summaryrefslogtreecommitdiffstats
path: root/sys/netinet/in.c
blob: b6381439b88bcc59b9308a4021942a8023464852 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
/*
 * Copyright (c) 1982, 1986, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)in.c	8.4 (Berkeley) 1/9/95
 * $FreeBSD$
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_var.h>

#include <netinet/igmp_var.h>

#include "gif.h"
#if NGIF > 0
#include <net/if_gif.h>
#endif

static MALLOC_DEFINE(M_IPMADDR, "in_multi", "internet multicast address");

static int in_mask2len __P((struct in_addr *));
static void in_len2mask __P((struct in_addr *, int));
static int in_lifaddr_ioctl __P((struct socket *, u_long, caddr_t,
	struct ifnet *, struct proc *));

static void	in_socktrim __P((struct sockaddr_in *));
static int	in_ifinit __P((struct ifnet *,
	    struct in_ifaddr *, struct sockaddr_in *, int));

static int subnetsarelocal = 0;
SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW, 
	&subnetsarelocal, 0, "");

struct in_multihead in_multihead; /* XXX BSS initialization */

/*
 * Return 1 if an internet address is for a ``local'' host
 * (one to which we have a connection).  If subnetsarelocal
 * is true, this includes other subnets of the local net.
 * Otherwise, it includes only the directly-connected (sub)nets.
 */
int
in_localaddr(in)
	struct in_addr in;
{
	register u_long i = ntohl(in.s_addr);
	register struct in_ifaddr *ia;

	if (subnetsarelocal) {
		for (ia = in_ifaddrhead.tqh_first; ia; 
		     ia = ia->ia_link.tqe_next)
			if ((i & ia->ia_netmask) == ia->ia_net)
				return (1);
	} else {
		for (ia = in_ifaddrhead.tqh_first; ia;
		     ia = ia->ia_link.tqe_next)
			if ((i & ia->ia_subnetmask) == ia->ia_subnet)
				return (1);
	}
	return (0);
}

/*
 * Determine whether an IP address is in a reserved set of addresses
 * that may not be forwarded, or whether datagrams to that destination
 * may be forwarded.
 */
int
in_canforward(in)
	struct in_addr in;
{
	register u_long i = ntohl(in.s_addr);
	register u_long net;

	if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
		return (0);
	if (IN_CLASSA(i)) {
		net = i & IN_CLASSA_NET;
		if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
			return (0);
	}
	return (1);
}

/*
 * Trim a mask in a sockaddr
 */
static void
in_socktrim(ap)
struct sockaddr_in *ap;
{
    register char *cplim = (char *) &ap->sin_addr;
    register char *cp = (char *) (&ap->sin_addr + 1);

    ap->sin_len = 0;
    while (--cp >= cplim)
        if (*cp) {
	    (ap)->sin_len = cp - (char *) (ap) + 1;
	    break;
	}
}

static int
in_mask2len(mask)
	struct in_addr *mask;
{
	int x, y;
	u_char *p;

	p = (u_char *)mask;
	for (x = 0; x < sizeof(*mask); x++) {
		if (p[x] != 0xff)
			break;
	}
	y = 0;
	if (x < sizeof(*mask)) {
		for (y = 0; y < 8; y++) {
			if ((p[x] & (0x80 >> y)) == 0)
				break;
		}
	}
	return x * 8 + y;
}

static void
in_len2mask(mask, len)
	struct in_addr *mask;
	int len;
{
	int i;
	u_char *p;

	p = (u_char *)mask;
	bzero(mask, sizeof(*mask));
	for (i = 0; i < len / 8; i++)
		p[i] = 0xff;
	if (len % 8)
		p[i] = (0xff00 >> (len % 8)) & 0xff;
}

static int in_interfaces;	/* number of external internet interfaces */

/*
 * Generic internet control operations (ioctl's).
 * Ifp is 0 if not an interface-specific ioctl.
 */
/* ARGSUSED */
int
in_control(so, cmd, data, ifp, p)
	struct socket *so;
	u_long cmd;
	caddr_t data;
	register struct ifnet *ifp;
	struct proc *p;
{
	register struct ifreq *ifr = (struct ifreq *)data;
	register struct in_ifaddr *ia = 0, *iap;
	register struct ifaddr *ifa;
	struct in_ifaddr *oia;
	struct in_aliasreq *ifra = (struct in_aliasreq *)data;
	struct sockaddr_in oldaddr;
	int error, hostIsNew, maskIsNew, s;
	u_long i;

#if NGIF > 0
        if (ifp && ifp->if_type == IFT_GIF) {
                switch (cmd) {
                case SIOCSIFPHYADDR:
			if (p &&
			    (error = suser(p)) != 0)
        			return(error);
                case SIOCGIFPSRCADDR:
                case SIOCGIFPDSTADDR:
                        return gif_ioctl(ifp, cmd, data);
                }
        }
#endif

	switch (cmd) {
	case SIOCALIFADDR:
	case SIOCDLIFADDR:
		if (p && (error = suser(p)) != 0)
			return error;
		/*fall through*/
	case SIOCGLIFADDR:
		if (!ifp)
			return EINVAL;
		return in_lifaddr_ioctl(so, cmd, data, ifp, p);
	}

	/*
	 * Find address for this interface, if it exists.
	 *
	 * If an alias address was specified, find that one instead of
	 * the first one on the interface.
	 */
	if (ifp)
		for (iap = in_ifaddrhead.tqh_first; iap; 
		     iap = iap->ia_link.tqe_next)
			if (iap->ia_ifp == ifp) {
				if (((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr.s_addr ==
				    iap->ia_addr.sin_addr.s_addr) {
					ia = iap;
					break;
				} else if (ia == NULL) {
					ia = iap;
					if (ifr->ifr_addr.sa_family != AF_INET)
						break;
				}
			}

	switch (cmd) {

	case SIOCAIFADDR:
	case SIOCDIFADDR:
		if (ifp == 0)
			return (EADDRNOTAVAIL);
		if (ifra->ifra_addr.sin_family == AF_INET) {
			for (oia = ia; ia; ia = ia->ia_link.tqe_next) {
				if (ia->ia_ifp == ifp  &&
				    ia->ia_addr.sin_addr.s_addr ==
				    ifra->ifra_addr.sin_addr.s_addr)
					break;
			}
			if ((ifp->if_flags & IFF_POINTOPOINT)
			    && (cmd == SIOCAIFADDR)
			    && (ifra->ifra_dstaddr.sin_addr.s_addr
				== INADDR_ANY)) {
				return EDESTADDRREQ;
			}
		}
		if (cmd == SIOCDIFADDR && ia == 0)
			return (EADDRNOTAVAIL);
		/* FALLTHROUGH */
	case SIOCSIFADDR:
	case SIOCSIFNETMASK:
	case SIOCSIFDSTADDR:
		if (p && (error = suser(p)) != 0)
			return error;

		if (ifp == 0)
			return (EADDRNOTAVAIL);
		if (ia == (struct in_ifaddr *)0) {
			ia = (struct in_ifaddr *)
				malloc(sizeof *ia, M_IFADDR, M_WAITOK);
			if (ia == (struct in_ifaddr *)NULL)
				return (ENOBUFS);
			bzero((caddr_t)ia, sizeof *ia);
			/*
			 * Protect from ipintr() traversing address list
			 * while we're modifying it.
			 */
			s = splnet();
			
			TAILQ_INSERT_TAIL(&in_ifaddrhead, ia, ia_link);
			ifa = &ia->ia_ifa;
			TAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);

			ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
			ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
			ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
			ia->ia_sockmask.sin_len = 8;
			if (ifp->if_flags & IFF_BROADCAST) {
				ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
				ia->ia_broadaddr.sin_family = AF_INET;
			}
			ia->ia_ifp = ifp;
			if (!(ifp->if_flags & IFF_LOOPBACK))
				in_interfaces++;
			splx(s);
		}
		break;

	case SIOCSIFBRDADDR:
		if (p && (error = suser(p)) != 0)
			return error;
		/* FALLTHROUGH */

	case SIOCGIFADDR:
	case SIOCGIFNETMASK:
	case SIOCGIFDSTADDR:
	case SIOCGIFBRDADDR:
		if (ia == (struct in_ifaddr *)0)
			return (EADDRNOTAVAIL);
		break;
	}
	switch (cmd) {

	case SIOCGIFADDR:
		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
		break;

	case SIOCGIFBRDADDR:
		if ((ifp->if_flags & IFF_BROADCAST) == 0)
			return (EINVAL);
		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
		break;

	case SIOCGIFDSTADDR:
		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
			return (EINVAL);
		*((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
		break;

	case SIOCGIFNETMASK:
		*((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
		break;

	case SIOCSIFDSTADDR:
		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
			return (EINVAL);
		oldaddr = ia->ia_dstaddr;
		ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
		if (ifp->if_ioctl && (error = (*ifp->if_ioctl)
					(ifp, SIOCSIFDSTADDR, (caddr_t)ia))) {
			ia->ia_dstaddr = oldaddr;
			return (error);
		}
		if (ia->ia_flags & IFA_ROUTE) {
			ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
			ia->ia_ifa.ifa_dstaddr =
					(struct sockaddr *)&ia->ia_dstaddr;
			rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
		}
		break;

	case SIOCSIFBRDADDR:
		if ((ifp->if_flags & IFF_BROADCAST) == 0)
			return (EINVAL);
		ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
		break;

	case SIOCSIFADDR:
		return (in_ifinit(ifp, ia,
		    (struct sockaddr_in *) &ifr->ifr_addr, 1));

	case SIOCSIFNETMASK:
		i = ifra->ifra_addr.sin_addr.s_addr;
		ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i);
		break;

	case SIOCAIFADDR:
		maskIsNew = 0;
		hostIsNew = 1;
		error = 0;
		if (ia->ia_addr.sin_family == AF_INET) {
			if (ifra->ifra_addr.sin_len == 0) {
				ifra->ifra_addr = ia->ia_addr;
				hostIsNew = 0;
			} else if (ifra->ifra_addr.sin_addr.s_addr ==
					       ia->ia_addr.sin_addr.s_addr)
				hostIsNew = 0;
		}
		if (ifra->ifra_mask.sin_len) {
			in_ifscrub(ifp, ia);
			ia->ia_sockmask = ifra->ifra_mask;
			ia->ia_subnetmask =
			     ntohl(ia->ia_sockmask.sin_addr.s_addr);
			maskIsNew = 1;
		}
		if ((ifp->if_flags & IFF_POINTOPOINT) &&
		    (ifra->ifra_dstaddr.sin_family == AF_INET)) {
			in_ifscrub(ifp, ia);
			ia->ia_dstaddr = ifra->ifra_dstaddr;
			maskIsNew  = 1; /* We lie; but the effect's the same */
		}
		if (ifra->ifra_addr.sin_family == AF_INET &&
		    (hostIsNew || maskIsNew))
			error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
		if ((ifp->if_flags & IFF_BROADCAST) &&
		    (ifra->ifra_broadaddr.sin_family == AF_INET))
			ia->ia_broadaddr = ifra->ifra_broadaddr;
		return (error);

	case SIOCDIFADDR:
		in_ifscrub(ifp, ia);
		/*
		 * Protect from ipintr() traversing address list
		 * while we're modifying it.
		 */
		s = splnet();

		ifa = &ia->ia_ifa;
		TAILQ_REMOVE(&ifp->if_addrhead, ifa, ifa_link);
		oia = ia;
		TAILQ_REMOVE(&in_ifaddrhead, oia, ia_link);
		IFAFREE(&oia->ia_ifa);
		splx(s);
		break;

	default:
		if (ifp == 0 || ifp->if_ioctl == 0)
			return (EOPNOTSUPP);
		return ((*ifp->if_ioctl)(ifp, cmd, data));
	}
	return (0);
}

/*
 * SIOC[GAD]LIFADDR.
 *	SIOCGLIFADDR: get first address. (?!?)
 *	SIOCGLIFADDR with IFLR_PREFIX:
 *		get first address that matches the specified prefix.
 *	SIOCALIFADDR: add the specified address.
 *	SIOCALIFADDR with IFLR_PREFIX:
 *		EINVAL since we can't deduce hostid part of the address.
 *	SIOCDLIFADDR: delete the specified address.
 *	SIOCDLIFADDR with IFLR_PREFIX:
 *		delete the first address that matches the specified prefix.
 * return values:
 *	EINVAL on invalid parameters
 *	EADDRNOTAVAIL on prefix match failed/specified address not found
 *	other values may be returned from in_ioctl()
 */
static int
in_lifaddr_ioctl(so, cmd, data, ifp, p)
	struct socket *so;
	u_long cmd;
	caddr_t	data;
	struct ifnet *ifp;
	struct proc *p;
{
	struct if_laddrreq *iflr = (struct if_laddrreq *)data;
	struct ifaddr *ifa;

	/* sanity checks */
	if (!data || !ifp) {
		panic("invalid argument to in_lifaddr_ioctl");
		/*NOTRECHED*/
	}

	switch (cmd) {
	case SIOCGLIFADDR:
		/* address must be specified on GET with IFLR_PREFIX */
		if ((iflr->flags & IFLR_PREFIX) == 0)
			break;
		/*FALLTHROUGH*/
	case SIOCALIFADDR:
	case SIOCDLIFADDR:
		/* address must be specified on ADD and DELETE */
		if (iflr->addr.__ss_family != AF_INET)
			return EINVAL;
		if (iflr->addr.__ss_len != sizeof(struct sockaddr_in))
			return EINVAL;
		/* XXX need improvement */
		if (iflr->dstaddr.__ss_family
		 && iflr->dstaddr.__ss_family != AF_INET)
			return EINVAL;
		if (iflr->dstaddr.__ss_family
		 && iflr->dstaddr.__ss_len != sizeof(struct sockaddr_in))
			return EINVAL;
		break;
	default: /*shouldn't happen*/
		return EOPNOTSUPP;
	}
	if (sizeof(struct in_addr) * 8 < iflr->prefixlen)
		return EINVAL;

	switch (cmd) {
	case SIOCALIFADDR:
	    {
		struct in_aliasreq ifra;

		if (iflr->flags & IFLR_PREFIX)
			return EINVAL;

		/* copy args to in_aliasreq, perform ioctl(SIOCAIFADDR_IN6). */
		bzero(&ifra, sizeof(ifra));
		bcopy(iflr->iflr_name, ifra.ifra_name,
			sizeof(ifra.ifra_name));

		bcopy(&iflr->addr, &ifra.ifra_addr, iflr->addr.__ss_len);

		if (iflr->dstaddr.__ss_family) {	/*XXX*/
			bcopy(&iflr->dstaddr, &ifra.ifra_dstaddr,
				iflr->dstaddr.__ss_len);
		}

		ifra.ifra_mask.sin_family = AF_INET;
		ifra.ifra_mask.sin_len = sizeof(struct sockaddr_in);
		in_len2mask(&ifra.ifra_mask.sin_addr, iflr->prefixlen);

		return in_control(so, SIOCAIFADDR, (caddr_t)&ifra, ifp, p);
	    }
	case SIOCGLIFADDR:
	case SIOCDLIFADDR:
	    {
		struct in_ifaddr *ia;
		struct in_addr mask, candidate, match;
		struct sockaddr_in *sin;
		int cmp;

		bzero(&mask, sizeof(mask));
		if (iflr->flags & IFLR_PREFIX) {
			/* lookup a prefix rather than address. */
			in_len2mask(&mask, iflr->prefixlen);

			sin = (struct sockaddr_in *)&iflr->addr;
			match.s_addr = sin->sin_addr.s_addr;
			match.s_addr &= mask.s_addr;

			/* if you set extra bits, that's wrong */
			if (match.s_addr != sin->sin_addr.s_addr)
				return EINVAL;

			cmp = 1;
		} else {
			if (cmd == SIOCGLIFADDR) {
				/* on getting an address, take the 1st match */
				cmp = 0;	/*XXX*/
			} else {
				/* on deleting an address, do exact match */
				in_len2mask(&mask, 32);
				sin = (struct sockaddr_in *)&iflr->addr;
				match.s_addr = sin->sin_addr.s_addr;

				cmp = 1;
			}
		}

		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)	{
			if (ifa->ifa_addr->sa_family != AF_INET6)
				continue;
			if (!cmp)
				break;
			candidate.s_addr = ((struct sockaddr_in *)&ifa->ifa_addr)->sin_addr.s_addr;
			candidate.s_addr &= mask.s_addr;
			if (candidate.s_addr == match.s_addr)
				break;
		}
		if (!ifa)
			return EADDRNOTAVAIL;
		ia = (struct in_ifaddr *)ifa;

		if (cmd == SIOCGLIFADDR) {
			/* fill in the if_laddrreq structure */
			bcopy(&ia->ia_addr, &iflr->addr, ia->ia_addr.sin_len);

			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
				bcopy(&ia->ia_dstaddr, &iflr->dstaddr,
					ia->ia_dstaddr.sin_len);
			} else
				bzero(&iflr->dstaddr, sizeof(iflr->dstaddr));

			iflr->prefixlen =
				in_mask2len(&ia->ia_sockmask.sin_addr);

			iflr->flags = 0;	/*XXX*/

			return 0;
		} else {
			struct in_aliasreq ifra;

			/* fill in_aliasreq and do ioctl(SIOCDIFADDR_IN6) */
			bzero(&ifra, sizeof(ifra));
			bcopy(iflr->iflr_name, ifra.ifra_name,
				sizeof(ifra.ifra_name));

			bcopy(&ia->ia_addr, &ifra.ifra_addr,
				ia->ia_addr.sin_len);
			if ((ifp->if_flags & IFF_POINTOPOINT) != 0) {
				bcopy(&ia->ia_dstaddr, &ifra.ifra_dstaddr,
					ia->ia_dstaddr.sin_len);
			}
			bcopy(&ia->ia_sockmask, &ifra.ifra_dstaddr,
				ia->ia_sockmask.sin_len);

			return in_control(so, SIOCDIFADDR, (caddr_t)&ifra,
					  ifp, p);
		}
	    }
	}

	return EOPNOTSUPP;	/*just for safety*/
}

/*
 * Delete any existing route for an interface.
 */
void
in_ifscrub(ifp, ia)
	register struct ifnet *ifp;
	register struct in_ifaddr *ia;
{

	if ((ia->ia_flags & IFA_ROUTE) == 0)
		return;
	if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT))
		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
	else
		rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0);
	ia->ia_flags &= ~IFA_ROUTE;
}

/*
 * Initialize an interface's internet address
 * and routing table entry.
 */
static int
in_ifinit(ifp, ia, sin, scrub)
	register struct ifnet *ifp;
	register struct in_ifaddr *ia;
	struct sockaddr_in *sin;
	int scrub;
{
	register u_long i = ntohl(sin->sin_addr.s_addr);
	struct sockaddr_in oldaddr;
	int s = splimp(), flags = RTF_UP, error;

	oldaddr = ia->ia_addr;
	ia->ia_addr = *sin;
	/*
	 * Give the interface a chance to initialize
	 * if this is its first address,
	 * and to validate the address if necessary.
	 */
	if (ifp->if_ioctl &&
	    (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) {
		splx(s);
		ia->ia_addr = oldaddr;
		return (error);
	}
	splx(s);
	if (scrub) {
		ia->ia_ifa.ifa_addr = (struct sockaddr *)&oldaddr;
		in_ifscrub(ifp, ia);
		ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
	}
	if (IN_CLASSA(i))
		ia->ia_netmask = IN_CLASSA_NET;
	else if (IN_CLASSB(i))
		ia->ia_netmask = IN_CLASSB_NET;
	else
		ia->ia_netmask = IN_CLASSC_NET;
	/*
	 * The subnet mask usually includes at least the standard network part,
	 * but may may be smaller in the case of supernetting.
	 * If it is set, we believe it.
	 */
	if (ia->ia_subnetmask == 0) {
		ia->ia_subnetmask = ia->ia_netmask;
		ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
	} else
		ia->ia_netmask &= ia->ia_subnetmask;
	ia->ia_net = i & ia->ia_netmask;
	ia->ia_subnet = i & ia->ia_subnetmask;
	in_socktrim(&ia->ia_sockmask);
	/*
	 * Add route for the network.
	 */
	ia->ia_ifa.ifa_metric = ifp->if_metric;
	if (ifp->if_flags & IFF_BROADCAST) {
		ia->ia_broadaddr.sin_addr.s_addr =
			htonl(ia->ia_subnet | ~ia->ia_subnetmask);
		ia->ia_netbroadcast.s_addr =
			htonl(ia->ia_net | ~ ia->ia_netmask);
	} else if (ifp->if_flags & IFF_LOOPBACK) {
		ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr;
		flags |= RTF_HOST;
	} else if (ifp->if_flags & IFF_POINTOPOINT) {
		if (ia->ia_dstaddr.sin_family != AF_INET)
			return (0);
		flags |= RTF_HOST;
	}
	if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0)
		ia->ia_flags |= IFA_ROUTE;

	/*
	 * If the interface supports multicast, join the "all hosts"
	 * multicast group on that interface.
	 */
	if (ifp->if_flags & IFF_MULTICAST) {
		struct in_addr addr;

		addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
		in_addmulti(&addr, ifp);
	}
	return (error);
}


/*
 * Return 1 if the address might be a local broadcast address.
 */
int
in_broadcast(in, ifp)
	struct in_addr in;
        struct ifnet *ifp;
{
	register struct ifaddr *ifa;
	u_long t;

	if (in.s_addr == INADDR_BROADCAST ||
	    in.s_addr == INADDR_ANY)
		return 1;
	if ((ifp->if_flags & IFF_BROADCAST) == 0)
		return 0;
	t = ntohl(in.s_addr);
	/*
	 * Look through the list of addresses for a match
	 * with a broadcast address.
	 */
#define ia ((struct in_ifaddr *)ifa)
	for (ifa = ifp->if_addrhead.tqh_first; ifa; 
	     ifa = ifa->ifa_link.tqe_next)
		if (ifa->ifa_addr->sa_family == AF_INET &&
		    (in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
		     in.s_addr == ia->ia_netbroadcast.s_addr ||
		     /*
		      * Check for old-style (host 0) broadcast.
		      */
		     t == ia->ia_subnet || t == ia->ia_net) &&
		     /*
		      * Check for an all one subnetmask. These
		      * only exist when an interface gets a secondary
		      * address.
		      */
		     ia->ia_subnetmask != (u_long)0xffffffff)
			    return 1;
	return (0);
#undef ia
}
/*
 * Add an address to the list of IP multicast addresses for a given interface.
 */
struct in_multi *
in_addmulti(ap, ifp)
	register struct in_addr *ap;
	register struct ifnet *ifp;
{
	register struct in_multi *inm;
	int error;
	struct sockaddr_in sin;
	struct ifmultiaddr *ifma;
	int s = splnet();

	/*
	 * Call generic routine to add membership or increment
	 * refcount.  It wants addresses in the form of a sockaddr,
	 * so we build one here (being careful to zero the unused bytes).
	 */
	bzero(&sin, sizeof sin);
	sin.sin_family = AF_INET;
	sin.sin_len = sizeof sin;
	sin.sin_addr = *ap;
	error = if_addmulti(ifp, (struct sockaddr *)&sin, &ifma);
	if (error) {
		splx(s);
		return 0;
	}

	/*
	 * If ifma->ifma_protospec is null, then if_addmulti() created
	 * a new record.  Otherwise, we are done.
	 */
	if (ifma->ifma_protospec != 0)
		return ifma->ifma_protospec;

	/* XXX - if_addmulti uses M_WAITOK.  Can this really be called
	   at interrupt time?  If so, need to fix if_addmulti. XXX */
	inm = (struct in_multi *)malloc(sizeof(*inm), M_IPMADDR, M_NOWAIT);
	if (inm == NULL) {
		splx(s);
		return (NULL);
	}

	bzero(inm, sizeof *inm);
	inm->inm_addr = *ap;
	inm->inm_ifp = ifp;
	inm->inm_ifma = ifma;
	ifma->ifma_protospec = inm;
	LIST_INSERT_HEAD(&in_multihead, inm, inm_link);

	/*
	 * Let IGMP know that we have joined a new IP multicast group.
	 */
	igmp_joingroup(inm);
	splx(s);
	return (inm);
}

/*
 * Delete a multicast address record.
 */
void
in_delmulti(inm)
	register struct in_multi *inm;
{
	struct ifmultiaddr *ifma = inm->inm_ifma;
	struct in_multi my_inm;
	int s = splnet();

	my_inm.inm_ifp = NULL ; /* don't send the leave msg */
	if (ifma->ifma_refcount == 1) {
		/*
		 * No remaining claims to this record; let IGMP know that
		 * we are leaving the multicast group.
		 * But do it after the if_delmulti() which might reset
		 * the interface and nuke the packet.
		 */
		my_inm = *inm ;
		ifma->ifma_protospec = 0;
		LIST_REMOVE(inm, inm_link);
		free(inm, M_IPMADDR);
	}
	/* XXX - should be separate API for when we have an ifma? */
	if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
	if (my_inm.inm_ifp != NULL)
		igmp_leavegroup(&my_inm);
	splx(s);
}
OpenPOWER on IntegriCloud