1/*	$FreeBSD$	*/
2/*	$KAME: rrenum.c,v 1.12 2002/06/10 19:59:47 itojun Exp $	*/
3
4/*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
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#include <sys/types.h>
33#include <sys/param.h>
34#include <sys/ioctl.h>
35#include <sys/socket.h>
36#include <sys/sysctl.h>
37
38#include <net/if.h>
39#include <net/if_dl.h>
40#include <net/if_var.h>
41#include <net/route.h>
42#include <netinet/in.h>
43#include <netinet/in_var.h>
44#include <netinet/icmp6.h>
45
46#include <arpa/inet.h>
47
48#include <errno.h>
49#include <netdb.h>
50#include <string.h>
51#include <stdlib.h>
52#include <time.h>
53#include <syslog.h>
54#include "rtadvd.h"
55#include "rrenum.h"
56#include "if.h"
57
58#define	RR_ISSET_SEGNUM(segnum_bits, segnum) \
59	((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
60#define	RR_SET_SEGNUM(segnum_bits, segnum) \
61	(((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
62
63struct rr_operation {
64	u_long	rro_seqnum;
65	u_long	rro_segnum_bits[8];
66};
67
68static struct rr_operation rro;
69static int rr_rcvifindex;
70static int rrcmd2pco[RPM_PCO_MAX] = {
71	0,
72	SIOCAIFPREFIX_IN6,
73	SIOCCIFPREFIX_IN6,
74	SIOCSGIFPREFIX_IN6
75};
76static int s = -1;
77
78/*
79 * Check validity of a Prefix Control Operation(PCO).
80 * return 0 on success, 1 on failure.
81 */
82static int
83rr_pco_check(int len, struct rr_pco_match *rpm)
84{
85	struct rr_pco_use *rpu, *rpulim;
86	int checklen;
87
88	/* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
89	if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
90	    (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
91		syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
92		    __func__, rpm->rpm_len);
93		return (1);
94	}
95	/* rpm->rpm_code must be valid value */
96	switch (rpm->rpm_code) {
97	case RPM_PCO_ADD:
98	case RPM_PCO_CHANGE:
99	case RPM_PCO_SETGLOBAL:
100		break;
101	default:
102		syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
103		    rpm->rpm_code);
104		return (1);
105	}
106	/* rpm->rpm_matchlen must be 0 to 128 inclusive */
107	if (rpm->rpm_matchlen > 128) {
108		syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
109		    __func__, rpm->rpm_matchlen);
110		return (1);
111	}
112
113	/*
114	 * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
115	 * between 0 and 128 inclusive
116	 */
117	for (rpu = (struct rr_pco_use *)(rpm + 1),
118	     rpulim = (struct rr_pco_use *)((char *)rpm + len);
119	     rpu < rpulim;
120	     rpu += 1) {
121		checklen = rpu->rpu_uselen;
122		checklen += rpu->rpu_keeplen;
123		/*
124		 * omit these check, because either of rpu_uselen
125		 * and rpu_keeplen is unsigned char
126		 *  (128 > rpu_uselen > 0)
127		 *  (128 > rpu_keeplen > 0)
128		 *  (rpu_uselen + rpu_keeplen > 0)
129		 */
130		if (checklen > 128) {
131			syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
132			    " rpu_keeplen %d is %d(over 128)",
133			    __func__, rpu->rpu_uselen, rpu->rpu_keeplen,
134			    rpu->rpu_uselen + rpu->rpu_keeplen);
135			return (1);
136		}
137	}
138	return (0);
139}
140
141static void
142do_use_prefix(int len, struct rr_pco_match *rpm,
143	struct in6_rrenumreq *irr, int ifindex)
144{
145	struct rr_pco_use *rpu, *rpulim;
146	struct rainfo *rai;
147	struct ifinfo *ifi;
148	struct prefix *pfx;
149
150	rpu = (struct rr_pco_use *)(rpm + 1);
151	rpulim = (struct rr_pco_use *)((char *)rpm + len);
152
153	if (rpu == rpulim) {	/* no use prefix */
154		if (rpm->rpm_code == RPM_PCO_ADD)
155			return;
156
157		irr->irr_u_uselen = 0;
158		irr->irr_u_keeplen = 0;
159		irr->irr_raf_mask_onlink = 0;
160		irr->irr_raf_mask_auto = 0;
161		irr->irr_vltime = 0;
162		irr->irr_pltime = 0;
163		memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
164		irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
165		irr->irr_useprefix.sin6_family = 0;
166		irr->irr_useprefix.sin6_addr = in6addr_any;
167		if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
168		    errno != EADDRNOTAVAIL)
169			syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
170			    strerror(errno));
171		return;
172	}
173
174	for (rpu = (struct rr_pco_use *)(rpm + 1),
175	     rpulim = (struct rr_pco_use *)((char *)rpm + len);
176	     rpu < rpulim;
177	     rpu += 1) {
178		/* init in6_rrenumreq fields */
179		irr->irr_u_uselen = rpu->rpu_uselen;
180		irr->irr_u_keeplen = rpu->rpu_keeplen;
181		irr->irr_raf_mask_onlink =
182		    !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
183		irr->irr_raf_mask_auto =
184		    !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
185		irr->irr_vltime = ntohl(rpu->rpu_vltime);
186		irr->irr_pltime = ntohl(rpu->rpu_pltime);
187		irr->irr_raf_onlink =
188		    (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ?
189		    0 : 1;
190		irr->irr_raf_auto =
191		    (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ?
192		    0 : 1;
193		irr->irr_rrf_decrvalid =
194		    (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ?
195		    0 : 1;
196		irr->irr_rrf_decrprefd =
197		    (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ?
198		    0 : 1;
199		irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
200		irr->irr_useprefix.sin6_family = AF_INET6;
201		irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
202
203		if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
204		    errno != EADDRNOTAVAIL)
205			syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
206			    strerror(errno));
207
208		/* very adhoc: should be rewritten */
209		if (rpm->rpm_code == RPM_PCO_CHANGE &&
210		    IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
211		    rpm->rpm_matchlen == rpu->rpu_uselen &&
212		    rpu->rpu_uselen == rpu->rpu_keeplen) {
213			ifi = if_indextoifinfo(ifindex);
214			if (ifi == NULL || ifi->ifi_rainfo == NULL)
215				continue; /* non-advertising IF */
216			rai = ifi->ifi_rainfo;
217
218			TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
219				struct timespec now;
220
221				if (prefix_match(&pfx->pfx_prefix,
222				    pfx->pfx_prefixlen, &rpm->rpm_prefix,
223				    rpm->rpm_matchlen)) {
224					/* change parameters */
225					pfx->pfx_validlifetime =
226					    ntohl(rpu->rpu_vltime);
227					pfx->pfx_preflifetime =
228					    ntohl(rpu->rpu_pltime);
229					if (irr->irr_rrf_decrvalid) {
230						clock_gettime(CLOCK_MONOTONIC_FAST,
231						    &now);
232						pfx->pfx_vltimeexpire =
233						    now.tv_sec +
234						    pfx->pfx_validlifetime;
235					} else
236						pfx->pfx_vltimeexpire = 0;
237					if (irr->irr_rrf_decrprefd) {
238						clock_gettime(CLOCK_MONOTONIC_FAST,
239						    &now);
240						pfx->pfx_pltimeexpire =
241						    now.tv_sec +
242						    pfx->pfx_preflifetime;
243					} else
244						pfx->pfx_pltimeexpire = 0;
245				}
246			}
247		}
248	}
249}
250
251/*
252 * process a Prefix Control Operation(PCO).
253 * return 0 on success, 1 on failure
254 */
255static int
256do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
257{
258	int ifindex = 0;
259	struct in6_rrenumreq irr;
260	struct ifinfo *ifi;
261
262	if ((rr_pco_check(len, rpm) != 0))
263		return (1);
264
265	if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
266		syslog(LOG_ERR, "<%s> socket: %s", __func__,
267		    strerror(errno));
268		exit(1);
269	}
270
271	memset(&irr, 0, sizeof(irr));
272	irr.irr_origin = PR_ORIG_RR;
273	irr.irr_m_len = rpm->rpm_matchlen;
274	irr.irr_m_minlen = rpm->rpm_minlen;
275	irr.irr_m_maxlen = rpm->rpm_maxlen;
276	irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
277	irr.irr_matchprefix.sin6_family = AF_INET6;
278	irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
279
280	while (if_indextoname(++ifindex, irr.irr_name)) {
281		ifi = if_indextoifinfo(ifindex);
282		if (ifi == NULL) {
283			syslog(LOG_ERR, "<%s> ifindex not found.",
284			    __func__);
285			return (1);
286		}
287		/*
288		 * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and
289		 * IFF_UP is off, the interface is not applied
290		 */
291		if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
292		    (ifi->ifi_flags & IFF_UP) == 0)
293			continue;
294		/* TODO: interface scope check */
295		do_use_prefix(len, rpm, &irr, ifindex);
296	}
297	if (errno == ENXIO)
298		return (0);
299	else if (errno) {
300		syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
301		    strerror(errno));
302		return (1);
303	}
304	return (0);
305}
306
307/*
308 * call do_pco() for each Prefix Control Operations(PCOs) in a received
309 * Router Renumbering Command packet.
310 * return 0 on success, 1 on failure
311 */
312static int
313do_rr(int len, struct icmp6_router_renum *rr)
314{
315	struct rr_pco_match *rpm;
316	char *cp, *lim;
317
318	lim = (char *)rr + len;
319	cp = (char *)(rr + 1);
320	len -= sizeof(struct icmp6_router_renum);
321
322	update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
323
324	while (cp < lim) {
325		int rpmlen;
326
327		rpm = (struct rr_pco_match *)cp;
328		if ((size_t)len < sizeof(struct rr_pco_match)) {
329		    tooshort:
330			syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
331			    "garbage at end of pkt?", __func__, len);
332			return (1);
333		}
334		rpmlen = rpm->rpm_len << 3;
335		if (len < rpmlen)
336			goto tooshort;
337
338		if (do_pco(rr, rpmlen, rpm)) {
339			syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
340			goto next;
341		}
342
343	    next:
344		cp += rpmlen;
345		len -= rpmlen;
346	}
347
348	return (0);
349}
350
351/*
352 * check validity of a router renumbering command packet
353 * return 0 on success, 1 on failure
354 */
355static int
356rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
357	struct in6_addr *dst)
358{
359	u_char ntopbuf[INET6_ADDRSTRLEN];
360
361	/* omit rr minimal length check. hope kernel have done it. */
362	/* rr_command length check */
363	if ((size_t)len < (sizeof(struct icmp6_router_renum) +
364	    sizeof(struct rr_pco_match))) {
365		syslog(LOG_ERR,	"<%s> rr_command len %d is too short",
366		    __func__, len);
367		return (1);
368	}
369
370	/* destination check. only for multicast. omit unicast check. */
371	if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
372	    !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
373		syslog(LOG_ERR,	"<%s> dst mcast addr %s is illegal",
374		    __func__,
375		    inet_ntop(AF_INET6, dst, ntopbuf, sizeof(ntopbuf)));
376		return (1);
377	}
378
379	/* seqnum and segnum check */
380	if (rro.rro_seqnum > rr->rr_seqnum) {
381		syslog(LOG_WARNING,
382		    "<%s> rcvd old seqnum %d from %s",
383		    __func__, (u_int32_t)ntohl(rr->rr_seqnum),
384		   inet_ntop(AF_INET6, from, ntopbuf, sizeof(ntopbuf)));
385		return (1);
386	}
387	if (rro.rro_seqnum == rr->rr_seqnum &&
388	    (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
389	    RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
390		if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
391			syslog(LOG_WARNING,
392			    "<%s> rcvd duped segnum %d from %s",
393			    __func__, rr->rr_segnum, inet_ntop(AF_INET6, from,
394				ntopbuf, sizeof(ntopbuf)));
395		return (0);
396	}
397
398	/* update seqnum */
399	if (rro.rro_seqnum != rr->rr_seqnum) {
400		/* then must be "<" */
401
402		/* init rro_segnum_bits */
403		memset(rro.rro_segnum_bits, 0,
404		    sizeof(rro.rro_segnum_bits));
405	}
406	rro.rro_seqnum = rr->rr_seqnum;
407
408	return (0);
409}
410
411static void
412rr_command_input(int len, struct icmp6_router_renum *rr,
413	struct in6_addr *from, struct in6_addr *dst)
414{
415	/* rr_command validity check */
416	if (rr_command_check(len, rr, from, dst))
417		goto failed;
418	if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
419	    ICMP6_RR_FLAGS_TEST)
420		return;
421
422	/* do router renumbering */
423	if (do_rr(len, rr))
424		goto failed;
425
426	/* update segnum */
427	RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
428
429	return;
430
431    failed:
432	syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
433	return;
434}
435
436void
437rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
438	struct sockaddr_in6 *from, struct in6_addr *dst)
439{
440	u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
441
442	syslog(LOG_DEBUG,
443	    "<%s> RR received from %s to %s on %s",
444	    __func__,
445	    inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0] ,sizeof(ntopbuf[0])),
446	    inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
447	    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
448
449	/* packet validation based on Section 4.1 of RFC2894 */
450	if ((size_t)len < sizeof(struct icmp6_router_renum)) {
451		syslog(LOG_NOTICE,
452		    "<%s>: RR short message (size %d) from %s to %s on %s",
453		    __func__, len,
454		    inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0],
455			sizeof(ntopbuf[0])),
456		    inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
457		    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
458		return;
459	}
460
461	/*
462	 * If the IPv6 destination address is neither an All Routers multicast
463	 * address [AARCH] nor one of the receiving router's unicast addresses,
464	 * the message MUST be discarded and SHOULD be logged to network
465	 * management.
466	 * We rely on the kernel input routine for unicast addresses, and thus
467	 * check multicast destinations only.
468	 */
469	if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) && !IN6_ARE_ADDR_EQUAL(
470	    &sin6_sitelocal_allrouters.sin6_addr, &pi->ipi6_addr)) {
471		syslog(LOG_NOTICE,
472		    "<%s>: RR message with invalid destination (%s) "
473		    "from %s on %s",
474		    __func__,
475		    inet_ntop(AF_INET6, &dst, ntopbuf[0], sizeof(ntopbuf[0])),
476		    inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[1],
477			      sizeof(ntopbuf[1])),
478		    if_indextoname(pi->ipi6_ifindex, ifnamebuf));
479		return;
480	}
481
482	rr_rcvifindex = pi->ipi6_ifindex;
483
484	switch (rr->rr_code) {
485	case ICMP6_ROUTER_RENUMBERING_COMMAND:
486		rr_command_input(len, rr, &from->sin6_addr, dst);
487		/* TODO: send reply msg */
488		break;
489	case ICMP6_ROUTER_RENUMBERING_RESULT:
490		/* RESULT will be processed by rrenumd */
491		break;
492	case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
493		/* TODO: sequence number reset */
494		break;
495	default:
496		syslog(LOG_ERR,	"<%s> received unknown code %d",
497		    __func__, rr->rr_code);
498		break;
499
500	}
501
502	return;
503}
504