xref: /freebsd/sbin/ipfw/nat.c (revision 4848dd0858385db46fa4e0192a134605ee42ab01)
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/sockio.h>
28 #include <sys/sysctl.h>
29 
30 #include "ipfw2.h"
31 
32 #include <ctype.h>
33 #include <err.h>
34 #include <netdb.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <sysexits.h>
39 
40 #define IPFW_INTERNAL	/* Access to protected structures in ip_fw.h. */
41 
42 #include <net/if.h>
43 #include <net/if_dl.h>
44 #include <net/route.h> /* def. of struct route */
45 #include <netinet/in.h>
46 #include <netinet/in_systm.h>
47 #include <netinet/ip_fw.h>
48 #include <arpa/inet.h>
49 #include <alias.h>
50 
51 static struct _s_x nat_params[] = {
52 	{ "ip",	                TOK_IP },
53 	{ "if",	                TOK_IF },
54  	{ "log",                TOK_ALOG },
55  	{ "deny_in",	        TOK_DENY_INC },
56  	{ "same_ports",	        TOK_SAME_PORTS },
57  	{ "unreg_only",	        TOK_UNREG_ONLY },
58  	{ "reset",	        TOK_RESET_ADDR },
59  	{ "reverse",	        TOK_ALIAS_REV },
60  	{ "proxy_only",	        TOK_PROXY_ONLY },
61 	{ "redirect_addr",	TOK_REDIR_ADDR },
62 	{ "redirect_port",	TOK_REDIR_PORT },
63 	{ "redirect_proto",	TOK_REDIR_PROTO },
64  	{ NULL, 0 }	/* terminator */
65 };
66 
67 
68 /*
69  * Search for interface with name "ifn", and fill n accordingly:
70  *
71  * n->ip        ip address of interface "ifn"
72  * n->if_name   copy of interface name "ifn"
73  */
74 static void
75 set_addr_dynamic(const char *ifn, struct cfg_nat *n)
76 {
77 	size_t needed;
78 	int mib[6];
79 	char *buf, *lim, *next;
80 	struct if_msghdr *ifm;
81 	struct ifa_msghdr *ifam;
82 	struct sockaddr_dl *sdl;
83 	struct sockaddr_in *sin;
84 	int ifIndex, ifMTU;
85 
86 	mib[0] = CTL_NET;
87 	mib[1] = PF_ROUTE;
88 	mib[2] = 0;
89 	mib[3] = AF_INET;
90 	mib[4] = NET_RT_IFLIST;
91 	mib[5] = 0;
92 /*
93  * Get interface data.
94  */
95 	if (sysctl(mib, 6, NULL, &needed, NULL, 0) == -1)
96 		err(1, "iflist-sysctl-estimate");
97 	buf = safe_calloc(1, needed);
98 	if (sysctl(mib, 6, buf, &needed, NULL, 0) == -1)
99 		err(1, "iflist-sysctl-get");
100 	lim = buf + needed;
101 /*
102  * Loop through interfaces until one with
103  * given name is found. This is done to
104  * find correct interface index for routing
105  * message processing.
106  */
107 	ifIndex	= 0;
108 	next = buf;
109 	while (next < lim) {
110 		ifm = (struct if_msghdr *)next;
111 		next += ifm->ifm_msglen;
112 		if (ifm->ifm_version != RTM_VERSION) {
113 			if (co.verbose)
114 				warnx("routing message version %d "
115 				    "not understood", ifm->ifm_version);
116 			continue;
117 		}
118 		if (ifm->ifm_type == RTM_IFINFO) {
119 			sdl = (struct sockaddr_dl *)(ifm + 1);
120 			if (strlen(ifn) == sdl->sdl_nlen &&
121 			    strncmp(ifn, sdl->sdl_data, sdl->sdl_nlen) == 0) {
122 				ifIndex = ifm->ifm_index;
123 				ifMTU = ifm->ifm_data.ifi_mtu;
124 				break;
125 			}
126 		}
127 	}
128 	if (!ifIndex)
129 		errx(1, "unknown interface name %s", ifn);
130 /*
131  * Get interface address.
132  */
133 	sin = NULL;
134 	while (next < lim) {
135 		ifam = (struct ifa_msghdr *)next;
136 		next += ifam->ifam_msglen;
137 		if (ifam->ifam_version != RTM_VERSION) {
138 			if (co.verbose)
139 				warnx("routing message version %d "
140 				    "not understood", ifam->ifam_version);
141 			continue;
142 		}
143 		if (ifam->ifam_type != RTM_NEWADDR)
144 			break;
145 		if (ifam->ifam_addrs & RTA_IFA) {
146 			int i;
147 			char *cp = (char *)(ifam + 1);
148 
149 			for (i = 1; i < RTA_IFA; i <<= 1) {
150 				if (ifam->ifam_addrs & i)
151 					cp += SA_SIZE((struct sockaddr *)cp);
152 			}
153 			if (((struct sockaddr *)cp)->sa_family == AF_INET) {
154 				sin = (struct sockaddr_in *)cp;
155 				break;
156 			}
157 		}
158 	}
159 	if (sin == NULL)
160 		errx(1, "%s: cannot get interface address", ifn);
161 
162 	n->ip = sin->sin_addr;
163 	strncpy(n->if_name, ifn, IF_NAMESIZE);
164 
165 	free(buf);
166 }
167 
168 /*
169  * XXX - The following functions, macros and definitions come from natd.c:
170  * it would be better to move them outside natd.c, in a file
171  * (redirect_support.[ch]?) shared by ipfw and natd, but for now i can live
172  * with it.
173  */
174 
175 /*
176  * Definition of a port range, and macros to deal with values.
177  * FORMAT:  HI 16-bits == first port in range, 0 == all ports.
178  *          LO 16-bits == number of ports in range
179  * NOTES:   - Port values are not stored in network byte order.
180  */
181 
182 #define port_range u_long
183 
184 #define GETLOPORT(x)     ((x) >> 0x10)
185 #define GETNUMPORTS(x)   ((x) & 0x0000ffff)
186 #define GETHIPORT(x)     (GETLOPORT((x)) + GETNUMPORTS((x)))
187 
188 /* Set y to be the low-port value in port_range variable x. */
189 #define SETLOPORT(x,y)   ((x) = ((x) & 0x0000ffff) | ((y) << 0x10))
190 
191 /* Set y to be the number of ports in port_range variable x. */
192 #define SETNUMPORTS(x,y) ((x) = ((x) & 0xffff0000) | (y))
193 
194 static void
195 StrToAddr (const char* str, struct in_addr* addr)
196 {
197 	struct hostent* hp;
198 
199 	if (inet_aton (str, addr))
200 		return;
201 
202 	hp = gethostbyname (str);
203 	if (!hp)
204 		errx (1, "unknown host %s", str);
205 
206 	memcpy (addr, hp->h_addr, sizeof (struct in_addr));
207 }
208 
209 static int
210 StrToPortRange (const char* str, const char* proto, port_range *portRange)
211 {
212 	char*           sep;
213 	struct servent*	sp;
214 	char*		end;
215 	u_short         loPort;
216 	u_short         hiPort;
217 
218 	/* First see if this is a service, return corresponding port if so. */
219 	sp = getservbyname (str,proto);
220 	if (sp) {
221 	        SETLOPORT(*portRange, ntohs(sp->s_port));
222 		SETNUMPORTS(*portRange, 1);
223 		return 0;
224 	}
225 
226 	/* Not a service, see if it's a single port or port range. */
227 	sep = strchr (str, '-');
228 	if (sep == NULL) {
229 	        SETLOPORT(*portRange, strtol(str, &end, 10));
230 		if (end != str) {
231 		        /* Single port. */
232 		        SETNUMPORTS(*portRange, 1);
233 			return 0;
234 		}
235 
236 		/* Error in port range field. */
237 		errx (EX_DATAERR, "%s/%s: unknown service", str, proto);
238 	}
239 
240 	/* Port range, get the values and sanity check. */
241 	sscanf (str, "%hu-%hu", &loPort, &hiPort);
242 	SETLOPORT(*portRange, loPort);
243 	SETNUMPORTS(*portRange, 0);	/* Error by default */
244 	if (loPort <= hiPort)
245 	        SETNUMPORTS(*portRange, hiPort - loPort + 1);
246 
247 	if (GETNUMPORTS(*portRange) == 0)
248 	        errx (EX_DATAERR, "invalid port range %s", str);
249 
250 	return 0;
251 }
252 
253 static int
254 StrToProto (const char* str)
255 {
256 	if (!strcmp (str, "tcp"))
257 		return IPPROTO_TCP;
258 
259 	if (!strcmp (str, "udp"))
260 		return IPPROTO_UDP;
261 
262 	errx (EX_DATAERR, "unknown protocol %s. Expected tcp or udp", str);
263 }
264 
265 static int
266 StrToAddrAndPortRange (const char* str, struct in_addr* addr, char* proto,
267 		       port_range *portRange)
268 {
269 	char*	ptr;
270 
271 	ptr = strchr (str, ':');
272 	if (!ptr)
273 		errx (EX_DATAERR, "%s is missing port number", str);
274 
275 	*ptr = '\0';
276 	++ptr;
277 
278 	StrToAddr (str, addr);
279 	return StrToPortRange (ptr, proto, portRange);
280 }
281 
282 /* End of stuff taken from natd.c. */
283 
284 #define INC_ARGCV() do {        \
285 	(*_av)++;               \
286 	(*_ac)--;               \
287 	av = *_av;              \
288 	ac = *_ac;              \
289 } while(0)
290 
291 /*
292  * The next 3 functions add support for the addr, port and proto redirect and
293  * their logic is loosely based on SetupAddressRedirect(), SetupPortRedirect()
294  * and SetupProtoRedirect() from natd.c.
295  *
296  * Every setup_* function fills at least one redirect entry
297  * (struct cfg_redir) and zero or more server pool entry (struct cfg_spool)
298  * in buf.
299  *
300  * The format of data in buf is:
301  *
302  *
303  *     cfg_nat    cfg_redir    cfg_spool    ......  cfg_spool
304  *
305  *    -------------------------------------        ------------
306  *   |          | .....X ... |          |         |           |  .....
307  *    ------------------------------------- ...... ------------
308  *                     ^
309  *                spool_cnt       n=0       ......   n=(X-1)
310  *
311  * len points to the amount of available space in buf
312  * space counts the memory consumed by every function
313  *
314  * XXX - Every function get all the argv params so it
315  * has to check, in optional parameters, that the next
316  * args is a valid option for the redir entry and not
317  * another token. Only redir_port and redir_proto are
318  * affected by this.
319  */
320 
321 static int
322 setup_redir_addr(char *spool_buf, int len,
323 		 int *_ac, char ***_av)
324 {
325 	char **av, *sep; /* Token separator. */
326 	/* Temporary buffer used to hold server pool ip's. */
327 	char tmp_spool_buf[NAT_BUF_LEN];
328 	int ac, space, lsnat;
329 	struct cfg_redir *r;
330 	struct cfg_spool *tmp;
331 
332 	av = *_av;
333 	ac = *_ac;
334 	space = 0;
335 	lsnat = 0;
336 	if (len >= SOF_REDIR) {
337 		r = (struct cfg_redir *)spool_buf;
338 		/* Skip cfg_redir at beginning of buf. */
339 		spool_buf = &spool_buf[SOF_REDIR];
340 		space = SOF_REDIR;
341 		len -= SOF_REDIR;
342 	} else
343 		goto nospace;
344 	r->mode = REDIR_ADDR;
345 	/* Extract local address. */
346 	if (ac == 0)
347 		errx(EX_DATAERR, "redirect_addr: missing local address");
348 	sep = strchr(*av, ',');
349 	if (sep) {		/* LSNAT redirection syntax. */
350 		r->laddr.s_addr = INADDR_NONE;
351 		/* Preserve av, copy spool servers to tmp_spool_buf. */
352 		strncpy(tmp_spool_buf, *av, strlen(*av)+1);
353 		lsnat = 1;
354 	} else
355 		StrToAddr(*av, &r->laddr);
356 	INC_ARGCV();
357 
358 	/* Extract public address. */
359 	if (ac == 0)
360 		errx(EX_DATAERR, "redirect_addr: missing public address");
361 	StrToAddr(*av, &r->paddr);
362 	INC_ARGCV();
363 
364 	/* Setup LSNAT server pool. */
365 	if (sep) {
366 		sep = strtok(tmp_spool_buf, ",");
367 		while (sep != NULL) {
368 			tmp = (struct cfg_spool *)spool_buf;
369 			if (len < SOF_SPOOL)
370 				goto nospace;
371 			len -= SOF_SPOOL;
372 			space += SOF_SPOOL;
373 			StrToAddr(sep, &tmp->addr);
374 			tmp->port = ~0;
375 			r->spool_cnt++;
376 			/* Point to the next possible cfg_spool. */
377 			spool_buf = &spool_buf[SOF_SPOOL];
378 			sep = strtok(NULL, ",");
379 		}
380 	}
381 	return(space);
382 nospace:
383 	errx(EX_DATAERR, "redirect_addr: buf is too small\n");
384 }
385 
386 static int
387 setup_redir_port(char *spool_buf, int len,
388 		 int *_ac, char ***_av)
389 {
390 	char **av, *sep, *protoName;
391 	char tmp_spool_buf[NAT_BUF_LEN];
392 	int ac, space, lsnat;
393 	struct cfg_redir *r;
394 	struct cfg_spool *tmp;
395 	u_short numLocalPorts;
396 	port_range portRange;
397 
398 	av = *_av;
399 	ac = *_ac;
400 	space = 0;
401 	lsnat = 0;
402 	numLocalPorts = 0;
403 
404 	if (len >= SOF_REDIR) {
405 		r = (struct cfg_redir *)spool_buf;
406 		/* Skip cfg_redir at beginning of buf. */
407 		spool_buf = &spool_buf[SOF_REDIR];
408 		space = SOF_REDIR;
409 		len -= SOF_REDIR;
410 	} else
411 		goto nospace;
412 	r->mode = REDIR_PORT;
413 	/*
414 	 * Extract protocol.
415 	 */
416 	if (ac == 0)
417 		errx (EX_DATAERR, "redirect_port: missing protocol");
418 	r->proto = StrToProto(*av);
419 	protoName = *av;
420 	INC_ARGCV();
421 
422 	/*
423 	 * Extract local address.
424 	 */
425 	if (ac == 0)
426 		errx (EX_DATAERR, "redirect_port: missing local address");
427 
428 	sep = strchr(*av, ',');
429 	/* LSNAT redirection syntax. */
430 	if (sep) {
431 		r->laddr.s_addr = INADDR_NONE;
432 		r->lport = ~0;
433 		numLocalPorts = 1;
434 		/* Preserve av, copy spool servers to tmp_spool_buf. */
435 		strncpy(tmp_spool_buf, *av, strlen(*av)+1);
436 		lsnat = 1;
437 	} else {
438 		if (StrToAddrAndPortRange (*av, &r->laddr, protoName,
439 		    &portRange) != 0)
440 			errx(EX_DATAERR, "redirect_port:"
441 			    "invalid local port range");
442 
443 		r->lport = GETLOPORT(portRange);
444 		numLocalPorts = GETNUMPORTS(portRange);
445 	}
446 	INC_ARGCV();
447 
448 	/*
449 	 * Extract public port and optionally address.
450 	 */
451 	if (ac == 0)
452 		errx (EX_DATAERR, "redirect_port: missing public port");
453 
454 	sep = strchr (*av, ':');
455 	if (sep) {
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 	r->pport_cnt = GETNUMPORTS(portRange);
469 	INC_ARGCV();
470 
471 	/*
472 	 * Extract remote address and optionally port.
473 	 */
474 	/*
475 	 * NB: isalpha(**av) => we've to check that next parameter is really an
476 	 * option for this redirect entry, else stop here processing arg[cv].
477 	 */
478 	if (ac != 0 && !isalpha(**av)) {
479 		sep = strchr (*av, ':');
480 		if (sep) {
481 		        if (StrToAddrAndPortRange (*av, &r->raddr, protoName,
482 			    &portRange) != 0)
483 				errx(EX_DATAERR, "redirect_port:"
484 				    "invalid remote port range");
485 		} else {
486 		        SETLOPORT(portRange, 0);
487 			SETNUMPORTS(portRange, 1);
488 			StrToAddr (*av, &r->raddr);
489 		}
490 		INC_ARGCV();
491 	} else {
492 		SETLOPORT(portRange, 0);
493 		SETNUMPORTS(portRange, 1);
494 		r->raddr.s_addr = INADDR_ANY;
495 	}
496 	r->rport = GETLOPORT(portRange);
497 	r->rport_cnt = GETNUMPORTS(portRange);
498 
499 	/*
500 	 * Make sure port ranges match up, then add the redirect ports.
501 	 */
502 	if (numLocalPorts != r->pport_cnt)
503 	        errx(EX_DATAERR, "redirect_port:"
504 		    "port ranges must be equal in size");
505 
506 	/* Remote port range is allowed to be '0' which means all ports. */
507 	if (r->rport_cnt != numLocalPorts &&
508 	    (r->rport_cnt != 1 || r->rport != 0))
509 	        errx(EX_DATAERR, "redirect_port: remote port must"
510 		    "be 0 or equal to local port range in size");
511 
512 	/*
513 	 * Setup LSNAT server pool.
514 	 */
515 	if (lsnat) {
516 		sep = strtok(tmp_spool_buf, ",");
517 		while (sep != NULL) {
518 			tmp = (struct cfg_spool *)spool_buf;
519 			if (len < SOF_SPOOL)
520 				goto nospace;
521 			len -= SOF_SPOOL;
522 			space += SOF_SPOOL;
523 			if (StrToAddrAndPortRange(sep, &tmp->addr, protoName,
524 			    &portRange) != 0)
525 				errx(EX_DATAERR, "redirect_port:"
526 				    "invalid local port range");
527 			if (GETNUMPORTS(portRange) != 1)
528 				errx(EX_DATAERR, "redirect_port: local port"
529 				    "must be single in this context");
530 			tmp->port = GETLOPORT(portRange);
531 			r->spool_cnt++;
532 			/* Point to the next possible cfg_spool. */
533 			spool_buf = &spool_buf[SOF_SPOOL];
534 			sep = strtok(NULL, ",");
535 		}
536 	}
537 	return (space);
538 nospace:
539 	errx(EX_DATAERR, "redirect_port: buf is too small\n");
540 }
541 
542 static int
543 setup_redir_proto(char *spool_buf, int len,
544 		 int *_ac, char ***_av)
545 {
546 	char **av;
547 	int ac, space;
548 	struct protoent *protoent;
549 	struct cfg_redir *r;
550 
551 	av = *_av;
552 	ac = *_ac;
553 	if (len >= SOF_REDIR) {
554 		r = (struct cfg_redir *)spool_buf;
555 		/* Skip cfg_redir at beginning of buf. */
556 		spool_buf = &spool_buf[SOF_REDIR];
557 		space = SOF_REDIR;
558 		len -= SOF_REDIR;
559 	} else
560 		goto nospace;
561 	r->mode = REDIR_PROTO;
562 	/*
563 	 * Extract protocol.
564 	 */
565 	if (ac == 0)
566 		errx(EX_DATAERR, "redirect_proto: missing protocol");
567 
568 	protoent = getprotobyname(*av);
569 	if (protoent == NULL)
570 		errx(EX_DATAERR, "redirect_proto: unknown protocol %s", *av);
571 	else
572 		r->proto = protoent->p_proto;
573 
574 	INC_ARGCV();
575 
576 	/*
577 	 * Extract local address.
578 	 */
579 	if (ac == 0)
580 		errx(EX_DATAERR, "redirect_proto: missing local address");
581 	else
582 		StrToAddr(*av, &r->laddr);
583 
584 	INC_ARGCV();
585 
586 	/*
587 	 * Extract optional public address.
588 	 */
589 	if (ac == 0) {
590 		r->paddr.s_addr = INADDR_ANY;
591 		r->raddr.s_addr = INADDR_ANY;
592 	} else {
593 		/* see above in setup_redir_port() */
594 		if (!isalpha(**av)) {
595 			StrToAddr(*av, &r->paddr);
596 			INC_ARGCV();
597 
598 			/*
599 			 * Extract optional remote address.
600 			 */
601 			/* see above in setup_redir_port() */
602 			if (ac!=0 && !isalpha(**av)) {
603 				StrToAddr(*av, &r->raddr);
604 				INC_ARGCV();
605 			}
606 		}
607 	}
608 	return (space);
609 nospace:
610 	errx(EX_DATAERR, "redirect_proto: buf is too small\n");
611 }
612 
613 static void
614 print_nat_config(unsigned char *buf)
615 {
616 	struct cfg_nat *n;
617 	int i, cnt, flag, off;
618 	struct cfg_redir *t;
619 	struct cfg_spool *s;
620 	struct protoent *p;
621 
622 	n = (struct cfg_nat *)buf;
623 	flag = 1;
624 	off  = sizeof(*n);
625 	printf("ipfw nat %u config", n->id);
626 	if (strlen(n->if_name) != 0)
627 		printf(" if %s", n->if_name);
628 	else if (n->ip.s_addr != 0)
629 		printf(" ip %s", inet_ntoa(n->ip));
630 	while (n->mode != 0) {
631 		if (n->mode & PKT_ALIAS_LOG) {
632 			printf(" log");
633 			n->mode &= ~PKT_ALIAS_LOG;
634 		} else if (n->mode & PKT_ALIAS_DENY_INCOMING) {
635 			printf(" deny_in");
636 			n->mode &= ~PKT_ALIAS_DENY_INCOMING;
637 		} else if (n->mode & PKT_ALIAS_SAME_PORTS) {
638 			printf(" same_ports");
639 			n->mode &= ~PKT_ALIAS_SAME_PORTS;
640 		} else if (n->mode & PKT_ALIAS_UNREGISTERED_ONLY) {
641 			printf(" unreg_only");
642 			n->mode &= ~PKT_ALIAS_UNREGISTERED_ONLY;
643 		} else if (n->mode & PKT_ALIAS_RESET_ON_ADDR_CHANGE) {
644 			printf(" reset");
645 			n->mode &= ~PKT_ALIAS_RESET_ON_ADDR_CHANGE;
646 		} else if (n->mode & PKT_ALIAS_REVERSE) {
647 			printf(" reverse");
648 			n->mode &= ~PKT_ALIAS_REVERSE;
649 		} else if (n->mode & PKT_ALIAS_PROXY_ONLY) {
650 			printf(" proxy_only");
651 			n->mode &= ~PKT_ALIAS_PROXY_ONLY;
652 		}
653 	}
654 	/* Print all the redirect's data configuration. */
655 	for (cnt = 0; cnt < n->redir_cnt; cnt++) {
656 		t = (struct cfg_redir *)&buf[off];
657 		off += SOF_REDIR;
658 		switch (t->mode) {
659 		case REDIR_ADDR:
660 			printf(" redirect_addr");
661 			if (t->spool_cnt == 0)
662 				printf(" %s", inet_ntoa(t->laddr));
663 			else
664 				for (i = 0; i < t->spool_cnt; i++) {
665 					s = (struct cfg_spool *)&buf[off];
666 					if (i)
667 						printf(",");
668 					else
669 						printf(" ");
670 					printf("%s", inet_ntoa(s->addr));
671 					off += SOF_SPOOL;
672 				}
673 			printf(" %s", inet_ntoa(t->paddr));
674 			break;
675 		case REDIR_PORT:
676 			p = getprotobynumber(t->proto);
677 			printf(" redirect_port %s ", p->p_name);
678 			if (!t->spool_cnt) {
679 				printf("%s:%u", inet_ntoa(t->laddr), t->lport);
680 				if (t->pport_cnt > 1)
681 					printf("-%u", t->lport +
682 					    t->pport_cnt - 1);
683 			} else
684 				for (i=0; i < t->spool_cnt; i++) {
685 					s = (struct cfg_spool *)&buf[off];
686 					if (i)
687 						printf(",");
688 					printf("%s:%u", inet_ntoa(s->addr),
689 					    s->port);
690 					off += SOF_SPOOL;
691 				}
692 
693 			printf(" ");
694 			if (t->paddr.s_addr)
695 				printf("%s:", inet_ntoa(t->paddr));
696 			printf("%u", t->pport);
697 			if (!t->spool_cnt && t->pport_cnt > 1)
698 				printf("-%u", t->pport + t->pport_cnt - 1);
699 
700 			if (t->raddr.s_addr) {
701 				printf(" %s", inet_ntoa(t->raddr));
702 				if (t->rport) {
703 					printf(":%u", t->rport);
704 					if (!t->spool_cnt && t->rport_cnt > 1)
705 						printf("-%u", t->rport +
706 						    t->rport_cnt - 1);
707 				}
708 			}
709 			break;
710 		case REDIR_PROTO:
711 			p = getprotobynumber(t->proto);
712 			printf(" redirect_proto %s %s", p->p_name,
713 			    inet_ntoa(t->laddr));
714 			if (t->paddr.s_addr != 0) {
715 				printf(" %s", inet_ntoa(t->paddr));
716 				if (t->raddr.s_addr)
717 					printf(" %s", inet_ntoa(t->raddr));
718 			}
719 			break;
720 		default:
721 			errx(EX_DATAERR, "unknown redir mode");
722 			break;
723 		}
724 	}
725 	printf("\n");
726 }
727 
728 void
729 ipfw_config_nat(int ac, char **av)
730 {
731 	struct cfg_nat *n;              /* Nat instance configuration. */
732 	int i, len, off, tok;
733 	char *id, buf[NAT_BUF_LEN]; 	/* Buffer for serialized data. */
734 
735 	len = NAT_BUF_LEN;
736 	/* Offset in buf: save space for n at the beginning. */
737 	off = sizeof(*n);
738 	memset(buf, 0, sizeof(buf));
739 	n = (struct cfg_nat *)buf;
740 
741 	av++; ac--;
742 	/* Nat id. */
743 	if (ac && isdigit(**av)) {
744 		id = *av;
745 		i = atoi(*av);
746 		ac--; av++;
747 		n->id = i;
748 	} else
749 		errx(EX_DATAERR, "missing nat id");
750 	if (ac == 0)
751 		errx(EX_DATAERR, "missing option");
752 
753 	while (ac > 0) {
754 		tok = match_token(nat_params, *av);
755 		ac--; av++;
756 		switch (tok) {
757 		case TOK_IP:
758 			if (ac == 0)
759 				errx(EX_DATAERR, "missing option");
760 			if (!inet_aton(av[0], &(n->ip)))
761 				errx(EX_DATAERR, "bad ip address ``%s''",
762 				    av[0]);
763 			ac--; av++;
764 			break;
765 		case TOK_IF:
766 			if (ac == 0)
767 				errx(EX_DATAERR, "missing option");
768 			set_addr_dynamic(av[0], n);
769 			ac--; av++;
770 			break;
771 		case TOK_ALOG:
772 			n->mode |= PKT_ALIAS_LOG;
773 			break;
774 		case TOK_DENY_INC:
775 			n->mode |= PKT_ALIAS_DENY_INCOMING;
776 			break;
777 		case TOK_SAME_PORTS:
778 			n->mode |= PKT_ALIAS_SAME_PORTS;
779 			break;
780 		case TOK_UNREG_ONLY:
781 			n->mode |= PKT_ALIAS_UNREGISTERED_ONLY;
782 			break;
783 		case TOK_RESET_ADDR:
784 			n->mode |= PKT_ALIAS_RESET_ON_ADDR_CHANGE;
785 			break;
786 		case TOK_ALIAS_REV:
787 			n->mode |= PKT_ALIAS_REVERSE;
788 			break;
789 		case TOK_PROXY_ONLY:
790 			n->mode |= PKT_ALIAS_PROXY_ONLY;
791 			break;
792 			/*
793 			 * All the setup_redir_* functions work directly in the final
794 			 * buffer, see above for details.
795 			 */
796 		case TOK_REDIR_ADDR:
797 		case TOK_REDIR_PORT:
798 		case TOK_REDIR_PROTO:
799 			switch (tok) {
800 			case TOK_REDIR_ADDR:
801 				i = setup_redir_addr(&buf[off], len, &ac, &av);
802 				break;
803 			case TOK_REDIR_PORT:
804 				i = setup_redir_port(&buf[off], len, &ac, &av);
805 				break;
806 			case TOK_REDIR_PROTO:
807 				i = setup_redir_proto(&buf[off], len, &ac, &av);
808 				break;
809 			}
810 			n->redir_cnt++;
811 			off += i;
812 			len -= i;
813 			break;
814 		default:
815 			errx(EX_DATAERR, "unrecognised option ``%s''", av[-1]);
816 		}
817 	}
818 
819 	i = do_cmd(IP_FW_NAT_CFG, buf, off);
820 	if (i)
821 		err(1, "setsockopt(%s)", "IP_FW_NAT_CFG");
822 
823 	if (!co.do_quiet) {
824 		/* After every modification, we show the resultant rule. */
825 		int _ac = 3;
826 		char *_av[] = {"show", "config", id};
827 		ipfw_show_nat(_ac, _av);
828 	}
829 }
830 
831 
832 void
833 ipfw_show_nat(int ac, char **av)
834 {
835 	struct cfg_nat *n;
836 	struct cfg_redir *e;
837 	int cmd, i, nbytes, do_cfg, do_rule, frule, lrule, nalloc, size;
838 	int nat_cnt, redir_cnt, r;
839 	uint8_t *data, *p;
840 	char *endptr;
841 
842 	do_rule = 0;
843 	nalloc = 1024;
844 	size = 0;
845 	data = NULL;
846 	frule = 0;
847 	lrule = IPFW_DEFAULT_RULE; /* max ipfw rule number */
848 	ac--; av++;
849 
850 	if (co.test_only)
851 		return;
852 
853 	/* Parse parameters. */
854 	for (cmd = IP_FW_NAT_GET_LOG, do_cfg = 0; ac != 0; ac--, av++) {
855 		if (!strncmp(av[0], "config", strlen(av[0]))) {
856 			cmd = IP_FW_NAT_GET_CONFIG, do_cfg = 1;
857 			continue;
858 		}
859 		/* Convert command line rule #. */
860 		frule = lrule = strtoul(av[0], &endptr, 10);
861 		if (*endptr == '-')
862 			lrule = strtoul(endptr+1, &endptr, 10);
863 		if (lrule == 0)
864 			err(EX_USAGE, "invalid rule number: %s", av[0]);
865 		do_rule = 1;
866 	}
867 
868 	nbytes = nalloc;
869 	while (nbytes >= nalloc) {
870 		nalloc = nalloc * 2;
871 		nbytes = nalloc;
872 		data = safe_realloc(data, nbytes);
873 		if (do_cmd(cmd, data, (uintptr_t)&nbytes) < 0)
874 			err(EX_OSERR, "getsockopt(IP_FW_GET_%s)",
875 			    (cmd == IP_FW_NAT_GET_LOG) ? "LOG" : "CONFIG");
876 	}
877 	if (nbytes == 0)
878 		exit(0);
879 	if (do_cfg) {
880 		nat_cnt = *((int *)data);
881 		for (i = sizeof(nat_cnt); nat_cnt; nat_cnt--) {
882 			n = (struct cfg_nat *)&data[i];
883 			if (frule <= n->id && lrule >= n->id)
884 				print_nat_config(&data[i]);
885 			i += sizeof(struct cfg_nat);
886 			for (redir_cnt = 0; redir_cnt < n->redir_cnt; redir_cnt++) {
887 				e = (struct cfg_redir *)&data[i];
888 				i += sizeof(struct cfg_redir) + e->spool_cnt *
889 				    sizeof(struct cfg_spool);
890 			}
891 		}
892 	} else {
893 		for (i = 0; 1; i += LIBALIAS_BUF_SIZE + sizeof(int)) {
894 			p = &data[i];
895 			if (p == data + nbytes)
896 				break;
897 			bcopy(p, &r, sizeof(int));
898 			if (do_rule) {
899 				if (!(frule <= r && lrule >= r))
900 					continue;
901 			}
902 			printf("nat %u: %s\n", r, p+sizeof(int));
903 		}
904 	}
905 }
906