1 /*
2  * Copyright (C) 2002-2003 by Ryan Beasley <ryanb@goddamnbastard.org>
3  *
4  * See the IPFILTER.LICENCE file for details on licencing.
5  *
6  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
7  * Use is subject to license terms.
8  */
9 /*
10  * Overview:
11  *   This is an in-kernel application proxy for Sun's RPCBIND (nee portmap)
12  *   protocol as defined in RFC1833.  It is far from complete, mostly
13  *   lacking in less-likely corner cases, but it's definitely functional.
14  *
15  *   Invocation:
16  *     rdr <int> <e_ip>/32 port <e_p> -> <i_ip> port <i_p> udp proxy rpcbu
17  *
18  *   If the host running IP Filter is the same as the RPC server, it's
19  *   perfectly legal for both the internal and external addresses and ports
20  *   to match.
21  *
22  *   When triggered by appropriate IP NAT rules, this proxy works by
23  *   examining data contained in received packets.  Requests and replies are
24  *   modified, NAT and state table entries created, etc., as necessary.
25  */
26 /*
27  * TODO / NOTES
28  *
29  *   o Must implement locking to protect proxy session data.
30  *   o Fragmentation isn't supported.
31  *   o Only supports UDP.
32  *   o Doesn't support multiple RPC records in a single request.
33  *   o Errors should be more fine-grained.  (e.g., malloc failure vs.
34  *     illegal RPCB request / reply)
35  *   o Even with the limit on the total amount of recorded transactions,
36  *     should there be a timeout on transaction removal?
37  *   o There is a potential collision between cloning, wildcard NAT and
38  *     state entries.  There should be an appr_getport routine for
39  *     to avoid this.
40  *   o The enclosed hack of STREAMS support is pretty sick and most likely
41  *     broken.
42  *
43  *	$Id: ip_rpcb_pxy.c,v 2.25.2.3 2005/02/04 10:22:56 darrenr Exp $
44  */
45 
46 #pragma ident	"%Z%%M%	%I%	%E% SMI"
47 
48 #define	IPF_RPCB_PROXY
49 
50 typedef struct ifs_rpcbpxy {
51 	frentry_t	rpcbfr;	/* Skeleton rule for reference by entities
52 				   this proxy creates. */
53 	int		rpcbcnt;/* Upper bound of allocated RPCB sessions. */
54 				/* XXX rpcbcnt still requires locking. */
55 	int		rpcb_proxy_init;
56 } ifs_rpcbpxy_t;
57 
58 /*
59  * Function prototypes
60  */
61 int	ippr_rpcb_init __P((void **, ipf_stack_t *));
62 void	ippr_rpcb_fini __P((void **, ipf_stack_t *));
63 int	ippr_rpcb_new __P((fr_info_t *, ap_session_t *, nat_t *, void *));
64 void	ippr_rpcb_del __P((ap_session_t *, void *, ipf_stack_t *));
65 int	ippr_rpcb_in __P((fr_info_t *, ap_session_t *, nat_t *, void *));
66 int	ippr_rpcb_out __P((fr_info_t *, ap_session_t *, nat_t *, void *));
67 
68 static void	ippr_rpcb_flush __P((rpcb_session_t *));
69 static int	ippr_rpcb_decodereq __P((fr_info_t *, nat_t *,
70 	rpcb_session_t *, rpc_msg_t *, ifs_rpcbpxy_t *));
71 static int	ippr_rpcb_skipauth __P((rpc_msg_t *, xdr_auth_t *, u_32_t **));
72 static int	ippr_rpcb_insert __P((rpcb_session_t *, rpcb_xact_t *,
73 				      ifs_rpcbpxy_t *));
74 static int	ippr_rpcb_xdrrpcb __P((rpc_msg_t *, u_32_t *, rpcb_args_t *));
75 static int	ippr_rpcb_getuaddr __P((rpc_msg_t *, xdr_uaddr_t *,
76 	u_32_t **));
77 static u_int	ippr_rpcb_atoi __P((char *));
78 static int	ippr_rpcb_modreq __P((fr_info_t *, nat_t *, rpc_msg_t *,
79 	mb_t *, u_int));
80 static int	ippr_rpcb_decoderep __P((fr_info_t *, nat_t *,
81 	rpcb_session_t *, rpc_msg_t *, rpcb_xact_t **, ifs_rpcbpxy_t *));
82 static rpcb_xact_t *	ippr_rpcb_lookup __P((rpcb_session_t *, u_32_t));
83 static void	ippr_rpcb_deref __P((rpcb_session_t *, rpcb_xact_t *,
84 				     ifs_rpcbpxy_t *));
85 static int	ippr_rpcb_getproto __P((rpc_msg_t *, xdr_proto_t *,
86 	u_32_t **));
87 static int	ippr_rpcb_getnat __P((fr_info_t *, nat_t *, u_int, u_int, ifs_rpcbpxy_t *));
88 static int	ippr_rpcb_modv3 __P((fr_info_t *, nat_t *, rpc_msg_t *,
89 	mb_t *, u_int));
90 static int	ippr_rpcb_modv4 __P((fr_info_t *, nat_t *, rpc_msg_t *,
91 	mb_t *, u_int));
92 static void     ippr_rpcb_fixlen __P((fr_info_t *, int));
93 
94 /*
95  * Since rpc_msg contains only pointers, one should use this macro as a
96  * handy way to get to the goods.  (In case you're wondering about the name,
97  * this started as BYTEREF -> BREF -> B.)
98  */
99 #define	B(r)	(u_32_t)ntohl(*(r))
100 
101 /*
102  * Public subroutines
103  */
104 
105 /* --------------------------------------------------------------------	*/
106 /* Function:	ippr_rpcb_init						*/
107 /* Returns:	int - 0 == success					*/
108 /* Parameters:	(void)							*/
109 /*									*/
110 /* Initialize the filter rule entry and session limiter.		*/
111 /* --------------------------------------------------------------------	*/
112 /*ARGSUSED*/
113 int
114 ippr_rpcb_init(private, ifs)
115 void **private;
116 ipf_stack_t *ifs;
117 {
118 	ifs_rpcbpxy_t *ifsrpcb;
119 
120 	KMALLOC(ifsrpcb, ifs_rpcbpxy_t *);
121 	if (ifsrpcb == NULL)
122 		return -1;
123 
124 	ifsrpcb->rpcbcnt = 0;
125 
126 	bzero((char *)&ifsrpcb->rpcbfr, sizeof(ifsrpcb->rpcbfr));
127 	ifsrpcb->rpcbfr.fr_ref = 1;
128 	ifsrpcb->rpcbfr.fr_flags = FR_PASS|FR_QUICK|FR_KEEPSTATE;
129 	MUTEX_INIT(&ifsrpcb->rpcbfr.fr_lock, "ipf Sun RPCB proxy rule lock");
130 	ifsrpcb->rpcb_proxy_init = 1;
131 
132 	*private = (void *)ifsrpcb;
133 
134 	return(0);
135 }
136 
137 /* --------------------------------------------------------------------	*/
138 /* Function:	ippr_rpcb_fini						*/
139 /* Returns:	void							*/
140 /* Parameters:	(void)							*/
141 /*									*/
142 /* Destroy rpcbfr's mutex to avoid a lock leak.				*/
143 /* --------------------------------------------------------------------	*/
144 /*ARGSUSED*/
145 void
146 ippr_rpcb_fini(private, ifs)
147 void **private;
148 ipf_stack_t *ifs;
149 {
150 	ifs_rpcbpxy_t *ifsrpcb = *((ifs_rpcbpxy_t **)private);
151 
152 	if (ifsrpcb->rpcb_proxy_init == 1) {
153 		MUTEX_DESTROY(&ifsrpcb->rpcbfr.fr_lock);
154 		ifsrpcb->rpcb_proxy_init = 0;
155 	}
156 
157 	KFREE(ifsrpcb);
158 	*private = NULL;
159 }
160 
161 /* --------------------------------------------------------------------	*/
162 /* Function:	ippr_rpcb_new						*/
163 /* Returns:	int - -1 == failure, 0 == success			*/
164 /* Parameters:	fin(I)	- pointer to packet information			*/
165 /*		aps(I)	- pointer to proxy session structure		*/
166 /*		nat(I)	- pointer to NAT session structure		*/
167 /*									*/
168 /* Allocate resources for per-session proxy structures.			*/
169 /* --------------------------------------------------------------------	*/
170 /*ARGSUSED*/
171 int
172 ippr_rpcb_new(fin, aps, nat, private)
173 	fr_info_t *fin;
174 	ap_session_t *aps;
175 	nat_t *nat;
176 	void *private;
177 {
178 	rpcb_session_t *rs;
179 
180 	fin = fin;	/* LINT */
181 	nat = nat;	/* LINT */
182 
183 	KMALLOC(rs, rpcb_session_t *);
184 	if (rs == NULL)
185 		return(-1);
186 
187 	bzero((char *)rs, sizeof(*rs));
188 	MUTEX_INIT(&rs->rs_rxlock, "ipf Sun RPCB proxy session lock");
189 
190 	aps->aps_data = rs;
191 
192 	return(0);
193 }
194 
195 /* --------------------------------------------------------------------	*/
196 /* Function:	ippr_rpcb_del						*/
197 /* Returns:	void							*/
198 /* Parameters:	aps(I)	- pointer to proxy session structure		*/
199 /*									*/
200 /* Free up a session's list of RPCB requests.				*/
201 /* --------------------------------------------------------------------	*/
202 /*ARGSUSED*/
203 void
204 ippr_rpcb_del(aps, private, ifs)
205 	ap_session_t *aps;
206 	void *private;
207 	ipf_stack_t *ifs;
208 {
209 	rpcb_session_t *rs;
210 	rs = (rpcb_session_t *)aps->aps_data;
211 
212 	ifs = ifs;	/* LINT */
213 
214 	MUTEX_ENTER(&rs->rs_rxlock);
215 	ippr_rpcb_flush(rs);
216 	MUTEX_EXIT(&rs->rs_rxlock);
217 	MUTEX_DESTROY(&rs->rs_rxlock);
218 }
219 
220 /* --------------------------------------------------------------------	*/
221 /* Function:	ippr_rpcb_in						*/
222 /* Returns:	int - APR_ERR(1) == drop the packet, 			*/
223 /*		      APR_ERR(2) == kill the proxy session,		*/
224 /*		      else change in packet length (in bytes)		*/
225 /* Parameters:	fin(I)	- pointer to packet information			*/
226 /*		ip(I)	- pointer to packet header			*/
227 /*		aps(I)	- pointer to proxy session structure		*/
228 /*		nat(I)	- pointer to NAT session structure		*/
229 /*									*/
230 /* Given a presumed RPCB request, perform some minor tests and pass off */
231 /* for decoding.  Also pass packet off for a rewrite if necessary.	*/
232 /* --------------------------------------------------------------------	*/
233 int
234 ippr_rpcb_in(fin, aps, nat, private)
235 	fr_info_t *fin;
236 	ap_session_t *aps;
237 	nat_t *nat;
238 	void *private;
239 {
240 	rpc_msg_t rpcmsg, *rm;
241 	rpcb_session_t *rs;
242 	u_int off, dlen;
243 	mb_t *m;
244 	int rv;
245 
246 	/* Disallow fragmented or illegally short packets. */
247 	if ((fin->fin_flx & (FI_FRAG|FI_SHORT)) != 0)
248 		return(APR_ERR(1));
249 
250 	/* Perform basic variable initialization. */
251 	rs = (rpcb_session_t *)aps->aps_data;
252 
253 	m = fin->fin_m;
254 	off = (char *)fin->fin_dp - (char *)fin->fin_ip;
255 	off += sizeof(udphdr_t) + fin->fin_ipoff;
256 	dlen = fin->fin_dlen - sizeof(udphdr_t);
257 
258 	/* Disallow packets outside legal range for supported requests. */
259 	if ((dlen < RPCB_REQMIN) || (dlen > RPCB_REQMAX))
260 		return(APR_ERR(1));
261 
262 	/* Copy packet over to convenience buffer. */
263 	rm = &rpcmsg;
264 	bzero((char *)rm, sizeof(*rm));
265 	COPYDATA(m, off, dlen, (caddr_t)&rm->rm_msgbuf);
266 	rm->rm_buflen = dlen;
267 
268 	/* Send off to decode request. */
269 	rv = ippr_rpcb_decodereq(fin, nat, rs, rm, (ifs_rpcbpxy_t *)private);
270 
271 	switch(rv)
272 	{
273 	case -1:
274 		return(APR_ERR(1));
275 	case 0:
276 		break;
277 	case 1:
278 		rv = ippr_rpcb_modreq(fin, nat, rm, m, off);
279 		break;
280 	default:
281 		/*CONSTANTCONDITION*/
282 		IPF_PANIC(1, ("illegal rv %d (ippr_rpcb_req)", rv));
283 	}
284 
285 	return(rv);
286 }
287 
288 /* --------------------------------------------------------------------	*/
289 /* Function:	ippr_rpcb_out						*/
290 /* Returns:	int - APR_ERR(1) == drop the packet, 			*/
291 /*		      APR_ERR(2) == kill the proxy session,		*/
292 /*		      else change in packet length (in bytes)		*/
293 /* Parameters:	fin(I)	- pointer to packet information			*/
294 /*		ip(I)	- pointer to packet header			*/
295 /*		aps(I)	- pointer to proxy session structure		*/
296 /*		nat(I)	- pointer to NAT session structure		*/
297 /*									*/
298 /* Given a presumed RPCB reply, perform some minor tests and pass off	*/
299 /* for decoding.  If the message indicates a successful request with	*/
300 /* valid addressing information, create NAT and state structures to	*/
301 /* allow direct communication between RPC client and server.		*/
302 /* --------------------------------------------------------------------	*/
303 int
304 ippr_rpcb_out(fin, aps, nat, private)
305 	fr_info_t *fin;
306 	ap_session_t *aps;
307 	nat_t *nat;
308 	void *private;
309 {
310 	rpc_msg_t rpcmsg, *rm;
311 	rpcb_session_t *rs;
312 	rpcb_xact_t *rx;
313 	u_int off, dlen;
314 	int rv, diff;
315 	mb_t *m;
316 	ifs_rpcbpxy_t *ifsrpcb = (ifs_rpcbpxy_t *)private;
317 
318 	/* Disallow fragmented or illegally short packets. */
319 	if ((fin->fin_flx & (FI_FRAG|FI_SHORT)) != 0)
320 		return(APR_ERR(1));
321 
322 	/* Perform basic variable initialization. */
323 	rs = (rpcb_session_t *)aps->aps_data;
324 
325 	m = fin->fin_m;
326 	off = (char *)fin->fin_dp - (char *)fin->fin_ip;
327 	off += sizeof(udphdr_t) + fin->fin_ipoff;
328 	dlen = fin->fin_dlen - sizeof(udphdr_t);
329 	diff = 0;
330 
331 	/* Disallow packets outside legal range for supported requests. */
332 	if ((dlen < RPCB_REPMIN) || (dlen > RPCB_REPMAX))
333 		return(APR_ERR(1));
334 
335 	/* Copy packet over to convenience buffer. */
336 	rm = &rpcmsg;
337 	bzero((char *)rm, sizeof(*rm));
338 	COPYDATA(m, off, dlen, (caddr_t)&rm->rm_msgbuf);
339 	rm->rm_buflen = dlen;
340 
341 	/* Send off to decode reply. */
342 	rv = ippr_rpcb_decoderep(fin, nat, rs, rm, &rx, ifsrpcb);
343 
344 	switch(rv)
345 	{
346 	case -1: /* Bad packet */
347                 if (rx != NULL) {
348                         MUTEX_ENTER(&rs->rs_rxlock);
349                         ippr_rpcb_deref(rs, rx, ifsrpcb);
350                         MUTEX_EXIT(&rs->rs_rxlock);
351                 }
352 		return(APR_ERR(1));
353 	case  0: /* Negative reply / request rejected */
354 		break;
355 	case  1: /* Positive reply */
356 		/*
357 		 * With the IP address embedded in a GETADDR(LIST) reply,
358 		 * we'll need to rewrite the packet in the very possible
359 		 * event that the internal & external addresses aren't the
360 		 * same.  (i.e., this box is either a router or rpcbind
361 		 * only listens on loopback.)
362 		 */
363 		if (nat->nat_inip.s_addr != nat->nat_outip.s_addr) {
364 			if (rx->rx_type == RPCB_RES_STRING)
365 				diff = ippr_rpcb_modv3(fin, nat, rm, m, off);
366 			else if (rx->rx_type == RPCB_RES_LIST)
367 				diff = ippr_rpcb_modv4(fin, nat, rm, m, off);
368 		}
369 		break;
370 	default:
371 		/*CONSTANTCONDITION*/
372 		IPF_PANIC(1, ("illegal rv %d (ippr_rpcb_decoderep)", rv));
373 	}
374 
375 	if (rx != NULL) {
376                 MUTEX_ENTER(&rs->rs_rxlock);
377                 /* XXX Gross hack - I'm overloading the reference
378                  * counter to deal with both threads and retransmitted
379                  * requests.  One deref signals that this thread is
380                  * finished with rx, and the other signals that we've
381                  * processed its reply.
382                  */
383                 ippr_rpcb_deref(rs, rx, ifsrpcb);
384                 ippr_rpcb_deref(rs, rx, ifsrpcb);
385                 MUTEX_EXIT(&rs->rs_rxlock);
386 	}
387 
388 	return(diff);
389 }
390 
391 /*
392  * Private support subroutines
393  */
394 
395 /* --------------------------------------------------------------------	*/
396 /* Function:	ippr_rpcb_flush						*/
397 /* Returns:	void							*/
398 /* Parameters:	rs(I)	- pointer to RPCB session structure		*/
399 /*									*/
400 /* Simply flushes the list of outstanding transactions, if any.		*/
401 /* --------------------------------------------------------------------	*/
402 static void
403 ippr_rpcb_flush(rs)
404 	rpcb_session_t *rs;
405 {
406 	rpcb_xact_t *r1, *r2;
407 
408 	r1 = rs->rs_rxlist;
409 	if (r1 == NULL)
410 		return;
411 
412 	while (r1 != NULL) {
413 		r2 = r1;
414 		r1 = r1->rx_next;
415 		KFREE(r2);
416 	}
417 }
418 
419 /* --------------------------------------------------------------------	*/
420 /* Function:	ippr_rpcb_decodereq					*/
421 /* Returns:	int - -1 == bad request or critical failure,		*/
422 /*		       0 == request successfully decoded,		*/
423 /*		       1 == request successfully decoded; requires	*/
424 /*			    address rewrite/modification		*/
425 /* Parameters:	fin(I)	- pointer to packet information			*/
426 /*		nat(I)	- pointer to NAT session structure		*/
427 /*		rs(I)	- pointer to RPCB session structure		*/
428 /*		rm(I)	- pointer to RPC message structure		*/
429 /*									*/
430 /* Take a presumed RPCB request, decode it, and store the results in	*/
431 /* the transaction list.  If the internal target address needs to be	*/
432 /* modified, store its location in ptr.					*/
433 /* WARNING:  It's the responsibility of the caller to make sure there	*/
434 /* is enough room in rs_buf for the basic RPC message "preamble".	*/
435 /* --------------------------------------------------------------------	*/
436 static int
437 ippr_rpcb_decodereq(fin, nat, rs, rm, ifsrpcb)
438 	fr_info_t *fin;
439 	nat_t *nat;
440 	rpcb_session_t *rs;
441 	rpc_msg_t *rm;
442 	ifs_rpcbpxy_t *ifsrpcb;
443 {
444 	rpcb_args_t *ra;
445 	u_32_t xdr, *p;
446 	rpc_call_t *rc;
447 	rpcb_xact_t rx;
448 	int mod;
449 
450 	p = (u_32_t *)rm->rm_msgbuf;
451 	mod = 0;
452 
453 	bzero((char *)&rx, sizeof(rx));
454 	rc = &rm->rm_call;
455 
456 	rm->rm_xid = p;
457 	rx.rx_xid = B(p++);	/* Record this message's XID. */
458 
459 	/* Parse out and test the RPC header. */
460 	if ((B(p++) != RPCB_CALL) ||
461 	    (B(p++) != RPCB_MSG_VERSION) ||
462 	    (B(p++) != RPCB_PROG))
463 		return(-1);
464 
465 	/* Record the RPCB version and procedure. */
466 	rc->rc_vers = p++;
467 	rc->rc_proc = p++;
468 
469 	/* Bypass RPC authentication stuff. */
470 	if (ippr_rpcb_skipauth(rm, &rc->rc_authcred, &p) != 0)
471 		return(-1);
472 	if (ippr_rpcb_skipauth(rm, &rc->rc_authverf, &p) != 0)
473 		return(-1);
474 
475 	/* Compare RPCB version and procedure numbers. */
476 	switch(B(rc->rc_vers))
477 	{
478 	case 2:
479 		/* This proxy only supports PMAP_GETPORT. */
480 		if (B(rc->rc_proc) != RPCB_GETPORT)
481 			return(-1);
482 
483 		/* Portmap requests contain four 4 byte parameters. */
484 		if (RPCB_BUF_EQ(rm, p, 16) == 0)
485 			return(-1);
486 
487 		p += 2; /* Skip requested program and version numbers. */
488 
489 		/* Sanity check the requested protocol. */
490 		xdr = B(p);
491 		if (!(xdr == IPPROTO_UDP || xdr == IPPROTO_TCP))
492 			return(-1);
493 
494 		rx.rx_type = RPCB_RES_PMAP;
495 		rx.rx_proto = xdr;
496 		break;
497 	case 3:
498 	case 4:
499 		/* GETADDRLIST is exclusive to v4; GETADDR for v3 & v4 */
500 		switch(B(rc->rc_proc))
501 		{
502 		case RPCB_GETADDR:
503 			rx.rx_type = RPCB_RES_STRING;
504 			rx.rx_proto = (u_int)fin->fin_p;
505 			break;
506 		case RPCB_GETADDRLIST:
507 			if (B(rc->rc_vers) != 4)
508 				return(-1);
509 			rx.rx_type = RPCB_RES_LIST;
510 			break;
511 		default:
512 			return(-1);
513 		}
514 
515 		ra = &rc->rc_rpcbargs;
516 
517 		/* Decode the 'struct rpcb' request. */
518 		if (ippr_rpcb_xdrrpcb(rm, p, ra) != 0)
519 			return(-1);
520 
521 		/* Are the target address & port valid? */
522 		if ((ra->ra_maddr.xu_ip != nat->nat_outip.s_addr) ||
523 		    (ra->ra_maddr.xu_port != nat->nat_outport))
524 		    	return(-1);
525 
526 		/* Do we need to rewrite this packet? */
527 		if ((nat->nat_outip.s_addr != nat->nat_inip.s_addr) ||
528 		    (nat->nat_outport != nat->nat_inport))
529 		    	mod = 1;
530 		break;
531 	default:
532 		return(-1);
533 	}
534 
535         MUTEX_ENTER(&rs->rs_rxlock);
536 	if (ippr_rpcb_insert(rs, &rx, ifsrpcb) != 0) {
537                 MUTEX_EXIT(&rs->rs_rxlock);
538 		return(-1);
539 	}
540         MUTEX_EXIT(&rs->rs_rxlock);
541 
542 	return(mod);
543 }
544 
545 /* --------------------------------------------------------------------	*/
546 /* Function:	ippr_rpcb_skipauth					*/
547 /* Returns:	int -- -1 == illegal auth parameters (lengths)		*/
548 /*			0 == valid parameters, pointer advanced		*/
549 /* Parameters:	rm(I)	- pointer to RPC message structure		*/
550 /*		auth(I)	- pointer to RPC auth structure			*/
551 /*		buf(IO)	- pointer to location within convenience buffer	*/
552 /*									*/
553 /* Record auth data length & location of auth data, then advance past	*/
554 /* it.									*/
555 /* --------------------------------------------------------------------	*/
556 static int
557 ippr_rpcb_skipauth(rm, auth, buf)
558 	rpc_msg_t *rm;
559 	xdr_auth_t *auth;
560 	u_32_t **buf;
561 {
562 	u_32_t *p, xdr;
563 
564 	p = *buf;
565 
566 	/* Make sure we have enough space for expected fixed auth parms. */
567 	if (RPCB_BUF_GEQ(rm, p, 8) == 0)
568 		return(-1);
569 
570 	p++; /* We don't care about auth_flavor. */
571 
572 	auth->xa_string.xs_len = p;
573 	xdr = B(p++);		/* Length of auth_data */
574 
575 	/* Test for absurdity / illegality of auth_data length. */
576 	if ((XDRALIGN(xdr) < xdr) || (RPCB_BUF_GEQ(rm, p, XDRALIGN(xdr)) == 0))
577 		return(-1);
578 
579 	auth->xa_string.xs_str = (char *)p;
580 
581 	p += XDRALIGN(xdr);	/* Advance our location. */
582 
583 	*buf = (u_32_t *)p;
584 
585 	return(0);
586 }
587 
588 /* --------------------------------------------------------------------	*/
589 /* Function:	ippr_rpcb_insert					*/
590 /* Returns:	int -- -1 == list insertion failed,			*/
591 /*			0 == item successfully added			*/
592 /* Parameters:	rs(I)	- pointer to RPCB session structure		*/
593 /*		rx(I)	- pointer to RPCB transaction structure		*/
594 /* --------------------------------------------------------------------	*/
595 static int
596 ippr_rpcb_insert(rs, rx, ifsrpcb)
597 	rpcb_session_t *rs;
598 	rpcb_xact_t *rx;
599 	ifs_rpcbpxy_t *ifsrpcb;
600 {
601 	rpcb_xact_t *rxp;
602 
603 	rxp = ippr_rpcb_lookup(rs, rx->rx_xid);
604 	if (rxp != NULL) {
605                 ++rxp->rx_ref;
606 		return(0);
607         }
608 
609 	if (ifsrpcb->rpcbcnt == RPCB_MAXREQS)
610 		return(-1);
611 
612 	KMALLOC(rxp, rpcb_xact_t *);
613 	if (rxp == NULL)
614 		return(-1);
615 
616 	bcopy((char *)rx, (char *)rxp, sizeof(*rx));
617 
618 	if (rs->rs_rxlist != NULL)
619 		rs->rs_rxlist->rx_pnext = &rxp->rx_next;
620 
621 	rxp->rx_pnext = &rs->rs_rxlist;
622 	rxp->rx_next = rs->rs_rxlist;
623 	rs->rs_rxlist = rxp;
624 
625 	rxp->rx_ref = 1;
626 
627 	++ifsrpcb->rpcbcnt;
628 
629 	return(0);
630 }
631 
632 /* --------------------------------------------------------------------	*/
633 /* Function:	ippr_rpcb_xdrrpcb					*/
634 /* Returns:	int -- -1 == failure to properly decode the request	*/
635 /*			0 == rpcb successfully decoded			*/
636 /* Parameters:	rs(I)	- pointer to RPCB session structure		*/
637 /*		p(I)	- pointer to location within session buffer	*/
638 /*		rpcb(O)	- pointer to rpcb (xdr type) structure		*/
639 /*									*/
640 /* Decode a XDR encoded rpcb structure and record its contents in rpcb  */
641 /* within only the context of TCP/UDP over IP networks.			*/
642 /* --------------------------------------------------------------------	*/
643 static int
644 ippr_rpcb_xdrrpcb(rm, p, ra)
645 	rpc_msg_t *rm;
646 	u_32_t *p;
647 	rpcb_args_t *ra;
648 {
649 	if (!RPCB_BUF_GEQ(rm, p, 20))
650 		return(-1);
651 
652 	/* Bypass target program & version. */
653 	p += 2;
654 
655 	/* Decode r_netid.  Must be "tcp" or "udp". */
656 	if (ippr_rpcb_getproto(rm, &ra->ra_netid, &p) != 0)
657 		return(-1);
658 
659 	/* Decode r_maddr. */
660 	if (ippr_rpcb_getuaddr(rm, &ra->ra_maddr, &p) != 0)
661 		return(-1);
662 
663 	/* Advance to r_owner and make sure it's empty. */
664 	if (!RPCB_BUF_EQ(rm, p, 4) || (B(p) != 0))
665 		return(-1);
666 
667 	return(0);
668 }
669 
670 /* --------------------------------------------------------------------	*/
671 /* Function:	ippr_rpcb_getuaddr					*/
672 /* Returns:	int -- -1 == illegal string,				*/
673 /*			0 == string parsed; contents recorded		*/
674 /* Parameters:	rm(I)	- pointer to RPC message structure		*/
675 /*		xu(I)	- pointer to universal address structure	*/
676 /*		p(IO)	- pointer to location within message buffer	*/
677 /*									*/
678 /* Decode the IP address / port at p and record them in xu.		*/
679 /* --------------------------------------------------------------------	*/
680 static int
681 ippr_rpcb_getuaddr(rm, xu, p)
682 	rpc_msg_t *rm;
683 	xdr_uaddr_t *xu;
684 	u_32_t **p;
685 {
686 	char *c, *i, *b, *pp;
687 	u_int d, dd, l, t;
688 	char uastr[24];
689 
690 	/* Test for string length. */
691 	if (!RPCB_BUF_GEQ(rm, *p, 4))
692 		return(-1);
693 
694 	xu->xu_xslen = (*p)++;
695 	xu->xu_xsstr = (char *)*p;
696 
697 	/* Length check */
698 	l = B(xu->xu_xslen);
699 	if (l < 11 || l > 23 || !RPCB_BUF_GEQ(rm, *p, XDRALIGN(l)))
700 		return(-1);
701 
702 	/* Advance p */
703 	*(char **)p += XDRALIGN(l);
704 
705 	/* Copy string to local buffer & terminate C style */
706 	bcopy(xu->xu_xsstr, uastr, l);
707 	uastr[l] = '\0';
708 
709 	i = (char *)&xu->xu_ip;
710 	pp = (char *)&xu->xu_port;
711 
712 	/*
713 	 * Expected format: a.b.c.d.e.f where [a-d] correspond to bytes of
714 	 * an IP address and [ef] are the bytes of a L4 port.
715 	 */
716 	if (!(ISDIGIT(uastr[0]) && ISDIGIT(uastr[l-1])))
717 		return(-1);
718 	b = uastr;
719 	for (c = &uastr[1], d = 0, dd = 0; c < &uastr[l-1]; c++) {
720 		if (ISDIGIT(*c)) {
721 			dd = 0;
722 			continue;
723 		}
724 		if (*c == '.') {
725 			if (dd != 0)
726 				return(-1);
727 
728 			/* Check for ASCII byte. */
729 			*c = '\0';
730 			t = ippr_rpcb_atoi(b);
731 			if (t > 255)
732 				return(-1);
733 
734 			/* Aim b at beginning of the next byte. */
735 			b = c + 1;
736 
737 			/* Switch off IP addr vs port parsing. */
738 			if (d < 4)
739 				i[d++] = t & 0xff;
740 			else
741 				pp[d++ - 4] = t & 0xff;
742 
743 			dd = 1;
744 			continue;
745 		}
746 		return(-1);
747 	}
748 	if (d != 5) /* String must contain exactly 5 periods. */
749 		return(-1);
750 
751 	/* Handle the last byte (port low byte) */
752 	t = ippr_rpcb_atoi(b);
753 	if (t > 255)
754 		return(-1);
755 	pp[d - 4] = t & 0xff;
756 
757 	return(0);
758 }
759 
760 /* --------------------------------------------------------------------	*/
761 /* Function:	ippr_rpcb_atoi (XXX should be generic for all proxies)	*/
762 /* Returns:	int -- integer representation of supplied string	*/
763 /* Parameters:	ptr(I)	- input string					*/
764 /*									*/
765 /* Simple version of atoi(3) ripped from ip_rcmd_pxy.c.			*/
766 /* --------------------------------------------------------------------	*/
767 static u_int
768 ippr_rpcb_atoi(ptr)
769 	char *ptr;
770 {
771 	register char *s = ptr, c;
772 	register u_int i = 0;
773 
774 	while (((c = *s++) != '\0') && ISDIGIT(c)) {
775 		i *= 10;
776 		i += c - '0';
777 	}
778 	return i;
779 }
780 
781 /* --------------------------------------------------------------------	*/
782 /* Function:	ippr_rpcb_modreq					*/
783 /* Returns:	int -- change in datagram length			*/
784 /*			APR_ERR(2) - critical failure			*/
785 /* Parameters:	fin(I)	- pointer to packet information			*/
786 /*		nat(I)	- pointer to NAT session			*/
787 /*		rm(I)	- pointer to RPC message structure		*/
788 /*		m(I)	- pointer to mbuf chain				*/
789 /*		off(I)	- current offset within mbuf chain		*/
790 /*									*/
791 /* When external and internal addresses differ, we rewrite the former	*/
792 /* with the latter.  (This is exclusive to protocol versions 3 & 4).	*/
793 /* --------------------------------------------------------------------	*/
794 static int
795 ippr_rpcb_modreq(fin, nat, rm, m, off)
796 	fr_info_t *fin;
797 	nat_t *nat;
798 	rpc_msg_t *rm;
799 	mb_t *m;
800 	u_int off;
801 {
802 	u_int len, xlen, pos, bogo;
803 	rpcb_args_t *ra;
804 	char uaddr[24];
805 	udphdr_t *udp;
806 	char *i, *p;
807 	int diff;
808 
809 	ra = &rm->rm_call.rc_rpcbargs;
810 	i = (char *)&nat->nat_inip.s_addr;
811 	p = (char *)&nat->nat_inport;
812 
813 	/* Form new string. */
814 	bzero(uaddr, sizeof(uaddr)); /* Just in case we need padding. */
815 #if defined(SNPRINTF) && defined(_KERNEL)
816 	(void) SNPRINTF(uaddr, sizeof(uaddr),
817 #else
818 	(void) sprintf(uaddr,
819 #endif
820 		       "%u.%u.%u.%u.%u.%u", i[0] & 0xff, i[1] & 0xff,
821 		       i[2] & 0xff, i[3] & 0xff, p[0] & 0xff, p[1] & 0xff);
822 	len = strlen(uaddr);
823 	xlen = XDRALIGN(len);
824 
825 	/* Determine mbuf offset to start writing to. */
826 	pos = (char *)ra->ra_maddr.xu_xslen - rm->rm_msgbuf;
827 	off += pos;
828 
829 	/* Write new string length. */
830 	bogo = htonl(len);
831 	COPYBACK(m, off, 4, (caddr_t)&bogo);
832 	off += 4;
833 
834 	/* Write new string. */
835 	COPYBACK(m, off, xlen, uaddr);
836 	off += xlen;
837 
838 	/* Write in zero r_owner. */
839 	bogo = 0;
840 	COPYBACK(m, off, 4, (caddr_t)&bogo);
841 
842 	/* Determine difference in data lengths. */
843 	diff = xlen - XDRALIGN(B(ra->ra_maddr.xu_xslen));
844 
845 	/*
846 	 * If our new string has a different length, make necessary
847 	 * adjustments.
848 	 */
849 	if (diff != 0) {
850 		udp = fin->fin_dp;
851 		udp->uh_ulen = htons(ntohs(udp->uh_ulen) + diff);
852 		fin->fin_ip->ip_len += diff;
853 		fin->fin_dlen += diff;
854 		fin->fin_plen += diff;
855 		/* XXX Storage lengths. */
856 	}
857 
858 	return(diff);
859 }
860 
861 /* --------------------------------------------------------------------	*/
862 /* Function:	ippr_rpcb_decoderep					*/
863 /* Returns:	int - -1 == bad request or critical failure,		*/
864 /*		       0 == valid, negative reply			*/
865 /*		       1 == vaddlid, positive reply; needs no changes	*/
866 /* Parameters:	fin(I)	- pointer to packet information			*/
867 /*		nat(I)	- pointer to NAT session structure		*/
868 /*		rs(I)	- pointer to RPCB session structure		*/
869 /*		rm(I)	- pointer to RPC message structure		*/
870 /*		rxp(O)	- pointer to RPCB transaction structure		*/
871 /*									*/
872 /* Take a presumed RPCB reply, extract the XID, search for the original */
873 /* request information, and determine whether the request was accepted	*/
874 /* or rejected.  With a valid accepted reply, go ahead and create NAT	*/
875 /* and state entries, and finish up by rewriting the packet as 		*/
876 /* required.								*/
877 /*									*/
878 /* WARNING:  It's the responsibility of the caller to make sure there	*/
879 /* is enough room in rs_buf for the basic RPC message "preamble".	*/
880 /* --------------------------------------------------------------------	*/
881 static int
882 ippr_rpcb_decoderep(fin, nat, rs, rm, rxp, ifsrpcb)
883 	fr_info_t *fin;
884 	nat_t *nat;
885 	rpcb_session_t *rs;
886 	rpc_msg_t *rm;
887 	rpcb_xact_t **rxp;
888 	ifs_rpcbpxy_t *ifsrpcb;
889 {
890 	rpcb_listp_t *rl;
891 	rpcb_entry_t *re;
892 	rpcb_xact_t *rx;
893 	u_32_t xdr, *p;
894 	rpc_resp_t *rr;
895 	int rv, cnt;
896 
897 	p = (u_32_t *)rm->rm_msgbuf;
898 
899 	bzero((char *)&rx, sizeof(rx));
900 	rr = &rm->rm_resp;
901 
902 	rm->rm_xid = p;
903 	xdr = B(p++);		/* Record this message's XID. */
904 
905 	/* Lookup XID */
906         MUTEX_ENTER(&rs->rs_rxlock);
907 	if ((rx = ippr_rpcb_lookup(rs, xdr)) == NULL) {
908                 MUTEX_EXIT(&rs->rs_rxlock);
909 		return(-1);
910         }
911         ++rx->rx_ref;        /* per thread reference */
912         MUTEX_EXIT(&rs->rs_rxlock);
913 
914 	*rxp = rx;
915 
916 	/* Test call vs reply */
917 	if (B(p++) != RPCB_REPLY)
918 		return(-1);
919 
920 	/* Test reply_stat */
921 	switch(B(p++))
922 	{
923 	case RPCB_MSG_DENIED:
924 		return(0);
925 	case RPCB_MSG_ACCEPTED:
926 		break;
927 	default:
928 		return(-1);
929 	}
930 
931 	/* Bypass RPC authentication stuff. */
932 	if (ippr_rpcb_skipauth(rm, &rr->rr_authverf, &p) != 0)
933 		return(-1);
934 
935 	/* Test accept status */
936 	if (!RPCB_BUF_GEQ(rm, p, 4))
937 		return(-1);
938 	if (B(p++) != 0)
939 		return(0);
940 
941 	/* Parse out the expected reply */
942 	switch(rx->rx_type)
943 	{
944 	case RPCB_RES_PMAP:
945 		/* There must be only one 4 byte argument. */
946 		if (!RPCB_BUF_EQ(rm, p, 4))
947 			return(-1);
948 
949 		rr->rr_v2 = p;
950 		xdr = B(rr->rr_v2);
951 
952 		/* Reply w/ a 0 port indicates service isn't registered */
953 		if (xdr == 0)
954 			return(0);
955 
956 		/* Is the value sane? */
957 		if (xdr > 65535)
958 			return(-1);
959 
960 		/* Create NAT & state table entries. */
961 		if (ippr_rpcb_getnat(fin, nat, rx->rx_proto, (u_int)xdr, ifsrpcb) != 0)
962 			return(-1);
963 		break;
964 	case RPCB_RES_STRING:
965 		/* Expecting a XDR string; need 4 bytes for length */
966 		if (!RPCB_BUF_GEQ(rm, p, 4))
967 			return(-1);
968 
969 		rr->rr_v3.xu_str.xs_len = p++;
970 		rr->rr_v3.xu_str.xs_str = (char *)p;
971 
972 		xdr = B(rr->rr_v3.xu_xslen);
973 
974 		/* A null string indicates an unregistered service */
975 		if ((xdr == 0) && RPCB_BUF_EQ(rm, p, 0))
976 			return(0);
977 
978 		/* Decode the target IP address / port. */
979 		if (ippr_rpcb_getuaddr(rm, &rr->rr_v3, &p) != 0)
980 			return(-1);
981 
982 		/* Validate the IP address and port contained. */
983 		if (nat->nat_inip.s_addr != rr->rr_v3.xu_ip)
984 			return(-1);
985 
986 		/* Create NAT & state table entries. */
987 		if (ippr_rpcb_getnat(fin, nat, rx->rx_proto,
988 				     (u_int)rr->rr_v3.xu_port, ifsrpcb) != 0)
989 			return(-1);
990 		break;
991 	case RPCB_RES_LIST:
992 		if (!RPCB_BUF_GEQ(rm, p, 4))
993 			return(-1);
994 		/* rpcb_entry_list_ptr */
995 		switch(B(p))
996 		{
997 		case 0:
998 			return(0);
999 		case 1:
1000 			break;
1001 		default:
1002 			return(-1);
1003 		}
1004 		rl = &rr->rr_v4;
1005 		rl->rl_list = p++;
1006 		cnt = 0;
1007 
1008 		for(;;) {
1009 			re = &rl->rl_entries[rl->rl_cnt];
1010 			if (ippr_rpcb_getuaddr(rm, &re->re_maddr, &p) != 0)
1011 				return(-1);
1012 			if (ippr_rpcb_getproto(rm, &re->re_netid, &p) != 0)
1013 				return(-1);
1014 			/* re_semantics & re_pfamily length */
1015 			if (!RPCB_BUF_GEQ(rm, p, 12))
1016 				return(-1);
1017 			p++; /* Skipping re_semantics. */
1018 			xdr = B(p++);
1019 			if ((xdr != 4) || strncmp((char *)p, "inet", 4))
1020 				return(-1);
1021 			p++;
1022 			if (ippr_rpcb_getproto(rm, &re->re_proto, &p) != 0)
1023 				return(-1);
1024 			if (!RPCB_BUF_GEQ(rm, p, 4))
1025 				return(-1);
1026 			re->re_more = p;
1027 			if (B(re->re_more) > 1) /* 0,1 only legal values */
1028 				return(-1);
1029 			++rl->rl_cnt;
1030 			++cnt;
1031 			if (B(re->re_more) == 0)
1032 				break;
1033 			/* Replies in  max out at 2; TCP and/or UDP */
1034 			if (cnt > 2)
1035 				return(-1);
1036 			p++;
1037 		}
1038 
1039 		for(rl->rl_cnt = 0; rl->rl_cnt < cnt; rl->rl_cnt++) {
1040 			re = &rl->rl_entries[rl->rl_cnt];
1041 			rv = ippr_rpcb_getnat(fin, nat,
1042 			                      re->re_proto.xp_proto,
1043 				              (u_int)re->re_maddr.xu_port,
1044 					      ifsrpcb);
1045 			if (rv != 0)
1046 				return(-1);
1047 		}
1048 		break;
1049 	default:
1050 		/*CONSTANTCONDITION*/
1051 		IPF_PANIC(1, ("illegal rx_type %d", rx->rx_type));
1052 	}
1053 
1054 	return(1);
1055 }
1056 
1057 /* --------------------------------------------------------------------	*/
1058 /* Function:	ippr_rpcb_lookup					*/
1059 /* Returns:	rpcb_xact_t * 	- NULL == no matching record,		*/
1060 /*				  else pointer to relevant entry	*/
1061 /* Parameters:	rs(I)	- pointer to RPCB session			*/
1062 /*		xid(I)	- XID to look for				*/
1063 /* --------------------------------------------------------------------	*/
1064 static rpcb_xact_t *
1065 ippr_rpcb_lookup(rs, xid)
1066 	rpcb_session_t *rs;
1067 	u_32_t xid;
1068 {
1069 	rpcb_xact_t *rx;
1070 
1071 	if (rs->rs_rxlist == NULL)
1072 		return(NULL);
1073 
1074 	for (rx = rs->rs_rxlist; rx != NULL; rx = rx->rx_next)
1075 		if (rx->rx_xid == xid)
1076 			break;
1077 
1078 	return(rx);
1079 }
1080 
1081 /* --------------------------------------------------------------------	*/
1082 /* Function:	ippr_rpcb_deref					        */
1083 /* Returns:	(void)							*/
1084 /* Parameters:	rs(I)	- pointer to RPCB session			*/
1085 /*		rx(I)	- pointer to RPC transaction struct to remove	*/
1086 /*              force(I) - indicates to delete entry regardless of      */
1087 /*                         reference count                              */
1088 /* Locking:	rs->rs_rxlock must be held write only			*/
1089 /*									*/
1090 /* Free the RPCB transaction record rx from the chain of entries.	*/
1091 /* --------------------------------------------------------------------	*/
1092 static void
1093 ippr_rpcb_deref(rs, rx, ifsrpcb)
1094 	rpcb_session_t *rs;
1095 	rpcb_xact_t *rx;
1096 	ifs_rpcbpxy_t *ifsrpcb;
1097 {
1098 	rs = rs;	/* LINT */
1099 
1100 	if (rx == NULL)
1101 		return;
1102 
1103 	if (--rx->rx_ref != 0)
1104 		return;
1105 
1106 	if (rx->rx_next != NULL)
1107 		rx->rx_next->rx_pnext = rx->rx_pnext;
1108 
1109 	*rx->rx_pnext = rx->rx_next;
1110 
1111 	KFREE(rx);
1112 
1113 	--ifsrpcb->rpcbcnt;
1114 }
1115 
1116 /* --------------------------------------------------------------------	*/
1117 /* Function:	ippr_rpcb_getproto					*/
1118 /* Returns:	int - -1 == illegal protocol/netid,			*/
1119 /*		       0 == legal protocol/netid			*/
1120 /* Parameters:	rm(I)	- pointer to RPC message structure		*/
1121 /*		xp(I)	- pointer to netid structure			*/
1122 /*		p(IO)	- pointer to location within packet buffer	*/
1123 /* 									*/
1124 /* Decode netid/proto stored at p and record its numeric value.	 	*/
1125 /* --------------------------------------------------------------------	*/
1126 static int
1127 ippr_rpcb_getproto(rm, xp, p)
1128 	rpc_msg_t *rm;
1129 	xdr_proto_t *xp;
1130 	u_32_t **p;
1131 {
1132 	u_int len;
1133 
1134 	/* Must have 4 bytes for length & 4 bytes for "tcp" or "udp". */
1135 	if (!RPCB_BUF_GEQ(rm, p, 8))
1136 		return(-1);
1137 
1138 	xp->xp_xslen = (*p)++;
1139 	xp->xp_xsstr = (char *)*p;
1140 
1141 	/* Test the string length. */
1142 	len = B(xp->xp_xslen);
1143 	if (len != 3)
1144 	 	return(-1);
1145 
1146 	/* Test the actual string & record the protocol accordingly. */
1147 	if (!strncmp((char *)xp->xp_xsstr, "tcp\0", 4))
1148 		xp->xp_proto = IPPROTO_TCP;
1149 	else if (!strncmp((char *)xp->xp_xsstr, "udp\0", 4))
1150 		xp->xp_proto = IPPROTO_UDP;
1151 	else {
1152 		return(-1);
1153 	}
1154 
1155 	/* Advance past the string. */
1156 	(*p)++;
1157 
1158 	return(0);
1159 }
1160 
1161 /* --------------------------------------------------------------------	*/
1162 /* Function:	ippr_rpcb_getnat					*/
1163 /* Returns:	int -- -1 == failed to create table entries,		*/
1164 /*			0 == success					*/
1165 /* Parameters:	fin(I)	- pointer to packet information			*/
1166 /*		nat(I)	- pointer to NAT table entry			*/
1167 /*		proto(I) - transport protocol for new entries		*/
1168 /*		port(I)	- new port to use w/ wildcard table entries	*/
1169 /*									*/
1170 /* Create state and NAT entries to handle an anticipated connection	*/
1171 /* attempt between RPC client and server.				*/
1172 /* --------------------------------------------------------------------	*/
1173 static int
1174 ippr_rpcb_getnat(fin, nat, proto, port, ifsrpcb)
1175 	fr_info_t *fin;
1176 	nat_t *nat;
1177 	u_int proto;
1178 	u_int port;
1179 	ifs_rpcbpxy_t *ifsrpcb;
1180 {
1181 	ipnat_t *ipn, ipnat;
1182 	tcphdr_t tcp;
1183 	ipstate_t *is;
1184 	fr_info_t fi;
1185 	nat_t *natl;
1186 	int nflags;
1187 	ipf_stack_t *ifs = fin->fin_ifs;
1188 
1189 	ipn = nat->nat_ptr;
1190 
1191 	/* Generate dummy fr_info */
1192 	bcopy((char *)fin, (char *)&fi, sizeof(fi));
1193 	fi.fin_out = 0;
1194 	fi.fin_src = fin->fin_dst;
1195 	fi.fin_dst = nat->nat_outip;
1196 	fi.fin_p = proto;
1197 	fi.fin_sport = 0;
1198 	fi.fin_dport = port & 0xffff;
1199 	fi.fin_flx |= FI_IGNORE;
1200 
1201 	bzero((char *)&tcp, sizeof(tcp));
1202 	tcp.th_dport = htons(port);
1203 
1204 	if (proto == IPPROTO_TCP) {
1205 		tcp.th_win = htons(8192);
1206 		TCP_OFF_A(&tcp, sizeof(tcphdr_t) >> 2);
1207 		fi.fin_dlen = sizeof(tcphdr_t);
1208 		tcp.th_flags = TH_SYN;
1209 		nflags = NAT_TCP;
1210 	} else {
1211 		fi.fin_dlen = sizeof(udphdr_t);
1212 		nflags = NAT_UDP;
1213 	}
1214 
1215 	nflags |= SI_W_SPORT|NAT_SEARCH;
1216 	fi.fin_dp = &tcp;
1217 	fi.fin_plen = fi.fin_hlen + fi.fin_dlen;
1218 
1219 	/*
1220 	 * Search for existing NAT & state entries.  Pay close attention to
1221 	 * mutexes / locks grabbed from lookup routines, as not doing so could
1222 	 * lead to bad things.
1223 	 *
1224 	 * If successful, fr_stlookup returns with ipf_state locked.  We have
1225 	 * no use for this lock, so simply unlock it if necessary.
1226 	 */
1227 	is = fr_stlookup(&fi, &tcp, NULL);
1228 	if (is != NULL)
1229 		RWLOCK_EXIT(&ifs->ifs_ipf_state);
1230 
1231 	RWLOCK_EXIT(&ifs->ifs_ipf_nat);
1232 
1233 	WRITE_ENTER(&ifs->ifs_ipf_nat);
1234 	natl = nat_inlookup(&fi, nflags, proto, fi.fin_src, fi.fin_dst);
1235 
1236 	if ((natl != NULL) && (is != NULL)) {
1237 		MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat);
1238 		return(0);
1239 	}
1240 
1241 	/* Slightly modify the following structures for actual use in creating
1242 	 * NAT and/or state entries.  We're primarily concerned with stripping
1243 	 * flags that may be detrimental to the creation process or simply
1244 	 * shouldn't be associated with a table entry.
1245 	 */
1246 	fi.fin_fr = &ifsrpcb->rpcbfr;
1247 	fi.fin_flx &= ~FI_IGNORE;
1248 	nflags &= ~NAT_SEARCH;
1249 
1250 	if (natl == NULL) {
1251 		/* XXX Since we're just copying the original ipn contents
1252 		 * back, would we be better off just sending a pointer to
1253 		 * the 'temp' copy off to nat_new instead?
1254 		 */
1255 		/* Generate template/bogus NAT rule. */
1256 		bcopy((char *)ipn, (char *)&ipnat, sizeof(ipnat));
1257 		ipn->in_flags = nflags & IPN_TCPUDP;
1258 		ipn->in_apr = NULL;
1259 		ipn->in_p = proto;
1260 		ipn->in_pmin = htons(fi.fin_dport);
1261 		ipn->in_pmax = htons(fi.fin_dport);
1262 		ipn->in_pnext = htons(fi.fin_dport);
1263 		ipn->in_space = 1;
1264 		ipn->in_ippip = 1;
1265 		if (ipn->in_flags & IPN_FILTER) {
1266 			ipn->in_scmp = 0;
1267 			ipn->in_dcmp = 0;
1268 		}
1269 		*ipn->in_plabel = '\0';
1270 
1271 		/* Create NAT entry.  return NULL if this fails. */
1272 		natl = nat_new(&fi, ipn, NULL, nflags|SI_CLONE|NAT_SLAVE,
1273 			       NAT_INBOUND);
1274 
1275 		bcopy((char *)&ipnat, (char *)ipn, sizeof(ipnat));
1276 
1277 		if (natl == NULL) {
1278 			MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat);
1279 			return(-1);
1280 		}
1281 
1282 		ipn->in_use++;
1283 		(void) nat_proto(&fi, natl, nflags);
1284 		nat_update(&fi, natl, natl->nat_ptr);
1285 	}
1286 	MUTEX_DOWNGRADE(&ifs->ifs_ipf_nat);
1287 
1288 	if (is == NULL) {
1289 		/* Create state entry.  Return NULL if this fails. */
1290 		fi.fin_dst = nat->nat_inip;
1291 		fi.fin_nat = (void *)natl;
1292 		fi.fin_flx |= FI_NATED;
1293 		fi.fin_flx &= ~FI_STATE;
1294 		nflags &= NAT_TCPUDP;
1295 		nflags |= SI_W_SPORT|SI_CLONE;
1296 
1297 		is = fr_addstate(&fi, NULL, nflags);
1298 		if (is == NULL) {
1299 			/*
1300 			 * XXX nat_delete is private to ip_nat.c.  Should
1301 			 * check w/ Darren about this one.
1302 			 *
1303 			 * nat_delete(natl, NL_EXPIRE, ifs);
1304 			 */
1305 			return(-1);
1306 		}
1307 		if (fi.fin_state != NULL)
1308 			fr_statederef(&fi, (ipstate_t **)&fi.fin_state, ifs);
1309 	}
1310 
1311 	return(0);
1312 }
1313 
1314 /* --------------------------------------------------------------------	*/
1315 /* Function:	ippr_rpcb_modv3						*/
1316 /* Returns:	int -- change in packet length				*/
1317 /* Parameters:	fin(I)	- pointer to packet information			*/
1318 /*		nat(I)	- pointer to NAT session			*/
1319 /*		rm(I)	- pointer to RPC message structure		*/
1320 /*		m(I)	- pointer to mbuf chain				*/
1321 /*		off(I)	- offset within mbuf chain			*/
1322 /*									*/
1323 /* Write a new universal address string to this packet, adjusting	*/
1324 /* lengths as necessary.						*/
1325 /* --------------------------------------------------------------------	*/
1326 static int
1327 ippr_rpcb_modv3(fin, nat, rm, m, off)
1328 	fr_info_t *fin;
1329 	nat_t *nat;
1330 	rpc_msg_t *rm;
1331 	mb_t *m;
1332 	u_int off;
1333 {
1334 	u_int len, xlen, pos, bogo;
1335 	rpc_resp_t *rr;
1336 	char uaddr[24];
1337 	char *i, *p;
1338 	int diff;
1339 
1340 	rr = &rm->rm_resp;
1341 	i = (char *)&nat->nat_outip.s_addr;
1342 	p = (char *)&rr->rr_v3.xu_port;
1343 
1344 	/* Form new string. */
1345 	bzero(uaddr, sizeof(uaddr)); /* Just in case we need padding. */
1346 #if defined(SNPRINTF) && defined(_KERNEL)
1347 	(void) SNPRINTF(uaddr, sizeof(uaddr),
1348 #else
1349 	(void) sprintf(uaddr,
1350 #endif
1351 		       "%u.%u.%u.%u.%u.%u", i[0] & 0xff, i[1] & 0xff,
1352 		       i[2] & 0xff, i[3] & 0xff, p[0] & 0xff, p[1] & 0xff);
1353 	len = strlen(uaddr);
1354 	xlen = XDRALIGN(len);
1355 
1356 	/* Determine mbuf offset to write to. */
1357 	pos = (char *)rr->rr_v3.xu_xslen - rm->rm_msgbuf;
1358 	off += pos;
1359 
1360 	/* Write new string length. */
1361 	bogo = htonl(len);
1362 	COPYBACK(m, off, 4, (caddr_t)&bogo);
1363 	off += 4;
1364 
1365 	/* Write new string. */
1366 	COPYBACK(m, off, xlen, uaddr);
1367 
1368 	/* Determine difference in data lengths. */
1369 	diff = xlen - XDRALIGN(B(rr->rr_v3.xu_xslen));
1370 
1371 	/*
1372 	 * If our new string has a different length, make necessary
1373 	 * adjustments.
1374 	 */
1375 	if (diff != 0)
1376 		ippr_rpcb_fixlen(fin, diff);
1377 
1378 	return(diff);
1379 }
1380 
1381 /* --------------------------------------------------------------------	*/
1382 /* Function:	ippr_rpcb_modv4						*/
1383 /* Returns:	int -- change in packet length				*/
1384 /* Parameters:	fin(I)	- pointer to packet information			*/
1385 /*		nat(I)	- pointer to NAT session			*/
1386 /*		rm(I)	- pointer to RPC message structure		*/
1387 /*		m(I)	- pointer to mbuf chain				*/
1388 /*		off(I)	- offset within mbuf chain			*/
1389 /*									*/
1390 /* Write new rpcb_entry list, adjusting	lengths as necessary.		*/
1391 /* --------------------------------------------------------------------	*/
1392 static int
1393 ippr_rpcb_modv4(fin, nat, rm, m, off)
1394 	fr_info_t *fin;
1395 	nat_t *nat;
1396 	rpc_msg_t *rm;
1397 	mb_t *m;
1398 	u_int off;
1399 {
1400 	u_int len, xlen, pos, bogo;
1401 	rpcb_listp_t *rl;
1402 	rpcb_entry_t *re;
1403 	rpc_resp_t *rr;
1404 	char uaddr[24];
1405 	int diff, cnt;
1406 	char *i, *p;
1407 
1408 	diff = 0;
1409 	rr = &rm->rm_resp;
1410 	rl = &rr->rr_v4;
1411 
1412 	i = (char *)&nat->nat_outip.s_addr;
1413 
1414 	/* Determine mbuf offset to write to. */
1415 	re = &rl->rl_entries[0];
1416 	pos = (char *)re->re_maddr.xu_xslen - rm->rm_msgbuf;
1417 	off += pos;
1418 
1419 	for (cnt = 0; cnt < rl->rl_cnt; cnt++) {
1420 		re = &rl->rl_entries[cnt];
1421 		p = (char *)&re->re_maddr.xu_port;
1422 
1423 		/* Form new string. */
1424 		bzero(uaddr, sizeof(uaddr)); /* Just in case we need
1425 						padding. */
1426 #if defined(SNPRINTF) && defined(_KERNEL)
1427 		(void) SNPRINTF(uaddr, sizeof(uaddr),
1428 #else
1429 		(void) sprintf(uaddr,
1430 #endif
1431 			       "%u.%u.%u.%u.%u.%u", i[0] & 0xff,
1432 			       i[1] & 0xff, i[2] & 0xff, i[3] & 0xff,
1433 			       p[0] & 0xff, p[1] & 0xff);
1434 		len = strlen(uaddr);
1435 		xlen = XDRALIGN(len);
1436 
1437 		/* Write new string length. */
1438 		bogo = htonl(len);
1439 		COPYBACK(m, off, 4, (caddr_t)&bogo);
1440 		off += 4;
1441 
1442 		/* Write new string. */
1443 		COPYBACK(m, off, xlen, uaddr);
1444 		off += xlen;
1445 
1446 		/* Record any change in length. */
1447 		diff += xlen - XDRALIGN(B(re->re_maddr.xu_xslen));
1448 
1449 		/* If the length changed, copy back the rest of this entry. */
1450 		len = ((char *)re->re_more + 4) -
1451 		       (char *)re->re_netid.xp_xslen;
1452 		if (diff != 0) {
1453 			COPYBACK(m, off, len, (caddr_t)re->re_netid.xp_xslen);
1454 		}
1455 		off += len;
1456 	}
1457 
1458 	/*
1459 	 * If our new string has a different length, make necessary
1460 	 * adjustments.
1461 	 */
1462 	if (diff != 0)
1463 		ippr_rpcb_fixlen(fin, diff);
1464 
1465 	return(diff);
1466 }
1467 
1468 
1469 /* --------------------------------------------------------------------	*/
1470 /* Function:    ippr_rpcb_fixlen                                        */
1471 /* Returns:     (void)                                                  */
1472 /* Parameters:  fin(I)  - pointer to packet information                 */
1473 /*              len(I)  - change in packet length                       */
1474 /*                                                                      */
1475 /* Adjust various packet related lengths held in structure and packet   */
1476 /* header fields.                                                       */
1477 /* --------------------------------------------------------------------	*/
1478 static void
1479 ippr_rpcb_fixlen(fin, len)
1480         fr_info_t *fin;
1481         int len;
1482 {
1483         udphdr_t *udp;
1484 
1485         udp = fin->fin_dp;
1486         udp->uh_ulen = htons(ntohs(udp->uh_ulen) + len);
1487         fin->fin_ip->ip_len += len;
1488         fin->fin_dlen += len;
1489         fin->fin_plen += len;
1490 }
1491 
1492 #undef B
1493