xref: /freebsd/sys/netgraph/ng_cisco.c (revision 6fd05b64b5b65dd4ba9b86482a0634a5f0b96c29)
1 
2 /*
3  * ng_cisco.c
4  *
5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
6  * All rights reserved.
7  *
8  * Subject to the following obligations and disclaimer of warranty, use and
9  * redistribution of this software, in source or object code forms, with or
10  * without modifications are expressly permitted by Whistle Communications;
11  * provided, however, that:
12  * 1. Any and all reproductions of the source or object code must include the
13  *    copyright notice above and the following disclaimer of warranties; and
14  * 2. No rights are granted, in any manner or form, to use Whistle
15  *    Communications, Inc. trademarks, including the mark "WHISTLE
16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17  *    such appears in the above copyright notice or in the software.
18  *
19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  *
37  * Author: Julian Elischer <julian@freebsd.org>
38  *
39  * $FreeBSD$
40  * $Whistle: ng_cisco.c,v 1.25 1999/11/01 09:24:51 julian Exp $
41  */
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/errno.h>
46 #include <sys/kernel.h>
47 #include <sys/socket.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/syslog.h>
51 
52 #include <net/if.h>
53 
54 #include <netinet/in.h>
55 #include <netinet/if_ether.h>
56 
57 #include <netatalk/at.h>
58 
59 #include <netipx/ipx.h>
60 #include <netipx/ipx_if.h>
61 
62 #include <netgraph/ng_message.h>
63 #include <netgraph/netgraph.h>
64 #include <netgraph/ng_parse.h>
65 #include <netgraph/ng_cisco.h>
66 
67 #define CISCO_MULTICAST         0x8f	/* Cisco multicast address */
68 #define CISCO_UNICAST           0x0f	/* Cisco unicast address */
69 #define CISCO_KEEPALIVE         0x8035	/* Cisco keepalive protocol */
70 #define CISCO_ADDR_REQ          0	/* Cisco address request */
71 #define CISCO_ADDR_REPLY        1	/* Cisco address reply */
72 #define CISCO_KEEPALIVE_REQ     2	/* Cisco keepalive request */
73 
74 #define KEEPALIVE_SECS		10
75 
76 struct cisco_header {
77 	u_char  address;
78 	u_char  control;
79 	u_short protocol;
80 };
81 
82 #define CISCO_HEADER_LEN          sizeof (struct cisco_header)
83 
84 struct cisco_packet {
85 	u_long  type;
86 	u_long  par1;
87 	u_long  par2;
88 	u_short rel;
89 	u_short time0;
90 	u_short time1;
91 };
92 
93 #define CISCO_PACKET_LEN (sizeof(struct cisco_packet))
94 
95 struct protoent {
96 	hook_p  hook;		/* the hook for this proto */
97 	u_short af;		/* address family, -1 = downstream */
98 };
99 
100 struct cisco_priv {
101 	u_long  local_seq;
102 	u_long  remote_seq;
103 	u_long  seqRetries;	/* how many times we've been here throwing out
104 				 * the same sequence number without ack */
105 	node_p  node;
106 	struct callout_handle handle;
107 	struct protoent downstream;
108 	struct protoent inet;		/* IP information */
109 	struct in_addr localip;
110 	struct in_addr localmask;
111 	struct protoent inet6;		/* IPv6 information */
112 	struct protoent atalk;		/* AppleTalk information */
113 	struct protoent ipx;		/* IPX information */
114 };
115 typedef struct cisco_priv *sc_p;
116 
117 /* Netgraph methods */
118 static ng_constructor_t		cisco_constructor;
119 static ng_rcvmsg_t		cisco_rcvmsg;
120 static ng_shutdown_t		cisco_shutdown;
121 static ng_newhook_t		cisco_newhook;
122 static ng_rcvdata_t		cisco_rcvdata;
123 static ng_disconnect_t		cisco_disconnect;
124 
125 /* Other functions */
126 static int	cisco_input(sc_p sc, item_p item);
127 static void	cisco_keepalive(void *arg);
128 static int	cisco_send(sc_p sc, int type, long par1, long par2);
129 
130 /* Parse type for struct ng_cisco_ipaddr */
131 static const struct ng_parse_struct_field ng_cisco_ipaddr_type_fields[]
132 	= NG_CISCO_IPADDR_TYPE_INFO;
133 static const struct ng_parse_type ng_cisco_ipaddr_type = {
134 	&ng_parse_struct_type,
135 	&ng_cisco_ipaddr_type_fields
136 };
137 
138 /* Parse type for struct ng_async_stat */
139 static const struct ng_parse_struct_field ng_cisco_stats_type_fields[]
140 	= NG_CISCO_STATS_TYPE_INFO;
141 static const struct ng_parse_type ng_cisco_stats_type = {
142 	&ng_parse_struct_type,
143 	&ng_cisco_stats_type_fields
144 };
145 
146 /* List of commands and how to convert arguments to/from ASCII */
147 static const struct ng_cmdlist ng_cisco_cmdlist[] = {
148 	{
149 	  NGM_CISCO_COOKIE,
150 	  NGM_CISCO_SET_IPADDR,
151 	  "setipaddr",
152 	  &ng_cisco_ipaddr_type,
153 	  NULL
154 	},
155 	{
156 	  NGM_CISCO_COOKIE,
157 	  NGM_CISCO_GET_IPADDR,
158 	  "getipaddr",
159 	  NULL,
160 	  &ng_cisco_ipaddr_type
161 	},
162 	{
163 	  NGM_CISCO_COOKIE,
164 	  NGM_CISCO_GET_STATUS,
165 	  "getstats",
166 	  NULL,
167 	  &ng_cisco_stats_type
168 	},
169 	{ 0 }
170 };
171 
172 /* Node type */
173 static struct ng_type typestruct = {
174 	.version =	NG_ABI_VERSION,
175 	.name =		NG_CISCO_NODE_TYPE,
176 	.constructor =	cisco_constructor,
177 	.rcvmsg =	cisco_rcvmsg,
178 	.shutdown =	cisco_shutdown,
179 	.newhook =	cisco_newhook,
180 	.rcvdata =	cisco_rcvdata,
181 	.disconnect =	cisco_disconnect,
182 	.cmdlist =	ng_cisco_cmdlist,
183 };
184 NETGRAPH_INIT(cisco, &typestruct);
185 
186 /*
187  * Node constructor
188  */
189 static int
190 cisco_constructor(node_p node)
191 {
192 	sc_p sc;
193 
194 	MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_NOWAIT | M_ZERO);
195 	if (sc == NULL)
196 		return (ENOMEM);
197 
198 	callout_handle_init(&sc->handle);
199 	NG_NODE_SET_PRIVATE(node, sc);
200 	sc->node = node;
201 
202 	/* Initialise the varous protocol hook holders */
203 	sc->downstream.af = 0xffff;
204 	sc->inet.af = AF_INET;
205 	sc->inet6.af = AF_INET6;
206 	sc->atalk.af = AF_APPLETALK;
207 	sc->ipx.af = AF_IPX;
208 	return (0);
209 }
210 
211 /*
212  * Check new hook
213  */
214 static int
215 cisco_newhook(node_p node, hook_p hook, const char *name)
216 {
217 	const sc_p sc = NG_NODE_PRIVATE(node);
218 
219 	if (strcmp(name, NG_CISCO_HOOK_DOWNSTREAM) == 0) {
220 		sc->downstream.hook = hook;
221 		NG_HOOK_SET_PRIVATE(hook, &sc->downstream);
222 
223 		/* Start keepalives */
224 		sc->handle = timeout(cisco_keepalive, sc, hz * KEEPALIVE_SECS);
225 	} else if (strcmp(name, NG_CISCO_HOOK_INET) == 0) {
226 		sc->inet.hook = hook;
227 		NG_HOOK_SET_PRIVATE(hook, &sc->inet);
228 	} else if (strcmp(name, NG_CISCO_HOOK_APPLETALK) == 0) {
229 		sc->atalk.hook = hook;
230 		NG_HOOK_SET_PRIVATE(hook, &sc->atalk);
231 	} else if (strcmp(name, NG_CISCO_HOOK_IPX) == 0) {
232 		sc->ipx.hook = hook;
233 		NG_HOOK_SET_PRIVATE(hook, &sc->ipx);
234 	} else if (strcmp(name, NG_CISCO_HOOK_DEBUG) == 0) {
235 		NG_HOOK_SET_PRIVATE(hook, NULL);	/* unimplemented */
236 	} else
237 		return (EINVAL);
238 	return 0;
239 }
240 
241 /*
242  * Receive control message.
243  */
244 static int
245 cisco_rcvmsg(node_p node, item_p item, hook_p lasthook)
246 {
247 	struct ng_mesg *msg;
248 	const sc_p sc = NG_NODE_PRIVATE(node);
249 	struct ng_mesg *resp = NULL;
250 	int error = 0;
251 
252 	NGI_GET_MSG(item, msg);
253 	switch (msg->header.typecookie) {
254 	case NGM_GENERIC_COOKIE:
255 		switch (msg->header.cmd) {
256 		case NGM_TEXT_STATUS:
257 		    {
258 			char *arg;
259 			int pos;
260 
261 			NG_MKRESPONSE(resp, msg, sizeof(struct ng_mesg)
262 			    + NG_TEXTRESPONSE, M_NOWAIT);
263 			if (resp == NULL) {
264 				error = ENOMEM;
265 				break;
266 			}
267 			arg = (char *) resp->data;
268 			pos = sprintf(arg,
269 			  "keepalive period: %d sec; ", KEEPALIVE_SECS);
270 			pos += sprintf(arg + pos,
271 			  "unacknowledged keepalives: %ld", sc->seqRetries);
272 			resp->header.arglen = pos + 1;
273 			break;
274 		    }
275 		default:
276 			error = EINVAL;
277 			break;
278 		}
279 		break;
280 	case NGM_CISCO_COOKIE:
281 		switch (msg->header.cmd) {
282 		case NGM_CISCO_GET_IPADDR:	/* could be a late reply! */
283 			if ((msg->header.flags & NGF_RESP) == 0) {
284 				struct in_addr *ips;
285 
286 				NG_MKRESPONSE(resp, msg,
287 				    2 * sizeof(*ips), M_NOWAIT);
288 				if (!resp) {
289 					error = ENOMEM;
290 					break;
291 				}
292 				ips = (struct in_addr *) resp->data;
293 				ips[0] = sc->localip;
294 				ips[1] = sc->localmask;
295 				break;
296 			}
297 			/* FALLTHROUGH */	/* ...if it's a reply */
298 		case NGM_CISCO_SET_IPADDR:
299 		    {
300 			struct in_addr *const ips = (struct in_addr *)msg->data;
301 
302 			if (msg->header.arglen < 2 * sizeof(*ips)) {
303 				error = EINVAL;
304 				break;
305 			}
306 			sc->localip = ips[0];
307 			sc->localmask = ips[1];
308 			break;
309 		    }
310 		case NGM_CISCO_GET_STATUS:
311 		    {
312 			struct ng_cisco_stats *stat;
313 
314 			NG_MKRESPONSE(resp, msg, sizeof(*stat), M_NOWAIT);
315 			if (!resp) {
316 				error = ENOMEM;
317 				break;
318 			}
319 			stat = (struct ng_cisco_stats *)resp->data;
320 			stat->seqRetries = sc->seqRetries;
321 			stat->keepAlivePeriod = KEEPALIVE_SECS;
322 			break;
323 		    }
324 		default:
325 			error = EINVAL;
326 			break;
327 		}
328 		break;
329 	default:
330 		error = EINVAL;
331 		break;
332 	}
333 	NG_RESPOND_MSG(error, node, item, resp);
334 	NG_FREE_MSG(msg);
335 	return (error);
336 }
337 
338 /*
339  * Receive data
340  */
341 static int
342 cisco_rcvdata(hook_p hook, item_p item)
343 {
344 	const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
345 	struct protoent *pep;
346 	struct cisco_header *h;
347 	int error = 0;
348 	struct mbuf *m;
349 
350 	if ((pep = NG_HOOK_PRIVATE(hook)) == NULL)
351 		goto out;
352 
353 	/* If it came from our downlink, deal with it separately */
354 	if (pep->af == 0xffff)
355 		return (cisco_input(sc, item));
356 
357 	/* OK so it came from a protocol, heading out. Prepend general data
358 	   packet header. For now, IP,IPX only  */
359 	m = NGI_M(item); /* still associated with item */
360 	M_PREPEND(m, CISCO_HEADER_LEN, M_DONTWAIT);
361 	if (!m) {
362 		error = ENOBUFS;
363 		goto out;
364 	}
365 	h = mtod(m, struct cisco_header *);
366 	h->address = CISCO_UNICAST;
367 	h->control = 0;
368 
369 	switch (pep->af) {
370 	case AF_INET:		/* Internet Protocol */
371 		h->protocol = htons(ETHERTYPE_IP);
372 		break;
373 	case AF_INET6:
374 		h->protocol = htons(ETHERTYPE_IPV6);
375 		break;
376 	case AF_APPLETALK:	/* AppleTalk Protocol */
377 		h->protocol = htons(ETHERTYPE_AT);
378 		break;
379 	case AF_IPX:		/* Novell IPX Protocol */
380 		h->protocol = htons(ETHERTYPE_IPX);
381 		break;
382 	default:
383 		error = EAFNOSUPPORT;
384 		goto out;
385 	}
386 
387 	/* Send it */
388 	NG_FWD_NEW_DATA(error, item,  sc->downstream.hook, m);
389 	return (error);
390 
391 out:
392 	NG_FREE_ITEM(item);
393 	return (error);
394 }
395 
396 /*
397  * Shutdown node
398  */
399 static int
400 cisco_shutdown(node_p node)
401 {
402 	const sc_p sc = NG_NODE_PRIVATE(node);
403 
404 	NG_NODE_SET_PRIVATE(node, NULL);
405 	NG_NODE_UNREF(sc->node);
406 	FREE(sc, M_NETGRAPH);
407 	return (0);
408 }
409 
410 /*
411  * Disconnection of a hook
412  *
413  * For this type, removal of the last link destroys the node
414  */
415 static int
416 cisco_disconnect(hook_p hook)
417 {
418 	const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
419 	struct protoent *pep;
420 
421 	/* Check it's not the debug hook */
422 	if ((pep = NG_HOOK_PRIVATE(hook))) {
423 		pep->hook = NULL;
424 		if (pep->af == 0xffff) {
425 			/* If it is the downstream hook, stop the timers */
426 			untimeout(cisco_keepalive, sc, sc->handle);
427 		}
428 	}
429 
430 	/* If no more hooks, remove the node */
431 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
432 	&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
433 		ng_rmnode_self(NG_HOOK_NODE(hook));
434 	return (0);
435 }
436 
437 /*
438  * Receive data
439  */
440 static int
441 cisco_input(sc_p sc, item_p item)
442 {
443 	const struct cisco_header *h;
444 	struct cisco_header hdrbuf;
445 	struct protoent *pep;
446 	int error = 0;
447 	struct mbuf *m;
448 
449 	/* Get data */
450 	m = NGI_M(item);
451 
452 	/* Sanity check header length */
453 	if (m->m_pkthdr.len < sizeof(*h)) {
454 		error = EINVAL;
455 		goto drop;
456 	}
457 
458 	/* Get cisco header */
459 	if (m->m_len >= sizeof(*h))			/* the common case */
460 		h = mtod(m, const struct cisco_header *);
461 	else {
462 		m_copydata(m, 0, sizeof(*h), (caddr_t)&hdrbuf);
463 		h = &hdrbuf;
464 	}
465 	m_adj(m, sizeof(*h));
466 
467 	/* Check header address */
468 	switch (h->address) {
469 	default:		/* Invalid Cisco packet. */
470 		goto drop;
471 	case CISCO_UNICAST:
472 	case CISCO_MULTICAST:
473 		/* Don't check the control field here (RFC 1547). */
474 		switch (ntohs(h->protocol)) {
475 		default:
476 			goto drop;
477 		case CISCO_KEEPALIVE:
478 		    {
479 			const struct cisco_packet *p;
480 			struct cisco_packet pktbuf;
481 
482 			/* Sanity check packet length */
483 			if (m->m_pkthdr.len < sizeof(*p)) {
484 				error = EINVAL;
485 				goto drop;
486 			}
487 
488 			/* Get cisco packet */
489 			if (m->m_len >= sizeof(*p))	/* the common case */
490 				p = mtod(m, const struct cisco_packet *);
491 			else {
492 				m_copydata(m, 0, sizeof(*p), (caddr_t)&pktbuf);
493 				p = &pktbuf;
494 			}
495 
496 			/* Check packet type */
497 			switch (ntohl(p->type)) {
498 			default:
499 				log(LOG_WARNING,
500 				    "cisco: unknown cisco packet type: 0x%lx\n",
501 				       (long)ntohl(p->type));
502 				break;
503 			case CISCO_ADDR_REPLY:
504 				/* Reply on address request, ignore */
505 				break;
506 			case CISCO_KEEPALIVE_REQ:
507 				sc->remote_seq = ntohl(p->par1);
508 				if (sc->local_seq == ntohl(p->par2)) {
509 					sc->local_seq++;
510 					sc->seqRetries = 0;
511 				}
512 				break;
513 			case CISCO_ADDR_REQ:
514 			    {
515 				struct ng_mesg *msg;
516 				int dummy_error = 0;
517 
518 				/* Ask inet peer for IP address information */
519 				if (sc->inet.hook == NULL)
520 					goto nomsg;
521 				NG_MKMESSAGE(msg, NGM_CISCO_COOKIE,
522 				    NGM_CISCO_GET_IPADDR, 0, M_NOWAIT);
523 				if (msg == NULL)
524 					goto nomsg;
525 				NG_SEND_MSG_HOOK(dummy_error,
526 				    sc->node, msg, sc->inet.hook, 0);
527 		/*
528 		 * XXX Now maybe we should set a flag telling
529 		 * our receiver to send this message when the response comes in
530 		 * instead of now when the data may be bad.
531 		 */
532 		nomsg:
533 				/* Send reply to peer device */
534 				error = cisco_send(sc, CISCO_ADDR_REPLY,
535 					    ntohl(sc->localip.s_addr),
536 					    ntohl(sc->localmask.s_addr));
537 				break;
538 			    }
539 			}
540 			goto drop;
541 		    }
542 		case ETHERTYPE_IP:
543 			pep = &sc->inet;
544 			break;
545 		case ETHERTYPE_IPV6:
546 			pep = &sc->inet6;
547 			break;
548 		case ETHERTYPE_AT:
549 			pep = &sc->atalk;
550 			break;
551 		case ETHERTYPE_IPX:
552 			pep = &sc->ipx;
553 			break;
554 		}
555 		break;
556 	}
557 
558 	/* Drop if payload is empty */
559 	if (m->m_pkthdr.len == 0) {
560 		error = EINVAL;
561 		goto drop;
562 	}
563 
564 	/* Send it on */
565 	if (pep->hook == NULL)
566 		goto drop;
567 	NG_FWD_NEW_DATA(error, item, pep->hook, m);
568 	return (error);
569 
570 drop:
571 	NG_FREE_ITEM(item);
572 	return (error);
573 }
574 
575 
576 /*
577  * Send keepalive packets, every 10 seconds.
578  */
579 static void
580 cisco_keepalive(void *arg)
581 {
582 	const sc_p sc = arg;
583 	int s = splimp();
584 
585 	cisco_send(sc, CISCO_KEEPALIVE_REQ, sc->local_seq, sc->remote_seq);
586 	sc->seqRetries++;
587 	splx(s);
588 	sc->handle = timeout(cisco_keepalive, sc, hz * KEEPALIVE_SECS);
589 }
590 
591 /*
592  * Send Cisco keepalive packet.
593  */
594 static int
595 cisco_send(sc_p sc, int type, long par1, long par2)
596 {
597 	struct cisco_header *h;
598 	struct cisco_packet *ch;
599 	struct mbuf *m;
600 	u_long  t;
601 	int     error = 0;
602 	struct timeval time;
603 
604 	getmicrouptime(&time);
605 
606 	MGETHDR(m, M_DONTWAIT, MT_DATA);
607 	if (!m)
608 		return (ENOBUFS);
609 
610 	t = time.tv_sec * 1000 + time.tv_usec / 1000;
611 	m->m_pkthdr.len = m->m_len = CISCO_HEADER_LEN + CISCO_PACKET_LEN;
612 	m->m_pkthdr.rcvif = 0;
613 
614 	h = mtod(m, struct cisco_header *);
615 	h->address = CISCO_MULTICAST;
616 	h->control = 0;
617 	h->protocol = htons(CISCO_KEEPALIVE);
618 
619 	ch = (struct cisco_packet *) (h + 1);
620 	ch->type = htonl(type);
621 	ch->par1 = htonl(par1);
622 	ch->par2 = htonl(par2);
623 	ch->rel = -1;
624 	ch->time0 = htons((u_short) (t >> 16));
625 	ch->time1 = htons((u_short) t);
626 
627 	NG_SEND_DATA_ONLY(error, sc->downstream.hook, m);
628 	return (error);
629 }
630