1 /*-
2 * Copyright (c) 1984, 1985, 1986, 1987, 1993
3 * The Regents of the University of California.
4 * Copyright (c) 1995, Mike Mitchell
5 * Copyright (c) 2004-2005 Robert N. M. Watson
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)ipx_input.c
37 */
38
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/mbuf.h>
45 #include <sys/protosw.h>
46 #include <sys/socket.h>
47 #include <sys/kernel.h>
48 #include <sys/random.h>
49 #include <sys/sysctl.h>
50
51 #include <net/if.h>
52 #include <net/route.h>
53 #include <net/netisr.h>
54
55 #include <netipx/ipx.h>
56 #include <netipx/spx.h>
57 #include <netipx/ipx_if.h>
58 #include <netipx/ipx_pcb.h>
59 #include <netipx/ipx_var.h>
60
61 int ipxcksum = 0;
62 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, checksum, CTLFLAG_RW,
63 &ipxcksum, 0, "");
64
65 static int ipxprintfs = 0; /* printing forwarding information */
66 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxprintfs, CTLFLAG_RW,
67 &ipxprintfs, 0, "");
68
69 static int ipxforwarding = 0;
70 SYSCTL_INT(_net_ipx_ipx, OID_AUTO, ipxforwarding, CTLFLAG_RW,
71 &ipxforwarding, 0, "");
72
73 static int ipxnetbios = 0;
74 SYSCTL_INT(_net_ipx, OID_AUTO, ipxnetbios, CTLFLAG_RW,
75 &ipxnetbios, 0, "");
76
77 const union ipx_net ipx_zeronet;
78 const union ipx_host ipx_zerohost;
79
80 const union ipx_net ipx_broadnet = { .s_net[0] = 0xffff,
81 .s_net[1] = 0xffff };
82 const union ipx_host ipx_broadhost = { .s_host[0] = 0xffff,
83 .s_host[1] = 0xffff,
84 .s_host[2] = 0xffff };
85
86 struct ipxstat ipxstat;
87 struct sockaddr_ipx ipx_netmask, ipx_hostmask;
88
89 /*
90 * IPX protocol control block (pcb) lists.
91 */
92 struct mtx ipxpcb_list_mtx;
93 struct ipxpcbhead ipxpcb_list;
94 struct ipxpcbhead ipxrawpcb_list;
95
96 static int ipxqmaxlen = IFQ_MAXLEN;
97 static struct ifqueue ipxintrq;
98
99 long ipx_pexseq; /* Locked with ipxpcb_list_mtx. */
100
101 static int ipx_do_route(struct ipx_addr *src, struct route *ro);
102 static void ipx_undo_route(struct route *ro);
103 static void ipx_forward(struct mbuf *m);
104 static void ipxintr(struct mbuf *m);
105
106 /*
107 * IPX initialization.
108 */
109
110 void
111 ipx_init()
112 {
113
114 read_random(&ipx_pexseq, sizeof ipx_pexseq);
115
116 LIST_INIT(&ipxpcb_list);
117 LIST_INIT(&ipxrawpcb_list);
118
119 IPX_LIST_LOCK_INIT();
120
121 ipx_netmask.sipx_len = 6;
122 ipx_netmask.sipx_addr.x_net = ipx_broadnet;
123
124 ipx_hostmask.sipx_len = 12;
125 ipx_hostmask.sipx_addr.x_net = ipx_broadnet;
126 ipx_hostmask.sipx_addr.x_host = ipx_broadhost;
127
128 ipxintrq.ifq_maxlen = ipxqmaxlen;
129 mtx_init(&ipxintrq.ifq_mtx, "ipx_inq", NULL, MTX_DEF);
130 netisr_register(NETISR_IPX, ipxintr, &ipxintrq, NETISR_MPSAFE);
131 }
132
133 /*
134 * IPX input routine. Pass to next level.
135 */
136 static void
137 ipxintr(struct mbuf *m)
138 {
139 register struct ipx *ipx;
140 register struct ipxpcb *ipxp;
141 struct ipx_ifaddr *ia;
142 int len;
143
144 /*
145 * If no IPX addresses have been set yet but the interfaces
146 * are receiving, can't do anything with incoming packets yet.
147 */
148 if (ipx_ifaddr == NULL) {
149 m_freem(m);
150 return;
151 }
152
153 ipxstat.ipxs_total++;
154
155 if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
156 (m = m_pullup(m, sizeof(struct ipx))) == NULL) {
157 ipxstat.ipxs_toosmall++;
158 return;
159 }
160
161 /*
162 * Give any raw listeners a crack at the packet
163 */
164 IPX_LIST_LOCK();
165 LIST_FOREACH(ipxp, &ipxrawpcb_list, ipxp_list) {
166 struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
167 if (m1 != NULL) {
168 IPX_LOCK(ipxp);
169 ipx_input(m1, ipxp);
170 IPX_UNLOCK(ipxp);
171 }
172 }
173 IPX_LIST_UNLOCK();
174
175 ipx = mtod(m, struct ipx *);
176 len = ntohs(ipx->ipx_len);
177 /*
178 * Check that the amount of data in the buffers
179 * is as at least much as the IPX header would have us expect.
180 * Trim mbufs if longer than we expect.
181 * Drop packet if shorter than we expect.
182 */
183 if (m->m_pkthdr.len < len) {
184 ipxstat.ipxs_tooshort++;
185 m_freem(m);
186 return;
187 }
188 if (m->m_pkthdr.len > len) {
189 if (m->m_len == m->m_pkthdr.len) {
190 m->m_len = len;
191 m->m_pkthdr.len = len;
192 } else
193 m_adj(m, len - m->m_pkthdr.len);
194 }
195 if (ipxcksum && ipx->ipx_sum != 0xffff) {
196 if (ipx->ipx_sum != ipx_cksum(m, len)) {
197 ipxstat.ipxs_badsum++;
198 m_freem(m);
199 return;
200 }
201 }
202
203 /*
204 * Propagated (Netbios) packets (type 20) has to be handled
205 * different. :-(
206 */
207 if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
208 if (ipxnetbios) {
209 ipx_output_type20(m);
210 return;
211 } else {
212 m_freem(m);
213 return;
214 }
215 }
216
217 /*
218 * Is this a directed broadcast?
219 */
220 if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.x_host)) {
221 if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
222 (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_broadnet)) &&
223 (!ipx_neteqnn(ipx->ipx_sna.x_net, ipx_zeronet)) &&
224 (!ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)) ) {
225 /*
226 * If it is a broadcast to the net where it was
227 * received from, treat it as ours.
228 */
229 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
230 if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
231 ipx_neteq(ia->ia_addr.sipx_addr,
232 ipx->ipx_dna))
233 goto ours;
234
235 /*
236 * Look to see if I need to eat this packet.
237 * Algorithm is to forward all young packets
238 * and prematurely age any packets which will
239 * by physically broadcasted.
240 * Any very old packets eaten without forwarding
241 * would die anyway.
242 *
243 * Suggestion of Bill Nesheim, Cornell U.
244 */
245 if (ipx->ipx_tc < IPX_MAXHOPS) {
246 ipx_forward(m);
247 return;
248 }
249 }
250 /*
251 * Is this our packet? If not, forward.
252 */
253 } else {
254 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
255 if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
256 (ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
257 ipx_neteqnn(ipx->ipx_dna.x_net, ipx_zeronet)))
258 break;
259
260 if (ia == NULL) {
261 ipx_forward(m);
262 return;
263 }
264 }
265 ours:
266 /*
267 * Locate pcb for datagram.
268 */
269 IPX_LIST_LOCK();
270 ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.x_port, IPX_WILDCARD);
271 /*
272 * Switch out to protocol's input routine.
273 */
274 if (ipxp != NULL) {
275 ipxstat.ipxs_delivered++;
276 if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
277 switch (ipx->ipx_pt) {
278 case IPXPROTO_SPX:
279 IPX_LOCK(ipxp);
280 /* Will release both locks. */
281 spx_input(m, ipxp);
282 return;
283 }
284 IPX_LOCK(ipxp);
285 ipx_input(m, ipxp);
286 IPX_UNLOCK(ipxp);
287 } else
288 m_freem(m);
289 IPX_LIST_UNLOCK();
290 }
291
292 void
293 ipx_ctlinput(cmd, arg_as_sa, dummy)
294 int cmd;
295 struct sockaddr *arg_as_sa; /* XXX should be swapped with dummy */
296 void *dummy;
297 {
298
299 /* Currently, nothing. */
300 }
301
302 /*
303 * Forward a packet. If some error occurs drop the packet. IPX don't
304 * have a way to return errors to the sender.
305 */
306
307 static struct route ipx_droute;
308 static struct route ipx_sroute;
309
310 static void
311 ipx_forward(m)
312 struct mbuf *m;
313 {
314 register struct ipx *ipx = mtod(m, struct ipx *);
315 register int error;
316 int agedelta = 1;
317 int flags = IPX_FORWARDING;
318 int ok_there = 0;
319 int ok_back = 0;
320
321 if (ipxforwarding == 0) {
322 /* can't tell difference between net and host */
323 ipxstat.ipxs_cantforward++;
324 m_freem(m);
325 goto cleanup;
326 }
327 ipx->ipx_tc++;
328 if (ipx->ipx_tc > IPX_MAXHOPS) {
329 ipxstat.ipxs_cantforward++;
330 m_freem(m);
331 goto cleanup;
332 }
333
334 if ((ok_there = ipx_do_route(&ipx->ipx_dna,&ipx_droute)) == 0) {
335 ipxstat.ipxs_noroute++;
336 m_freem(m);
337 goto cleanup;
338 }
339 /*
340 * Here we think about forwarding broadcast packets,
341 * so we try to insure that it doesn't go back out
342 * on the interface it came in on. Also, if we
343 * are going to physically broadcast this, let us
344 * age the packet so we can eat it safely the second time around.
345 */
346 if (ipx->ipx_dna.x_host.c_host[0] & 0x1) {
347 struct ipx_ifaddr *ia = ipx_iaonnetof(&ipx->ipx_dna);
348 struct ifnet *ifp;
349 if (ia != NULL) {
350 /* I'm gonna hafta eat this packet */
351 agedelta += IPX_MAXHOPS - ipx->ipx_tc;
352 ipx->ipx_tc = IPX_MAXHOPS;
353 }
354 if ((ok_back = ipx_do_route(&ipx->ipx_sna,&ipx_sroute)) == 0) {
355 /* error = ENETUNREACH; He'll never get it! */
356 ipxstat.ipxs_noroute++;
357 m_freem(m);
358 goto cleanup;
359 }
360 if (ipx_droute.ro_rt &&
361 (ifp = ipx_droute.ro_rt->rt_ifp) &&
362 ipx_sroute.ro_rt &&
363 (ifp != ipx_sroute.ro_rt->rt_ifp)) {
364 flags |= IPX_ALLOWBROADCAST;
365 } else {
366 ipxstat.ipxs_noroute++;
367 m_freem(m);
368 goto cleanup;
369 }
370 }
371 /*
372 * We don't need to recompute checksum because ipx_tc field
373 * is ignored by checksum calculation routine, however
374 * it may be desirable to reset checksum if ipxcksum == 0
375 */
376 #if 0
377 if (!ipxcksum)
378 ipx->ipx_sum = 0xffff;
379 #endif
380
381 error = ipx_outputfl(m, &ipx_droute, flags);
382 if (error == 0) {
383 ipxstat.ipxs_forward++;
384
385 if (ipxprintfs) {
386 printf("forward: ");
387 ipx_printhost(&ipx->ipx_sna);
388 printf(" to ");
389 ipx_printhost(&ipx->ipx_dna);
390 printf(" hops %d\n", ipx->ipx_tc);
391 }
392 }
393 cleanup:
394 if (ok_there)
395 ipx_undo_route(&ipx_droute);
396 if (ok_back)
397 ipx_undo_route(&ipx_sroute);
398 }
399
400 static int
401 ipx_do_route(src, ro)
402 struct ipx_addr *src;
403 struct route *ro;
404 {
405 struct sockaddr_ipx *dst;
406
407 bzero((caddr_t)ro, sizeof(*ro));
408 dst = (struct sockaddr_ipx *)&ro->ro_dst;
409
410 dst->sipx_len = sizeof(*dst);
411 dst->sipx_family = AF_IPX;
412 dst->sipx_addr = *src;
413 dst->sipx_addr.x_port = 0;
414 rtalloc_ign(ro, 0);
415 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp == NULL) {
416 return (0);
417 }
418 ro->ro_rt->rt_use++;
419 return (1);
420 }
421
422 static void
423 ipx_undo_route(ro)
424 register struct route *ro;
425 {
426 if (ro->ro_rt != NULL) {
427 RTFREE(ro->ro_rt);
428 }
429 }
430
431 /*
432 * XXXRW: This code should be run in its own netisr dispatch to avoid a call
433 * back into the socket code from the IPX output path.
434 */
435 void
436 ipx_watch_output(m, ifp)
437 struct mbuf *m;
438 struct ifnet *ifp;
439 {
440 register struct ipxpcb *ipxp;
441 register struct ifaddr *ifa;
442 register struct ipx_ifaddr *ia;
443 /*
444 * Give any raw listeners a crack at the packet
445 */
446 IPX_LIST_LOCK();
447 LIST_FOREACH(ipxp, &ipxrawpcb_list, ipxp_list) {
448 struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
449 if (m0 != NULL) {
450 register struct ipx *ipx;
451
452 M_PREPEND(m0, sizeof(*ipx), M_DONTWAIT);
453 if (m0 == NULL)
454 continue;
455 ipx = mtod(m0, struct ipx *);
456 ipx->ipx_sna.x_net = ipx_zeronet;
457 for (ia = ipx_ifaddr; ia != NULL; ia = ia->ia_next)
458 if (ifp == ia->ia_ifp)
459 break;
460 if (ia == NULL)
461 ipx->ipx_sna.x_host = ipx_zerohost;
462 else
463 ipx->ipx_sna.x_host =
464 ia->ia_addr.sipx_addr.x_host;
465
466 if (ifp != NULL && (ifp->if_flags & IFF_POINTOPOINT))
467 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
468 if (ifa->ifa_addr->sa_family == AF_IPX) {
469 ipx->ipx_sna = IA_SIPX(ifa)->sipx_addr;
470 break;
471 }
472 }
473 ipx->ipx_len = ntohl(m0->m_pkthdr.len);
474 IPX_LOCK(ipxp);
475 ipx_input(m0, ipxp);
476 IPX_UNLOCK(ipxp);
477 }
478 }
479 IPX_LIST_UNLOCK();
480 }
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