxintr_swtch = 0;
static u_short allones[] = {-1, -1, -1};
struct ipxpcb ipxpcb;
struct ipxpcb ipxrawpcb;
struct ifqueue ipxintrq;
int ipxqmaxlen = IFQ_MAXLEN;
long ipx_pexseq;
NETISR_SET(NETISR_IPX, ipxintr);
/*
* IPX initialization.
*/
void
ipx_init()
{
ipx_broadnet = * (union ipx_net *) allones;
ipx_broadhost = * (union ipx_host *) allones;
ipx_pexseq = time.tv_usec;
ipxintrq.ifq_maxlen = ipxqmaxlen;
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;
}
/*
* IPX input routine. Pass to next level.
*/
void
ipxintr()
{
register struct ipx *ipx;
register struct mbuf *m;
register struct ipxpcb *ipxp;
register int i;
int len, s, error;
char oddshortpacket = 0;
next:
/*
* Get next datagram off input queue and get IPX header
* in first mbuf.
*/
s = splimp();
IF_DEQUEUE(&ipxintrq, m);
splx(s);
ipxintr_getpck++;
if (m == 0)
return;
if ((m->m_flags & M_EXT || m->m_len < sizeof (struct ipx)) &&
(m = m_pullup(m, sizeof (struct ipx))) == 0) {
ipxstat.ipxs_toosmall++;
goto next;
}
/*
* 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) ipx_input(m1, ipxp);
}
ipx = mtod(m, struct ipx *);
len = ntohs(ipx->ipx_len);
if ((len < m->m_pkthdr.len) && (oddshortpacket = len & 1)) {
/*
* If this packet is of odd length, and the length
* inside the header is less than the received packet
* length, preserve garbage byte for possible checksum.
*/
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 && ((i = ipx->ipx_sum)!=0xffff)) {
ipx->ipx_sum = 0;
if (i != (ipx->ipx_sum = ipx_cksum(m, len))) {
ipxstat.ipxs_badsum++;
ipx->ipx_sum = i;
if (ipx_hosteqnh(ipx_thishost, ipx->ipx_dna.x_host))
error = IPX_ERR_BADSUM;
else
error = IPX_ERR_BADSUM_T;
ipx_error(m, error, 0);
goto next;
}
}
/*
* 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)) ) {
/*
* 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);
goto next;
}
}
/*
* Is this our packet? If not, forward.
*/
} else if (!ipx_hosteqnh(ipx_thishost,ipx->ipx_dna.x_host)) {
ipx_forward(m);
goto next;
}
/*
* Locate pcb for datagram.
*/
ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
/*
* Switch out to protocol's input routine.
*/
ipxintr_swtch++;
if (ipxp) {
if (oddshortpacket) {
m_adj(m, -1);
}
if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS)==0)
switch (ipx->ipx_pt) {
case IPXPROTO_SPX:
spx_input(m, ipxp);
goto next;
case IPXPROTO_ERROR:
ipx_err_input(m);
goto next;
}
ipx_input(m, ipxp);
} else {
ipx_error(m, IPX_ERR_NOSOCK, 0);
}
goto next;
bad:
m_freem(m);
goto next;
}
u_char ipxctlerrmap[PRC_NCMDS] = {
ECONNABORTED, ECONNABORTED, 0, 0,
0, 0, EHOSTDOWN, EHOSTUNREACH,
ENETUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
EMSGSIZE, 0, 0, 0,
0, 0, 0, 0
};
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;
struct ipxpcb *ipxp;
struct ipx_errp *errp;
int type;
if (cmd < 0 || cmd > PRC_NCMDS)
return;
if (ipxctlerrmap[cmd] == 0)
return; /* XXX */
type = IPX_ERR_UNREACH_HOST;
errp = (struct ipx_errp *)arg;
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:
ipx = &errp->ipx_err_ipx.ipx_dna;
type = errp->ipx_err_num;
type = ntohs((u_short)type);
break;
}
switch (type) {
case IPX_ERR_UNREACH_HOST:
ipx_pcbnotify(ipx, (int)ipxctlerrmap[cmd], ipx_abort, (long)0);
break;
case IPX_ERR_NOSOCK:
ipxp = ipx_pcblookup(ipx, errp->ipx_err_ipx.ipx_sna.x_port,
IPX_WILDCARD);
if(ipxp && ipxdonosocks && ! ipx_nullhost(ipxp->ipxp_faddr))
(void) ipx_drop(ipxp, (int)ipxctlerrmap[cmd]);
}
}
/*
* Forward a packet. If some error occurs return the sender
* an error packet. Note we can't always generate a meaningful
* error message because the IPX errors don't have a large enough repetoire
* of codes and types.
*/
struct route ipx_droute;
struct route ipx_sroute;
void
ipx_forward(m)
struct mbuf *m;
{
register struct ipx *ipx = mtod(m, struct ipx *);
register int error, type, code;
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 */
type = IPX_ERR_UNREACH_HOST, code = 0;
goto senderror;
}
ipx->ipx_tc++;
if (ipx->ipx_tc > IPX_MAXHOPS) {
type = IPX_ERR_TOO_OLD, code = 0;
goto senderror;
}
/*
* Save at most 42 bytes of the packet in case
* we need to generate an IPX error message to the src.
*/
mcopy = m_copy(m, 0, imin((int)ntohs(ipx->ipx_len), 42));
if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute))==0) {
type = IPX_ERR_UNREACH_HOST, code = 0;
goto senderror;
}
/*
* 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) {
/* 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! */
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 {
type = IPX_ERR_UNREACH_HOST, code = 0;
goto senderror;
}
}
/* need to adjust checksum */
if (ipxcksum && ipx->ipx_sum != 0xffff) {
union bytes {
u_char c[4];
u_short s[2];
long l;
} x;
register int shift;
x.l = 0; x.c[0] = agedelta;
shift = (((((int)ntohs(ipx->ipx_len))+1)>>1)-2) & 0xf;
x.l = ipx->ipx_sum + (x.s[0] << shift);
x.l = x.s[0] + x.s[1];
x.l = x.s[0] + x.s[1];
if (x.l==0xffff) ipx->ipx_sum = 0; else ipx->ipx_sum = x.l;
} else
ipx->ipx_sum = 0xffff;
error = ipx_outputfl(m, &ipx_droute, flags);
if (ipxprintfs && !error) {
printf("forward: ");
ipx_printhost(&ipx->ipx_sna);
printf(" to ");
ipx_printhost(&ipx->ipx_dna);
printf(" hops %d\n", ipx->ipx_tc);
}
if (error && mcopy != NULL) {
ipx = mtod(mcopy, struct ipx *);
type = IPX_ERR_UNSPEC_T, code = 0;
switch (error) {
case ENETUNREACH:
case EHOSTDOWN:
case EHOSTUNREACH:
case ENETDOWN:
case EPERM:
type = IPX_ERR_UNREACH_HOST;
break;
case EMSGSIZE:
type = IPX_ERR_TOO_BIG;
code = 576; /* too hard to figure out mtu here */
break;
case ENOBUFS:
type = IPX_ERR_UNSPEC_T;
break;
}
mcopy = NULL;
senderror:
ipx_error(m, type, code);
}
cleanup:
if (ok_there)
ipx_undo_route(&ipx_droute);
if (ok_back)
ipx_undo_route(&ipx_sroute);
if (mcopy != NULL)
m_freem(mcopy);
}
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 == 0 || ro->ro_rt->rt_ifp == 0) {
return (0);
}
ro->ro_rt->rt_use++;
return (1);
}
void
ipx_undo_route(ro)
register struct route *ro;
{
if (ro->ro_rt) {RTFREE(ro->ro_rt);}
}
void
ipx_watch_output(m, ifp)
struct mbuf *m;
struct ifnet *ifp;
{
register struct ipxpcb *ipxp;
register struct ifaddr *ifa;
/*
* 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) {
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;
ipx->ipx_sna.x_host = ipx_thishost;
if (ifp && (ifp->if_flags & IFF_POINTOPOINT))
for(ifa = ifp->if_addrlist; ifa;
ifa = ifa->ifa_next) {
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);
}
}
}