xref: /netbsd-src/sys/netipsec/xform_ah.c (revision 4fee23f98c45552038ad6b5bd05124a41302fb01)
1 /*	$NetBSD: xform_ah.c,v 1.33 2011/05/24 19:10:08 drochner Exp $	*/
2 /*	$FreeBSD: src/sys/netipsec/xform_ah.c,v 1.1.4.1 2003/01/24 05:11:36 sam Exp $	*/
3 /*	$OpenBSD: ip_ah.c,v 1.63 2001/06/26 06:18:58 angelos Exp $ */
4 /*
5  * The authors of this code are John Ioannidis (ji@tla.org),
6  * Angelos D. Keromytis (kermit@csd.uch.gr) and
7  * Niels Provos (provos@physnet.uni-hamburg.de).
8  *
9  * The original version of this code was written by John Ioannidis
10  * for BSD/OS in Athens, Greece, in November 1995.
11  *
12  * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
13  * by Angelos D. Keromytis.
14  *
15  * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
16  * and Niels Provos.
17  *
18  * Additional features in 1999 by Angelos D. Keromytis and Niklas Hallqvist.
19  *
20  * Copyright (c) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
21  * Angelos D. Keromytis and Niels Provos.
22  * Copyright (c) 1999 Niklas Hallqvist.
23  * Copyright (c) 2001 Angelos D. Keromytis.
24  *
25  * Permission to use, copy, and modify this software with or without fee
26  * is hereby granted, provided that this entire notice is included in
27  * all copies of any software which is or includes a copy or
28  * modification of this software.
29  * You may use this code under the GNU public license if you so wish. Please
30  * contribute changes back to the authors under this freer than GPL license
31  * so that we may further the use of strong encryption without limitations to
32  * all.
33  *
34  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
35  * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
36  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
37  * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
38  * PURPOSE.
39  */
40 
41 #include <sys/cdefs.h>
42 __KERNEL_RCSID(0, "$NetBSD: xform_ah.c,v 1.33 2011/05/24 19:10:08 drochner Exp $");
43 
44 #include "opt_inet.h"
45 #ifdef __FreeBSD__
46 #include "opt_inet6.h"
47 #endif
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/mbuf.h>
52 #include <sys/socket.h>
53 #include <sys/syslog.h>
54 #include <sys/kernel.h>
55 #include <sys/sysctl.h>
56 #include <sys/socketvar.h> /* for softnet_lock */
57 
58 #include <net/if.h>
59 
60 #include <netinet/in.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/ip.h>
63 #include <netinet/ip_ecn.h>
64 #include <netinet/ip6.h>
65 
66 #include <net/route.h>
67 #include <netipsec/ipsec.h>
68 #include <netipsec/ipsec_private.h>
69 #include <netipsec/ah.h>
70 #include <netipsec/ah_var.h>
71 #include <netipsec/xform.h>
72 
73 #ifdef INET6
74 #include <netinet6/ip6_var.h>
75 #include <netipsec/ipsec6.h>
76 #  ifdef __FreeBSD__
77 #  include <netinet6/ip6_ecn.h>
78 #  endif
79 #endif
80 
81 #include <netipsec/key.h>
82 #include <netipsec/key_debug.h>
83 #include <netipsec/ipsec_osdep.h>
84 
85 #include <opencrypto/cryptodev.h>
86 
87 /*
88  * Return header size in bytes.  The old protocol did not support
89  * the replay counter; the new protocol always includes the counter.
90  */
91 #define HDRSIZE(sav) \
92 	(((sav)->flags & SADB_X_EXT_OLD) ? \
93 		sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
94 /*
95  * Return authenticator size in bytes.  The old protocol is known
96  * to use a fixed 16-byte authenticator.  The new algorithm gets
97  * this size from the xform but is (currently) always 12.
98  */
99 #define	AUTHSIZE(sav) \
100 	((sav->flags & SADB_X_EXT_OLD) ? 16 : (sav)->tdb_authalgxform->authsize)
101 
102 percpu_t *ahstat_percpu;
103 
104 int	ah_enable = 1;			/* control flow of packets with AH */
105 int	ip4_ah_cleartos = 1;		/* clear ip_tos when doing AH calc */
106 
107 #ifdef __FreeBSD__
108 SYSCTL_DECL(_net_inet_ah);
109 SYSCTL_INT(_net_inet_ah, OID_AUTO,
110 	ah_enable,	CTLFLAG_RW,	&ah_enable,	0, "");
111 SYSCTL_INT(_net_inet_ah, OID_AUTO,
112 	ah_cleartos,	CTLFLAG_RW,	&ip4_ah_cleartos,	0, "");
113 SYSCTL_STRUCT(_net_inet_ah, IPSECCTL_STATS,
114 	stats,		CTLFLAG_RD,	&ahstat,	ahstat, "");
115 
116 #endif /* __FreeBSD__ */
117 
118 static unsigned char ipseczeroes[256];	/* larger than an ip6 extension hdr */
119 
120 static int ah_input_cb(struct cryptop*);
121 static int ah_output_cb(struct cryptop*);
122 
123 /*
124  * NB: this is public for use by the PF_KEY support.
125  */
126 const struct auth_hash *
127 ah_algorithm_lookup(int alg)
128 {
129 	if (alg >= AH_ALG_MAX)
130 		return NULL;
131 	switch (alg) {
132 	case SADB_X_AALG_NULL:
133 		return &auth_hash_null;
134 	case SADB_AALG_MD5HMAC:
135 		return &auth_hash_hmac_md5_96;
136 	case SADB_AALG_SHA1HMAC:
137 		return &auth_hash_hmac_sha1_96;
138 	case SADB_X_AALG_RIPEMD160HMAC:
139 		return &auth_hash_hmac_ripemd_160_96;
140 	case SADB_X_AALG_MD5:
141 		return &auth_hash_key_md5;
142 	case SADB_X_AALG_SHA:
143 		return &auth_hash_key_sha1;
144 	case SADB_X_AALG_SHA2_256:
145 		return &auth_hash_hmac_sha2_256;
146 	case SADB_X_AALG_SHA2_384:
147 		return &auth_hash_hmac_sha2_384;
148 	case SADB_X_AALG_SHA2_512:
149 		return &auth_hash_hmac_sha2_512;
150 	case SADB_X_AALG_AES_XCBC_MAC:
151 		return &auth_hash_aes_xcbc_mac_96;
152 	}
153 	return NULL;
154 }
155 
156 size_t
157 ah_hdrsiz(const struct secasvar *sav)
158 {
159 	size_t size;
160 
161 	if (sav != NULL) {
162 		int authsize;
163 		IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
164 			("ah_hdrsiz: null xform"));
165 		/*XXX not right for null algorithm--does it matter??*/
166 		authsize = AUTHSIZE(sav);
167 		size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
168 	} else {
169 		/* default guess */
170 		size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
171 	}
172 	return size;
173 }
174 
175 /*
176  * NB: public for use by esp_init.
177  */
178 int
179 ah_init0(struct secasvar *sav, const struct xformsw *xsp,
180 	 struct cryptoini *cria)
181 {
182 	const struct auth_hash *thash;
183 	int keylen;
184 
185 	thash = ah_algorithm_lookup(sav->alg_auth);
186 	if (thash == NULL) {
187 		DPRINTF(("ah_init: unsupported authentication algorithm %u\n",
188 			sav->alg_auth));
189 		return EINVAL;
190 	}
191 	/*
192 	 * Verify the replay state block allocation is consistent with
193 	 * the protocol type.  We check here so we can make assumptions
194 	 * later during protocol processing.
195 	 */
196 	/* NB: replay state is setup elsewhere (sigh) */
197 	if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
198 		DPRINTF(("ah_init: replay state block inconsistency, "
199 			"%s algorithm %s replay state\n",
200 			(sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
201 			sav->replay == NULL ? "without" : "with"));
202 		return EINVAL;
203 	}
204 	if (sav->key_auth == NULL) {
205 		DPRINTF(("ah_init: no authentication key for %s "
206 			"algorithm\n", thash->name));
207 		return EINVAL;
208 	}
209 	keylen = _KEYLEN(sav->key_auth);
210 	if (keylen != thash->keysize && thash->keysize != 0) {
211 		DPRINTF(("ah_init: invalid keylength %d, algorithm "
212 			 "%s requires keysize %d\n",
213 			 keylen, thash->name, thash->keysize));
214 		return EINVAL;
215 	}
216 
217 	sav->tdb_xform = xsp;
218 	sav->tdb_authalgxform = thash;
219 
220 	/* Initialize crypto session. */
221 	memset(cria, 0, sizeof (*cria));
222 	cria->cri_alg = sav->tdb_authalgxform->type;
223 	cria->cri_klen = _KEYBITS(sav->key_auth);
224 	cria->cri_key = _KEYBUF(sav->key_auth);
225 
226 	return 0;
227 }
228 
229 /*
230  * ah_init() is called when an SPI is being set up.
231  */
232 static int
233 ah_init(struct secasvar *sav, const struct xformsw *xsp)
234 {
235 	struct cryptoini cria;
236 	int error;
237 
238 	error = ah_init0(sav, xsp, &cria);
239 	if (!error)
240 		error = crypto_newsession(&sav->tdb_cryptoid,
241 					   &cria, crypto_support);
242 	return error;
243 }
244 
245 /*
246  * Paranoia.
247  *
248  * NB: public for use by esp_zeroize (XXX).
249  */
250 int
251 ah_zeroize(struct secasvar *sav)
252 {
253 	int err;
254 
255 	if (sav->key_auth)
256 		memset(_KEYBUF(sav->key_auth), 0, _KEYLEN(sav->key_auth));
257 
258 	err = crypto_freesession(sav->tdb_cryptoid);
259 	sav->tdb_cryptoid = 0;
260 	sav->tdb_authalgxform = NULL;
261 	sav->tdb_xform = NULL;
262 	return err;
263 }
264 
265 /*
266  * Massage IPv4/IPv6 headers for AH processing.
267  */
268 static int
269 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
270 {
271 	struct mbuf *m = *m0;
272 	unsigned char *ptr;
273 	int off, count;
274 
275 #ifdef INET
276 	struct ip *ip;
277 #endif /* INET */
278 
279 #ifdef INET6
280 	struct ip6_ext *ip6e;
281 	struct ip6_hdr ip6;
282 	int alloc, len, ad;
283 #endif /* INET6 */
284 
285 	switch (proto) {
286 #ifdef INET
287 	case AF_INET:
288 		/*
289 		 * This is the least painful way of dealing with IPv4 header
290 		 * and option processing -- just make sure they're in
291 		 * contiguous memory.
292 		 */
293 		*m0 = m = m_pullup(m, skip);
294 		if (m == NULL) {
295 			DPRINTF(("ah_massage_headers: m_pullup failed\n"));
296 			return ENOBUFS;
297 		}
298 
299 		/* Fix the IP header */
300 		ip = mtod(m, struct ip *);
301 		if (ip4_ah_cleartos)
302 			ip->ip_tos = 0;
303 		ip->ip_ttl = 0;
304 		ip->ip_sum = 0;
305 		ip->ip_off = htons(ntohs(ip->ip_off) & ip4_ah_offsetmask);
306 
307 		/*
308 		 * On FreeBSD, ip_off and ip_len assumed in host endian;
309 		 * they are converted (if necessary) by ip_input().
310 		 * On NetBSD, ip_off and ip_len are in network byte order.
311 		 * They must be massaged back to network byte order
312 		 * before verifying the  HMAC. Moreover, on FreeBSD,
313 		 * we should add `skip' back into the massaged ip_len
314 		 * (presumably ip_input() deducted it before we got here?)
315 		 * whereas on NetBSD, we should not.
316 		 */
317 #ifdef __FreeBSD__
318   #define TOHOST(x) (x)
319 #else
320   #define TOHOST(x) (ntohs(x))
321 #endif
322 		if (!out) {
323 			u_int16_t inlen = TOHOST(ip->ip_len);
324 
325 #ifdef __FreeBSD__
326 			ip->ip_len = htons(inlen + skip);
327 #else  /*!__FreeBSD__ */
328 			ip->ip_len = htons(inlen);
329 #endif /*!__FreeBSD__ */
330 			DPRINTF(("ip len: skip %d, "
331 				 "in %d host %d: new: raw %d host %d\n",
332 				 skip,
333 				 inlen, TOHOST(inlen),
334 				 ip->ip_len, ntohs(ip->ip_len)));
335 
336 
337 			if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
338 				ip->ip_off  &= IP_OFF_CONVERT(IP_DF);
339 			else
340 				ip->ip_off = 0;
341 		} else {
342 			if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
343 				ip->ip_off &= IP_OFF_CONVERT(IP_DF);
344 			else
345 				ip->ip_off = 0;
346 		}
347 
348 		ptr = mtod(m, unsigned char *) + sizeof(struct ip);
349 
350 		/* IPv4 option processing */
351 		for (off = sizeof(struct ip); off < skip;) {
352 			if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
353 			    off + 1 < skip)
354 				;
355 			else {
356 				DPRINTF(("ah_massage_headers: illegal IPv4 "
357 				    "option length for option %d\n",
358 				    ptr[off]));
359 
360 				m_freem(m);
361 				return EINVAL;
362 			}
363 
364 			switch (ptr[off]) {
365 			case IPOPT_EOL:
366 				off = skip;  /* End the loop. */
367 				break;
368 
369 			case IPOPT_NOP:
370 				off++;
371 				break;
372 
373 			case IPOPT_SECURITY:	/* 0x82 */
374 			case 0x85:	/* Extended security. */
375 			case 0x86:	/* Commercial security. */
376 			case 0x94:	/* Router alert */
377 			case 0x95:	/* RFC1770 */
378 				/* Sanity check for option length. */
379 				if (ptr[off + 1] < 2) {
380 					DPRINTF(("ah_massage_headers: "
381 					    "illegal IPv4 option length for "
382 					    "option %d\n", ptr[off]));
383 
384 					m_freem(m);
385 					return EINVAL;
386 				}
387 
388 				off += ptr[off + 1];
389 				break;
390 
391 			case IPOPT_LSRR:
392 			case IPOPT_SSRR:
393 				/* Sanity check for option length. */
394 				if (ptr[off + 1] < 2) {
395 					DPRINTF(("ah_massage_headers: "
396 					    "illegal IPv4 option length for "
397 					    "option %d\n", ptr[off]));
398 
399 					m_freem(m);
400 					return EINVAL;
401 				}
402 
403 				/*
404 				 * On output, if we have either of the
405 				 * source routing options, we should
406 				 * swap the destination address of the
407 				 * IP header with the last address
408 				 * specified in the option, as that is
409 				 * what the destination's IP header
410 				 * will look like.
411 				 */
412 				if (out)
413 					bcopy(ptr + off + ptr[off + 1] -
414 					    sizeof(struct in_addr),
415 					    &(ip->ip_dst), sizeof(struct in_addr));
416 
417 				/* Fall through */
418 			default:
419 				/* Sanity check for option length. */
420 				if (ptr[off + 1] < 2) {
421 					DPRINTF(("ah_massage_headers: "
422 					    "illegal IPv4 option length for "
423 					    "option %d\n", ptr[off]));
424 					m_freem(m);
425 					return EINVAL;
426 				}
427 
428 				/* Zeroize all other options. */
429 				count = ptr[off + 1];
430 				memcpy(ptr, ipseczeroes, count);
431 				off += count;
432 				break;
433 			}
434 
435 			/* Sanity check. */
436 			if (off > skip)	{
437 				DPRINTF(("ah_massage_headers(): malformed "
438 				    "IPv4 options header\n"));
439 
440 				m_freem(m);
441 				return EINVAL;
442 			}
443 		}
444 
445 		break;
446 #endif /* INET */
447 
448 #ifdef INET6
449 	case AF_INET6:  /* Ugly... */
450 		/* Copy and "cook" the IPv6 header. */
451 		m_copydata(m, 0, sizeof(ip6), &ip6);
452 
453 		/* We don't do IPv6 Jumbograms. */
454 		if (ip6.ip6_plen == 0) {
455 			DPRINTF(("ah_massage_headers: unsupported IPv6 jumbogram\n"));
456 			m_freem(m);
457 			return EMSGSIZE;
458 		}
459 
460 		ip6.ip6_flow = 0;
461 		ip6.ip6_hlim = 0;
462 		ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
463 		ip6.ip6_vfc |= IPV6_VERSION;
464 
465 		/* Scoped address handling. */
466 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
467 			ip6.ip6_src.s6_addr16[1] = 0;
468 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
469 			ip6.ip6_dst.s6_addr16[1] = 0;
470 
471 		/* Done with IPv6 header. */
472 		m_copyback(m, 0, sizeof(struct ip6_hdr), &ip6);
473 
474 		/* Let's deal with the remaining headers (if any). */
475 		if (skip - sizeof(struct ip6_hdr) > 0) {
476 			if (m->m_len <= skip) {
477 				ptr = (unsigned char *) malloc(
478 				    skip - sizeof(struct ip6_hdr),
479 				    M_XDATA, M_NOWAIT);
480 				if (ptr == NULL) {
481 					DPRINTF(("ah_massage_headers: failed "
482 					    "to allocate memory for IPv6 "
483 					    "headers\n"));
484 					m_freem(m);
485 					return ENOBUFS;
486 				}
487 
488 				/*
489 				 * Copy all the protocol headers after
490 				 * the IPv6 header.
491 				 */
492 				m_copydata(m, sizeof(struct ip6_hdr),
493 				    skip - sizeof(struct ip6_hdr), ptr);
494 				alloc = 1;
495 			} else {
496 				/* No need to allocate memory. */
497 				ptr = mtod(m, unsigned char *) +
498 				    sizeof(struct ip6_hdr);
499 				alloc = 0;
500 			}
501 		} else
502 			break;
503 
504 		off = ip6.ip6_nxt & 0xff; /* Next header type. */
505 
506 		for (len = 0; len < skip - sizeof(struct ip6_hdr);)
507 			switch (off) {
508 			case IPPROTO_HOPOPTS:
509 			case IPPROTO_DSTOPTS:
510 				ip6e = (struct ip6_ext *) (ptr + len);
511 
512 				/*
513 				 * Process the mutable/immutable
514 				 * options -- borrows heavily from the
515 				 * KAME code.
516 				 */
517 				for (count = len + sizeof(struct ip6_ext);
518 				     count < len + ((ip6e->ip6e_len + 1) << 3);) {
519 					if (ptr[count] == IP6OPT_PAD1) {
520 						count++;
521 						continue; /* Skip padding. */
522 					}
523 
524 					/* Sanity check. */
525 					if (count > len +
526 					    ((ip6e->ip6e_len + 1) << 3)) {
527 						m_freem(m);
528 
529 						/* Free, if we allocated. */
530 						if (alloc)
531 							free(ptr, M_XDATA);
532 						return EINVAL;
533 					}
534 
535 					ad = ptr[count + 1];
536 
537 					/* If mutable option, zeroize. */
538 					if (ptr[count] & IP6OPT_MUTABLE)
539 						memcpy(ptr + count, ipseczeroes,
540 						    ptr[count + 1]);
541 
542 					count += ad;
543 
544 					/* Sanity check. */
545 					if (count >
546 					    skip - sizeof(struct ip6_hdr)) {
547 						m_freem(m);
548 
549 						/* Free, if we allocated. */
550 						if (alloc)
551 							free(ptr, M_XDATA);
552 						return EINVAL;
553 					}
554 				}
555 
556 				/* Advance. */
557 				len += ((ip6e->ip6e_len + 1) << 3);
558 				off = ip6e->ip6e_nxt;
559 				break;
560 
561 			case IPPROTO_ROUTING:
562 				/*
563 				 * Always include routing headers in
564 				 * computation.
565 				 */
566 				ip6e = (struct ip6_ext *) (ptr + len);
567 				len += ((ip6e->ip6e_len + 1) << 3);
568 				off = ip6e->ip6e_nxt;
569 				break;
570 
571 			default:
572 				DPRINTF(("ah_massage_headers: unexpected "
573 				    "IPv6 header type %d", off));
574 				if (alloc)
575 					free(ptr, M_XDATA);
576 				m_freem(m);
577 				return EINVAL;
578 			}
579 
580 		/* Copyback and free, if we allocated. */
581 		if (alloc) {
582 			m_copyback(m, sizeof(struct ip6_hdr),
583 			    skip - sizeof(struct ip6_hdr), ptr);
584 			free(ptr, M_XDATA);
585 		}
586 
587 		break;
588 #endif /* INET6 */
589 	}
590 
591 	return 0;
592 }
593 
594 /*
595  * ah_input() gets called to verify that an input packet
596  * passes authentication.
597  */
598 static int
599 ah_input(struct mbuf *m, const struct secasvar *sav, int skip, int protoff)
600 {
601 	const struct auth_hash *ahx;
602 	struct tdb_ident *tdbi;
603 	struct tdb_crypto *tc;
604 	struct m_tag *mtag;
605 	struct newah *ah;
606 	int hl, rplen, authsize;
607 
608 	struct cryptodesc *crda;
609 	struct cryptop *crp;
610 
611 	IPSEC_SPLASSERT_SOFTNET("ah_input");
612 
613 	IPSEC_ASSERT(sav != NULL, ("ah_input: null SA"));
614 	IPSEC_ASSERT(sav->key_auth != NULL,
615 		("ah_input: null authentication key"));
616 	IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
617 		("ah_input: null authentication xform"));
618 
619 	/* Figure out header size. */
620 	rplen = HDRSIZE(sav);
621 
622 	/* XXX don't pullup, just copy header */
623 	IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
624 	if (ah == NULL) {
625 		DPRINTF(("ah_input: cannot pullup header\n"));
626 		AH_STATINC(AH_STAT_HDROPS);	/*XXX*/
627 		m_freem(m);
628 		return ENOBUFS;
629 	}
630 
631 	/* Check replay window, if applicable. */
632 	if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
633 		AH_STATINC(AH_STAT_REPLAY);
634 		DPRINTF(("ah_input: packet replay failure: %s\n",
635 			  ipsec_logsastr(sav)));
636 		m_freem(m);
637 		return ENOBUFS;
638 	}
639 
640 	/* Verify AH header length. */
641 	hl = ah->ah_len * sizeof (u_int32_t);
642 	ahx = sav->tdb_authalgxform;
643 	authsize = AUTHSIZE(sav);
644 	if (hl != authsize + rplen - sizeof (struct ah)) {
645 		DPRINTF(("ah_input: bad authenticator length %u (expecting %lu)"
646 			" for packet in SA %s/%08lx\n",
647 			hl, (u_long) (authsize + rplen - sizeof (struct ah)),
648 			ipsec_address(&sav->sah->saidx.dst),
649 			(u_long) ntohl(sav->spi)));
650 		AH_STATINC(AH_STAT_BADAUTHL);
651 		m_freem(m);
652 		return EACCES;
653 	}
654 	AH_STATADD(AH_STAT_IBYTES, m->m_pkthdr.len - skip - hl);
655 	DPRINTF(("ah_input skip %d poff %d\n"
656 		 "len: hl %d authsize %d rpl %d expect %ld\n",
657 		 skip, protoff,
658 		 hl, authsize, rplen,
659 		 (long)(authsize + rplen - sizeof(struct ah))));
660 
661 	/* Get crypto descriptors. */
662 	crp = crypto_getreq(1);
663 	if (crp == NULL) {
664 		DPRINTF(("ah_input: failed to acquire crypto descriptor\n"));
665 		AH_STATINC(AH_STAT_CRYPTO);
666 		m_freem(m);
667 		return ENOBUFS;
668 	}
669 
670 	crda = crp->crp_desc;
671 	IPSEC_ASSERT(crda != NULL, ("ah_input: null crypto descriptor"));
672 
673 	crda->crd_skip = 0;
674 	crda->crd_len = m->m_pkthdr.len;
675 	crda->crd_inject = skip + rplen;
676 
677 	/* Authentication operation. */
678 	crda->crd_alg = ahx->type;
679 	crda->crd_key = _KEYBUF(sav->key_auth);
680 	crda->crd_klen = _KEYBITS(sav->key_auth);
681 
682 	/* Find out if we've already done crypto. */
683 	for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
684 	     mtag != NULL;
685 	     mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
686 		tdbi = (struct tdb_ident *) (mtag + 1);
687 		if (tdbi->proto == sav->sah->saidx.proto &&
688 		    tdbi->spi == sav->spi &&
689 		    !memcmp(&tdbi->dst, &sav->sah->saidx.dst,
690 			  sizeof (union sockaddr_union)))
691 			break;
692 	}
693 
694 	/* Allocate IPsec-specific opaque crypto info. */
695 	if (mtag == NULL) {
696 		tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
697 			skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
698 	} else {
699 		/* Hash verification has already been done successfully. */
700 		tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
701 						    M_XDATA, M_NOWAIT|M_ZERO);
702 	}
703 	if (tc == NULL) {
704 		DPRINTF(("ah_input: failed to allocate tdb_crypto\n"));
705 		AH_STATINC(AH_STAT_CRYPTO);
706 		crypto_freereq(crp);
707 		m_freem(m);
708 		return ENOBUFS;
709 	}
710 
711 	/* Only save information if crypto processing is needed. */
712 	if (mtag == NULL) {
713 		int error;
714 
715 		/*
716 		 * Save the authenticator, the skipped portion of the packet,
717 		 * and the AH header.
718 		 */
719 		m_copydata(m, 0, skip + rplen + authsize, (tc + 1));
720 
721 		{
722 			u_int8_t *pppp = ((char *)(tc+1))+skip+rplen;
723 			DPRINTF(("ah_input: zeroing %d bytes of authent " \
724 		    "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
725 				 authsize,
726 				 pppp[0], pppp[1], pppp[2], pppp[3],
727 				 pppp[4], pppp[5], pppp[6], pppp[7],
728 				 pppp[8], pppp[9], pppp[10], pppp[11]));
729 		}
730 
731 		/* Zeroize the authenticator on the packet. */
732 		m_copyback(m, skip + rplen, authsize, ipseczeroes);
733 
734 		/* "Massage" the packet headers for crypto processing. */
735 		error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
736 		    skip, ahx->type, 0);
737 		if (error != 0) {
738 			/* NB: mbuf is free'd by ah_massage_headers */
739 			AH_STATINC(AH_STAT_HDROPS);
740 			free(tc, M_XDATA);
741 			crypto_freereq(crp);
742 			return error;
743 		}
744 	}
745 
746 	/* Crypto operation descriptor. */
747 	crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
748 	crp->crp_flags = CRYPTO_F_IMBUF;
749 	crp->crp_buf = m;
750 	crp->crp_callback = ah_input_cb;
751 	crp->crp_sid = sav->tdb_cryptoid;
752 	crp->crp_opaque = tc;
753 
754 	/* These are passed as-is to the callback. */
755 	tc->tc_spi = sav->spi;
756 	tc->tc_dst = sav->sah->saidx.dst;
757 	tc->tc_proto = sav->sah->saidx.proto;
758 	tc->tc_nxt = ah->ah_nxt;
759 	tc->tc_protoff = protoff;
760 	tc->tc_skip = skip;
761 	tc->tc_ptr = mtag; /* Save the mtag we've identified. */
762 
763 	DPRINTF(("ah: hash over %d bytes, skip %d: "
764 		 "crda len %d skip %d inject %d\n",
765 		 crp->crp_ilen, tc->tc_skip,
766 		 crda->crd_len, crda->crd_skip, crda->crd_inject));
767 
768 	if (mtag == NULL)
769 		return crypto_dispatch(crp);
770 	else
771 		return ah_input_cb(crp);
772 }
773 
774 #ifdef INET6
775 #define	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do {		     \
776 	if (saidx->dst.sa.sa_family == AF_INET6) {			     \
777 		error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
778 	} else {							     \
779 		error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
780 	}								     \
781 } while (0)
782 #else
783 #define	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag)		     \
784 	(error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
785 #endif
786 
787 /*
788  * AH input callback from the crypto driver.
789  */
790 static int
791 ah_input_cb(struct cryptop *crp)
792 {
793 	int rplen, error, skip, protoff;
794 	unsigned char calc[AH_ALEN_MAX];
795 	struct mbuf *m;
796 	struct cryptodesc *crd;
797 	const struct auth_hash *ahx;
798 	struct tdb_crypto *tc;
799 	struct m_tag *mtag;
800 	struct secasvar *sav;
801 	struct secasindex *saidx;
802 	u_int8_t nxt;
803 	char *ptr;
804 	int s, authsize;
805 	u_int16_t dport = 0;
806 	u_int16_t sport = 0;
807 #ifdef IPSEC_NAT_T
808 	struct m_tag * tag = NULL;
809 #endif
810 
811 	crd = crp->crp_desc;
812 
813 	tc = (struct tdb_crypto *) crp->crp_opaque;
814 	IPSEC_ASSERT(tc != NULL, ("ah_input_cb: null opaque crypto data area!"));
815 	skip = tc->tc_skip;
816 	nxt = tc->tc_nxt;
817 	protoff = tc->tc_protoff;
818 	mtag = (struct m_tag *) tc->tc_ptr;
819 	m = (struct mbuf *) crp->crp_buf;
820 
821 
822 #ifdef IPSEC_NAT_T
823 	/* find the source port for NAT-T */
824 	if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) {
825 		sport = ((u_int16_t *)(tag + 1))[0];
826 		dport = ((u_int16_t *)(tag + 1))[1];
827 	}
828 #endif
829 
830 	s = splsoftnet();
831 	mutex_enter(softnet_lock);
832 
833 	sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, sport, dport);
834 	if (sav == NULL) {
835 		AH_STATINC(AH_STAT_NOTDB);
836 		DPRINTF(("ah_input_cb: SA expired while in crypto\n"));
837 		error = ENOBUFS;		/*XXX*/
838 		goto bad;
839 	}
840 
841 	saidx = &sav->sah->saidx;
842 	IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
843 		saidx->dst.sa.sa_family == AF_INET6,
844 		("ah_input_cb: unexpected protocol family %u",
845 		 saidx->dst.sa.sa_family));
846 
847 	ahx = sav->tdb_authalgxform;
848 
849 	/* Check for crypto errors. */
850 	if (crp->crp_etype) {
851 		if (sav->tdb_cryptoid != 0)
852 			sav->tdb_cryptoid = crp->crp_sid;
853 
854 		if (crp->crp_etype == EAGAIN) {
855 			mutex_exit(softnet_lock);
856 			splx(s);
857 			return crypto_dispatch(crp);
858 		}
859 
860 		AH_STATINC(AH_STAT_NOXFORM);
861 		DPRINTF(("ah_input_cb: crypto error %d\n", crp->crp_etype));
862 		error = crp->crp_etype;
863 		goto bad;
864 	} else {
865 		AH_STATINC(AH_STAT_HIST + sav->alg_auth);
866 		crypto_freereq(crp);		/* No longer needed. */
867 		crp = NULL;
868 	}
869 
870 	/* Shouldn't happen... */
871 	if (m == NULL) {
872 		AH_STATINC(AH_STAT_CRYPTO);
873 		DPRINTF(("ah_input_cb: bogus returned buffer from crypto\n"));
874 		error = EINVAL;
875 		goto bad;
876 	}
877 
878 	/* Figure out header size. */
879 	rplen = HDRSIZE(sav);
880 	authsize = AUTHSIZE(sav);
881 
882 	if (ipsec_debug)
883 	  memset(calc, 0, sizeof(calc));
884 
885 	/* Copy authenticator off the packet. */
886 	m_copydata(m, skip + rplen, authsize, calc);
887 
888 	/*
889 	 * If we have an mtag, we don't need to verify the authenticator --
890 	 * it has been verified by an IPsec-aware NIC.
891 	 */
892 	if (mtag == NULL) {
893 		ptr = (char *) (tc + 1);
894 
895 		/* Verify authenticator. */
896 		if (memcmp(ptr + skip + rplen, calc, authsize)) {
897 			u_int8_t *pppp = ptr + skip+rplen;
898 			DPRINTF(("ah_input: authentication hash mismatch " \
899 			    "over %d bytes " \
900 			    "for packet in SA %s/%08lx:\n" \
901 		    "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x, " \
902 		    "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
903 			    authsize,
904 			    ipsec_address(&saidx->dst),
905 			    (u_long) ntohl(sav->spi),
906 				 calc[0], calc[1], calc[2], calc[3],
907 				 calc[4], calc[5], calc[6], calc[7],
908 				 calc[8], calc[9], calc[10], calc[11],
909 				 pppp[0], pppp[1], pppp[2], pppp[3],
910 				 pppp[4], pppp[5], pppp[6], pppp[7],
911 				 pppp[8], pppp[9], pppp[10], pppp[11]
912 				 ));
913 			AH_STATINC(AH_STAT_BADAUTH);
914 			error = EACCES;
915 			goto bad;
916 		}
917 
918 		/* Fix the Next Protocol field. */
919 		((u_int8_t *) ptr)[protoff] = nxt;
920 
921 		/* Copyback the saved (uncooked) network headers. */
922 		m_copyback(m, 0, skip, ptr);
923 	} else {
924 		/* Fix the Next Protocol field. */
925 		m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
926 	}
927 
928 	free(tc, M_XDATA), tc = NULL;			/* No longer needed */
929 
930 	/*
931 	 * Header is now authenticated.
932 	 */
933 	m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
934 
935 	/*
936 	 * Update replay sequence number, if appropriate.
937 	 */
938 	if (sav->replay) {
939 		u_int32_t seq;
940 
941 		m_copydata(m, skip + offsetof(struct newah, ah_seq),
942 			   sizeof (seq), &seq);
943 		if (ipsec_updatereplay(ntohl(seq), sav)) {
944 			AH_STATINC(AH_STAT_REPLAY);
945 			error = ENOBUFS;			/*XXX as above*/
946 			goto bad;
947 		}
948 	}
949 
950 	/*
951 	 * Remove the AH header and authenticator from the mbuf.
952 	 */
953 	error = m_striphdr(m, skip, rplen + authsize);
954 	if (error) {
955 		DPRINTF(("ah_input_cb: mangled mbuf chain for SA %s/%08lx\n",
956 		    ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
957 
958 		AH_STATINC(AH_STAT_HDROPS);
959 		goto bad;
960 	}
961 
962 	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
963 
964 	KEY_FREESAV(&sav);
965 	mutex_exit(softnet_lock);
966 	splx(s);
967 	return error;
968 bad:
969 	if (sav)
970 		KEY_FREESAV(&sav);
971 	mutex_exit(softnet_lock);
972 	splx(s);
973 	if (m != NULL)
974 		m_freem(m);
975 	if (tc != NULL)
976 		free(tc, M_XDATA);
977 	if (crp != NULL)
978 		crypto_freereq(crp);
979 	return error;
980 }
981 
982 /*
983  * AH output routine, called by ipsec[46]_process_packet().
984  */
985 static int
986 ah_output(
987     struct mbuf *m,
988     struct ipsecrequest *isr,
989     struct mbuf **mp,
990     int skip,
991     int protoff
992 )
993 {
994 	const struct secasvar *sav;
995 	const struct auth_hash *ahx;
996 	struct cryptodesc *crda;
997 	struct tdb_crypto *tc;
998 	struct mbuf *mi;
999 	struct cryptop *crp;
1000 	u_int16_t iplen;
1001 	int error, rplen, authsize, maxpacketsize, roff;
1002 	u_int8_t prot;
1003 	struct newah *ah;
1004 
1005 	IPSEC_SPLASSERT_SOFTNET("ah_output");
1006 
1007 	sav = isr->sav;
1008 	IPSEC_ASSERT(sav != NULL, ("ah_output: null SA"));
1009 	ahx = sav->tdb_authalgxform;
1010 	IPSEC_ASSERT(ahx != NULL, ("ah_output: null authentication xform"));
1011 
1012 	AH_STATINC(AH_STAT_OUTPUT);
1013 
1014 	/* Figure out header size. */
1015 	rplen = HDRSIZE(sav);
1016 
1017 	/* Check for maximum packet size violations. */
1018 	switch (sav->sah->saidx.dst.sa.sa_family) {
1019 #ifdef INET
1020 	case AF_INET:
1021 		maxpacketsize = IP_MAXPACKET;
1022 		break;
1023 #endif /* INET */
1024 #ifdef INET6
1025 	case AF_INET6:
1026 		maxpacketsize = IPV6_MAXPACKET;
1027 		break;
1028 #endif /* INET6 */
1029 	default:
1030 		DPRINTF(("ah_output: unknown/unsupported protocol "
1031 		    "family %u, SA %s/%08lx\n",
1032 		    sav->sah->saidx.dst.sa.sa_family,
1033 		    ipsec_address(&sav->sah->saidx.dst),
1034 		    (u_long) ntohl(sav->spi)));
1035 		AH_STATINC(AH_STAT_NOPF);
1036 		error = EPFNOSUPPORT;
1037 		goto bad;
1038 	}
1039 	authsize = AUTHSIZE(sav);
1040 	if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
1041 		DPRINTF(("ah_output: packet in SA %s/%08lx got too big "
1042 		    "(len %u, max len %u)\n",
1043 		    ipsec_address(&sav->sah->saidx.dst),
1044 		    (u_long) ntohl(sav->spi),
1045 		    rplen + authsize + m->m_pkthdr.len, maxpacketsize));
1046 		AH_STATINC(AH_STAT_TOOBIG);
1047 		error = EMSGSIZE;
1048 		goto bad;
1049 	}
1050 
1051 	/* Update the counters. */
1052 	AH_STATADD(AH_STAT_OBYTES, m->m_pkthdr.len - skip);
1053 
1054 	m = m_clone(m);
1055 	if (m == NULL) {
1056 		DPRINTF(("ah_output: cannot clone mbuf chain, SA %s/%08lx\n",
1057 		    ipsec_address(&sav->sah->saidx.dst),
1058 		    (u_long) ntohl(sav->spi)));
1059 		AH_STATINC(AH_STAT_HDROPS);
1060 		error = ENOBUFS;
1061 		goto bad;
1062 	}
1063 
1064 	/* Inject AH header. */
1065 	mi = m_makespace(m, skip, rplen + authsize, &roff);
1066 	if (mi == NULL) {
1067 		DPRINTF(("ah_output: failed to inject %u byte AH header for SA "
1068 		    "%s/%08lx\n",
1069 		    rplen + authsize,
1070 		    ipsec_address(&sav->sah->saidx.dst),
1071 		    (u_long) ntohl(sav->spi)));
1072 		AH_STATINC(AH_STAT_HDROPS);	/*XXX differs from openbsd */
1073 		error = ENOBUFS;
1074 		goto bad;
1075 	}
1076 
1077 	/*
1078 	 * The AH header is guaranteed by m_makespace() to be in
1079 	 * contiguous memory, at roff bytes offset into the returned mbuf.
1080 	 */
1081 	ah = (struct newah *)(mtod(mi, char *) + roff);
1082 
1083 	/* Initialize the AH header. */
1084 	m_copydata(m, protoff, sizeof(u_int8_t), &ah->ah_nxt);
1085 	ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
1086 	ah->ah_reserve = 0;
1087 	ah->ah_spi = sav->spi;
1088 
1089 	/* Zeroize authenticator. */
1090 	m_copyback(m, skip + rplen, authsize, ipseczeroes);
1091 
1092 	/* Insert packet replay counter, as requested.  */
1093 	if (sav->replay) {
1094 		if (sav->replay->count == ~0 &&
1095 		    (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
1096 			DPRINTF(("ah_output: replay counter wrapped for SA "
1097 				"%s/%08lx\n",
1098 				ipsec_address(&sav->sah->saidx.dst),
1099 				(u_long) ntohl(sav->spi)));
1100 			AH_STATINC(AH_STAT_WRAP);
1101 			error = EINVAL;
1102 			goto bad;
1103 		}
1104 #ifdef IPSEC_DEBUG
1105 		/* Emulate replay attack when ipsec_replay is TRUE. */
1106 		if (!ipsec_replay)
1107 #endif
1108 			sav->replay->count++;
1109 		ah->ah_seq = htonl(sav->replay->count);
1110 	}
1111 
1112 	/* Get crypto descriptors. */
1113 	crp = crypto_getreq(1);
1114 	if (crp == NULL) {
1115 		DPRINTF(("ah_output: failed to acquire crypto descriptors\n"));
1116 		AH_STATINC(AH_STAT_CRYPTO);
1117 		error = ENOBUFS;
1118 		goto bad;
1119 	}
1120 
1121 	crda = crp->crp_desc;
1122 
1123 	crda->crd_skip = 0;
1124 	crda->crd_inject = skip + rplen;
1125 	crda->crd_len = m->m_pkthdr.len;
1126 
1127 	/* Authentication operation. */
1128 	crda->crd_alg = ahx->type;
1129 	crda->crd_key = _KEYBUF(sav->key_auth);
1130 	crda->crd_klen = _KEYBITS(sav->key_auth);
1131 
1132 	/* Allocate IPsec-specific opaque crypto info. */
1133 	tc = (struct tdb_crypto *) malloc(
1134 		sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1135 	if (tc == NULL) {
1136 		crypto_freereq(crp);
1137 		DPRINTF(("ah_output: failed to allocate tdb_crypto\n"));
1138 		AH_STATINC(AH_STAT_CRYPTO);
1139 		error = ENOBUFS;
1140 		goto bad;
1141 	}
1142 
1143 	/* Save the skipped portion of the packet. */
1144 	m_copydata(m, 0, skip, (tc + 1));
1145 
1146 	/*
1147 	 * Fix IP header length on the header used for
1148 	 * authentication. We don't need to fix the original
1149 	 * header length as it will be fixed by our caller.
1150 	 */
1151 	switch (sav->sah->saidx.dst.sa.sa_family) {
1152 #ifdef INET
1153 	case AF_INET:
1154 		bcopy(((char *)(tc + 1)) +
1155 		    offsetof(struct ip, ip_len),
1156 		    &iplen, sizeof(u_int16_t));
1157 		iplen = htons(ntohs(iplen) + rplen + authsize);
1158 		m_copyback(m, offsetof(struct ip, ip_len),
1159 		    sizeof(u_int16_t), &iplen);
1160 		break;
1161 #endif /* INET */
1162 
1163 #ifdef INET6
1164 	case AF_INET6:
1165 		bcopy(((char *)(tc + 1)) +
1166 		    offsetof(struct ip6_hdr, ip6_plen),
1167 		    &iplen, sizeof(u_int16_t));
1168 		iplen = htons(ntohs(iplen) + rplen + authsize);
1169 		m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1170 		    sizeof(u_int16_t), &iplen);
1171 		break;
1172 #endif /* INET6 */
1173 	}
1174 
1175 	/* Fix the Next Header field in saved header. */
1176 	((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1177 
1178 	/* Update the Next Protocol field in the IP header. */
1179 	prot = IPPROTO_AH;
1180 	m_copyback(m, protoff, sizeof(u_int8_t), &prot);
1181 
1182 	/* "Massage" the packet headers for crypto processing. */
1183 	error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1184 			skip, ahx->type, 1);
1185 	if (error != 0) {
1186 		m = NULL;	/* mbuf was free'd by ah_massage_headers. */
1187 		free(tc, M_XDATA);
1188 		crypto_freereq(crp);
1189 		goto bad;
1190 	}
1191 
1192 	/* Crypto operation descriptor. */
1193 	crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1194 	crp->crp_flags = CRYPTO_F_IMBUF;
1195 	crp->crp_buf = m;
1196 	crp->crp_callback = ah_output_cb;
1197 	crp->crp_sid = sav->tdb_cryptoid;
1198 	crp->crp_opaque = tc;
1199 
1200 	/* These are passed as-is to the callback. */
1201 	tc->tc_isr = isr;
1202 	tc->tc_spi = sav->spi;
1203 	tc->tc_dst = sav->sah->saidx.dst;
1204 	tc->tc_proto = sav->sah->saidx.proto;
1205 	tc->tc_skip = skip;
1206 	tc->tc_protoff = protoff;
1207 
1208 	return crypto_dispatch(crp);
1209 bad:
1210 	if (m)
1211 		m_freem(m);
1212 	return (error);
1213 }
1214 
1215 /*
1216  * AH output callback from the crypto driver.
1217  */
1218 static int
1219 ah_output_cb(struct cryptop *crp)
1220 {
1221 	int skip, protoff, error;
1222 	struct tdb_crypto *tc;
1223 	struct ipsecrequest *isr;
1224 	struct secasvar *sav;
1225 	struct mbuf *m;
1226 	void *ptr;
1227 	int s, err;
1228 
1229 	tc = (struct tdb_crypto *) crp->crp_opaque;
1230 	IPSEC_ASSERT(tc != NULL, ("ah_output_cb: null opaque data area!"));
1231 	skip = tc->tc_skip;
1232 	protoff = tc->tc_protoff;
1233 	ptr = (tc + 1);
1234 	m = (struct mbuf *) crp->crp_buf;
1235 
1236 	s = splsoftnet();
1237 	mutex_enter(softnet_lock);
1238 
1239 	isr = tc->tc_isr;
1240 	sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, 0, 0);
1241 	if (sav == NULL) {
1242 		AH_STATINC(AH_STAT_NOTDB);
1243 		DPRINTF(("ah_output_cb: SA expired while in crypto\n"));
1244 		error = ENOBUFS;		/*XXX*/
1245 		goto bad;
1246 	}
1247 	IPSEC_ASSERT(isr->sav == sav, ("ah_output_cb: SA changed\n"));
1248 
1249 	/* Check for crypto errors. */
1250 	if (crp->crp_etype) {
1251 		if (sav->tdb_cryptoid != 0)
1252 			sav->tdb_cryptoid = crp->crp_sid;
1253 
1254 		if (crp->crp_etype == EAGAIN) {
1255 			KEY_FREESAV(&sav);
1256 			mutex_exit(softnet_lock);
1257 			splx(s);
1258 			return crypto_dispatch(crp);
1259 		}
1260 
1261 		AH_STATINC(AH_STAT_NOXFORM);
1262 		DPRINTF(("ah_output_cb: crypto error %d\n", crp->crp_etype));
1263 		error = crp->crp_etype;
1264 		goto bad;
1265 	}
1266 
1267 	/* Shouldn't happen... */
1268 	if (m == NULL) {
1269 		AH_STATINC(AH_STAT_CRYPTO);
1270 		DPRINTF(("ah_output_cb: bogus returned buffer from crypto\n"));
1271 		error = EINVAL;
1272 		goto bad;
1273 	}
1274 	AH_STATINC(AH_STAT_HIST + sav->alg_auth);
1275 
1276 	/*
1277 	 * Copy original headers (with the new protocol number) back
1278 	 * in place.
1279 	 */
1280 	m_copyback(m, 0, skip, ptr);
1281 
1282 	/* No longer needed. */
1283 	free(tc, M_XDATA);
1284 	crypto_freereq(crp);
1285 
1286 #ifdef IPSEC_DEBUG
1287 	/* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1288 	if (ipsec_integrity) {
1289 		int alen;
1290 
1291 		/*
1292 		 * Corrupt HMAC if we want to test integrity verification of
1293 		 * the other side.
1294 		 */
1295 		alen = AUTHSIZE(sav);
1296 		m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1297 	}
1298 #endif
1299 
1300 	/* NB: m is reclaimed by ipsec_process_done. */
1301 	err = ipsec_process_done(m, isr);
1302 	KEY_FREESAV(&sav);
1303 	mutex_exit(softnet_lock);
1304 	splx(s);
1305 	return err;
1306 bad:
1307 	if (sav)
1308 		KEY_FREESAV(&sav);
1309 	mutex_exit(softnet_lock);
1310 	splx(s);
1311 	if (m)
1312 		m_freem(m);
1313 	free(tc, M_XDATA);
1314 	crypto_freereq(crp);
1315 	return error;
1316 }
1317 
1318 static struct xformsw ah_xformsw = {
1319 	XF_AH,		XFT_AUTH,	"IPsec AH",
1320 	ah_init,	ah_zeroize,	ah_input,	ah_output,
1321 	NULL,
1322 };
1323 
1324 INITFN void
1325 ah_attach(void)
1326 {
1327 	ahstat_percpu = percpu_alloc(sizeof(uint64_t) * AH_NSTATS);
1328 	xform_register(&ah_xformsw);
1329 }
1330 
1331 #ifdef __FreeBSD__
1332 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);
1333 #endif
1334