xref: /openbsd/usr.sbin/mrouted/rsrr.c (revision 479a6fb9)
1 /*	$NetBSD: rsrr.c,v 1.3 1995/12/10 10:07:14 mycroft Exp $	*/
2 
3 /*
4  * Copyright (c) 1993, 1998-2001.
5  * The University of Southern California/Information Sciences Institute.
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. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /* RSRR code written by Daniel Zappala, USC Information Sciences Institute,
34  * April 1995.
35  */
36 
37 /* May 1995 -- Added support for Route Change Notification */
38 
39 #ifdef RSRR
40 
41 #include "defs.h"
42 #include <sys/param.h>
43 #if (defined(BSD) && (BSD >= 199103))
44 #include <stddef.h>
45 #endif
46 
47 /* Taken from prune.c */
48 /*
49  * checks for scoped multicast addresses
50  */
51 #define GET_SCOPE(gt) { \
52 	register int _i; \
53 	if (((gt)->gt_mcastgrp & 0xff000000) == 0xef000000) \
54 	    for (_i = 0; _i < numvifs; _i++) \
55 		if (scoped_addr(_i, (gt)->gt_mcastgrp)) \
56 		    VIFM_SET(_i, (gt)->gt_scope); \
57 	}
58 
59 /*
60  * Exported variables.
61  */
62 int rsrr_socket;			/* interface to reservation protocol */
63 
64 /*
65  * Global RSRR variables.
66  */
67 char rsrr_recv_buf[RSRR_MAX_LEN];	/* RSRR receive buffer */
68 char rsrr_send_buf[RSRR_MAX_LEN];	/* RSRR send buffer */
69 
70 struct sockaddr_un client_addr;
71 int client_length = sizeof(client_addr);
72 
73 
74 /*
75  * Procedure definitions needed internally.
76  */
77 static void	rsrr_accept __P((int recvlen));
78 static void	rsrr_accept_iq __P((void));
79 static int	rsrr_accept_rq __P((struct rsrr_rq *route_query, int flags,
80 					struct gtable *gt_notify));
81 static int	rsrr_send __P((int sendlen));
82 static void	rsrr_cache __P((struct gtable *gt,
83 					struct rsrr_rq *route_query));
84 
85 /* Initialize RSRR socket */
86 void
87 rsrr_init()
88 {
89     int servlen;
90     struct sockaddr_un serv_addr;
91 
92     if ((rsrr_socket = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0)
93 	log(LOG_ERR, errno, "Can't create RSRR socket");
94 
95     unlink(RSRR_SERV_PATH);
96     bzero((char *) &serv_addr, sizeof(serv_addr));
97     serv_addr.sun_family = AF_UNIX;
98     strcpy(serv_addr.sun_path, RSRR_SERV_PATH);
99 #if (defined(BSD) && (BSD >= 199103))
100     servlen = offsetof(struct sockaddr_un, sun_path) +
101 		strlen(serv_addr.sun_path);
102     serv_addr.sun_len = servlen;
103 #else
104     servlen = sizeof(serv_addr.sun_family) + strlen(serv_addr.sun_path);
105 #endif
106 
107     if (bind(rsrr_socket, (struct sockaddr *) &serv_addr, servlen) < 0)
108 	log(LOG_ERR, errno, "Can't bind RSRR socket");
109 
110     if (register_input_handler(rsrr_socket,rsrr_read) < 0)
111 	log(LOG_WARNING, 0, "Couldn't register RSRR as an input handler");
112 }
113 
114 /* Read a message from the RSRR socket */
115 void
116 rsrr_read(f, rfd)
117 	int f;
118 	fd_set *rfd;
119 {
120     register int rsrr_recvlen;
121     register int omask;
122 
123     bzero((char *) &client_addr, sizeof(client_addr));
124     rsrr_recvlen = recvfrom(rsrr_socket, rsrr_recv_buf, sizeof(rsrr_recv_buf),
125 			    0, (struct sockaddr *)&client_addr, &client_length);
126     if (rsrr_recvlen < 0) {
127 	if (errno != EINTR)
128 	    log(LOG_ERR, errno, "RSRR recvfrom");
129 	return;
130     }
131     /* Use of omask taken from main() */
132     omask = sigblock(sigmask(SIGALRM));
133     rsrr_accept(rsrr_recvlen);
134     (void)sigsetmask(omask);
135 }
136 
137 /* Accept a message from the reservation protocol and take
138  * appropriate action.
139  */
140 static void
141 rsrr_accept(recvlen)
142     int recvlen;
143 {
144     struct rsrr_header *rsrr;
145     struct rsrr_rq *route_query;
146 
147     if (recvlen < RSRR_HEADER_LEN) {
148 	log(LOG_WARNING, 0,
149 	    "Received RSRR packet of %d bytes, which is less than min size",
150 	    recvlen);
151 	return;
152     }
153 
154     rsrr = (struct rsrr_header *) rsrr_recv_buf;
155 
156     if (rsrr->version > RSRR_MAX_VERSION) {
157 	log(LOG_WARNING, 0,
158 	    "Received RSRR packet version %d, which I don't understand",
159 	    rsrr->version);
160 	return;
161     }
162 
163     switch (rsrr->version) {
164       case 1:
165 	switch (rsrr->type) {
166 	  case RSRR_INITIAL_QUERY:
167 	    /* Send Initial Reply to client */
168 	    log(LOG_INFO, 0, "Received Initial Query\n");
169 	    rsrr_accept_iq();
170 	    break;
171 	  case RSRR_ROUTE_QUERY:
172 	    /* Check size */
173 	    if (recvlen < RSRR_RQ_LEN) {
174 		log(LOG_WARNING, 0,
175 		    "Received Route Query of %d bytes, which is too small",
176 		    recvlen);
177 		break;
178 	    }
179 	    /* Get the query */
180 	    route_query = (struct rsrr_rq *) (rsrr_recv_buf + RSRR_HEADER_LEN);
181 	    log(LOG_INFO, 0,
182 		"Received Route Query for src %s grp %s notification %d",
183 		inet_fmt(route_query->source_addr.s_addr, s1),
184 		inet_fmt(route_query->dest_addr.s_addr,s2),
185 		BIT_TST(rsrr->flags,RSRR_NOTIFICATION_BIT));
186 	    /* Send Route Reply to client */
187 	    rsrr_accept_rq(route_query,rsrr->flags,NULL);
188 	    break;
189 	  default:
190 	    log(LOG_WARNING, 0,
191 		"Received RSRR packet type %d, which I don't handle",
192 		rsrr->type);
193 	    break;
194 	}
195 	break;
196 
197       default:
198 	log(LOG_WARNING, 0,
199 	    "Received RSRR packet version %d, which I don't understand",
200 	    rsrr->version);
201 	break;
202     }
203 }
204 
205 /* Send an Initial Reply to the reservation protocol. */
206 static void
207 rsrr_accept_iq()
208 {
209     struct rsrr_header *rsrr;
210     struct rsrr_vif *vif_list;
211     struct uvif *v;
212     int vifi, sendlen;
213 
214     /* Check for space.  There should be room for plenty of vifs,
215      * but we should check anyway.
216      */
217     if (numvifs > RSRR_MAX_VIFS) {
218 	log(LOG_WARNING, 0,
219 	    "Can't send RSRR Route Reply because %d is too many vifs %d",
220 	    numvifs);
221 	return;
222     }
223 
224     /* Set up message */
225     rsrr = (struct rsrr_header *) rsrr_send_buf;
226     rsrr->version = 1;
227     rsrr->type = RSRR_INITIAL_REPLY;
228     rsrr->flags = 0;
229     rsrr->num = numvifs;
230 
231     vif_list = (struct rsrr_vif *) (rsrr_send_buf + RSRR_HEADER_LEN);
232 
233     /* Include the vif list. */
234     for (vifi=0, v = uvifs; vifi < numvifs; vifi++, v++) {
235 	vif_list[vifi].id = vifi;
236 	vif_list[vifi].status = 0;
237 	if (v->uv_flags & VIFF_DISABLED)
238 	    BIT_SET(vif_list[vifi].status,RSRR_DISABLED_BIT);
239 	vif_list[vifi].threshold = v->uv_threshold;
240 	vif_list[vifi].local_addr.s_addr = v->uv_lcl_addr;
241     }
242 
243     /* Get the size. */
244     sendlen = RSRR_HEADER_LEN + numvifs*RSRR_VIF_LEN;
245 
246     /* Send it. */
247     log(LOG_INFO, 0, "Send RSRR Initial Reply");
248     rsrr_send(sendlen);
249 }
250 
251 /* Send a Route Reply to the reservation protocol.  The Route Query
252  * contains the query to which we are responding.  The flags contain
253  * the incoming flags from the query or, for route change
254  * notification, the flags that should be set for the reply.  The
255  * kernel table entry contains the routing info to use for a route
256  * change notification.
257  */
258 static int
259 rsrr_accept_rq(route_query,flags,gt_notify)
260     struct rsrr_rq *route_query;
261     int flags;
262     struct gtable *gt_notify;
263 {
264     struct rsrr_header *rsrr;
265     struct rsrr_rr *route_reply;
266     struct gtable *gt,local_g;
267     struct rtentry *r;
268     int sendlen,i;
269     u_long mcastgrp;
270 
271     /* Set up message */
272     rsrr = (struct rsrr_header *) rsrr_send_buf;
273     rsrr->version = 1;
274     rsrr->type = RSRR_ROUTE_REPLY;
275     rsrr->flags = 0;
276     rsrr->num = 0;
277 
278     route_reply = (struct rsrr_rr *) (rsrr_send_buf + RSRR_HEADER_LEN);
279     route_reply->dest_addr.s_addr = route_query->dest_addr.s_addr;
280     route_reply->source_addr.s_addr = route_query->source_addr.s_addr;
281     route_reply->query_id = route_query->query_id;
282 
283     /* Blank routing entry for error. */
284     route_reply->in_vif = 0;
285     route_reply->reserved = 0;
286     route_reply->out_vif_bm = 0;
287 
288     /* Get the size. */
289     sendlen = RSRR_RR_LEN;
290 
291     /* If kernel table entry is defined, then we are sending a Route Reply
292      * due to a Route Change Notification event.  Use the kernel table entry
293      * to supply the routing info.
294      */
295     if (gt_notify) {
296 	/* Set flags */
297 	rsrr->flags = flags;
298 	/* Include the routing entry. */
299 	route_reply->in_vif = gt_notify->gt_route->rt_parent;
300 	route_reply->out_vif_bm = gt_notify->gt_grpmems;
301 
302     } else if (find_src_grp(route_query->source_addr.s_addr, 0,
303 			    route_query->dest_addr.s_addr)) {
304 
305 	/* Found kernel entry. Code taken from add_table_entry() */
306 	gt = gtp ? gtp->gt_gnext : kernel_table;
307 
308 	/* Include the routing entry. */
309 	route_reply->in_vif = gt->gt_route->rt_parent;
310 	route_reply->out_vif_bm = gt->gt_grpmems;
311 
312 	/* Cache reply if using route change notification. */
313 	if BIT_TST(flags,RSRR_NOTIFICATION_BIT) {
314 	    rsrr_cache(gt,route_query);
315 	    BIT_SET(rsrr->flags,RSRR_NOTIFICATION_BIT);
316 	}
317 
318     } else {
319 	/* No kernel entry; use routing table. */
320 	r = determine_route(route_query->source_addr.s_addr);
321 
322 	if (r != NULL) {
323 	    /* We need to mimic what will happen if a data packet
324 	     * is forwarded by multicast routing -- the kernel will
325 	     * make an upcall and mrouted will install a route in the kernel.
326 	     * Our outgoing vif bitmap should reflect what that table
327 	     * will look like.  Grab code from add_table_entry().
328 	     * This is gross, but it's probably better to be accurate.
329 	     */
330 
331 	    gt = &local_g;
332 	    mcastgrp = route_query->dest_addr.s_addr;
333 
334 	    gt->gt_mcastgrp    	= mcastgrp;
335 	    gt->gt_grpmems	= 0;
336 	    gt->gt_scope	= 0;
337 	    gt->gt_route        = r;
338 
339 	    /* obtain the multicast group membership list */
340 	    for (i = 0; i < numvifs; i++) {
341 		if (VIFM_ISSET(i, r->rt_children) &&
342 		    !(VIFM_ISSET(i, r->rt_leaves)))
343 		    VIFM_SET(i, gt->gt_grpmems);
344 
345 		if (VIFM_ISSET(i, r->rt_leaves) && grplst_mem(i, mcastgrp))
346 		    VIFM_SET(i, gt->gt_grpmems);
347 	    }
348 
349 	    GET_SCOPE(gt);
350 	    gt->gt_grpmems &= ~gt->gt_scope;
351 
352 	    /* Include the routing entry. */
353 	    route_reply->in_vif = gt->gt_route->rt_parent;
354 	    route_reply->out_vif_bm = gt->gt_grpmems;
355 
356 	} else {
357 	    /* Set error bit. */
358 	    BIT_SET(rsrr->flags,RSRR_ERROR_BIT);
359 	}
360     }
361 
362     if (gt_notify)
363 	log(LOG_INFO, 0, "Route Change: Send RSRR Route Reply");
364 
365     else
366 	log(LOG_INFO, 0, "Send RSRR Route Reply");
367 
368     log(LOG_INFO, 0, "for src %s dst %s in vif %d out vif %d\n",
369 	inet_fmt(route_reply->source_addr.s_addr,s1),
370 	inet_fmt(route_reply->dest_addr.s_addr,s2),
371 	route_reply->in_vif,route_reply->out_vif_bm);
372 
373     /* Send it. */
374     return rsrr_send(sendlen);
375 }
376 
377 /* Send an RSRR message. */
378 static int
379 rsrr_send(sendlen)
380     int sendlen;
381 {
382     int error;
383 
384     /* Send it. */
385     error = sendto(rsrr_socket, rsrr_send_buf, sendlen, 0,
386 		   (struct sockaddr *)&client_addr, client_length);
387 
388     /* Check for errors. */
389     if (error < 0) {
390 	log(LOG_WARNING, errno, "Failed send on RSRR socket");
391     } else if (error != sendlen) {
392 	log(LOG_WARNING, 0,
393 	    "Sent only %d out of %d bytes on RSRR socket\n", error, sendlen);
394     }
395     return error;
396 }
397 
398 /* Cache a message being sent to a client.  Currently only used for
399  * caching Route Reply messages for route change notification.
400  */
401 static void
402 rsrr_cache(gt,route_query)
403     struct gtable *gt;
404     struct rsrr_rq *route_query;
405 {
406     struct rsrr_cache *rc, **rcnp;
407     struct rsrr_header *rsrr;
408 
409     rsrr = (struct rsrr_header *) rsrr_send_buf;
410 
411     rcnp = &gt->gt_rsrr_cache;
412     while ((rc = *rcnp) != NULL) {
413 	if ((rc->route_query.source_addr.s_addr ==
414 	     route_query->source_addr.s_addr) &&
415 	    (rc->route_query.dest_addr.s_addr ==
416 	     route_query->dest_addr.s_addr) &&
417 	    (!strcmp(rc->client_addr.sun_path,client_addr.sun_path))) {
418 	    /* Cache entry already exists.
419 	     * Check if route notification bit has been cleared.
420 	     */
421 	    if (!BIT_TST(rsrr->flags,RSRR_NOTIFICATION_BIT)) {
422 		/* Delete cache entry. */
423 		*rcnp = rc->next;
424 		free(rc);
425 	    } else {
426 		/* Update */
427 		rc->route_query.query_id = route_query->query_id;
428 		log(LOG_DEBUG, 0,
429 			"Update cached query id %ld from client %s\n",
430 			rc->route_query.query_id, rc->client_addr.sun_path);
431 	    }
432 	    return;
433 	}
434 	rcnp = &rc->next;
435     }
436 
437     /* Cache entry doesn't already exist.  Create one and insert at
438      * front of list.
439      */
440     rc = (struct rsrr_cache *) malloc(sizeof(struct rsrr_cache));
441     if (rc == NULL)
442 	log(LOG_ERR, 0, "ran out of memory");
443     rc->route_query.source_addr.s_addr = route_query->source_addr.s_addr;
444     rc->route_query.dest_addr.s_addr = route_query->dest_addr.s_addr;
445     rc->route_query.query_id = route_query->query_id;
446     strcpy(rc->client_addr.sun_path, client_addr.sun_path);
447     rc->client_length = client_length;
448     rc->next = gt->gt_rsrr_cache;
449     gt->gt_rsrr_cache = rc;
450     log(LOG_DEBUG, 0, "Cached query id %ld from client %s\n",
451 	   rc->route_query.query_id,rc->client_addr.sun_path);
452 }
453 
454 /* Send all the messages in the cache.  Currently this is used to send
455  * all the cached Route Reply messages for route change notification.
456  */
457 void
458 rsrr_cache_send(gt,notify)
459     struct gtable *gt;
460     int notify;
461 {
462     struct rsrr_cache *rc, **rcnp;
463     int flags = 0;
464 
465     if (notify)
466 	BIT_SET(flags,RSRR_NOTIFICATION_BIT);
467 
468     rcnp = &gt->gt_rsrr_cache;
469     while ((rc = *rcnp) != NULL) {
470 	if (rsrr_accept_rq(&rc->route_query,flags,gt) < 0) {
471 	    log(LOG_DEBUG, 0, "Deleting cached query id %ld from client %s\n",
472 		   rc->route_query.query_id,rc->client_addr.sun_path);
473 	    /* Delete cache entry. */
474 	    *rcnp = rc->next;
475 	    free(rc);
476 	} else {
477 	    rcnp = &rc->next;
478 	}
479     }
480 }
481 
482 /* Clean the cache by deleting all entries. */
483 void
484 rsrr_cache_clean(gt)
485     struct gtable *gt;
486 {
487     struct rsrr_cache *rc,*rc_next;
488 
489     printf("cleaning cache for group %s\n",inet_fmt(gt->gt_mcastgrp, s1));
490     rc = gt->gt_rsrr_cache;
491     while (rc) {
492 	rc_next = rc->next;
493 	free(rc);
494 	rc = rc_next;
495     }
496     gt->gt_rsrr_cache = NULL;
497 }
498 
499 void
500 rsrr_clean()
501 {
502     unlink(RSRR_SERV_PATH);
503 }
504 
505 #endif /* RSRR */
506