xref: /freebsd/sbin/ipfw/nat.c (revision 586f63035fbe5e45cfc971037fd76375661ece26)
1 /*
2  * Copyright (c) 2002-2003 Luigi Rizzo
3  * Copyright (c) 1996 Alex Nash, Paul Traina, Poul-Henning Kamp
4  * Copyright (c) 1994 Ugen J.S.Antsilevich
5  *
6  * Idea and grammar partially left from:
7  * Copyright (c) 1993 Daniel Boulet
8  *
9  * Redistribution and use in source forms, with and without modification,
10  * are permitted provided that this entire comment appears intact.
11  *
12  * Redistribution in binary form may occur without any restrictions.
13  * Obviously, it would be nice if you gave credit where credit is due
14  * but requiring it would be too onerous.
15  *
16  * This software is provided ``AS IS'' without any warranties of any kind.
17  *
18  * NEW command line interface for IP firewall facility
19  *
20  * $FreeBSD$
21  *
22  * In-kernel nat support
23  */
24 
25 #include <sys/types.h>
26 #include <sys/socket.h>
27 #include <sys/sysctl.h>
28 
29 #include "ipfw2.h"
30 
31 #include <ctype.h>
32 #include <err.h>
33 #include <netdb.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <sysexits.h>
38 
39 #define IPFW_INTERNAL	/* Access to protected structures in ip_fw.h. */
40 
41 #include <net/if.h>
42 #include <net/if_dl.h>
43 #include <net/route.h> /* def. of struct route */
44 #include <netinet/in.h>
45 #include <netinet/ip_fw.h>
46 #include <arpa/inet.h>
47 #include <alias.h>
48 
49 static struct _s_x nat_params[] = {
50 	{ "ip",			TOK_IP },
51 	{ "if",			TOK_IF },
52  	{ "log",		TOK_ALOG },
53  	{ "deny_in",		TOK_DENY_INC },
54  	{ "same_ports",		TOK_SAME_PORTS },
55  	{ "unreg_only",		TOK_UNREG_ONLY },
56 	{ "skip_global",	TOK_SKIP_GLOBAL },
57  	{ "reset",		TOK_RESET_ADDR },
58  	{ "reverse",		TOK_ALIAS_REV },
59  	{ "proxy_only",		TOK_PROXY_ONLY },
60 	{ "redirect_addr",	TOK_REDIR_ADDR },
61 	{ "redirect_port",	TOK_REDIR_PORT },
62 	{ "redirect_proto",	TOK_REDIR_PROTO },
63  	{ NULL, 0 }	/* terminator */
64 };
65 
66 
67 /*
68  * Search for interface with name "ifn", and fill n accordingly:
69  *
70  * n->ip	ip address of interface "ifn"
71  * n->if_name   copy of interface name "ifn"
72  */
73 static void
74 set_addr_dynamic(const char *ifn, struct cfg_nat *n)
75 {
76 	size_t needed;
77 	int mib[6];
78 	char *buf, *lim, *next;
79 	struct if_msghdr *ifm;
80 	struct ifa_msghdr *ifam;
81 	struct sockaddr_dl *sdl;
82 	struct sockaddr_in *sin;
83 	int ifIndex, ifMTU;
84 
85 	mib[0] = CTL_NET;
86 	mib[1] = PF_ROUTE;
87 	mib[2] = 0;
88 	mib[3] = AF_INET;
89 	mib[4] = NET_RT_IFLIST;
90 	mib[5] = 0;
91 /*
92  * Get interface data.
93  */
94 	if (sysctl(mib, 6, NULL, &needed, NULL, 0) == -1)
95 		err(1, "iflist-sysctl-estimate");
96 	buf = safe_calloc(1, needed);
97 	if (sysctl(mib, 6, buf, &needed, NULL, 0) == -1)
98 		err(1, "iflist-sysctl-get");
99 	lim = buf + needed;
100 /*
101  * Loop through interfaces until one with
102  * given name is found. This is done to
103  * find correct interface index for routing
104  * message processing.
105  */
106 	ifIndex	= 0;
107 	next = buf;
108 	while (next < lim) {
109 		ifm = (struct if_msghdr *)next;
110 		next += ifm->ifm_msglen;
111 		if (ifm->ifm_version != RTM_VERSION) {
112 			if (co.verbose)
113 				warnx("routing message version %d "
114 				    "not understood", ifm->ifm_version);
115 			continue;
116 		}
117 		if (ifm->ifm_type == RTM_IFINFO) {
118 			sdl = (struct sockaddr_dl *)(ifm + 1);
119 			if (strlen(ifn) == sdl->sdl_nlen &&
120 			    strncmp(ifn, sdl->sdl_data, sdl->sdl_nlen) == 0) {
121 				ifIndex = ifm->ifm_index;
122 				ifMTU = ifm->ifm_data.ifi_mtu;
123 				break;
124 			}
125 		}
126 	}
127 	if (!ifIndex)
128 		errx(1, "unknown interface name %s", ifn);
129 /*
130  * Get interface address.
131  */
132 	sin = NULL;
133 	while (next < lim) {
134 		ifam = (struct ifa_msghdr *)next;
135 		next += ifam->ifam_msglen;
136 		if (ifam->ifam_version != RTM_VERSION) {
137 			if (co.verbose)
138 				warnx("routing message version %d "
139 				    "not understood", ifam->ifam_version);
140 			continue;
141 		}
142 		if (ifam->ifam_type != RTM_NEWADDR)
143 			break;
144 		if (ifam->ifam_addrs & RTA_IFA) {
145 			int i;
146 			char *cp = (char *)(ifam + 1);
147 
148 			for (i = 1; i < RTA_IFA; i <<= 1) {
149 				if (ifam->ifam_addrs & i)
150 					cp += SA_SIZE((struct sockaddr *)cp);
151 			}
152 			if (((struct sockaddr *)cp)->sa_family == AF_INET) {
153 				sin = (struct sockaddr_in *)cp;
154 				break;
155 			}
156 		}
157 	}
158 	if (sin == NULL)
159 		errx(1, "%s: cannot get interface address", ifn);
160 
161 	n->ip = sin->sin_addr;
162 	strncpy(n->if_name, ifn, IF_NAMESIZE);
163 
164 	free(buf);
165 }
166 
167 /*
168  * XXX - The following functions, macros and definitions come from natd.c:
169  * it would be better to move them outside natd.c, in a file
170  * (redirect_support.[ch]?) shared by ipfw and natd, but for now i can live
171  * with it.
172  */
173 
174 /*
175  * Definition of a port range, and macros to deal with values.
176  * FORMAT:  HI 16-bits == first port in range, 0 == all ports.
177  *	  LO 16-bits == number of ports in range
178  * NOTES:   - Port values are not stored in network byte order.
179  */
180 
181 #define port_range u_long
182 
183 #define GETLOPORT(x)	((x) >> 0x10)
184 #define GETNUMPORTS(x)	((x) & 0x0000ffff)
185 #define GETHIPORT(x)	(GETLOPORT((x)) + GETNUMPORTS((x)))
186 
187 /* Set y to be the low-port value in port_range variable x. */
188 #define SETLOPORT(x,y)   ((x) = ((x) & 0x0000ffff) | ((y) << 0x10))
189 
190 /* Set y to be the number of ports in port_range variable x. */
191 #define SETNUMPORTS(x,y) ((x) = ((x) & 0xffff0000) | (y))
192 
193 static void
194 StrToAddr (const char* str, struct in_addr* addr)
195 {
196 	struct hostent* hp;
197 
198 	if (inet_aton (str, addr))
199 		return;
200 
201 	hp = gethostbyname (str);
202 	if (!hp)
203 		errx (1, "unknown host %s", str);
204 
205 	memcpy (addr, hp->h_addr, sizeof (struct in_addr));
206 }
207 
208 static int
209 StrToPortRange (const char* str, const char* proto, port_range *portRange)
210 {
211 	char*	   sep;
212 	struct servent*	sp;
213 	char*		end;
214 	u_short	 loPort;
215 	u_short	 hiPort;
216 
217 	/* First see if this is a service, return corresponding port if so. */
218 	sp = getservbyname (str,proto);
219 	if (sp) {
220 		SETLOPORT(*portRange, ntohs(sp->s_port));
221 		SETNUMPORTS(*portRange, 1);
222 		return 0;
223 	}
224 
225 	/* Not a service, see if it's a single port or port range. */
226 	sep = strchr (str, '-');
227 	if (sep == NULL) {
228 		SETLOPORT(*portRange, strtol(str, &end, 10));
229 		if (end != str) {
230 			/* Single port. */
231 			SETNUMPORTS(*portRange, 1);
232 			return 0;
233 		}
234 
235 		/* Error in port range field. */
236 		errx (EX_DATAERR, "%s/%s: unknown service", str, proto);
237 	}
238 
239 	/* Port range, get the values and sanity check. */
240 	sscanf (str, "%hu-%hu", &loPort, &hiPort);
241 	SETLOPORT(*portRange, loPort);
242 	SETNUMPORTS(*portRange, 0);	/* Error by default */
243 	if (loPort <= hiPort)
244 		SETNUMPORTS(*portRange, hiPort - loPort + 1);
245 
246 	if (GETNUMPORTS(*portRange) == 0)
247 		errx (EX_DATAERR, "invalid port range %s", str);
248 
249 	return 0;
250 }
251 
252 static int
253 StrToProto (const char* str)
254 {
255 	if (!strcmp (str, "tcp"))
256 		return IPPROTO_TCP;
257 
258 	if (!strcmp (str, "udp"))
259 		return IPPROTO_UDP;
260 
261 	if (!strcmp (str, "sctp"))
262 		return IPPROTO_SCTP;
263 	errx (EX_DATAERR, "unknown protocol %s. Expected sctp, tcp or udp", str);
264 }
265 
266 static int
267 StrToAddrAndPortRange (const char* str, struct in_addr* addr, char* proto,
268 			port_range *portRange)
269 {
270 	char*	ptr;
271 
272 	ptr = strchr (str, ':');
273 	if (!ptr)
274 		errx (EX_DATAERR, "%s is missing port number", str);
275 
276 	*ptr = '\0';
277 	++ptr;
278 
279 	StrToAddr (str, addr);
280 	return StrToPortRange (ptr, proto, portRange);
281 }
282 
283 /* End of stuff taken from natd.c. */
284 
285 /*
286  * The next 3 functions add support for the addr, port and proto redirect and
287  * their logic is loosely based on SetupAddressRedirect(), SetupPortRedirect()
288  * and SetupProtoRedirect() from natd.c.
289  *
290  * Every setup_* function fills at least one redirect entry
291  * (struct cfg_redir) and zero or more server pool entry (struct cfg_spool)
292  * in buf.
293  *
294  * The format of data in buf is:
295  *
296  *     cfg_nat    cfg_redir    cfg_spool    ......  cfg_spool
297  *
298  *    -------------------------------------        ------------
299  *   |          | .....X ... |          |         |           |  .....
300  *    ------------------------------------- ...... ------------
301  *                     ^
302  *                spool_cnt       n=0       ......   n=(X-1)
303  *
304  * len points to the amount of available space in buf
305  * space counts the memory consumed by every function
306  *
307  * XXX - Every function get all the argv params so it
308  * has to check, in optional parameters, that the next
309  * args is a valid option for the redir entry and not
310  * another token. Only redir_port and redir_proto are
311  * affected by this.
312  */
313 
314 static int
315 estimate_redir_addr(int *ac, char ***av)
316 {
317 	size_t space = sizeof(struct cfg_redir);
318 	char *sep = **av;
319 	u_int c = 0;
320 
321 	while ((sep = strchr(sep, ',')) != NULL) {
322 		c++;
323 		sep++;
324 	}
325 
326 	if (c > 0)
327 		c++;
328 
329 	space += c * sizeof(struct cfg_spool);
330 
331 	return (space);
332 }
333 
334 static int
335 setup_redir_addr(char *buf, int *ac, char ***av)
336 {
337 	struct cfg_redir *r;
338 	char *sep;
339 	size_t space;
340 
341 	r = (struct cfg_redir *)buf;
342 	r->mode = REDIR_ADDR;
343 	/* Skip cfg_redir at beginning of buf. */
344 	buf = &buf[sizeof(struct cfg_redir)];
345 	space = sizeof(struct cfg_redir);
346 
347 	/* Extract local address. */
348 	if (strchr(**av, ',') != NULL) {
349 		struct cfg_spool *spool;
350 
351 		/* Setup LSNAT server pool. */
352 		r->laddr.s_addr = INADDR_NONE;
353 		sep = strtok(**av, ",");
354 		while (sep != NULL) {
355 			spool = (struct cfg_spool *)buf;
356 			space += sizeof(struct cfg_spool);
357 			StrToAddr(sep, &spool->addr);
358 			spool->port = ~0;
359 			r->spool_cnt++;
360 			/* Point to the next possible cfg_spool. */
361 			buf = &buf[sizeof(struct cfg_spool)];
362 			sep = strtok(NULL, ",");
363 		}
364 	} else
365 		StrToAddr(**av, &r->laddr);
366 	(*av)++; (*ac)--;
367 
368 	/* Extract public address. */
369 	StrToAddr(**av, &r->paddr);
370 	(*av)++; (*ac)--;
371 
372 	return (space);
373 }
374 
375 static int
376 estimate_redir_port(int *ac, char ***av)
377 {
378 	size_t space = sizeof(struct cfg_redir);
379 	char *sep = **av;
380 	u_int c = 0;
381 
382 	while ((sep = strchr(sep, ',')) != NULL) {
383 		c++;
384 		sep++;
385 	}
386 
387 	if (c > 0)
388 		c++;
389 
390 	space += c * sizeof(struct cfg_spool);
391 
392 	return (space);
393 }
394 
395 static int
396 setup_redir_port(char *buf, int *ac, char ***av)
397 {
398 	struct cfg_redir *r;
399 	char *sep, *protoName, *lsnat = NULL;
400 	size_t space;
401 	u_short numLocalPorts;
402 	port_range portRange;
403 
404 	numLocalPorts = 0;
405 
406 	r = (struct cfg_redir *)buf;
407 	r->mode = REDIR_PORT;
408 	/* Skip cfg_redir at beginning of buf. */
409 	buf = &buf[sizeof(struct cfg_redir)];
410 	space = sizeof(struct cfg_redir);
411 
412 	/*
413 	 * Extract protocol.
414 	 */
415 	r->proto = StrToProto(**av);
416 	protoName = **av;
417 	(*av)++; (*ac)--;
418 
419 	/*
420 	 * Extract local address.
421 	 */
422 	if ((sep = strchr(**av, ',')) != NULL) {
423 		r->laddr.s_addr = INADDR_NONE;
424 		r->lport = ~0;
425 		numLocalPorts = 1;
426 		lsnat = **av;
427 	} else {
428 		/*
429 		 * The sctp nat does not allow the port numbers to be mapped to
430 		 * new port numbers. Therefore, no ports are to be specified
431 		 * in the target port field.
432 		 */
433 		if (r->proto == IPPROTO_SCTP) {
434 			if (strchr(**av, ':'))
435 				errx(EX_DATAERR, "redirect_port:"
436 				    "port numbers do not change in sctp, so do "
437 				    "not specify them as part of the target");
438 			else
439 				StrToAddr(**av, &r->laddr);
440 		} else {
441 			if (StrToAddrAndPortRange(**av, &r->laddr, protoName,
442 			    &portRange) != 0)
443 				errx(EX_DATAERR, "redirect_port: "
444 				    "invalid local port range");
445 
446 			r->lport = GETLOPORT(portRange);
447 			numLocalPorts = GETNUMPORTS(portRange);
448 		}
449 	}
450 	(*av)++; (*ac)--;
451 
452 	/*
453 	 * Extract public port and optionally address.
454 	 */
455 	if ((sep = strchr(**av, ':')) != NULL) {
456 		if (StrToAddrAndPortRange(**av, &r->paddr, protoName,
457 		    &portRange) != 0)
458 			errx(EX_DATAERR, "redirect_port: "
459 			    "invalid public port range");
460 	} else {
461 		r->paddr.s_addr = INADDR_ANY;
462 		if (StrToPortRange(**av, protoName, &portRange) != 0)
463 			errx(EX_DATAERR, "redirect_port: "
464 			    "invalid public port range");
465 	}
466 
467 	r->pport = GETLOPORT(portRange);
468 	if (r->proto == IPPROTO_SCTP) { /* so the logic below still works */
469 		numLocalPorts = GETNUMPORTS(portRange);
470 		r->lport = r->pport;
471 	}
472 	r->pport_cnt = GETNUMPORTS(portRange);
473 	(*av)++; (*ac)--;
474 
475 	/*
476 	 * Extract remote address and optionally port.
477 	 */
478 	/*
479 	 * NB: isdigit(**av) => we've to check that next parameter is really an
480 	 * option for this redirect entry, else stop here processing arg[cv].
481 	 */
482 	if (*ac != 0 && isdigit(***av)) {
483 		if ((sep = strchr(**av, ':')) != NULL) {
484 			if (StrToAddrAndPortRange(**av, &r->raddr, protoName,
485 			    &portRange) != 0)
486 				errx(EX_DATAERR, "redirect_port: "
487 				    "invalid remote port range");
488 		} else {
489 			SETLOPORT(portRange, 0);
490 			SETNUMPORTS(portRange, 1);
491 			StrToAddr(**av, &r->raddr);
492 		}
493 		(*av)++; (*ac)--;
494 	} else {
495 		SETLOPORT(portRange, 0);
496 		SETNUMPORTS(portRange, 1);
497 		r->raddr.s_addr = INADDR_ANY;
498 	}
499 	r->rport = GETLOPORT(portRange);
500 	r->rport_cnt = GETNUMPORTS(portRange);
501 
502 	/*
503 	 * Make sure port ranges match up, then add the redirect ports.
504 	 */
505 	if (numLocalPorts != r->pport_cnt)
506 		errx(EX_DATAERR, "redirect_port: "
507 		    "port ranges must be equal in size");
508 
509 	/* Remote port range is allowed to be '0' which means all ports. */
510 	if (r->rport_cnt != numLocalPorts &&
511 	    (r->rport_cnt != 1 || r->rport != 0))
512 		errx(EX_DATAERR, "redirect_port: remote port must"
513 		    "be 0 or equal to local port range in size");
514 
515 	/* Setup LSNAT server pool. */
516 	if (lsnat != NULL) {
517 		struct cfg_spool *spool;
518 
519 		sep = strtok(lsnat, ",");
520 		while (sep != NULL) {
521 			spool = (struct cfg_spool *)buf;
522 			space += sizeof(struct cfg_spool);
523 			/*
524 			 * The sctp nat does not allow the port numbers to
525 			 * be mapped to new port numbers. Therefore, no ports
526 			 * are to be specified in the target port field.
527 			 */
528 			if (r->proto == IPPROTO_SCTP) {
529 				if (strchr (sep, ':')) {
530 					errx(EX_DATAERR, "redirect_port:"
531 					    "port numbers do not change in "
532 					    "sctp, so do not specify them as "
533 					    "part of the target");
534 				} else {
535 					StrToAddr(sep, &spool->addr);
536 					spool->port = r->pport;
537 				}
538 			} else {
539 				if (StrToAddrAndPortRange(sep, &spool->addr,
540 					protoName, &portRange) != 0)
541 					errx(EX_DATAERR, "redirect_port:"
542 					    "invalid local port range");
543 				if (GETNUMPORTS(portRange) != 1)
544 					errx(EX_DATAERR, "redirect_port: "
545 					    "local port must be single in "
546 					    "this context");
547 				spool->port = GETLOPORT(portRange);
548 			}
549 			r->spool_cnt++;
550 			/* Point to the next possible cfg_spool. */
551 			buf = &buf[sizeof(struct cfg_spool)];
552 			sep = strtok(NULL, ",");
553 		}
554 	}
555 
556 	return (space);
557 }
558 
559 static int
560 setup_redir_proto(char *buf, int *ac, char ***av)
561 {
562 	struct cfg_redir *r;
563 	struct protoent *protoent;
564 	size_t space;
565 
566 	r = (struct cfg_redir *)buf;
567 	r->mode = REDIR_PROTO;
568 	/* Skip cfg_redir at beginning of buf. */
569 	buf = &buf[sizeof(struct cfg_redir)];
570 	space = sizeof(struct cfg_redir);
571 
572 	/*
573 	 * Extract protocol.
574 	 */
575 	protoent = getprotobyname(**av);
576 	if (protoent == NULL)
577 		errx(EX_DATAERR, "redirect_proto: unknown protocol %s", **av);
578 	else
579 		r->proto = protoent->p_proto;
580 
581 	(*av)++; (*ac)--;
582 
583 	/*
584 	 * Extract local address.
585 	 */
586 	StrToAddr(**av, &r->laddr);
587 
588 	(*av)++; (*ac)--;
589 
590 	/*
591 	 * Extract optional public address.
592 	 */
593 	if (*ac == 0) {
594 		r->paddr.s_addr = INADDR_ANY;
595 		r->raddr.s_addr = INADDR_ANY;
596 	} else {
597 		/* see above in setup_redir_port() */
598 		if (isdigit(***av)) {
599 			StrToAddr(**av, &r->paddr);
600 			(*av)++; (*ac)--;
601 
602 			/*
603 			 * Extract optional remote address.
604 			 */
605 			/* see above in setup_redir_port() */
606 			if (*ac != 0 && isdigit(***av)) {
607 				StrToAddr(**av, &r->raddr);
608 				(*av)++; (*ac)--;
609 			}
610 		}
611 	}
612 
613 	return (space);
614 }
615 
616 static void
617 print_nat_config(unsigned char *buf)
618 {
619 	struct cfg_nat *n;
620 	int i, cnt, flag, off;
621 	struct cfg_redir *t;
622 	struct cfg_spool *s;
623 	struct protoent *p;
624 
625 	n = (struct cfg_nat *)buf;
626 	flag = 1;
627 	off  = sizeof(*n);
628 	printf("ipfw nat %u config", n->id);
629 	if (strlen(n->if_name) != 0)
630 		printf(" if %s", n->if_name);
631 	else if (n->ip.s_addr != 0)
632 		printf(" ip %s", inet_ntoa(n->ip));
633 	while (n->mode != 0) {
634 		if (n->mode & PKT_ALIAS_LOG) {
635 			printf(" log");
636 			n->mode &= ~PKT_ALIAS_LOG;
637 		} else if (n->mode & PKT_ALIAS_DENY_INCOMING) {
638 			printf(" deny_in");
639 			n->mode &= ~PKT_ALIAS_DENY_INCOMING;
640 		} else if (n->mode & PKT_ALIAS_SAME_PORTS) {
641 			printf(" same_ports");
642 			n->mode &= ~PKT_ALIAS_SAME_PORTS;
643 		} else if (n->mode & PKT_ALIAS_SKIP_GLOBAL) {
644 			printf(" skip_global");
645 			n->mode &= ~PKT_ALIAS_SKIP_GLOBAL;
646 		} else if (n->mode & PKT_ALIAS_UNREGISTERED_ONLY) {
647 			printf(" unreg_only");
648 			n->mode &= ~PKT_ALIAS_UNREGISTERED_ONLY;
649 		} else if (n->mode & PKT_ALIAS_RESET_ON_ADDR_CHANGE) {
650 			printf(" reset");
651 			n->mode &= ~PKT_ALIAS_RESET_ON_ADDR_CHANGE;
652 		} else if (n->mode & PKT_ALIAS_REVERSE) {
653 			printf(" reverse");
654 			n->mode &= ~PKT_ALIAS_REVERSE;
655 		} else if (n->mode & PKT_ALIAS_PROXY_ONLY) {
656 			printf(" proxy_only");
657 			n->mode &= ~PKT_ALIAS_PROXY_ONLY;
658 		}
659 	}
660 	/* Print all the redirect's data configuration. */
661 	for (cnt = 0; cnt < n->redir_cnt; cnt++) {
662 		t = (struct cfg_redir *)&buf[off];
663 		off += SOF_REDIR;
664 		switch (t->mode) {
665 		case REDIR_ADDR:
666 			printf(" redirect_addr");
667 			if (t->spool_cnt == 0)
668 				printf(" %s", inet_ntoa(t->laddr));
669 			else
670 				for (i = 0; i < t->spool_cnt; i++) {
671 					s = (struct cfg_spool *)&buf[off];
672 					if (i)
673 						printf(",");
674 					else
675 						printf(" ");
676 					printf("%s", inet_ntoa(s->addr));
677 					off += SOF_SPOOL;
678 				}
679 			printf(" %s", inet_ntoa(t->paddr));
680 			break;
681 		case REDIR_PORT:
682 			p = getprotobynumber(t->proto);
683 			printf(" redirect_port %s ", p->p_name);
684 			if (!t->spool_cnt) {
685 				printf("%s:%u", inet_ntoa(t->laddr), t->lport);
686 				if (t->pport_cnt > 1)
687 					printf("-%u", t->lport +
688 					    t->pport_cnt - 1);
689 			} else
690 				for (i=0; i < t->spool_cnt; i++) {
691 					s = (struct cfg_spool *)&buf[off];
692 					if (i)
693 						printf(",");
694 					printf("%s:%u", inet_ntoa(s->addr),
695 					    s->port);
696 					off += SOF_SPOOL;
697 				}
698 
699 			printf(" ");
700 			if (t->paddr.s_addr)
701 				printf("%s:", inet_ntoa(t->paddr));
702 			printf("%u", t->pport);
703 			if (!t->spool_cnt && t->pport_cnt > 1)
704 				printf("-%u", t->pport + t->pport_cnt - 1);
705 
706 			if (t->raddr.s_addr) {
707 				printf(" %s", inet_ntoa(t->raddr));
708 				if (t->rport) {
709 					printf(":%u", t->rport);
710 					if (!t->spool_cnt && t->rport_cnt > 1)
711 						printf("-%u", t->rport +
712 						    t->rport_cnt - 1);
713 				}
714 			}
715 			break;
716 		case REDIR_PROTO:
717 			p = getprotobynumber(t->proto);
718 			printf(" redirect_proto %s %s", p->p_name,
719 			    inet_ntoa(t->laddr));
720 			if (t->paddr.s_addr != 0) {
721 				printf(" %s", inet_ntoa(t->paddr));
722 				if (t->raddr.s_addr)
723 					printf(" %s", inet_ntoa(t->raddr));
724 			}
725 			break;
726 		default:
727 			errx(EX_DATAERR, "unknown redir mode");
728 			break;
729 		}
730 	}
731 	printf("\n");
732 }
733 
734 void
735 ipfw_config_nat(int ac, char **av)
736 {
737 	struct cfg_nat *n;		/* Nat instance configuration. */
738 	int i, off, tok, ac1;
739 	char *id, *buf, **av1, *end;
740 	size_t len;
741 
742 	av++;
743 	ac--;
744 	/* Nat id. */
745 	if (ac == 0)
746 		errx(EX_DATAERR, "missing nat id");
747 	id = *av;
748 	i = (int)strtol(id, &end, 0);
749 	if (i <= 0 || *end != '\0')
750 		errx(EX_DATAERR, "illegal nat id: %s", id);
751 	av++;
752 	ac--;
753 	if (ac == 0)
754 		errx(EX_DATAERR, "missing option");
755 
756 	len = sizeof(struct cfg_nat);
757 	ac1 = ac;
758 	av1 = av;
759 	while (ac1 > 0) {
760 		tok = match_token(nat_params, *av1);
761 		ac1--;
762 		av1++;
763 		switch (tok) {
764 		case TOK_IP:
765 		case TOK_IF:
766 			ac1--;
767 			av1++;
768 			break;
769 		case TOK_ALOG:
770 		case TOK_DENY_INC:
771 		case TOK_SAME_PORTS:
772 		case TOK_SKIP_GLOBAL:
773 		case TOK_UNREG_ONLY:
774 		case TOK_RESET_ADDR:
775 		case TOK_ALIAS_REV:
776 		case TOK_PROXY_ONLY:
777 			break;
778 		case TOK_REDIR_ADDR:
779 			if (ac1 < 2)
780 				errx(EX_DATAERR, "redirect_addr: "
781 				    "not enough arguments");
782 			len += estimate_redir_addr(&ac1, &av1);
783 			av1 += 2;
784 			ac1 -= 2;
785 			break;
786 		case TOK_REDIR_PORT:
787 			if (ac1 < 3)
788 				errx(EX_DATAERR, "redirect_port: "
789 				    "not enough arguments");
790 			av1++;
791 			ac1--;
792 			len += estimate_redir_port(&ac1, &av1);
793 			av1 += 2;
794 			ac1 -= 2;
795 			/* Skip optional remoteIP/port */
796 			if (ac1 != 0 && isdigit(**av1)) {
797 				av1++;
798 				ac1--;
799 			}
800 			break;
801 		case TOK_REDIR_PROTO:
802 			if (ac1 < 2)
803 				errx(EX_DATAERR, "redirect_proto: "
804 				    "not enough arguments");
805 			len += sizeof(struct cfg_redir);
806 			av1 += 2;
807 			ac1 -= 2;
808 			/* Skip optional remoteIP/port */
809 			if (ac1 != 0 && isdigit(**av1)) {
810 				av1++;
811 				ac1--;
812 			}
813 			if (ac1 != 0 && isdigit(**av1)) {
814 				av1++;
815 				ac1--;
816 			}
817 			break;
818 		default:
819 			errx(EX_DATAERR, "unrecognised option ``%s''", av1[-1]);
820 		}
821 	}
822 
823 	if ((buf = malloc(len)) == NULL)
824 		errx(EX_OSERR, "malloc failed");
825 
826 	/* Offset in buf: save space for n at the beginning. */
827 	off = sizeof(*n);
828 	memset(buf, 0, len);
829 	n = (struct cfg_nat *)buf;
830 	n->id = i;
831 
832 	while (ac > 0) {
833 		tok = match_token(nat_params, *av);
834 		ac--;
835 		av++;
836 		switch (tok) {
837 		case TOK_IP:
838 			if (ac == 0)
839 				errx(EX_DATAERR, "missing option");
840 			if (!inet_aton(av[0], &(n->ip)))
841 				errx(EX_DATAERR, "bad ip address ``%s''",
842 				    av[0]);
843 			ac--;
844 			av++;
845 			break;
846 		case TOK_IF:
847 			if (ac == 0)
848 				errx(EX_DATAERR, "missing option");
849 			set_addr_dynamic(av[0], n);
850 			ac--;
851 			av++;
852 			break;
853 		case TOK_ALOG:
854 			n->mode |= PKT_ALIAS_LOG;
855 			break;
856 		case TOK_DENY_INC:
857 			n->mode |= PKT_ALIAS_DENY_INCOMING;
858 			break;
859 		case TOK_SAME_PORTS:
860 			n->mode |= PKT_ALIAS_SAME_PORTS;
861 			break;
862 		case TOK_UNREG_ONLY:
863 			n->mode |= PKT_ALIAS_UNREGISTERED_ONLY;
864 			break;
865 		case TOK_SKIP_GLOBAL:
866 			n->mode |= PKT_ALIAS_SKIP_GLOBAL;
867 			break;
868 		case TOK_RESET_ADDR:
869 			n->mode |= PKT_ALIAS_RESET_ON_ADDR_CHANGE;
870 			break;
871 		case TOK_ALIAS_REV:
872 			n->mode |= PKT_ALIAS_REVERSE;
873 			break;
874 		case TOK_PROXY_ONLY:
875 			n->mode |= PKT_ALIAS_PROXY_ONLY;
876 			break;
877 			/*
878 			 * All the setup_redir_* functions work directly in
879 			 * the final buffer, see above for details.
880 			 */
881 		case TOK_REDIR_ADDR:
882 		case TOK_REDIR_PORT:
883 		case TOK_REDIR_PROTO:
884 			switch (tok) {
885 			case TOK_REDIR_ADDR:
886 				i = setup_redir_addr(&buf[off], &ac, &av);
887 				break;
888 			case TOK_REDIR_PORT:
889 				i = setup_redir_port(&buf[off], &ac, &av);
890 				break;
891 			case TOK_REDIR_PROTO:
892 				i = setup_redir_proto(&buf[off], &ac, &av);
893 				break;
894 			}
895 			n->redir_cnt++;
896 			off += i;
897 			break;
898 		}
899 	}
900 
901 	i = do_cmd(IP_FW_NAT_CFG, buf, off);
902 	if (i)
903 		err(1, "setsockopt(%s)", "IP_FW_NAT_CFG");
904 
905 	if (!co.do_quiet) {
906 		/* After every modification, we show the resultant rule. */
907 		int _ac = 3;
908 		const char *_av[] = {"show", "config", id};
909 		ipfw_show_nat(_ac, (char **)(void *)_av);
910 	}
911 }
912 
913 
914 void
915 ipfw_show_nat(int ac, char **av)
916 {
917 	struct cfg_nat *n;
918 	struct cfg_redir *e;
919 	int cmd, i, nbytes, do_cfg, do_rule, frule, lrule, nalloc, size;
920 	int nat_cnt, redir_cnt, r;
921 	uint8_t *data, *p;
922 	char *endptr;
923 
924 	do_rule = 0;
925 	nalloc = 1024;
926 	size = 0;
927 	data = NULL;
928 	frule = 0;
929 	lrule = IPFW_DEFAULT_RULE; /* max ipfw rule number */
930 	ac--;
931 	av++;
932 
933 	if (co.test_only)
934 		return;
935 
936 	/* Parse parameters. */
937 	for (cmd = IP_FW_NAT_GET_LOG, do_cfg = 0; ac != 0; ac--, av++) {
938 		if (!strncmp(av[0], "config", strlen(av[0]))) {
939 			cmd = IP_FW_NAT_GET_CONFIG, do_cfg = 1;
940 			continue;
941 		}
942 		/* Convert command line rule #. */
943 		frule = lrule = strtoul(av[0], &endptr, 10);
944 		if (*endptr == '-')
945 			lrule = strtoul(endptr+1, &endptr, 10);
946 		if (lrule == 0)
947 			err(EX_USAGE, "invalid rule number: %s", av[0]);
948 		do_rule = 1;
949 	}
950 
951 	nbytes = nalloc;
952 	while (nbytes >= nalloc) {
953 		nalloc = nalloc * 2;
954 		nbytes = nalloc;
955 		data = safe_realloc(data, nbytes);
956 		if (do_cmd(cmd, data, (uintptr_t)&nbytes) < 0)
957 			err(EX_OSERR, "getsockopt(IP_FW_GET_%s)",
958 			    (cmd == IP_FW_NAT_GET_LOG) ? "LOG" : "CONFIG");
959 	}
960 	if (nbytes == 0)
961 		exit(0);
962 	if (do_cfg) {
963 		nat_cnt = *((int *)data);
964 		for (i = sizeof(nat_cnt); nat_cnt; nat_cnt--) {
965 			n = (struct cfg_nat *)&data[i];
966 			if (frule <= n->id && lrule >= n->id)
967 				print_nat_config(&data[i]);
968 			i += sizeof(struct cfg_nat);
969 			for (redir_cnt = 0; redir_cnt < n->redir_cnt; redir_cnt++) {
970 				e = (struct cfg_redir *)&data[i];
971 				i += sizeof(struct cfg_redir) + e->spool_cnt *
972 				    sizeof(struct cfg_spool);
973 			}
974 		}
975 	} else {
976 		for (i = 0; 1; i += LIBALIAS_BUF_SIZE + sizeof(int)) {
977 			p = &data[i];
978 			if (p == data + nbytes)
979 				break;
980 			bcopy(p, &r, sizeof(int));
981 			if (do_rule) {
982 				if (!(frule <= r && lrule >= r))
983 					continue;
984 			}
985 			printf("nat %u: %s\n", r, p+sizeof(int));
986 		}
987 	}
988 }
989