1 /*
2 * Copyright (c) 1995, Mike Mitchell
3 * Copyright (c) 1984, 1985, 1986, 1987, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by the University of
17 * California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)ipx_input.c
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/5.2/sys/netipx/ipx_input.c 122320 2003-11-08 22:28:40Z sam $");
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/mbuf.h>
43 #include <sys/protosw.h>
44 #include <sys/socket.h>
45 #include <sys/kernel.h>
46 #include <sys/random.h>
47 #include <sys/sysctl.h>
48
49 #include <net/if.h>
50 #include <net/route.h>
51 #include <net/netisr.h>
52
53 #include <netipx/ipx.h>
54 #include <netipx/spx.h>
55 #include <netipx/ipx_if.h>
56 #include <netipx/ipx_pcb.h>
57 #include <netipx/ipx_var.h>
58
59 int ipxcksum = 0;
60 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, checksum, CTLFLAG_RW,
61 &ipxcksum, 0, "");
62
63 static int ipxprintfs = 0; /* printing forwarding information */
64 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxprintfs, CTLFLAG_RW,
65 &ipxprintfs, 0, "");
66
67 static int ipxforwarding = 0;
68 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxforwarding, CTLFLAG_RW,
69 &ipxforwarding, 0, "");
70
71 static int ipxnetbios = 0;
72 SYSCTL_INT(_net_ipx, OID_AUTO, ipxnetbios, CTLFLAG_RW,
73 &ipxnetbios, 0, "");
74
75 union ipx_net ipx_zeronet;
76 union ipx_host ipx_zerohost;
77
78 union ipx_net ipx_broadnet;
79 union ipx_host ipx_broadhost;
80
81 struct ipxstat ipxstat;
82 struct sockaddr_ipx ipx_netmask, ipx_hostmask;
83
84 static u_short allones[] = {-1, -1, -1};
85
86 struct ipxpcb ipxpcb;
87 struct ipxpcb ipxrawpcb;
88
89 static int ipxqmaxlen = IFQ_MAXLEN;
90 static struct ifqueue ipxintrq;
91
92 long ipx_pexseq;
93
94 static int ipx_do_route(struct ipx_addr *src, struct route *ro);
95 static void ipx_undo_route(struct route *ro);
96 static void ipx_forward(struct mbuf *m);
97 static void ipxintr(struct mbuf *m);
98
99 /*
100 * IPX initialization.
101 */
102
103 void
104 ipx_init()
105 {
106 ipx_broadnet = *(union ipx_net *)allones;
107 ipx_broadhost = *(union ipx_host *)allones;
108
109 read_random(&ipx_pexseq, sizeof ipx_pexseq);
110 ipxpcb.ipxp_next = ipxpcb.ipxp_prev = &ipxpcb;
111 ipxrawpcb.ipxp_next = ipxrawpcb.ipxp_prev = &ipxrawpcb;
112
113 ipx_netmask.sipx_len = 6;
114 ipx_netmask.sipx_addr.x_net = ipx_broadnet;
115
116 ipx_hostmask.sipx_len = 12;
117 ipx_hostmask.sipx_addr.x_net = ipx_broadnet;
118 ipx_hostmask.sipx_addr.x_host = ipx_broadhost;
119
120 ipxintrq.ifq_maxlen = ipxqmaxlen;
121 mtx_init(&ipxintrq.ifq_mtx, "ipx_inq", NULL, MTX_DEF);
122 netisr_register(NETISR_IPX, ipxintr, &ipxintrq, 0);
123 }
124
125 /*
126 * IPX input routine. Pass to next level.
127 */
128 static void
129 ipxintr(struct mbuf *m)
130 {
131 register struct ipx *ipx;
132 register struct ipxpcb *ipxp;
133 struct ipx_ifaddr *ia;
134 int len;
135
136 GIANT_REQUIRED;
137
138 /*
139 * If no IPX addresses have been set yet but the interfaces
140 * are receiving, can't do anything with incoming packets yet.
141 */
142 if (ipx_ifaddr == NULL)
143 goto bad;
144
145 ipxstat.ipxs_total++;
146
147 if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
148 (m = m_pullup(m, sizeof(struct ipx))) == 0) {
149 ipxstat.ipxs_toosmall++;
150 return;
151 }
152
153 /*
154 * Give any raw listeners a crack at the packet
155 */
156 for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
157 ipxp = ipxp->ipxp_next) {
158 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
159 if (m1 != NULL)
160 ipx_input(m1, ipxp);
161 }
162
163 ipx = mtod(m, struct ipx *);
164 len = ntohs(ipx->ipx_len);
165 /*
166 * Check that the amount of data in the buffers
167 * is as at least much as the IPX header would have us expect.
168 * Trim mbufs if longer than we expect.
169 * Drop packet if shorter than we expect.
170 */
171 if (m->m_pkthdr.len < len) {
172 ipxstat.ipxs_tooshort++;
173 goto bad;
174 }
175 if (m->m_pkthdr.len > len) {
176 if (m->m_len == m->m_pkthdr.len) {
177 m->m_len = len;
178 m->m_pkthdr.len = len;
179 } else
180 m_adj(m, len - m->m_pkthdr.len);
181 }
182 if (ipxcksum && ipx->ipx_sum != 0xffff) {
183 if (ipx->ipx_sum != ipx_cksum(m, len)) {
184 ipxstat.ipxs_badsum++;
185 goto bad;
186 }
187 }
188
189 /*
190 * Propagated (Netbios) packets (type 20) has to be handled
191 * different. :-(
192 */
193 if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
194 if (ipxnetbios) {
195 ipx_output_type20(m);
196 return;
197 } else
198 goto bad;
199 }
200
201 /*
202 * Is this a directed broadcast?
203 */
204 if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.x_host)) {
205 if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
206 (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_broadnet)) &&
207 (!ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet)) &&
208 (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)) ) {
209 /*
210 * If it is a broadcast to the net where it was
211 * received from, treat it as ours.
212 */
213 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
214 if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
215 ipx_neteq(ia->ia_addr.sipx_addr,
216 ipx->ipx_dna))
217 goto ours;
218
219 /*
220 * Look to see if I need to eat this packet.
221 * Algorithm is to forward all young packets
222 * and prematurely age any packets which will
223 * by physically broadcasted.
224 * Any very old packets eaten without forwarding
225 * would die anyway.
226 *
227 * Suggestion of Bill Nesheim, Cornell U.
228 */
229 if (ipx->ipx_tc < IPX_MAXHOPS) {
230 ipx_forward(m);
231 return;
232 }
233 }
234 /*
235 * Is this our packet? If not, forward.
236 */
237 } else {
238 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
239 if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
240 (ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
241 ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)))
242 break;
243
244 if (ia == NULL) {
245 ipx_forward(m);
246 return;
247 }
248 }
249 ours:
250 /*
251 * Locate pcb for datagram.
252 */
253 ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
254 /*
255 * Switch out to protocol's input routine.
256 */
257 if (ipxp != NULL) {
258 ipxstat.ipxs_delivered++;
259 if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
260 switch (ipx->ipx_pt) {
261 case IPXPROTO_SPX:
262 spx_input(m, ipxp);
263 return;
264 }
265 ipx_input(m, ipxp);
266 } else
267 goto bad;
268
269 return;
270
271 bad:
272 m_freem(m);
273 }
274
275 void
276 ipx_ctlinput(cmd, arg_as_sa, dummy)
277 int cmd;
278 struct sockaddr *arg_as_sa; /* XXX should be swapped with dummy */
279 void *dummy;
280 {
281 caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
282 struct ipx_addr *ipx;
283
284 if (cmd < 0 || cmd >= PRC_NCMDS)
285 return;
286 switch (cmd) {
287 struct sockaddr_ipx *sipx;
288
289 case PRC_IFDOWN:
290 case PRC_HOSTDEAD:
291 case PRC_HOSTUNREACH:
292 sipx = (struct sockaddr_ipx *)arg;
293 if (sipx->sipx_family != AF_IPX)
294 return;
295 ipx = &sipx->sipx_addr;
296 break;
297
298 default:
299 if (ipxprintfs)
300 printf("ipx_ctlinput: cmd %d.\n", cmd);
301 break;
302 }
303 }
304
305 /*
306 * Forward a packet. If some error occurs drop the packet. IPX don't
307 * have a way to return errors to the sender.
308 */
309
310 static struct route ipx_droute;
311 static struct route ipx_sroute;
312
313 static void
314 ipx_forward(m)
315 struct mbuf *m;
316 {
317 register struct ipx *ipx = mtod(m, struct ipx *);
318 register int error;
319 struct mbuf *mcopy = NULL;
320 int agedelta = 1;
321 int flags = IPX_FORWARDING;
322 int ok_there = 0;
323 int ok_back = 0;
324
325 if (ipxforwarding == 0) {
326 /* can't tell difference between net and host */
327 ipxstat.ipxs_cantforward++;
328 m_freem(m);
329 goto cleanup;
330 }
331 ipx->ipx_tc++;
332 if (ipx->ipx_tc > IPX_MAXHOPS) {
333 ipxstat.ipxs_cantforward++;
334 m_freem(m);
335 goto cleanup;
336 }
337
338 if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
339 ipxstat.ipxs_noroute++;
340 m_freem(m);
341 goto cleanup;
342 }
343 /*
344 * Here we think about forwarding broadcast packets,
345 * so we try to insure that it doesn't go back out
346 * on the interface it came in on. Also, if we
347 * are going to physically broadcast this, let us
348 * age the packet so we can eat it safely the second time around.
349 */
350 if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
351 struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
352 struct ifnet *ifp;
353 if (ia != NULL) {
354 /* I'm gonna hafta eat this packet */
355 agedelta += IPX_MAXHOPS - ipx->ipx_tc;
356 ipx->ipx_tc = IPX_MAXHOPS;
357 }
358 if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
359 /* error = ENETUNREACH; He'll never get it! */
360 ipxstat.ipxs_noroute++;
361 m_freem(m);
362 goto cleanup;
363 }
364 if (ipx_droute.ro_rt &&
365 (ifp = ipx_droute.ro_rt->rt_ifp) &&
366 ipx_sroute.ro_rt &&
367 (ifp != ipx_sroute.ro_rt->rt_ifp)) {
368 flags |= IPX_ALLOWBROADCAST;
369 } else {
370 ipxstat.ipxs_noroute++;
371 m_freem(m);
372 goto cleanup;
373 }
374 }
375 /*
376 * We don't need to recompute checksum because ipx_tc field
377 * is ignored by checksum calculation routine, however
378 * it may be desirable to reset checksum if ipxcksum == 0
379 */
380 #if 0
381 if (!ipxcksum)
382 ipx->ipx_sum = 0xffff;
383 #endif
384
385 error = ipx_outputfl(m, &ipx_droute, flags);
386 if (error == 0) {
387 ipxstat.ipxs_forward++;
388
389 if (ipxprintfs) {
390 printf("forward: ");
391 ipx_printhost(&ipx->ipx_sna);
392 printf(" to ");
393 ipx_printhost(&ipx->ipx_dna);
394 printf(" hops %d\n", ipx->ipx_tc);
395 }
396 } else if (mcopy != NULL) {
397 ipx = mtod(mcopy, struct ipx *);
398 switch (error) {
399
400 case ENETUNREACH:
401 case EHOSTDOWN:
402 case EHOSTUNREACH:
403 case ENETDOWN:
404 case EPERM:
405 ipxstat.ipxs_noroute++;
406 break;
407
408 case EMSGSIZE:
409 ipxstat.ipxs_mtutoosmall++;
410 break;
411
412 case ENOBUFS:
413 ipxstat.ipxs_odropped++;
414 break;
415 }
416 mcopy = NULL;
417 m_freem(m);
418 }
419 cleanup:
420 if (ok_there)
421 ipx_undo_route(&ipx_droute);
422 if (ok_back)
423 ipx_undo_route(&ipx_sroute);
424 if (mcopy != NULL)
425 m_freem(mcopy);
426 }
427
428 static int
429 ipx_do_route(src, ro)
430 struct ipx_addr *src;
431 struct route *ro;
432 {
433 struct sockaddr_ipx *dst;
434
435 bzero((caddr_t)ro, sizeof(*ro));
436 dst = (struct sockaddr_ipx *)&ro->ro_dst;
437
438 dst->sipx_len = sizeof(*dst);
439 dst->sipx_family = AF_IPX;
440 dst->sipx_addr = *src;
441 dst->sipx_addr.x_port = 0;
442 rtalloc(ro);
443 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
444 return (0);
445 }
446 ro->ro_rt->rt_use++;
447 return (1);
448 }
449
450 static void
451 ipx_undo_route(ro)
452 register struct route *ro;
453 {
454 if (ro->ro_rt != NULL) {
455 RTFREE(ro->ro_rt);
456 }
457 }
458
459 void
460 ipx_watch_output(m, ifp)
461 struct mbuf *m;
462 struct ifnet *ifp;
463 {
464 register struct ipxpcb *ipxp;
465 register struct ifaddr *ifa;
466 register struct ipx_ifaddr *ia;
467 /*
468 * Give any raw listeners a crack at the packet
469 */
470 for (ipxp = ipxrawpcb.ipxp_next; ipxp != &ipxrawpcb;
471 ipxp = ipxp->ipxp_next) {
472 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
473 if (m0 != NULL) {
474 register struct ipx *ipx;
475
476 M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
477 if (m0 == NULL)
478 continue;
479 ipx = mtod(m0, struct ipx *);
480 ipx->ipx_sna.x_net = ipx_zeronet;
481 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
482 if (ifp == ia->ia_ifp)
483 break;
484 if (ia == NULL)
485 ipx->ipx_sna.x_host = ipx_zerohost;
486 else
487 ipx->ipx_sna.x_host =
488 ia->ia_addr.sipx_addr.x_host;
489
490 if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
491 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
492 if (ifa->ifa_addr->sa_family == AF_IPX) {
493 ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
494 break;
495 }
496 }
497 ipx->ipx_len = ntohl(m0->m_pkthdr.len);
498 ipx_input(m0, ipxp);
499 }
500 }
501 }
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