xref: /netbsd-src/sys/netipsec/xform_ah.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	$NetBSD: xform_ah.c,v 1.44 2015/03/30 03:51:50 ozaki-r 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 1.44 2015/03/30 03:51:50 ozaki-r Exp $");
43 
44 #include "opt_inet.h"
45 #ifdef __FreeBSD__
46 #include "opt_inet6.h"
47 #endif
48 #include "opt_ipsec.h"
49 
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/mbuf.h>
53 #include <sys/socket.h>
54 #include <sys/syslog.h>
55 #include <sys/kernel.h>
56 #include <sys/sysctl.h>
57 #include <sys/socketvar.h> /* for softnet_lock */
58 
59 #include <net/if.h>
60 
61 #include <netinet/in.h>
62 #include <netinet/in_systm.h>
63 #include <netinet/ip.h>
64 #include <netinet/ip_ecn.h>
65 #include <netinet/ip6.h>
66 
67 #include <net/route.h>
68 #include <netipsec/ipsec.h>
69 #include <netipsec/ipsec_private.h>
70 #include <netipsec/ah.h>
71 #include <netipsec/ah_var.h>
72 #include <netipsec/xform.h>
73 
74 #ifdef INET6
75 #include <netinet6/ip6_var.h>
76 #include <netinet6/scope6_var.h>
77 #include <netipsec/ipsec6.h>
78 #  ifdef __FreeBSD__
79 #  include <netinet6/ip6_ecn.h>
80 #  endif
81 #endif
82 
83 #include <netipsec/key.h>
84 #include <netipsec/key_debug.h>
85 #include <netipsec/ipsec_osdep.h>
86 
87 #include <opencrypto/cryptodev.h>
88 
89 /*
90  * Return header size in bytes.  The old protocol did not support
91  * the replay counter; the new protocol always includes the counter.
92  */
93 #define HDRSIZE(sav) \
94 	(((sav)->flags & SADB_X_EXT_OLD) ? \
95 		sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
96 /*
97  * Return authenticator size in bytes.  The old protocol is known
98  * to use a fixed 16-byte authenticator.  The new algorithm gets
99  * this size from the xform but is (currently) always 12.
100  */
101 #define	AUTHSIZE(sav) \
102 	((sav->flags & SADB_X_EXT_OLD) ? 16 : (sav)->tdb_authalgxform->authsize)
103 
104 percpu_t *ahstat_percpu;
105 
106 int	ah_enable = 1;			/* control flow of packets with AH */
107 int	ip4_ah_cleartos = 1;		/* clear ip_tos when doing AH calc */
108 
109 #ifdef __FreeBSD__
110 SYSCTL_DECL(_net_inet_ah);
111 SYSCTL_INT(_net_inet_ah, OID_AUTO,
112 	ah_enable,	CTLFLAG_RW,	&ah_enable,	0, "");
113 SYSCTL_INT(_net_inet_ah, OID_AUTO,
114 	ah_cleartos,	CTLFLAG_RW,	&ip4_ah_cleartos,	0, "");
115 SYSCTL_STRUCT(_net_inet_ah, IPSECCTL_STATS,
116 	stats,		CTLFLAG_RD,	&ahstat,	ahstat, "");
117 
118 #endif /* __FreeBSD__ */
119 
120 static unsigned char ipseczeroes[256];	/* larger than an ip6 extension hdr */
121 
122 static int ah_input_cb(struct cryptop*);
123 static int ah_output_cb(struct cryptop*);
124 
125 /*
126  * NB: this is public for use by the PF_KEY support.
127  */
128 const struct auth_hash *
129 ah_algorithm_lookup(int alg)
130 {
131 	if (alg >= AH_ALG_MAX)
132 		return NULL;
133 	switch (alg) {
134 	case SADB_X_AALG_NULL:
135 		return &auth_hash_null;
136 	case SADB_AALG_MD5HMAC:
137 		return &auth_hash_hmac_md5_96;
138 	case SADB_AALG_SHA1HMAC:
139 		return &auth_hash_hmac_sha1_96;
140 	case SADB_X_AALG_RIPEMD160HMAC:
141 		return &auth_hash_hmac_ripemd_160_96;
142 	case SADB_X_AALG_MD5:
143 		return &auth_hash_key_md5;
144 	case SADB_X_AALG_SHA:
145 		return &auth_hash_key_sha1;
146 	case SADB_X_AALG_SHA2_256:
147 		return &auth_hash_hmac_sha2_256;
148 	case SADB_X_AALG_SHA2_384:
149 		return &auth_hash_hmac_sha2_384;
150 	case SADB_X_AALG_SHA2_512:
151 		return &auth_hash_hmac_sha2_512;
152 	case SADB_X_AALG_AES_XCBC_MAC:
153 		return &auth_hash_aes_xcbc_mac_96;
154 	}
155 	return NULL;
156 }
157 
158 size_t
159 ah_hdrsiz(const struct secasvar *sav)
160 {
161 	size_t size;
162 
163 	if (sav != NULL) {
164 		int authsize;
165 		IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
166 			("ah_hdrsiz: null xform"));
167 		/*XXX not right for null algorithm--does it matter??*/
168 		authsize = AUTHSIZE(sav);
169 		size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
170 	} else {
171 		/* default guess */
172 		size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
173 	}
174 	return size;
175 }
176 
177 /*
178  * NB: public for use by esp_init.
179  */
180 int
181 ah_init0(struct secasvar *sav, const struct xformsw *xsp,
182 	 struct cryptoini *cria)
183 {
184 	const struct auth_hash *thash;
185 	int keylen;
186 
187 	thash = ah_algorithm_lookup(sav->alg_auth);
188 	if (thash == NULL) {
189 		DPRINTF(("ah_init: unsupported authentication algorithm %u\n",
190 			sav->alg_auth));
191 		return EINVAL;
192 	}
193 	/*
194 	 * Verify the replay state block allocation is consistent with
195 	 * the protocol type.  We check here so we can make assumptions
196 	 * later during protocol processing.
197 	 */
198 	/* NB: replay state is setup elsewhere (sigh) */
199 	if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
200 		DPRINTF(("ah_init: replay state block inconsistency, "
201 			"%s algorithm %s replay state\n",
202 			(sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
203 			sav->replay == NULL ? "without" : "with"));
204 		return EINVAL;
205 	}
206 	if (sav->key_auth == NULL) {
207 		DPRINTF(("ah_init: no authentication key for %s "
208 			"algorithm\n", thash->name));
209 		return EINVAL;
210 	}
211 	keylen = _KEYLEN(sav->key_auth);
212 	if (keylen != thash->keysize && thash->keysize != 0) {
213 		DPRINTF(("ah_init: invalid keylength %d, algorithm "
214 			 "%s requires keysize %d\n",
215 			 keylen, thash->name, thash->keysize));
216 		return EINVAL;
217 	}
218 
219 	sav->tdb_xform = xsp;
220 	sav->tdb_authalgxform = thash;
221 
222 	/* Initialize crypto session. */
223 	memset(cria, 0, sizeof (*cria));
224 	cria->cri_alg = sav->tdb_authalgxform->type;
225 	cria->cri_klen = _KEYBITS(sav->key_auth);
226 	cria->cri_key = _KEYBUF(sav->key_auth);
227 
228 	return 0;
229 }
230 
231 /*
232  * ah_init() is called when an SPI is being set up.
233  */
234 static int
235 ah_init(struct secasvar *sav, const struct xformsw *xsp)
236 {
237 	struct cryptoini cria;
238 	int error;
239 
240 	error = ah_init0(sav, xsp, &cria);
241 	if (!error)
242 		error = crypto_newsession(&sav->tdb_cryptoid,
243 					   &cria, crypto_support);
244 	return error;
245 }
246 
247 /*
248  * Paranoia.
249  *
250  * NB: public for use by esp_zeroize (XXX).
251  */
252 int
253 ah_zeroize(struct secasvar *sav)
254 {
255 	int err;
256 
257 	if (sav->key_auth)
258 		memset(_KEYBUF(sav->key_auth), 0, _KEYLEN(sav->key_auth));
259 
260 	err = crypto_freesession(sav->tdb_cryptoid);
261 	sav->tdb_cryptoid = 0;
262 	sav->tdb_authalgxform = NULL;
263 	sav->tdb_xform = NULL;
264 	return err;
265 }
266 
267 /*
268  * Massage IPv4/IPv6 headers for AH processing.
269  */
270 static int
271 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
272 {
273 	struct mbuf *m = *m0;
274 	unsigned char *ptr;
275 	int off, count;
276 
277 #ifdef INET
278 	struct ip *ip;
279 #endif /* INET */
280 
281 #ifdef INET6
282 	struct ip6_ext *ip6e;
283 	struct ip6_hdr ip6;
284 	int alloc, ad, nxt;
285 #endif /* INET6 */
286 
287 	switch (proto) {
288 #ifdef INET
289 	case AF_INET:
290 		/*
291 		 * This is the least painful way of dealing with IPv4 header
292 		 * and option processing -- just make sure they're in
293 		 * contiguous memory.
294 		 */
295 		*m0 = m = m_pullup(m, skip);
296 		if (m == NULL) {
297 			DPRINTF(("ah_massage_headers: m_pullup failed\n"));
298 			return ENOBUFS;
299 		}
300 
301 		/* Fix the IP header */
302 		ip = mtod(m, struct ip *);
303 		if (ip4_ah_cleartos)
304 			ip->ip_tos = 0;
305 		ip->ip_ttl = 0;
306 		ip->ip_sum = 0;
307 		ip->ip_off = htons(ntohs(ip->ip_off) & ip4_ah_offsetmask);
308 
309 		/*
310 		 * On FreeBSD, ip_off and ip_len assumed in host endian;
311 		 * they are converted (if necessary) by ip_input().
312 		 * On NetBSD, ip_off and ip_len are in network byte order.
313 		 * They must be massaged back to network byte order
314 		 * before verifying the  HMAC. Moreover, on FreeBSD,
315 		 * we should add `skip' back into the massaged ip_len
316 		 * (presumably ip_input() deducted it before we got here?)
317 		 * whereas on NetBSD, we should not.
318 		 */
319 #ifdef __FreeBSD__
320   #define TOHOST(x) (x)
321 #else
322   #define TOHOST(x) (ntohs(x))
323 #endif
324 		if (!out) {
325 			u_int16_t inlen = TOHOST(ip->ip_len);
326 
327 #ifdef __FreeBSD__
328 			ip->ip_len = htons(inlen + skip);
329 #else  /*!__FreeBSD__ */
330 			ip->ip_len = htons(inlen);
331 #endif /*!__FreeBSD__ */
332 
333 			if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
334 				ip->ip_off  &= IP_OFF_CONVERT(IP_DF);
335 			else
336 				ip->ip_off = 0;
337 		} else {
338 			if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
339 				ip->ip_off &= IP_OFF_CONVERT(IP_DF);
340 			else
341 				ip->ip_off = 0;
342 		}
343 
344 		ptr = mtod(m, unsigned char *);
345 
346 		/* IPv4 option processing */
347 		for (off = sizeof(struct ip); off < skip;) {
348 			if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
349 			    off + 1 < skip)
350 				;
351 			else {
352 				DPRINTF(("ah_massage_headers: illegal IPv4 "
353 				    "option length for option %d\n",
354 				    ptr[off]));
355 
356 				m_freem(m);
357 				return EINVAL;
358 			}
359 
360 			switch (ptr[off]) {
361 			case IPOPT_EOL:
362 				off = skip;  /* End the loop. */
363 				break;
364 
365 			case IPOPT_NOP:
366 				off++;
367 				break;
368 
369 			case IPOPT_SECURITY:	/* 0x82 */
370 			case 0x85:	/* Extended security. */
371 			case 0x86:	/* Commercial security. */
372 			case 0x94:	/* Router alert */
373 			case 0x95:	/* RFC1770 */
374 				/* Sanity check for option length. */
375 				if (ptr[off + 1] < 2) {
376 					DPRINTF(("ah_massage_headers: "
377 					    "illegal IPv4 option length for "
378 					    "option %d\n", ptr[off]));
379 
380 					m_freem(m);
381 					return EINVAL;
382 				}
383 
384 				off += ptr[off + 1];
385 				break;
386 
387 			case IPOPT_LSRR:
388 			case IPOPT_SSRR:
389 				/* Sanity check for option length. */
390 				if (ptr[off + 1] < 2) {
391 					DPRINTF(("ah_massage_headers: "
392 					    "illegal IPv4 option length for "
393 					    "option %d\n", ptr[off]));
394 
395 					m_freem(m);
396 					return EINVAL;
397 				}
398 
399 				/*
400 				 * On output, if we have either of the
401 				 * source routing options, we should
402 				 * swap the destination address of the
403 				 * IP header with the last address
404 				 * specified in the option, as that is
405 				 * what the destination's IP header
406 				 * will look like.
407 				 */
408 				if (out)
409 					bcopy(ptr + off + ptr[off + 1] -
410 					    sizeof(struct in_addr),
411 					    &(ip->ip_dst), sizeof(struct in_addr));
412 
413 				/* Fall through */
414 			default:
415 				/* Sanity check for option length. */
416 				if (ptr[off + 1] < 2) {
417 					DPRINTF(("ah_massage_headers: "
418 					    "illegal IPv4 option length for "
419 					    "option %d\n", ptr[off]));
420 					m_freem(m);
421 					return EINVAL;
422 				}
423 
424 				/* Zeroize all other options. */
425 				count = ptr[off + 1];
426 				memcpy(ptr + off, ipseczeroes, count);
427 				off += count;
428 				break;
429 			}
430 
431 			/* Sanity check. */
432 			if (off > skip)	{
433 				DPRINTF(("ah_massage_headers(): malformed "
434 				    "IPv4 options header\n"));
435 
436 				m_freem(m);
437 				return EINVAL;
438 			}
439 		}
440 
441 		break;
442 #endif /* INET */
443 
444 #ifdef INET6
445 	case AF_INET6:  /* Ugly... */
446 		/* Copy and "cook" the IPv6 header. */
447 		m_copydata(m, 0, sizeof(ip6), &ip6);
448 
449 		/* We don't do IPv6 Jumbograms. */
450 		if (ip6.ip6_plen == 0) {
451 			DPRINTF(("ah_massage_headers: unsupported IPv6 jumbogram\n"));
452 			m_freem(m);
453 			return EMSGSIZE;
454 		}
455 
456 		ip6.ip6_flow = 0;
457 		ip6.ip6_hlim = 0;
458 		ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
459 		ip6.ip6_vfc |= IPV6_VERSION;
460 
461 		/* Scoped address handling. */
462 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
463 			ip6.ip6_src.s6_addr16[1] = 0;
464 		if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
465 			ip6.ip6_dst.s6_addr16[1] = 0;
466 
467 		/* Done with IPv6 header. */
468 		m_copyback(m, 0, sizeof(struct ip6_hdr), &ip6);
469 
470 		/* Let's deal with the remaining headers (if any). */
471 		if (skip - sizeof(struct ip6_hdr) > 0) {
472 			if (m->m_len <= skip) {
473 				ptr = (unsigned char *) malloc(
474 				    skip - sizeof(struct ip6_hdr),
475 				    M_XDATA, M_NOWAIT);
476 				if (ptr == NULL) {
477 					DPRINTF(("ah_massage_headers: failed "
478 					    "to allocate memory for IPv6 "
479 					    "headers\n"));
480 					m_freem(m);
481 					return ENOBUFS;
482 				}
483 
484 				/*
485 				 * Copy all the protocol headers after
486 				 * the IPv6 header.
487 				 */
488 				m_copydata(m, sizeof(struct ip6_hdr),
489 				    skip - sizeof(struct ip6_hdr), ptr);
490 				alloc = 1;
491 			} else {
492 				/* No need to allocate memory. */
493 				ptr = mtod(m, unsigned char *) +
494 				    sizeof(struct ip6_hdr);
495 				alloc = 0;
496 			}
497 		} else
498 			break;
499 
500 		nxt = ip6.ip6_nxt & 0xff; /* Next header type. */
501 
502 		for (off = 0; off < skip - sizeof(struct ip6_hdr);)
503 			switch (nxt) {
504 			case IPPROTO_HOPOPTS:
505 			case IPPROTO_DSTOPTS:
506 				ip6e = (struct ip6_ext *) (ptr + off);
507 
508 				/*
509 				 * Process the mutable/immutable
510 				 * options -- borrows heavily from the
511 				 * KAME code.
512 				 */
513 				for (count = off + sizeof(struct ip6_ext);
514 				     count < off + ((ip6e->ip6e_len + 1) << 3);) {
515 					if (ptr[count] == IP6OPT_PAD1) {
516 						count++;
517 						continue; /* Skip padding. */
518 					}
519 
520 					/* Sanity check. */
521 					if (count > off +
522 					    ((ip6e->ip6e_len + 1) << 3)) {
523 						m_freem(m);
524 
525 						/* Free, if we allocated. */
526 						if (alloc)
527 							free(ptr, M_XDATA);
528 						return EINVAL;
529 					}
530 
531 					ad = ptr[count + 1];
532 
533 					/* If mutable option, zeroize. */
534 					if (ptr[count] & IP6OPT_MUTABLE)
535 						memcpy(ptr + count, ipseczeroes,
536 						    ptr[count + 1]);
537 
538 					count += ad;
539 
540 					/* Sanity check. */
541 					if (count >
542 					    skip - sizeof(struct ip6_hdr)) {
543 						m_freem(m);
544 
545 						/* Free, if we allocated. */
546 						if (alloc)
547 							free(ptr, M_XDATA);
548 						return EINVAL;
549 					}
550 				}
551 
552 				/* Advance. */
553 				off += ((ip6e->ip6e_len + 1) << 3);
554 				nxt = ip6e->ip6e_nxt;
555 				break;
556 
557 			case IPPROTO_ROUTING:
558 				/*
559 				 * Always include routing headers in
560 				 * computation.
561 				 */
562 				{
563 					struct ip6_rthdr *rh;
564 
565 					ip6e = (struct ip6_ext *) (ptr + off);
566 					rh = (struct ip6_rthdr *)(ptr + off);
567 					/*
568 					 * must adjust content to make it look like
569 					 * its final form (as seen at the final
570 					 * destination).
571 					 * we only know how to massage type 0 routing
572 					 * header.
573 					 */
574 					if (out && rh->ip6r_type == IPV6_RTHDR_TYPE_0) {
575 						struct ip6_rthdr0 *rh0;
576 						struct in6_addr *addr, finaldst;
577 						int i;
578 
579 						rh0 = (struct ip6_rthdr0 *)rh;
580 						addr = (struct in6_addr *)(rh0 + 1);
581 
582 						for (i = 0; i < rh0->ip6r0_segleft; i++)
583 							in6_clearscope(&addr[i]);
584 
585 						finaldst = addr[rh0->ip6r0_segleft - 1];
586 						memmove(&addr[1], &addr[0],
587 							sizeof(struct in6_addr) *
588 							(rh0->ip6r0_segleft - 1));
589 
590 						m_copydata(m, 0, sizeof(ip6), &ip6);
591 						addr[0] = ip6.ip6_dst;
592 						ip6.ip6_dst = finaldst;
593 						m_copyback(m, 0, sizeof(ip6), &ip6);
594 
595 						rh0->ip6r0_segleft = 0;
596 					}
597 
598 					/* advance */
599 					off += ((ip6e->ip6e_len + 1) << 3);
600 					nxt = ip6e->ip6e_nxt;
601 					break;
602 				}
603 
604 			default:
605 				DPRINTF(("ah_massage_headers: unexpected "
606 				    "IPv6 header type %d", off));
607 				if (alloc)
608 					free(ptr, M_XDATA);
609 				m_freem(m);
610 				return EINVAL;
611 			}
612 
613 		/* Copyback and free, if we allocated. */
614 		if (alloc) {
615 			m_copyback(m, sizeof(struct ip6_hdr),
616 			    skip - sizeof(struct ip6_hdr), ptr);
617 			free(ptr, M_XDATA);
618 		}
619 
620 		break;
621 #endif /* INET6 */
622 	}
623 
624 	return 0;
625 }
626 
627 /*
628  * ah_input() gets called to verify that an input packet
629  * passes authentication.
630  */
631 static int
632 ah_input(struct mbuf *m, const struct secasvar *sav, int skip, int protoff)
633 {
634 	const struct auth_hash *ahx;
635 	struct tdb_ident *tdbi;
636 	struct tdb_crypto *tc;
637 	struct m_tag *mtag;
638 	struct newah *ah;
639 	int hl, rplen, authsize, error;
640 
641 	struct cryptodesc *crda;
642 	struct cryptop *crp;
643 
644 	IPSEC_SPLASSERT_SOFTNET("ah_input");
645 
646 	IPSEC_ASSERT(sav != NULL, ("ah_input: null SA"));
647 	IPSEC_ASSERT(sav->key_auth != NULL,
648 		("ah_input: null authentication key"));
649 	IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
650 		("ah_input: null authentication xform"));
651 
652 	/* Figure out header size. */
653 	rplen = HDRSIZE(sav);
654 
655 	/* XXX don't pullup, just copy header */
656 	IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
657 	if (ah == NULL) {
658 		DPRINTF(("ah_input: cannot pullup header\n"));
659 		AH_STATINC(AH_STAT_HDROPS);	/*XXX*/
660 		m_freem(m);
661 		return ENOBUFS;
662 	}
663 
664 	/* Check replay window, if applicable. */
665 	if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
666 		AH_STATINC(AH_STAT_REPLAY);
667 		DPRINTF(("ah_input: packet replay failure: %s\n",
668 			  ipsec_logsastr(sav)));
669 		m_freem(m);
670 		return ENOBUFS;
671 	}
672 
673 	/* Verify AH header length. */
674 	hl = ah->ah_len * sizeof (u_int32_t);
675 	ahx = sav->tdb_authalgxform;
676 	authsize = AUTHSIZE(sav);
677 	if (hl != authsize + rplen - sizeof (struct ah)) {
678 		DPRINTF(("ah_input: bad authenticator length %u (expecting %lu)"
679 			" for packet in SA %s/%08lx\n",
680 			hl, (u_long) (authsize + rplen - sizeof (struct ah)),
681 			ipsec_address(&sav->sah->saidx.dst),
682 			(u_long) ntohl(sav->spi)));
683 		AH_STATINC(AH_STAT_BADAUTHL);
684 		m_freem(m);
685 		return EACCES;
686 	}
687 	AH_STATADD(AH_STAT_IBYTES, m->m_pkthdr.len - skip - hl);
688 
689 	/* Get crypto descriptors. */
690 	crp = crypto_getreq(1);
691 	if (crp == NULL) {
692 		DPRINTF(("ah_input: failed to acquire crypto descriptor\n"));
693 		AH_STATINC(AH_STAT_CRYPTO);
694 		m_freem(m);
695 		return ENOBUFS;
696 	}
697 
698 	crda = crp->crp_desc;
699 	IPSEC_ASSERT(crda != NULL, ("ah_input: null crypto descriptor"));
700 
701 	crda->crd_skip = 0;
702 	crda->crd_len = m->m_pkthdr.len;
703 	crda->crd_inject = skip + rplen;
704 
705 	/* Authentication operation. */
706 	crda->crd_alg = ahx->type;
707 	crda->crd_key = _KEYBUF(sav->key_auth);
708 	crda->crd_klen = _KEYBITS(sav->key_auth);
709 
710 	/* Find out if we've already done crypto. */
711 	for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
712 	     mtag != NULL;
713 	     mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
714 		tdbi = (struct tdb_ident *) (mtag + 1);
715 		if (tdbi->proto == sav->sah->saidx.proto &&
716 		    tdbi->spi == sav->spi &&
717 		    !memcmp(&tdbi->dst, &sav->sah->saidx.dst,
718 			  sizeof (union sockaddr_union)))
719 			break;
720 	}
721 
722 	/* Allocate IPsec-specific opaque crypto info. */
723 	if (mtag == NULL) {
724 		tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
725 			skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
726 	} else {
727 		/* Hash verification has already been done successfully. */
728 		tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
729 						    M_XDATA, M_NOWAIT|M_ZERO);
730 	}
731 	if (tc == NULL) {
732 		DPRINTF(("ah_input: failed to allocate tdb_crypto\n"));
733 		AH_STATINC(AH_STAT_CRYPTO);
734 		crypto_freereq(crp);
735 		m_freem(m);
736 		return ENOBUFS;
737 	}
738 
739 	error = m_makewritable(&m, 0, skip + rplen + authsize, M_NOWAIT);
740 	if (error) {
741 		m_freem(m);
742 		DPRINTF(("ah_input: failed to copyback_cow\n"));
743 		AH_STATINC(AH_STAT_HDROPS);
744 		free(tc, M_XDATA);
745 		crypto_freereq(crp);
746 		return error;
747 	}
748 
749 	/* Only save information if crypto processing is needed. */
750 	if (mtag == NULL) {
751 		/*
752 		 * Save the authenticator, the skipped portion of the packet,
753 		 * and the AH header.
754 		 */
755 		m_copydata(m, 0, skip + rplen + authsize, (tc + 1));
756 
757 		/* Zeroize the authenticator on the packet. */
758 		m_copyback(m, skip + rplen, authsize, ipseczeroes);
759 
760 		/* "Massage" the packet headers for crypto processing. */
761 		error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
762 		    skip, ahx->type, 0);
763 		if (error != 0) {
764 			/* NB: mbuf is free'd by ah_massage_headers */
765 			AH_STATINC(AH_STAT_HDROPS);
766 			free(tc, M_XDATA);
767 			crypto_freereq(crp);
768 			return error;
769 		}
770 	}
771 
772 	/* Crypto operation descriptor. */
773 	crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
774 	crp->crp_flags = CRYPTO_F_IMBUF;
775 	crp->crp_buf = m;
776 	crp->crp_callback = ah_input_cb;
777 	crp->crp_sid = sav->tdb_cryptoid;
778 	crp->crp_opaque = tc;
779 
780 	/* These are passed as-is to the callback. */
781 	tc->tc_spi = sav->spi;
782 	tc->tc_dst = sav->sah->saidx.dst;
783 	tc->tc_proto = sav->sah->saidx.proto;
784 	tc->tc_nxt = ah->ah_nxt;
785 	tc->tc_protoff = protoff;
786 	tc->tc_skip = skip;
787 	tc->tc_ptr = mtag; /* Save the mtag we've identified. */
788 
789 	DPRINTF(("ah: hash over %d bytes, skip %d: "
790 		 "crda len %d skip %d inject %d\n",
791 		 crp->crp_ilen, tc->tc_skip,
792 		 crda->crd_len, crda->crd_skip, crda->crd_inject));
793 
794 	if (mtag == NULL)
795 		return crypto_dispatch(crp);
796 	else
797 		return ah_input_cb(crp);
798 }
799 
800 #ifdef INET6
801 #define	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do {		     \
802 	if (saidx->dst.sa.sa_family == AF_INET6) {			     \
803 		error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
804 	} else {							     \
805 		error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
806 	}								     \
807 } while (0)
808 #else
809 #define	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag)		     \
810 	(error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
811 #endif
812 
813 /*
814  * AH input callback from the crypto driver.
815  */
816 static int
817 ah_input_cb(struct cryptop *crp)
818 {
819 	int rplen, error, skip, protoff;
820 	unsigned char calc[AH_ALEN_MAX];
821 	struct mbuf *m;
822 	struct tdb_crypto *tc;
823 	struct m_tag *mtag;
824 	struct secasvar *sav;
825 	struct secasindex *saidx;
826 	u_int8_t nxt;
827 	char *ptr;
828 	int s, authsize;
829 	u_int16_t dport;
830 	u_int16_t sport;
831 
832 	tc = (struct tdb_crypto *) crp->crp_opaque;
833 	IPSEC_ASSERT(tc != NULL, ("ah_input_cb: null opaque crypto data area!"));
834 	skip = tc->tc_skip;
835 	nxt = tc->tc_nxt;
836 	protoff = tc->tc_protoff;
837 	mtag = (struct m_tag *) tc->tc_ptr;
838 	m = (struct mbuf *) crp->crp_buf;
839 
840 
841 	/* find the source port for NAT-T */
842 	nat_t_ports_get(m, &dport, &sport);
843 
844 	s = splsoftnet();
845 	mutex_enter(softnet_lock);
846 
847 	sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, sport, dport);
848 	if (sav == NULL) {
849 		AH_STATINC(AH_STAT_NOTDB);
850 		DPRINTF(("ah_input_cb: SA expired while in crypto\n"));
851 		error = ENOBUFS;		/*XXX*/
852 		goto bad;
853 	}
854 
855 	saidx = &sav->sah->saidx;
856 	IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
857 		saidx->dst.sa.sa_family == AF_INET6,
858 		("ah_input_cb: unexpected protocol family %u",
859 		 saidx->dst.sa.sa_family));
860 
861 	/* Check for crypto errors. */
862 	if (crp->crp_etype) {
863 		if (sav->tdb_cryptoid != 0)
864 			sav->tdb_cryptoid = crp->crp_sid;
865 
866 		if (crp->crp_etype == EAGAIN) {
867 			mutex_exit(softnet_lock);
868 			splx(s);
869 			return crypto_dispatch(crp);
870 		}
871 
872 		AH_STATINC(AH_STAT_NOXFORM);
873 		DPRINTF(("ah_input_cb: crypto error %d\n", crp->crp_etype));
874 		error = crp->crp_etype;
875 		goto bad;
876 	} else {
877 		AH_STATINC(AH_STAT_HIST + sav->alg_auth);
878 		crypto_freereq(crp);		/* No longer needed. */
879 		crp = NULL;
880 	}
881 
882 	/* Shouldn't happen... */
883 	if (m == NULL) {
884 		AH_STATINC(AH_STAT_CRYPTO);
885 		DPRINTF(("ah_input_cb: bogus returned buffer from crypto\n"));
886 		error = EINVAL;
887 		goto bad;
888 	}
889 
890 	/* Figure out header size. */
891 	rplen = HDRSIZE(sav);
892 	authsize = AUTHSIZE(sav);
893 
894 	if (ipsec_debug)
895 		memset(calc, 0, sizeof(calc));
896 
897 	/* Copy authenticator off the packet. */
898 	m_copydata(m, skip + rplen, authsize, calc);
899 
900 	/*
901 	 * If we have an mtag, we don't need to verify the authenticator --
902 	 * it has been verified by an IPsec-aware NIC.
903 	 */
904 	if (mtag == NULL) {
905 		ptr = (char *) (tc + 1);
906 
907 		/* Verify authenticator. */
908 		if (!consttime_memequal(ptr + skip + rplen, calc, authsize)) {
909 			u_int8_t *pppp = ptr + skip+rplen;
910 			DPRINTF(("ah_input: authentication hash mismatch " \
911 			    "over %d bytes " \
912 			    "for packet in SA %s/%08lx:\n" \
913 		    "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x, " \
914 		    "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
915 			    authsize,
916 			    ipsec_address(&saidx->dst),
917 			    (u_long) ntohl(sav->spi),
918 				 calc[0], calc[1], calc[2], calc[3],
919 				 calc[4], calc[5], calc[6], calc[7],
920 				 calc[8], calc[9], calc[10], calc[11],
921 				 pppp[0], pppp[1], pppp[2], pppp[3],
922 				 pppp[4], pppp[5], pppp[6], pppp[7],
923 				 pppp[8], pppp[9], pppp[10], pppp[11]
924 				 ));
925 			AH_STATINC(AH_STAT_BADAUTH);
926 			error = EACCES;
927 			goto bad;
928 		}
929 
930 		/* Fix the Next Protocol field. */
931 		((u_int8_t *) ptr)[protoff] = nxt;
932 
933 		/* Copyback the saved (uncooked) network headers. */
934 		m_copyback(m, 0, skip, ptr);
935 	} else {
936 		/* Fix the Next Protocol field. */
937 		m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
938 	}
939 
940 	free(tc, M_XDATA), tc = NULL;			/* No longer needed */
941 
942 	/*
943 	 * Header is now authenticated.
944 	 */
945 	m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
946 
947 	/*
948 	 * Update replay sequence number, if appropriate.
949 	 */
950 	if (sav->replay) {
951 		u_int32_t seq;
952 
953 		m_copydata(m, skip + offsetof(struct newah, ah_seq),
954 			   sizeof (seq), &seq);
955 		if (ipsec_updatereplay(ntohl(seq), sav)) {
956 			AH_STATINC(AH_STAT_REPLAY);
957 			error = ENOBUFS;			/*XXX as above*/
958 			goto bad;
959 		}
960 	}
961 
962 	/*
963 	 * Remove the AH header and authenticator from the mbuf.
964 	 */
965 	error = m_striphdr(m, skip, rplen + authsize);
966 	if (error) {
967 		DPRINTF(("ah_input_cb: mangled mbuf chain for SA %s/%08lx\n",
968 		    ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
969 
970 		AH_STATINC(AH_STAT_HDROPS);
971 		goto bad;
972 	}
973 
974 	IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
975 
976 	KEY_FREESAV(&sav);
977 	mutex_exit(softnet_lock);
978 	splx(s);
979 	return error;
980 bad:
981 	if (sav)
982 		KEY_FREESAV(&sav);
983 	mutex_exit(softnet_lock);
984 	splx(s);
985 	if (m != NULL)
986 		m_freem(m);
987 	if (tc != NULL)
988 		free(tc, M_XDATA);
989 	if (crp != NULL)
990 		crypto_freereq(crp);
991 	return error;
992 }
993 
994 /*
995  * AH output routine, called by ipsec[46]_process_packet().
996  */
997 static int
998 ah_output(
999     struct mbuf *m,
1000     struct ipsecrequest *isr,
1001     struct mbuf **mp,
1002     int skip,
1003     int protoff
1004 )
1005 {
1006 	const struct secasvar *sav;
1007 	const struct auth_hash *ahx;
1008 	struct cryptodesc *crda;
1009 	struct tdb_crypto *tc;
1010 	struct mbuf *mi;
1011 	struct cryptop *crp;
1012 	u_int16_t iplen;
1013 	int error, rplen, authsize, maxpacketsize, roff;
1014 	u_int8_t prot;
1015 	struct newah *ah;
1016 
1017 	IPSEC_SPLASSERT_SOFTNET("ah_output");
1018 
1019 	sav = isr->sav;
1020 	IPSEC_ASSERT(sav != NULL, ("ah_output: null SA"));
1021 	ahx = sav->tdb_authalgxform;
1022 	IPSEC_ASSERT(ahx != NULL, ("ah_output: null authentication xform"));
1023 
1024 	AH_STATINC(AH_STAT_OUTPUT);
1025 
1026 	/* Figure out header size. */
1027 	rplen = HDRSIZE(sav);
1028 
1029 	/* Check for maximum packet size violations. */
1030 	switch (sav->sah->saidx.dst.sa.sa_family) {
1031 #ifdef INET
1032 	case AF_INET:
1033 		maxpacketsize = IP_MAXPACKET;
1034 		break;
1035 #endif /* INET */
1036 #ifdef INET6
1037 	case AF_INET6:
1038 		maxpacketsize = IPV6_MAXPACKET;
1039 		break;
1040 #endif /* INET6 */
1041 	default:
1042 		DPRINTF(("ah_output: unknown/unsupported protocol "
1043 		    "family %u, SA %s/%08lx\n",
1044 		    sav->sah->saidx.dst.sa.sa_family,
1045 		    ipsec_address(&sav->sah->saidx.dst),
1046 		    (u_long) ntohl(sav->spi)));
1047 		AH_STATINC(AH_STAT_NOPF);
1048 		error = EPFNOSUPPORT;
1049 		goto bad;
1050 	}
1051 	authsize = AUTHSIZE(sav);
1052 	if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
1053 		DPRINTF(("ah_output: packet in SA %s/%08lx got too big "
1054 		    "(len %u, max len %u)\n",
1055 		    ipsec_address(&sav->sah->saidx.dst),
1056 		    (u_long) ntohl(sav->spi),
1057 		    rplen + authsize + m->m_pkthdr.len, maxpacketsize));
1058 		AH_STATINC(AH_STAT_TOOBIG);
1059 		error = EMSGSIZE;
1060 		goto bad;
1061 	}
1062 
1063 	/* Update the counters. */
1064 	AH_STATADD(AH_STAT_OBYTES, m->m_pkthdr.len - skip);
1065 
1066 	m = m_clone(m);
1067 	if (m == NULL) {
1068 		DPRINTF(("ah_output: cannot clone mbuf chain, SA %s/%08lx\n",
1069 		    ipsec_address(&sav->sah->saidx.dst),
1070 		    (u_long) ntohl(sav->spi)));
1071 		AH_STATINC(AH_STAT_HDROPS);
1072 		error = ENOBUFS;
1073 		goto bad;
1074 	}
1075 
1076 	/* Inject AH header. */
1077 	mi = m_makespace(m, skip, rplen + authsize, &roff);
1078 	if (mi == NULL) {
1079 		DPRINTF(("ah_output: failed to inject %u byte AH header for SA "
1080 		    "%s/%08lx\n",
1081 		    rplen + authsize,
1082 		    ipsec_address(&sav->sah->saidx.dst),
1083 		    (u_long) ntohl(sav->spi)));
1084 		AH_STATINC(AH_STAT_HDROPS);	/*XXX differs from openbsd */
1085 		error = ENOBUFS;
1086 		goto bad;
1087 	}
1088 
1089 	/*
1090 	 * The AH header is guaranteed by m_makespace() to be in
1091 	 * contiguous memory, at roff bytes offset into the returned mbuf.
1092 	 */
1093 	ah = (struct newah *)(mtod(mi, char *) + roff);
1094 
1095 	/* Initialize the AH header. */
1096 	m_copydata(m, protoff, sizeof(u_int8_t), &ah->ah_nxt);
1097 	ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
1098 	ah->ah_reserve = 0;
1099 	ah->ah_spi = sav->spi;
1100 
1101 	/* Zeroize authenticator. */
1102 	m_copyback(m, skip + rplen, authsize, ipseczeroes);
1103 
1104 	/* Insert packet replay counter, as requested.  */
1105 	if (sav->replay) {
1106 		if (sav->replay->count == ~0 &&
1107 		    (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
1108 			DPRINTF(("ah_output: replay counter wrapped for SA "
1109 				"%s/%08lx\n",
1110 				ipsec_address(&sav->sah->saidx.dst),
1111 				(u_long) ntohl(sav->spi)));
1112 			AH_STATINC(AH_STAT_WRAP);
1113 			error = EINVAL;
1114 			goto bad;
1115 		}
1116 #ifdef IPSEC_DEBUG
1117 		/* Emulate replay attack when ipsec_replay is TRUE. */
1118 		if (!ipsec_replay)
1119 #endif
1120 			sav->replay->count++;
1121 		ah->ah_seq = htonl(sav->replay->count);
1122 	}
1123 
1124 	/* Get crypto descriptors. */
1125 	crp = crypto_getreq(1);
1126 	if (crp == NULL) {
1127 		DPRINTF(("ah_output: failed to acquire crypto descriptors\n"));
1128 		AH_STATINC(AH_STAT_CRYPTO);
1129 		error = ENOBUFS;
1130 		goto bad;
1131 	}
1132 
1133 	crda = crp->crp_desc;
1134 
1135 	crda->crd_skip = 0;
1136 	crda->crd_inject = skip + rplen;
1137 	crda->crd_len = m->m_pkthdr.len;
1138 
1139 	/* Authentication operation. */
1140 	crda->crd_alg = ahx->type;
1141 	crda->crd_key = _KEYBUF(sav->key_auth);
1142 	crda->crd_klen = _KEYBITS(sav->key_auth);
1143 
1144 	/* Allocate IPsec-specific opaque crypto info. */
1145 	tc = (struct tdb_crypto *) malloc(
1146 		sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
1147 	if (tc == NULL) {
1148 		crypto_freereq(crp);
1149 		DPRINTF(("ah_output: failed to allocate tdb_crypto\n"));
1150 		AH_STATINC(AH_STAT_CRYPTO);
1151 		error = ENOBUFS;
1152 		goto bad;
1153 	}
1154 
1155 	/* Save the skipped portion of the packet. */
1156 	m_copydata(m, 0, skip, (tc + 1));
1157 
1158 	/*
1159 	 * Fix IP header length on the header used for
1160 	 * authentication. We don't need to fix the original
1161 	 * header length as it will be fixed by our caller.
1162 	 */
1163 	switch (sav->sah->saidx.dst.sa.sa_family) {
1164 #ifdef INET
1165 	case AF_INET:
1166 		bcopy(((char *)(tc + 1)) +
1167 		    offsetof(struct ip, ip_len),
1168 		    &iplen, sizeof(u_int16_t));
1169 		iplen = htons(ntohs(iplen) + rplen + authsize);
1170 		m_copyback(m, offsetof(struct ip, ip_len),
1171 		    sizeof(u_int16_t), &iplen);
1172 		break;
1173 #endif /* INET */
1174 
1175 #ifdef INET6
1176 	case AF_INET6:
1177 		bcopy(((char *)(tc + 1)) +
1178 		    offsetof(struct ip6_hdr, ip6_plen),
1179 		    &iplen, sizeof(u_int16_t));
1180 		iplen = htons(ntohs(iplen) + rplen + authsize);
1181 		m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
1182 		    sizeof(u_int16_t), &iplen);
1183 		break;
1184 #endif /* INET6 */
1185 	}
1186 
1187 	/* Fix the Next Header field in saved header. */
1188 	((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
1189 
1190 	/* Update the Next Protocol field in the IP header. */
1191 	prot = IPPROTO_AH;
1192 	m_copyback(m, protoff, sizeof(u_int8_t), &prot);
1193 
1194 	/* "Massage" the packet headers for crypto processing. */
1195 	error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
1196 			skip, ahx->type, 1);
1197 	if (error != 0) {
1198 		m = NULL;	/* mbuf was free'd by ah_massage_headers. */
1199 		free(tc, M_XDATA);
1200 		crypto_freereq(crp);
1201 		goto bad;
1202 	}
1203 
1204 	/* Crypto operation descriptor. */
1205 	crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
1206 	crp->crp_flags = CRYPTO_F_IMBUF;
1207 	crp->crp_buf = m;
1208 	crp->crp_callback = ah_output_cb;
1209 	crp->crp_sid = sav->tdb_cryptoid;
1210 	crp->crp_opaque = tc;
1211 
1212 	/* These are passed as-is to the callback. */
1213 	tc->tc_isr = isr;
1214 	tc->tc_spi = sav->spi;
1215 	tc->tc_dst = sav->sah->saidx.dst;
1216 	tc->tc_proto = sav->sah->saidx.proto;
1217 	tc->tc_skip = skip;
1218 	tc->tc_protoff = protoff;
1219 
1220 	return crypto_dispatch(crp);
1221 bad:
1222 	if (m)
1223 		m_freem(m);
1224 	return (error);
1225 }
1226 
1227 /*
1228  * AH output callback from the crypto driver.
1229  */
1230 static int
1231 ah_output_cb(struct cryptop *crp)
1232 {
1233 	int skip, error;
1234 	struct tdb_crypto *tc;
1235 	struct ipsecrequest *isr;
1236 	struct secasvar *sav;
1237 	struct mbuf *m;
1238 	void *ptr;
1239 	int s, err;
1240 
1241 	tc = (struct tdb_crypto *) crp->crp_opaque;
1242 	IPSEC_ASSERT(tc != NULL, ("ah_output_cb: null opaque data area!"));
1243 	skip = tc->tc_skip;
1244 	ptr = (tc + 1);
1245 	m = (struct mbuf *) crp->crp_buf;
1246 
1247 	s = splsoftnet();
1248 	mutex_enter(softnet_lock);
1249 
1250 	isr = tc->tc_isr;
1251 	sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, 0, 0);
1252 	if (sav == NULL) {
1253 		AH_STATINC(AH_STAT_NOTDB);
1254 		DPRINTF(("ah_output_cb: SA expired while in crypto\n"));
1255 		error = ENOBUFS;		/*XXX*/
1256 		goto bad;
1257 	}
1258 	IPSEC_ASSERT(isr->sav == sav, ("ah_output_cb: SA changed\n"));
1259 
1260 	/* Check for crypto errors. */
1261 	if (crp->crp_etype) {
1262 		if (sav->tdb_cryptoid != 0)
1263 			sav->tdb_cryptoid = crp->crp_sid;
1264 
1265 		if (crp->crp_etype == EAGAIN) {
1266 			KEY_FREESAV(&sav);
1267 			mutex_exit(softnet_lock);
1268 			splx(s);
1269 			return crypto_dispatch(crp);
1270 		}
1271 
1272 		AH_STATINC(AH_STAT_NOXFORM);
1273 		DPRINTF(("ah_output_cb: crypto error %d\n", crp->crp_etype));
1274 		error = crp->crp_etype;
1275 		goto bad;
1276 	}
1277 
1278 	/* Shouldn't happen... */
1279 	if (m == NULL) {
1280 		AH_STATINC(AH_STAT_CRYPTO);
1281 		DPRINTF(("ah_output_cb: bogus returned buffer from crypto\n"));
1282 		error = EINVAL;
1283 		goto bad;
1284 	}
1285 	AH_STATINC(AH_STAT_HIST + sav->alg_auth);
1286 
1287 	/*
1288 	 * Copy original headers (with the new protocol number) back
1289 	 * in place.
1290 	 */
1291 	m_copyback(m, 0, skip, ptr);
1292 
1293 	/* No longer needed. */
1294 	free(tc, M_XDATA);
1295 	crypto_freereq(crp);
1296 
1297 #ifdef IPSEC_DEBUG
1298 	/* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
1299 	if (ipsec_integrity) {
1300 		int alen;
1301 
1302 		/*
1303 		 * Corrupt HMAC if we want to test integrity verification of
1304 		 * the other side.
1305 		 */
1306 		alen = AUTHSIZE(sav);
1307 		m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
1308 	}
1309 #endif
1310 
1311 	/* NB: m is reclaimed by ipsec_process_done. */
1312 	err = ipsec_process_done(m, isr);
1313 	KEY_FREESAV(&sav);
1314 	mutex_exit(softnet_lock);
1315 	splx(s);
1316 	return err;
1317 bad:
1318 	if (sav)
1319 		KEY_FREESAV(&sav);
1320 	mutex_exit(softnet_lock);
1321 	splx(s);
1322 	if (m)
1323 		m_freem(m);
1324 	free(tc, M_XDATA);
1325 	crypto_freereq(crp);
1326 	return error;
1327 }
1328 
1329 static struct xformsw ah_xformsw = {
1330 	XF_AH,		XFT_AUTH,	"IPsec AH",
1331 	ah_init,	ah_zeroize,	ah_input,	ah_output,
1332 	NULL,
1333 };
1334 
1335 INITFN void
1336 ah_attach(void)
1337 {
1338 	ahstat_percpu = percpu_alloc(sizeof(uint64_t) * AH_NSTATS);
1339 	xform_register(&ah_xformsw);
1340 }
1341 
1342 #ifdef __FreeBSD__
1343 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);
1344 #endif
1345