xref: /netbsd-src/sys/netinet/in_proto.c (revision 3816d47b2c42fcd6e549e3407f842a5b1a1d23ad)
1 /*	$NetBSD: in_proto.c,v 1.99 2009/09/16 15:23:05 pooka Exp $	*/
2 
3 /*
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1982, 1986, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)in_proto.c	8.2 (Berkeley) 2/9/95
61  */
62 
63 #include <sys/cdefs.h>
64 __KERNEL_RCSID(0, "$NetBSD: in_proto.c,v 1.99 2009/09/16 15:23:05 pooka Exp $");
65 
66 #include "opt_mrouting.h"
67 #include "opt_eon.h"			/* ISO CLNL over IP */
68 #include "opt_iso.h"			/* ISO TP tunneled over IP */
69 #include "opt_inet.h"
70 #include "opt_ipsec.h"
71 #include "opt_pim.h"
72 #include "opt_gateway.h"
73 
74 #include <sys/param.h>
75 #include <sys/socket.h>
76 #include <sys/protosw.h>
77 #include <sys/domain.h>
78 #include <sys/mbuf.h>
79 
80 #include <net/if.h>
81 #include <net/radix.h>
82 #include <net/route.h>
83 
84 #include <netinet/in.h>
85 #include <netinet/in_systm.h>
86 #include <netinet/ip.h>
87 #include <netinet/ip_var.h>
88 #include <netinet/ip_icmp.h>
89 #include <netinet/in_ifattach.h>
90 #include <netinet/in_pcb.h>
91 #include <netinet/in_proto.h>
92 
93 #ifdef INET6
94 #ifndef INET
95 #include <netinet/in.h>
96 #endif
97 #include <netinet/ip6.h>
98 #endif
99 
100 #include <netinet/igmp_var.h>
101 #ifdef PIM
102 #include <netinet/pim_var.h>
103 #endif
104 #include <netinet/tcp.h>
105 #include <netinet/tcp_fsm.h>
106 #include <netinet/tcp_seq.h>
107 #include <netinet/tcp_timer.h>
108 #include <netinet/tcp_var.h>
109 #include <netinet/tcpip.h>
110 #include <netinet/tcp_debug.h>
111 #include <netinet/udp.h>
112 #include <netinet/udp_var.h>
113 #include <netinet/ip_encap.h>
114 
115 /*
116  * TCP/IP protocol family: IP, ICMP, UDP, TCP.
117  */
118 
119 #ifdef IPSEC
120 #include <netinet6/ipsec.h>
121 #include <netinet6/ah.h>
122 #ifdef IPSEC_ESP
123 #include <netinet6/esp.h>
124 #endif
125 #include <netinet6/ipcomp.h>
126 #endif /* IPSEC */
127 
128 #ifdef FAST_IPSEC
129 #include <netipsec/ipsec.h>
130 #include <netipsec/key.h>
131 #endif	/* FAST_IPSEC */
132 
133 #ifdef TPIP
134 #include <netiso/tp_param.h>
135 #include <netiso/tp_var.h>
136 #endif /* TPIP */
137 
138 #ifdef EON
139 #include <netiso/eonvar.h>
140 #endif /* EON */
141 
142 #include "carp.h"
143 #if NCARP > 0
144 #include <netinet/ip_carp.h>
145 #endif
146 
147 #include "pfsync.h"
148 #if NPFSYNC > 0
149 #include <net/pfvar.h>
150 #include <net/if_pfsync.h>
151 #endif
152 
153 #include "etherip.h"
154 #if NETHERIP > 0
155 #include <netinet/ip_etherip.h>
156 #endif
157 
158 DOMAIN_DEFINE(inetdomain);	/* forward declare and add to link set */
159 
160 /* Wrappers to acquire kernel_lock. */
161 
162 PR_WRAP_USRREQ(rip_usrreq)
163 PR_WRAP_USRREQ(udp_usrreq)
164 PR_WRAP_USRREQ(tcp_usrreq)
165 
166 #define	rip_usrreq 	rip_usrreq_wrapper
167 #define	udp_usrreq 	udp_usrreq_wrapper
168 #define	tcp_usrreq 	tcp_usrreq_wrapper
169 
170 PR_WRAP_CTLINPUT(rip_ctlinput)
171 PR_WRAP_CTLINPUT(udp_ctlinput)
172 PR_WRAP_CTLINPUT(tcp_ctlinput)
173 
174 #define	rip_ctlinput	rip_ctlinput_wrapper
175 #define	udp_ctlinput	udp_ctlinput_wrapper
176 #define	tcp_ctlinput	tcp_ctlinput_wrapper
177 
178 PR_WRAP_CTLOUTPUT(rip_ctloutput)
179 PR_WRAP_CTLOUTPUT(udp_ctloutput)
180 PR_WRAP_CTLOUTPUT(tcp_ctloutput)
181 
182 #define	rip_ctloutput	rip_ctloutput_wrapper
183 #define	udp_ctloutput	udp_ctloutput_wrapper
184 #define	tcp_ctloutput	tcp_ctloutput_wrapper
185 
186 #if defined(IPSEC) || defined(FAST_IPSEC)
187 PR_WRAP_CTLINPUT(ah4_ctlinput)
188 
189 #define	ah4_ctlinput	ah4_ctlinput_wrapper
190 #endif
191 
192 #if defined(IPSEC_ESP) || defined(FAST_IPSEC)
193 PR_WRAP_CTLINPUT(esp4_ctlinput)
194 
195 #define	esp4_ctlinput	esp4_ctlinput_wrapper
196 #endif
197 
198 #ifdef TPIP
199 PR_WRAP_CTLOUTPUT(tp_ctloutput)
200 
201 #define	tp_ctloutput	tp_ctloutput_wrapper
202 
203 PR_WRAP_CTLINPUT(tpip_ctlinput)
204 
205 #define	tpip_ctlinput	tpip_ctlinput_wrapper
206 #endif
207 
208 #ifdef EON
209 PR_WRAP_CTLINPUT(eonctlinput)
210 
211 #define	eonctlinput	eonctlinput_wrapper
212 #endif
213 
214 const struct protosw inetsw[] = {
215 {	.pr_domain = &inetdomain,
216 	.pr_init = ip_init,
217 	.pr_output = ip_output,
218 	.pr_slowtimo = ip_slowtimo,
219 	.pr_drain = ip_drain,
220 },
221 {	.pr_type = SOCK_DGRAM,
222 	.pr_domain = &inetdomain,
223 	.pr_protocol = IPPROTO_UDP,
224 	.pr_flags = PR_ATOMIC|PR_ADDR|PR_PURGEIF,
225 	.pr_input = udp_input,
226 	.pr_ctlinput = udp_ctlinput,
227 	.pr_ctloutput = udp_ctloutput,
228 	.pr_usrreq = udp_usrreq,
229 	.pr_init = udp_init,
230 },
231 {	.pr_type = SOCK_STREAM,
232 	.pr_domain = &inetdomain,
233 	.pr_protocol = IPPROTO_TCP,
234 	.pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_LISTEN|PR_ABRTACPTDIS|PR_PURGEIF,
235 	.pr_input = tcp_input,
236 	.pr_ctlinput = tcp_ctlinput,
237 	.pr_ctloutput = tcp_ctloutput,
238 	.pr_usrreq = tcp_usrreq,
239 	.pr_init = tcp_init,
240 	.pr_slowtimo = tcp_slowtimo,
241 	.pr_drain = tcp_drain,
242 },
243 {	.pr_type = SOCK_RAW,
244 	.pr_domain = &inetdomain,
245 	.pr_protocol = IPPROTO_RAW,
246 	.pr_flags = PR_ATOMIC|PR_ADDR|PR_PURGEIF,
247 	.pr_input = rip_input,
248 	.pr_output = rip_output,
249 	.pr_ctlinput = rip_ctlinput,
250 	.pr_ctloutput = rip_ctloutput,
251 	.pr_usrreq = rip_usrreq,
252 },
253 {	.pr_type = SOCK_RAW,
254 	.pr_domain = &inetdomain,
255 	.pr_protocol = IPPROTO_ICMP,
256 	.pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
257 	.pr_input = icmp_input,
258 	.pr_output = rip_output,
259 	.pr_ctlinput = rip_ctlinput,
260 	.pr_ctloutput = rip_ctloutput,
261 	.pr_usrreq = rip_usrreq,
262 	.pr_init = icmp_init,
263 },
264 #ifdef GATEWAY
265 {	.pr_domain = &inetdomain,
266 	.pr_protocol = IPPROTO_IP,
267 	.pr_slowtimo = ipflow_slowtimo,
268 	.pr_init = ipflow_poolinit,
269 },
270 #endif /* GATEWAY */
271 #ifdef IPSEC
272 {	.pr_type = SOCK_RAW,
273 	.pr_domain = &inetdomain,
274 	.pr_protocol = IPPROTO_AH,
275 	.pr_flags = PR_ATOMIC|PR_ADDR,
276 	.pr_input = ah4_input,
277 	.pr_ctlinput = ah4_ctlinput,
278 	.pr_init = ah4_init,
279 },
280 #ifdef IPSEC_ESP
281 {	.pr_type = SOCK_RAW,
282 	.pr_domain = &inetdomain,
283 	.pr_protocol = IPPROTO_ESP,
284 	.pr_flags = PR_ATOMIC|PR_ADDR,
285 	.pr_input = esp4_input,
286 	.pr_ctlinput = esp4_ctlinput,
287 	.pr_init = esp4_init,
288 },
289 #endif /* IPSEC_ESP */
290 {	.pr_type = SOCK_RAW,
291 	.pr_domain = &inetdomain,
292 	.pr_protocol = IPPROTO_IPCOMP,
293 	.pr_flags = PR_ATOMIC|PR_ADDR,
294 	.pr_input = ipcomp4_input,
295 	.pr_init = ipcomp4_init,
296 },
297 #endif /* IPSEC */
298 #ifdef FAST_IPSEC
299 {	.pr_type = SOCK_RAW,
300 	.pr_domain = &inetdomain,
301 	.pr_protocol = IPPROTO_AH,
302 	.pr_flags = PR_ATOMIC|PR_ADDR,
303 	.pr_input = ipsec4_common_input,
304 	.pr_ctlinput = ah4_ctlinput,
305 },
306 {	.pr_type = SOCK_RAW,
307 	.pr_domain = &inetdomain,
308 	.pr_protocol = IPPROTO_ESP,
309 	.pr_flags = PR_ATOMIC|PR_ADDR,
310 	.pr_input = ipsec4_common_input,
311 	.pr_ctlinput = esp4_ctlinput,
312 },
313 {	.pr_type = SOCK_RAW,
314 	.pr_domain = &inetdomain,
315 	.pr_protocol = IPPROTO_IPCOMP,
316 	.pr_flags = PR_ATOMIC|PR_ADDR,
317 	.pr_input = ipsec4_common_input,
318 },
319 #endif /* FAST_IPSEC */
320 {	.pr_type = SOCK_RAW,
321 	.pr_domain = &inetdomain,
322 	.pr_protocol = IPPROTO_IPV4,
323 	.pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
324 	.pr_input = encap4_input,
325 	.pr_output = rip_output,
326 	.pr_ctlinput = rip_ctlinput,
327 	.pr_ctloutput = rip_ctloutput,
328 	.pr_usrreq = rip_usrreq,
329 	.pr_init = encap_init,
330 },
331 #ifdef INET6
332 {	.pr_type = SOCK_RAW,
333 	.pr_domain = &inetdomain,
334 	.pr_protocol = IPPROTO_IPV6,
335 	.pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
336 	.pr_input = encap4_input,
337 	.pr_output = rip_output,
338 	.pr_ctlinput = rip_ctlinput,
339 	.pr_ctloutput = rip_ctloutput,
340 	.pr_usrreq = rip_usrreq,
341 	.pr_init = encap_init,
342 },
343 #endif /* INET6 */
344 #if NETHERIP > 0
345 {	.pr_type = SOCK_RAW,
346 	.pr_domain = &inetdomain,
347 	.pr_protocol = IPPROTO_ETHERIP,
348 	.pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
349 	.pr_input = ip_etherip_input,
350 	.pr_output = rip_output,
351 	.pr_ctlinput = rip_ctlinput,
352 	.pr_ctloutput = rip_ctloutput,
353 	.pr_usrreq = rip_usrreq,
354 },
355 #endif /* NETHERIP > 0 */
356 #if NCARP > 0
357 {	.pr_type = SOCK_RAW,
358 	.pr_domain = &inetdomain,
359 	.pr_protocol = IPPROTO_CARP,
360 	.pr_flags = PR_ATOMIC|PR_ADDR,
361 	.pr_input = carp_proto_input,
362 	.pr_output = rip_output,
363 	.pr_ctloutput = rip_ctloutput,
364 	.pr_usrreq = rip_usrreq,
365 	.pr_init = carp_init,
366 },
367 #endif /* NCARP > 0 */
368 #if NPFSYNC > 0
369 {	.pr_type = SOCK_RAW,
370 	.pr_domain = &inetdomain,
371 	.pr_protocol = IPPROTO_PFSYNC,
372 	.pr_flags	 = PR_ATOMIC|PR_ADDR,
373 	.pr_input	 = pfsync_input,
374 	.pr_output	 = rip_output,
375 	.pr_ctloutput = rip_ctloutput,
376 	.pr_usrreq	 = rip_usrreq,
377 },
378 #endif /* NPFSYNC > 0 */
379 {	.pr_type = SOCK_RAW,
380 	.pr_domain = &inetdomain,
381 	.pr_protocol = IPPROTO_IGMP,
382 	.pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
383 	.pr_input = igmp_input,
384 	.pr_output = rip_output,
385 	.pr_ctloutput = rip_ctloutput,
386 	.pr_ctlinput = rip_ctlinput,
387 	.pr_usrreq = rip_usrreq,
388 	.pr_fasttimo = igmp_fasttimo,
389 	.pr_slowtimo = igmp_slowtimo,
390 	.pr_init = igmp_init,
391 },
392 #ifdef PIM
393 {	.pr_type = SOCK_RAW,
394 	.pr_domain = &inetdomain,
395 	.pr_protocol = IPPROTO_PIM,
396 	.pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
397 	.pr_input = pim_input,
398 	.pr_output = rip_output,
399 	.pr_ctloutput = rip_ctloutput,
400 	.pr_ctlinput = rip_ctlinput,
401 	.pr_usrreq = rip_usrreq,
402 },
403 #endif /* PIM */
404 #ifdef TPIP
405 {	.pr_type = SOCK_SEQPACKET,
406 	.pr_domain = &inetdomain,
407 	.pr_protocol = IPPROTO_TP,
408 	.pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_LISTEN|PR_LASTHDR|PR_ABRTACPTDIS,
409 	.pr_input = tpip_input,
410 	.pr_ctloutput = tp_ctloutput,
411 	.pr_ctlinput = tpip_ctlinput,
412 	.pr_usrreq = tp_usrreq,
413 	.pr_init = tp_init,
414 	.pr_slowtimo = tp_slowtimo,
415 	.pr_drain = tp_drain,
416 },
417 #endif /* TPIP */
418 #ifdef ISO
419 /* EON (ISO CLNL over IP) */
420 #ifdef EON
421 {	.pr_type = SOCK_RAW,
422 	.pr_domain = &inetdomain,
423 	.pr_protocol = IPPROTO_EON,
424 	.pr_flags = PR_LASTHDR,
425 	.pr_input = eoninput,
426 	.pr_ctlinput = eonctlinput,
427 	.pr_init = eonprotoinit,
428 },
429 #else
430 {	.pr_type = SOCK_RAW,
431 	.pr_domain = &inetdomain,
432 	.pr_protocol = IPPROTO_EON,
433 	.pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
434 	.pr_input = encap4_input,
435 	.pr_output = rip_output,
436 	.pr_ctloutput = rip_ctloutput,
437 	.pr_ctlinput = rip_ctlinput,
438 	.pr_usrreq = rip_usrreq,
439 	.pr_init = encap_init,
440 },
441 #endif /* EON */
442 #endif /* ISO */
443 /* raw wildcard */
444 {	.pr_type = SOCK_RAW,
445 	.pr_domain = &inetdomain,
446 	.pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,
447 	.pr_input = rip_input,
448 	.pr_output = rip_output,
449 	.pr_ctloutput = rip_ctloutput,
450 	.pr_ctlinput = rip_ctlinput,
451 	.pr_usrreq = rip_usrreq,
452 	.pr_init = rip_init,
453 },
454 };
455 
456 extern struct ifqueue ipintrq;
457 
458 const struct sockaddr_in in_any = {
459 	  .sin_len = sizeof(struct sockaddr_in)
460 	, .sin_family = AF_INET
461 	, .sin_port = 0
462 	, .sin_addr = {.s_addr = 0 /* INADDR_ANY */}
463 };
464 
465 struct domain inetdomain = {
466 	.dom_family = PF_INET, .dom_name = "internet", .dom_init = NULL,
467 	.dom_externalize = NULL, .dom_dispose = NULL,
468 	.dom_protosw = inetsw,
469 	.dom_protoswNPROTOSW = &inetsw[__arraycount(inetsw)],
470 	.dom_rtattach = rn_inithead,
471 	.dom_rtoffset = 32,
472 	.dom_maxrtkey = sizeof(struct ip_pack4),
473 #ifdef IPSELSRC
474 	.dom_ifattach = in_domifattach,
475 	.dom_ifdetach = in_domifdetach,
476 #else
477 	.dom_ifattach = NULL,
478 	.dom_ifdetach = NULL,
479 #endif
480 	.dom_ifqueues = { &ipintrq, NULL },
481 	.dom_link = { NULL },
482 	.dom_mowner = MOWNER_INIT("",""),
483 	.dom_sa_cmpofs = offsetof(struct sockaddr_in, sin_addr),
484 	.dom_sa_cmplen = sizeof(struct in_addr),
485 	.dom_sa_any = (const struct sockaddr *)&in_any,
486 	.dom_sockaddr_const_addr = sockaddr_in_const_addr,
487 	.dom_sockaddr_addr = sockaddr_in_addr,
488 	.dom_rtcache = LIST_HEAD_INITIALIZER(inetdomain.dom_rtcache)
489 };
490 
491 u_char	ip_protox[IPPROTO_MAX];
492 
493 int icmperrppslim = 100;			/* 100pps */
494 
495 static void
496 sockaddr_in_addrlen(const struct sockaddr *sa, socklen_t *slenp)
497 {
498 	socklen_t slen;
499 
500 	if (slenp == NULL)
501 		return;
502 
503 	slen = sockaddr_getlen(sa);
504 	*slenp = (socklen_t)MIN(sizeof(struct in_addr),
505 	    slen - MIN(slen, offsetof(struct sockaddr_in, sin_addr)));
506 }
507 
508 const void *
509 sockaddr_in_const_addr(const struct sockaddr *sa, socklen_t *slenp)
510 {
511 	const struct sockaddr_in *sin;
512 
513 	sockaddr_in_addrlen(sa, slenp);
514 	sin = (const struct sockaddr_in *)sa;
515 	return &sin->sin_addr;
516 }
517 
518 void *
519 sockaddr_in_addr(struct sockaddr *sa, socklen_t *slenp)
520 {
521 	struct sockaddr_in *sin;
522 
523 	sockaddr_in_addrlen(sa, slenp);
524 	sin = (struct sockaddr_in *)sa;
525 	return &sin->sin_addr;
526 }
527 
528 int
529 sockaddr_in_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
530 {
531 	uint_fast8_t len;
532 	const uint_fast8_t addrofs = offsetof(struct sockaddr_in, sin_addr),
533 			   addrend = addrofs + sizeof(struct in_addr);
534 	int rc;
535 	const struct sockaddr_in *sin1, *sin2;
536 
537 	sin1 = satocsin(sa1);
538 	sin2 = satocsin(sa2);
539 
540 	len = MIN(addrend, MIN(sin1->sin_len, sin2->sin_len));
541 
542 	if (len > addrofs &&
543 	     (rc = memcmp(&sin1->sin_addr, &sin2->sin_addr,
544 	                  len - addrofs)) != 0)
545 		return rc;
546 
547 	return sin1->sin_len - sin2->sin_len;
548 }
549