xref: /freebsd/sbin/ipfw/nat.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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  * In-kernel nat support
21  */
22 
23 #include <sys/types.h>
24 #include <sys/socket.h>
25 #include <sys/sysctl.h>
26 
27 #include "ipfw2.h"
28 
29 #include <ctype.h>
30 #include <err.h>
31 #include <errno.h>
32 #include <netdb.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <sysexits.h>
37 
38 #include <net/if.h>
39 #include <net/if_dl.h>
40 #include <net/route.h> /* def. of struct route */
41 #include <netinet/in.h>
42 #include <netinet/ip_fw.h>
43 #include <arpa/inet.h>
44 #include <alias.h>
45 
46 typedef int (nat_cb_t)(struct nat44_cfg_nat *cfg, void *arg);
47 static void nat_show_cfg(struct nat44_cfg_nat *n, void *arg);
48 static void nat_show_log(struct nat44_cfg_nat *n, void *arg);
49 static int nat_show_data(struct nat44_cfg_nat *cfg, void *arg);
50 static int natname_cmp(const void *a, const void *b);
51 static int nat_foreach(nat_cb_t *f, void *arg, int sort);
52 static int nat_get_cmd(char *name, uint16_t cmd, ipfw_obj_header **ooh);
53 
54 static struct _s_x nat_params[] = {
55 	{ "ip",			TOK_IP },
56 	{ "if",			TOK_IF },
57  	{ "log",		TOK_ALOG },
58  	{ "deny_in",		TOK_DENY_INC },
59  	{ "same_ports",		TOK_SAME_PORTS },
60  	{ "unreg_only",		TOK_UNREG_ONLY },
61  	{ "unreg_cgn",		TOK_UNREG_CGN },
62 	{ "skip_global",	TOK_SKIP_GLOBAL },
63  	{ "reset",		TOK_RESET_ADDR },
64  	{ "reverse",		TOK_ALIAS_REV },
65  	{ "proxy_only",		TOK_PROXY_ONLY },
66 	{ "port_range",		TOK_PORT_ALIAS },
67 	{ "redirect_addr",	TOK_REDIR_ADDR },
68 	{ "redirect_port",	TOK_REDIR_PORT },
69 	{ "redirect_proto",	TOK_REDIR_PROTO },
70 	{ "udp_eim",		TOK_UDP_EIM },
71  	{ NULL, 0 }	/* terminator */
72 };
73 
74 
75 /*
76  * Search for interface with name "ifn", and fill n accordingly:
77  *
78  * n->ip	ip address of interface "ifn"
79  * n->if_name   copy of interface name "ifn"
80  */
81 static void
82 set_addr_dynamic(const char *ifn, struct nat44_cfg_nat *n)
83 {
84 	size_t needed;
85 	int mib[6];
86 	char *buf, *lim, *next;
87 	struct if_msghdr *ifm;
88 	struct ifa_msghdr *ifam;
89 	struct sockaddr_dl *sdl;
90 	struct sockaddr_in *sin;
91 	int ifIndex;
92 
93 	mib[0] = CTL_NET;
94 	mib[1] = PF_ROUTE;
95 	mib[2] = 0;
96 	mib[3] = AF_INET;
97 	mib[4] = NET_RT_IFLIST;
98 	mib[5] = 0;
99 /*
100  * Get interface data.
101  */
102 	if (sysctl(mib, 6, NULL, &needed, NULL, 0) == -1)
103 		err(1, "iflist-sysctl-estimate");
104 	buf = safe_calloc(1, needed);
105 	if (sysctl(mib, 6, buf, &needed, NULL, 0) == -1)
106 		err(1, "iflist-sysctl-get");
107 	lim = buf + needed;
108 /*
109  * Loop through interfaces until one with
110  * given name is found. This is done to
111  * find correct interface index for routing
112  * message processing.
113  */
114 	ifIndex	= 0;
115 	next = buf;
116 	while (next < lim) {
117 		ifm = (struct if_msghdr *)next;
118 		next += ifm->ifm_msglen;
119 		if (ifm->ifm_version != RTM_VERSION) {
120 			if (g_co.verbose)
121 				warnx("routing message version %d "
122 				    "not understood", ifm->ifm_version);
123 			continue;
124 		}
125 		if (ifm->ifm_type == RTM_IFINFO) {
126 			sdl = (struct sockaddr_dl *)(ifm + 1);
127 			if (strlen(ifn) == sdl->sdl_nlen &&
128 			    strncmp(ifn, sdl->sdl_data, sdl->sdl_nlen) == 0) {
129 				ifIndex = ifm->ifm_index;
130 				break;
131 			}
132 		}
133 	}
134 	if (!ifIndex)
135 		errx(1, "unknown interface name %s", ifn);
136 /*
137  * Get interface address.
138  */
139 	sin = NULL;
140 	while (next < lim) {
141 		ifam = (struct ifa_msghdr *)next;
142 		next += ifam->ifam_msglen;
143 		if (ifam->ifam_version != RTM_VERSION) {
144 			if (g_co.verbose)
145 				warnx("routing message version %d "
146 				    "not understood", ifam->ifam_version);
147 			continue;
148 		}
149 		if (ifam->ifam_type != RTM_NEWADDR)
150 			break;
151 		if (ifam->ifam_addrs & RTA_IFA) {
152 			int i;
153 			char *cp = (char *)(ifam + 1);
154 
155 			for (i = 1; i < RTA_IFA; i <<= 1) {
156 				if (ifam->ifam_addrs & i)
157 					cp += SA_SIZE((struct sockaddr *)cp);
158 			}
159 			if (((struct sockaddr *)cp)->sa_family == AF_INET) {
160 				sin = (struct sockaddr_in *)cp;
161 				break;
162 			}
163 		}
164 	}
165 	if (sin == NULL)
166 		n->ip.s_addr = htonl(INADDR_ANY);
167 	else
168 		n->ip = sin->sin_addr;
169 	strncpy(n->if_name, ifn, IF_NAMESIZE);
170 
171 	free(buf);
172 }
173 
174 /*
175  * XXX - The following functions, macros and definitions come from natd.c:
176  * it would be better to move them outside natd.c, in a file
177  * (redirect_support.[ch]?) shared by ipfw and natd, but for now i can live
178  * with it.
179  */
180 
181 /*
182  * Definition of a port range, and macros to deal with values.
183  * FORMAT:  HI 16-bits == first port in range, 0 == all ports.
184  *	  LO 16-bits == number of ports in range
185  * NOTES:   - Port values are not stored in network byte order.
186  */
187 
188 #define port_range u_long
189 
190 #define GETLOPORT(x)	((x) >> 0x10)
191 #define GETNUMPORTS(x)	((x) & 0x0000ffff)
192 #define GETHIPORT(x)	(GETLOPORT((x)) + GETNUMPORTS((x)))
193 
194 /* Set y to be the low-port value in port_range variable x. */
195 #define SETLOPORT(x,y)   ((x) = ((x) & 0x0000ffff) | ((y) << 0x10))
196 
197 /* Set y to be the number of ports in port_range variable x. */
198 #define SETNUMPORTS(x,y) ((x) = ((x) & 0xffff0000) | (y))
199 
200 static void
201 StrToAddr (const char* str, struct in_addr* addr)
202 {
203 	struct hostent* hp;
204 
205 	if (inet_aton (str, addr))
206 		return;
207 
208 	hp = gethostbyname (str);
209 	if (!hp)
210 		errx (1, "unknown host %s", str);
211 
212 	memcpy (addr, hp->h_addr, sizeof (struct in_addr));
213 }
214 
215 static int
216 StrToPortRange (const char* str, const char* proto, port_range *portRange)
217 {
218 	char*	   sep;
219 	struct servent*	sp;
220 	char*		end;
221 	u_short	 loPort;
222 	u_short	 hiPort;
223 
224 	/* First see if this is a service, return corresponding port if so. */
225 	sp = getservbyname (str,proto);
226 	if (sp) {
227 		SETLOPORT(*portRange, ntohs(sp->s_port));
228 		SETNUMPORTS(*portRange, 1);
229 		return 0;
230 	}
231 
232 	/* Not a service, see if it's a single port or port range. */
233 	sep = strchr (str, '-');
234 	if (sep == NULL) {
235 		SETLOPORT(*portRange, strtol(str, &end, 10));
236 		if (end != str) {
237 			/* Single port. */
238 			SETNUMPORTS(*portRange, 1);
239 			return 0;
240 		}
241 
242 		/* Error in port range field. */
243 		errx (EX_DATAERR, "%s/%s: unknown service", str, proto);
244 	}
245 
246 	/* Port range, get the values and sanity check. */
247 	sscanf (str, "%hu-%hu", &loPort, &hiPort);
248 	SETLOPORT(*portRange, loPort);
249 	SETNUMPORTS(*portRange, 0);	/* Error by default */
250 	if (loPort <= hiPort)
251 		SETNUMPORTS(*portRange, hiPort - loPort + 1);
252 
253 	if (GETNUMPORTS(*portRange) == 0)
254 		errx (EX_DATAERR, "invalid port range %s", str);
255 
256 	return 0;
257 }
258 
259 static int
260 StrToProto (const char* str)
261 {
262 	if (!strcmp (str, "tcp"))
263 		return IPPROTO_TCP;
264 
265 	if (!strcmp (str, "udp"))
266 		return IPPROTO_UDP;
267 
268 	if (!strcmp (str, "sctp"))
269 		return IPPROTO_SCTP;
270 	errx (EX_DATAERR, "unknown protocol %s. Expected sctp, tcp or udp", str);
271 }
272 
273 static int
274 StrToAddrAndPortRange (const char* str, struct in_addr* addr, char* proto,
275 			port_range *portRange)
276 {
277 	char*	ptr;
278 
279 	ptr = strchr (str, ':');
280 	if (!ptr)
281 		errx (EX_DATAERR, "%s is missing port number", str);
282 
283 	*ptr = '\0';
284 	++ptr;
285 
286 	StrToAddr (str, addr);
287 	return StrToPortRange (ptr, proto, portRange);
288 }
289 
290 /* End of stuff taken from natd.c. */
291 
292 /*
293  * The next 3 functions add support for the addr, port and proto redirect and
294  * their logic is loosely based on SetupAddressRedirect(), SetupPortRedirect()
295  * and SetupProtoRedirect() from natd.c.
296  *
297  * Every setup_* function fills at least one redirect entry
298  * (struct nat44_cfg_redir) and zero or more server pool entry
299  * (struct nat44_cfg_spool) in buf.
300  *
301  * The format of data in buf is:
302  *
303  *  nat44_cfg_nat nat44_cfg_redir nat44_cfg_spool    ......  nat44_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 estimate_redir_addr(int *ac, char ***av)
323 {
324 	size_t space = sizeof(struct nat44_cfg_redir);
325 	char *sep = **av;
326 	u_int c = 0;
327 
328 	(void)ac;	/* UNUSED */
329 	while ((sep = strchr(sep, ',')) != NULL) {
330 		c++;
331 		sep++;
332 	}
333 
334 	if (c > 0)
335 		c++;
336 
337 	space += c * sizeof(struct nat44_cfg_spool);
338 
339 	return (space);
340 }
341 
342 static int
343 setup_redir_addr(char *buf, int *ac, char ***av)
344 {
345 	struct nat44_cfg_redir *r;
346 	char *sep;
347 	size_t space;
348 
349 	r = (struct nat44_cfg_redir *)buf;
350 	r->mode = REDIR_ADDR;
351 	/* Skip nat44_cfg_redir at beginning of buf. */
352 	buf = &buf[sizeof(struct nat44_cfg_redir)];
353 	space = sizeof(struct nat44_cfg_redir);
354 
355 	/* Extract local address. */
356 	if (strchr(**av, ',') != NULL) {
357 		struct nat44_cfg_spool *spool;
358 
359 		/* Setup LSNAT server pool. */
360 		r->laddr.s_addr = INADDR_NONE;
361 		sep = strtok(**av, ",");
362 		while (sep != NULL) {
363 			spool = (struct nat44_cfg_spool *)buf;
364 			space += sizeof(struct nat44_cfg_spool);
365 			StrToAddr(sep, &spool->addr);
366 			spool->port = ~0;
367 			r->spool_cnt++;
368 			/* Point to the next possible nat44_cfg_spool. */
369 			buf = &buf[sizeof(struct nat44_cfg_spool)];
370 			sep = strtok(NULL, ",");
371 		}
372 	} else
373 		StrToAddr(**av, &r->laddr);
374 	(*av)++; (*ac)--;
375 
376 	/* Extract public address. */
377 	StrToAddr(**av, &r->paddr);
378 	(*av)++; (*ac)--;
379 
380 	return (space);
381 }
382 
383 static int
384 estimate_redir_port(int *ac, char ***av)
385 {
386 	size_t space = sizeof(struct nat44_cfg_redir);
387 	char *sep = **av;
388 	u_int c = 0;
389 
390 	(void)ac;	/* UNUSED */
391 	while ((sep = strchr(sep, ',')) != NULL) {
392 		c++;
393 		sep++;
394 	}
395 
396 	if (c > 0)
397 		c++;
398 
399 	space += c * sizeof(struct nat44_cfg_spool);
400 
401 	return (space);
402 }
403 
404 static int
405 setup_redir_port(char *buf, int *ac, char ***av)
406 {
407 	struct nat44_cfg_redir *r;
408 	char *sep, *protoName, *lsnat = NULL;
409 	size_t space;
410 	u_short numLocalPorts;
411 	port_range portRange;
412 
413 	numLocalPorts = 0;
414 
415 	r = (struct nat44_cfg_redir *)buf;
416 	r->mode = REDIR_PORT;
417 	/* Skip nat44_cfg_redir at beginning of buf. */
418 	buf = &buf[sizeof(struct nat44_cfg_redir)];
419 	space = sizeof(struct nat44_cfg_redir);
420 
421 	/*
422 	 * Extract protocol.
423 	 */
424 	r->proto = StrToProto(**av);
425 	protoName = **av;
426 	(*av)++; (*ac)--;
427 
428 	/*
429 	 * Extract local address.
430 	 */
431 	if (strchr(**av, ',') != NULL) {
432 		r->laddr.s_addr = INADDR_NONE;
433 		r->lport = ~0;
434 		numLocalPorts = 1;
435 		lsnat = **av;
436 	} else {
437 		/*
438 		 * The sctp nat does not allow the port numbers to be mapped to
439 		 * new port numbers. Therefore, no ports are to be specified
440 		 * in the target port field.
441 		 */
442 		if (r->proto == IPPROTO_SCTP) {
443 			if (strchr(**av, ':'))
444 				errx(EX_DATAERR, "redirect_port:"
445 				    "port numbers do not change in sctp, so do "
446 				    "not specify them as part of the target");
447 			else
448 				StrToAddr(**av, &r->laddr);
449 		} else {
450 			if (StrToAddrAndPortRange(**av, &r->laddr, protoName,
451 			    &portRange) != 0)
452 				errx(EX_DATAERR, "redirect_port: "
453 				    "invalid local port range");
454 
455 			r->lport = GETLOPORT(portRange);
456 			numLocalPorts = GETNUMPORTS(portRange);
457 		}
458 	}
459 	(*av)++; (*ac)--;
460 
461 	/*
462 	 * Extract public port and optionally address.
463 	 */
464 	if (strchr(**av, ':') != NULL) {
465 		if (StrToAddrAndPortRange(**av, &r->paddr, protoName,
466 		    &portRange) != 0)
467 			errx(EX_DATAERR, "redirect_port: "
468 			    "invalid public port range");
469 	} else {
470 		r->paddr.s_addr = INADDR_ANY;
471 		if (StrToPortRange(**av, protoName, &portRange) != 0)
472 			errx(EX_DATAERR, "redirect_port: "
473 			    "invalid public port range");
474 	}
475 
476 	r->pport = GETLOPORT(portRange);
477 	if (r->proto == IPPROTO_SCTP) { /* so the logic below still works */
478 		numLocalPorts = GETNUMPORTS(portRange);
479 		r->lport = r->pport;
480 	}
481 	r->pport_cnt = GETNUMPORTS(portRange);
482 	(*av)++; (*ac)--;
483 
484 	/*
485 	 * Extract remote address and optionally port.
486 	 */
487 	/*
488 	 * NB: isdigit(**av) => we've to check that next parameter is really an
489 	 * option for this redirect entry, else stop here processing arg[cv].
490 	 */
491 	if (*ac != 0 && isdigit(***av)) {
492 		if (strchr(**av, ':') != NULL) {
493 			if (StrToAddrAndPortRange(**av, &r->raddr, protoName,
494 			    &portRange) != 0)
495 				errx(EX_DATAERR, "redirect_port: "
496 				    "invalid remote port range");
497 		} else {
498 			SETLOPORT(portRange, 0);
499 			SETNUMPORTS(portRange, 1);
500 			StrToAddr(**av, &r->raddr);
501 		}
502 		(*av)++; (*ac)--;
503 	} else {
504 		SETLOPORT(portRange, 0);
505 		SETNUMPORTS(portRange, 1);
506 		r->raddr.s_addr = INADDR_ANY;
507 	}
508 	r->rport = GETLOPORT(portRange);
509 	r->rport_cnt = GETNUMPORTS(portRange);
510 
511 	/*
512 	 * Make sure port ranges match up, then add the redirect ports.
513 	 */
514 	if (numLocalPorts != r->pport_cnt)
515 		errx(EX_DATAERR, "redirect_port: "
516 		    "port ranges must be equal in size");
517 
518 	/* Remote port range is allowed to be '0' which means all ports. */
519 	if (r->rport_cnt != numLocalPorts &&
520 	    (r->rport_cnt != 1 || r->rport != 0))
521 		errx(EX_DATAERR, "redirect_port: remote port must"
522 		    "be 0 or equal to local port range in size");
523 
524 	/* Setup LSNAT server pool. */
525 	if (lsnat != NULL) {
526 		struct nat44_cfg_spool *spool;
527 
528 		sep = strtok(lsnat, ",");
529 		while (sep != NULL) {
530 			spool = (struct nat44_cfg_spool *)buf;
531 			space += sizeof(struct nat44_cfg_spool);
532 			/*
533 			 * The sctp nat does not allow the port numbers to
534 			 * be mapped to new port numbers. Therefore, no ports
535 			 * are to be specified in the target port field.
536 			 */
537 			if (r->proto == IPPROTO_SCTP) {
538 				if (strchr (sep, ':')) {
539 					errx(EX_DATAERR, "redirect_port:"
540 					    "port numbers do not change in "
541 					    "sctp, so do not specify them as "
542 					    "part of the target");
543 				} else {
544 					StrToAddr(sep, &spool->addr);
545 					spool->port = r->pport;
546 				}
547 			} else {
548 				if (StrToAddrAndPortRange(sep, &spool->addr,
549 					protoName, &portRange) != 0)
550 					errx(EX_DATAERR, "redirect_port:"
551 					    "invalid local port range");
552 				if (GETNUMPORTS(portRange) != 1)
553 					errx(EX_DATAERR, "redirect_port: "
554 					    "local port must be single in "
555 					    "this context");
556 				spool->port = GETLOPORT(portRange);
557 			}
558 			r->spool_cnt++;
559 			/* Point to the next possible nat44_cfg_spool. */
560 			buf = &buf[sizeof(struct nat44_cfg_spool)];
561 			sep = strtok(NULL, ",");
562 		}
563 	}
564 
565 	return (space);
566 }
567 
568 static int
569 setup_redir_proto(char *buf, int *ac, char ***av)
570 {
571 	struct nat44_cfg_redir *r;
572 	struct protoent *protoent;
573 	size_t space;
574 
575 	r = (struct nat44_cfg_redir *)buf;
576 	r->mode = REDIR_PROTO;
577 	/* Skip nat44_cfg_redir at beginning of buf. */
578 	buf = &buf[sizeof(struct nat44_cfg_redir)];
579 	space = sizeof(struct nat44_cfg_redir);
580 
581 	/*
582 	 * Extract protocol.
583 	 */
584 	protoent = getprotobyname(**av);
585 	if (protoent == NULL)
586 		errx(EX_DATAERR, "redirect_proto: unknown protocol %s", **av);
587 	else
588 		r->proto = protoent->p_proto;
589 
590 	(*av)++; (*ac)--;
591 
592 	/*
593 	 * Extract local address.
594 	 */
595 	StrToAddr(**av, &r->laddr);
596 
597 	(*av)++; (*ac)--;
598 
599 	/*
600 	 * Extract optional public address.
601 	 */
602 	if (*ac == 0) {
603 		r->paddr.s_addr = INADDR_ANY;
604 		r->raddr.s_addr = INADDR_ANY;
605 	} else {
606 		/* see above in setup_redir_port() */
607 		if (isdigit(***av)) {
608 			StrToAddr(**av, &r->paddr);
609 			(*av)++; (*ac)--;
610 
611 			/*
612 			 * Extract optional remote address.
613 			 */
614 			/* see above in setup_redir_port() */
615 			if (*ac != 0 && isdigit(***av)) {
616 				StrToAddr(**av, &r->raddr);
617 				(*av)++; (*ac)--;
618 			}
619 		}
620 	}
621 
622 	return (space);
623 }
624 
625 static void
626 nat_show_log(struct nat44_cfg_nat *n, void *arg __unused)
627 {
628 	char *buf;
629 
630 	buf = (char *)(n + 1);
631 	if (buf[0] != '\0')
632 		printf("nat %s: %s\n", n->name, buf);
633 }
634 
635 static void
636 nat_show_cfg(struct nat44_cfg_nat *n, void *arg __unused)
637 {
638 	struct nat44_cfg_redir *t;
639 	struct nat44_cfg_spool *s;
640 	caddr_t buf;
641 	struct protoent *p;
642 	uint32_t cnt;
643 	int i, off;
644 
645 	buf = (caddr_t)n;
646 	off = sizeof(*n);
647 	printf("ipfw nat %s config", n->name);
648 	if (strlen(n->if_name) != 0)
649 		printf(" if %s", n->if_name);
650 	else if (n->ip.s_addr != 0)
651 		printf(" ip %s", inet_ntoa(n->ip));
652 	while (n->mode != 0) {
653 		if (n->mode & PKT_ALIAS_LOG) {
654 			printf(" log");
655 			n->mode &= ~PKT_ALIAS_LOG;
656 		} else if (n->mode & PKT_ALIAS_DENY_INCOMING) {
657 			printf(" deny_in");
658 			n->mode &= ~PKT_ALIAS_DENY_INCOMING;
659 		} else if (n->mode & PKT_ALIAS_SAME_PORTS) {
660 			printf(" same_ports");
661 			n->mode &= ~PKT_ALIAS_SAME_PORTS;
662 		} else if (n->mode & PKT_ALIAS_SKIP_GLOBAL) {
663 			printf(" skip_global");
664 			n->mode &= ~PKT_ALIAS_SKIP_GLOBAL;
665 		} else if (n->mode & PKT_ALIAS_UNREGISTERED_ONLY) {
666 			printf(" unreg_only");
667 			n->mode &= ~PKT_ALIAS_UNREGISTERED_ONLY;
668 		} else if (n->mode & PKT_ALIAS_UNREGISTERED_CGN) {
669 			printf(" unreg_cgn");
670 			n->mode &= ~PKT_ALIAS_UNREGISTERED_CGN;
671 		} else if (n->mode & PKT_ALIAS_RESET_ON_ADDR_CHANGE) {
672 			printf(" reset");
673 			n->mode &= ~PKT_ALIAS_RESET_ON_ADDR_CHANGE;
674 		} else if (n->mode & PKT_ALIAS_REVERSE) {
675 			printf(" reverse");
676 			n->mode &= ~PKT_ALIAS_REVERSE;
677 		} else if (n->mode & PKT_ALIAS_PROXY_ONLY) {
678 			printf(" proxy_only");
679 			n->mode &= ~PKT_ALIAS_PROXY_ONLY;
680 		} else if (n->mode & PKT_ALIAS_UDP_EIM) {
681 			printf(" udp_eim");
682 			n->mode &= ~PKT_ALIAS_UDP_EIM;
683 		}
684 	}
685 	/* Print all the redirect's data configuration. */
686 	for (cnt = 0; cnt < n->redir_cnt; cnt++) {
687 		t = (struct nat44_cfg_redir *)&buf[off];
688 		off += sizeof(struct nat44_cfg_redir);
689 		switch (t->mode) {
690 		case REDIR_ADDR:
691 			printf(" redirect_addr");
692 			if (t->spool_cnt == 0)
693 				printf(" %s", inet_ntoa(t->laddr));
694 			else
695 				for (i = 0; i < t->spool_cnt; i++) {
696 					s = (struct nat44_cfg_spool *)&buf[off];
697 					if (i)
698 						printf(",");
699 					else
700 						printf(" ");
701 					printf("%s", inet_ntoa(s->addr));
702 					off += sizeof(struct nat44_cfg_spool);
703 				}
704 			printf(" %s", inet_ntoa(t->paddr));
705 			break;
706 		case REDIR_PORT:
707 			p = getprotobynumber(t->proto);
708 			printf(" redirect_port %s ", p->p_name);
709 			if (!t->spool_cnt) {
710 				printf("%s:%u", inet_ntoa(t->laddr), t->lport);
711 				if (t->pport_cnt > 1)
712 					printf("-%u", t->lport +
713 					    t->pport_cnt - 1);
714 			} else
715 				for (i=0; i < t->spool_cnt; i++) {
716 					s = (struct nat44_cfg_spool *)&buf[off];
717 					if (i)
718 						printf(",");
719 					printf("%s:%u", inet_ntoa(s->addr),
720 					    s->port);
721 					off += sizeof(struct nat44_cfg_spool);
722 				}
723 
724 			printf(" ");
725 			if (t->paddr.s_addr)
726 				printf("%s:", inet_ntoa(t->paddr));
727 			printf("%u", t->pport);
728 			if (!t->spool_cnt && t->pport_cnt > 1)
729 				printf("-%u", t->pport + t->pport_cnt - 1);
730 
731 			if (t->raddr.s_addr) {
732 				printf(" %s", inet_ntoa(t->raddr));
733 				if (t->rport) {
734 					printf(":%u", t->rport);
735 					if (!t->spool_cnt && t->rport_cnt > 1)
736 						printf("-%u", t->rport +
737 						    t->rport_cnt - 1);
738 				}
739 			}
740 			break;
741 		case REDIR_PROTO:
742 			p = getprotobynumber(t->proto);
743 			printf(" redirect_proto %s %s", p->p_name,
744 			    inet_ntoa(t->laddr));
745 			if (t->paddr.s_addr != 0) {
746 				printf(" %s", inet_ntoa(t->paddr));
747 				if (t->raddr.s_addr)
748 					printf(" %s", inet_ntoa(t->raddr));
749 			}
750 			break;
751 		default:
752 			errx(EX_DATAERR, "unknown redir mode");
753 			break;
754 		}
755 	}
756 	printf("\n");
757 }
758 
759 static int
760 nat_port_alias_parse(char *str, u_short *lpout, u_short *hpout) {
761 	long lp, hp;
762 	char *ptr;
763 	/* Lower port parsing */
764 	lp = (long) strtol(str, &ptr, 10);
765 	if (lp < 1024 || lp > 65535)
766 		return 0;
767 	if (!ptr || *ptr != '-')
768 		return 0;
769 	/* Upper port parsing */
770 	hp = (long) strtol(ptr, &ptr, 10);
771 	if (hp < 1024 || hp > 65535)
772 		return 0;
773 	if (ptr)
774 		return 0;
775 
776 	*lpout = (u_short) lp;
777 	*hpout = (u_short) hp;
778 	return 1;
779 }
780 
781 void
782 ipfw_config_nat(int ac, char **av)
783 {
784 	ipfw_obj_header *oh;
785 	struct nat44_cfg_nat *n;		/* Nat instance configuration. */
786 	int i, off, tok, ac1;
787 	u_short lp, hp;
788 	char *id, *buf, **av1, *end;
789 	size_t len;
790 
791 	av++;
792 	ac--;
793 	/* Nat id. */
794 	if (ac == 0)
795 		errx(EX_DATAERR, "missing nat id");
796 	id = *av;
797 	i = (int)strtol(id, &end, 0);
798 	if (i <= 0 || *end != '\0')
799 		errx(EX_DATAERR, "illegal nat id: %s", id);
800 	av++;
801 	ac--;
802 	if (ac == 0)
803 		errx(EX_DATAERR, "missing option");
804 
805 	len = sizeof(*oh) + sizeof(*n);
806 	ac1 = ac;
807 	av1 = av;
808 	while (ac1 > 0) {
809 		tok = match_token(nat_params, *av1);
810 		ac1--;
811 		av1++;
812 		switch (tok) {
813 		case TOK_IP:
814 		case TOK_IF:
815 		case TOK_PORT_ALIAS:
816 			ac1--;
817 			av1++;
818 			break;
819 		case TOK_ALOG:
820 		case TOK_DENY_INC:
821 		case TOK_SAME_PORTS:
822 		case TOK_SKIP_GLOBAL:
823 		case TOK_UNREG_ONLY:
824 		case TOK_UNREG_CGN:
825 		case TOK_RESET_ADDR:
826 		case TOK_ALIAS_REV:
827 		case TOK_PROXY_ONLY:
828 		case TOK_UDP_EIM:
829 			break;
830 		case TOK_REDIR_ADDR:
831 			if (ac1 < 2)
832 				errx(EX_DATAERR, "redirect_addr: "
833 				    "not enough arguments");
834 			len += estimate_redir_addr(&ac1, &av1);
835 			av1 += 2;
836 			ac1 -= 2;
837 			break;
838 		case TOK_REDIR_PORT:
839 			if (ac1 < 3)
840 				errx(EX_DATAERR, "redirect_port: "
841 				    "not enough arguments");
842 			av1++;
843 			ac1--;
844 			len += estimate_redir_port(&ac1, &av1);
845 			av1 += 2;
846 			ac1 -= 2;
847 			/* Skip optional remoteIP/port */
848 			if (ac1 != 0 && isdigit(**av1)) {
849 				av1++;
850 				ac1--;
851 			}
852 			break;
853 		case TOK_REDIR_PROTO:
854 			if (ac1 < 2)
855 				errx(EX_DATAERR, "redirect_proto: "
856 				    "not enough arguments");
857 			len += sizeof(struct nat44_cfg_redir);
858 			av1 += 2;
859 			ac1 -= 2;
860 			/* Skip optional remoteIP/port */
861 			if (ac1 != 0 && isdigit(**av1)) {
862 				av1++;
863 				ac1--;
864 			}
865 			if (ac1 != 0 && isdigit(**av1)) {
866 				av1++;
867 				ac1--;
868 			}
869 			break;
870 		default:
871 			errx(EX_DATAERR, "unrecognised option ``%s''", av1[-1]);
872 		}
873 	}
874 
875 	if ((buf = malloc(len)) == NULL)
876 		errx(EX_OSERR, "malloc failed");
877 
878 	/* Offset in buf: save space for header at the beginning. */
879 	off = sizeof(*oh) + sizeof(*n);
880 	memset(buf, 0, len);
881 	oh = (ipfw_obj_header *)buf;
882 	n = (struct nat44_cfg_nat *)(oh + 1);
883 	oh->ntlv.head.length = sizeof(oh->ntlv);
884 	snprintf(oh->ntlv.name, sizeof(oh->ntlv.name), "%d", i);
885 	snprintf(n->name, sizeof(n->name), "%d", i);
886 
887 	while (ac > 0) {
888 		tok = match_token(nat_params, *av);
889 		ac--;
890 		av++;
891 		switch (tok) {
892 		case TOK_IP:
893 			if (ac == 0)
894 				errx(EX_DATAERR, "missing option");
895 			if (!inet_aton(av[0], &(n->ip)))
896 				errx(EX_DATAERR, "bad ip address ``%s''",
897 				    av[0]);
898 			ac--;
899 			av++;
900 			break;
901 		case TOK_IF:
902 			if (ac == 0)
903 				errx(EX_DATAERR, "missing option");
904 			set_addr_dynamic(av[0], n);
905 			ac--;
906 			av++;
907 			break;
908 		case TOK_ALOG:
909 			n->mode |= PKT_ALIAS_LOG;
910 			break;
911 		case TOK_DENY_INC:
912 			n->mode |= PKT_ALIAS_DENY_INCOMING;
913 			break;
914 		case TOK_SAME_PORTS:
915 			n->mode |= PKT_ALIAS_SAME_PORTS;
916 			break;
917 		case TOK_UNREG_ONLY:
918 			n->mode |= PKT_ALIAS_UNREGISTERED_ONLY;
919 			break;
920 		case TOK_UNREG_CGN:
921 			n->mode |= PKT_ALIAS_UNREGISTERED_CGN;
922 			break;
923 		case TOK_SKIP_GLOBAL:
924 			n->mode |= PKT_ALIAS_SKIP_GLOBAL;
925 			break;
926 		case TOK_RESET_ADDR:
927 			n->mode |= PKT_ALIAS_RESET_ON_ADDR_CHANGE;
928 			break;
929 		case TOK_ALIAS_REV:
930 			n->mode |= PKT_ALIAS_REVERSE;
931 			break;
932 		case TOK_PROXY_ONLY:
933 			n->mode |= PKT_ALIAS_PROXY_ONLY;
934 			break;
935 		case TOK_UDP_EIM:
936 			n->mode |= PKT_ALIAS_UDP_EIM;
937 			break;
938 			/*
939 			 * All the setup_redir_* functions work directly in
940 			 * the final buffer, see above for details.
941 			 */
942 		case TOK_REDIR_ADDR:
943 		case TOK_REDIR_PORT:
944 		case TOK_REDIR_PROTO:
945 			switch (tok) {
946 			case TOK_REDIR_ADDR:
947 				i = setup_redir_addr(&buf[off], &ac, &av);
948 				break;
949 			case TOK_REDIR_PORT:
950 				i = setup_redir_port(&buf[off], &ac, &av);
951 				break;
952 			case TOK_REDIR_PROTO:
953 				i = setup_redir_proto(&buf[off], &ac, &av);
954 				break;
955 			}
956 			n->redir_cnt++;
957 			off += i;
958 			break;
959 		case TOK_PORT_ALIAS:
960 			if (ac == 0)
961 				errx(EX_DATAERR, "missing option");
962 			if (!nat_port_alias_parse(av[0], &lp, &hp))
963 				errx(EX_DATAERR,
964 				    "You need a range of port(s) from 1024 <= x < 65536");
965 			if (lp >= hp)
966 				errx(EX_DATAERR,
967 				    "Upper port has to be greater than lower port");
968 			n->alias_port_lo = lp;
969 			n->alias_port_hi = hp;
970 			ac--;
971 			av++;
972 			break;
973 		}
974 	}
975 	if (n->mode & PKT_ALIAS_SAME_PORTS && n->alias_port_lo)
976 		errx(EX_DATAERR, "same_ports and port_range cannot both be selected");
977 
978 	i = do_set3(IP_FW_NAT44_XCONFIG, &oh->opheader, len);
979 	if (i != 0)
980 		err(1, "setsockopt(%s)", "IP_FW_NAT44_XCONFIG");
981 
982 	if (!g_co.do_quiet) {
983 		/* After every modification, we show the resultant rule. */
984 		int _ac = 3;
985 		const char *_av[] = {"show", "config", id};
986 		ipfw_show_nat(_ac, (char **)(void *)_av);
987 	}
988 }
989 
990 static void
991 nat_fill_ntlv(ipfw_obj_ntlv *ntlv, int i)
992 {
993 
994 	ntlv->head.type = IPFW_TLV_EACTION_NAME(1); /* it doesn't matter */
995 	ntlv->head.length = sizeof(ipfw_obj_ntlv);
996 	ntlv->idx = 1;
997 	ntlv->set = 0; /* not yet */
998 	snprintf(ntlv->name, sizeof(ntlv->name), "%d", i);
999 }
1000 
1001 int
1002 ipfw_delete_nat(int i)
1003 {
1004 	ipfw_obj_header oh;
1005 	int ret;
1006 
1007 	memset(&oh, 0, sizeof(oh));
1008 	nat_fill_ntlv(&oh.ntlv, i);
1009 	ret = do_set3(IP_FW_NAT44_DESTROY, &oh.opheader, sizeof(oh));
1010 	if (ret == -1) {
1011 		if (!g_co.do_quiet)
1012 			warn("nat %u not available", i);
1013 		return (EX_UNAVAILABLE);
1014 	}
1015 	return (EX_OK);
1016 }
1017 
1018 struct nat_list_arg {
1019 	uint16_t	cmd;
1020 	int		is_all;
1021 };
1022 
1023 static int
1024 nat_show_data(struct nat44_cfg_nat *cfg, void *arg)
1025 {
1026 	struct nat_list_arg *nla;
1027 	ipfw_obj_header *oh;
1028 
1029 	nla = (struct nat_list_arg *)arg;
1030 
1031 	switch (nla->cmd) {
1032 	case IP_FW_NAT44_XGETCONFIG:
1033 		if (nat_get_cmd(cfg->name, nla->cmd, &oh) != 0) {
1034 			warnx("Error getting nat instance %s info", cfg->name);
1035 			break;
1036 		}
1037 		nat_show_cfg((struct nat44_cfg_nat *)(oh + 1), NULL);
1038 		free(oh);
1039 		break;
1040 	case IP_FW_NAT44_XGETLOG:
1041 		if (nat_get_cmd(cfg->name, nla->cmd, &oh) == 0) {
1042 			nat_show_log((struct nat44_cfg_nat *)(oh + 1), NULL);
1043 			free(oh);
1044 			break;
1045 		}
1046 		/* Handle error */
1047 		if (nla->is_all != 0 && errno == ENOENT)
1048 			break;
1049 		warn("Error getting nat instance %s info", cfg->name);
1050 		break;
1051 	}
1052 
1053 	return (0);
1054 }
1055 
1056 /*
1057  * Compare nat names.
1058  * Honor number comparison.
1059  */
1060 static int
1061 natname_cmp(const void *a, const void *b)
1062 {
1063 	const struct nat44_cfg_nat *ia, *ib;
1064 
1065 	ia = (const struct nat44_cfg_nat *)a;
1066 	ib = (const struct nat44_cfg_nat *)b;
1067 
1068 	return (stringnum_cmp(ia->name, ib->name));
1069 }
1070 
1071 /*
1072  * Retrieves nat list from kernel,
1073  * optionally sorts it and calls requested function for each table.
1074  * Returns 0 on success.
1075  */
1076 static int
1077 nat_foreach(nat_cb_t *f, void *arg, int sort)
1078 {
1079 	ipfw_obj_lheader *olh;
1080 	struct nat44_cfg_nat *cfg;
1081 	size_t sz;
1082 	uint32_t i;
1083 
1084 	/* Start with reasonable default */
1085 	sz = sizeof(*olh) + 16 * sizeof(struct nat44_cfg_nat);
1086 
1087 	for (;;) {
1088 		if ((olh = calloc(1, sz)) == NULL)
1089 			return (ENOMEM);
1090 
1091 		olh->size = sz;
1092 		if (do_get3(IP_FW_NAT44_LIST_NAT, &olh->opheader, &sz) != 0) {
1093 			sz = olh->size;
1094 			free(olh);
1095 			if (errno == ENOMEM)
1096 				continue;
1097 			return (errno);
1098 		}
1099 
1100 		if (sort != 0)
1101 			qsort(olh + 1, olh->count, olh->objsize, natname_cmp);
1102 
1103 		cfg = (struct nat44_cfg_nat*)(olh + 1);
1104 		for (i = 0; i < olh->count; i++) {
1105 			(void)f(cfg, arg); /* Ignore errors for now */
1106 			cfg = (struct nat44_cfg_nat *)((caddr_t)cfg +
1107 			    olh->objsize);
1108 		}
1109 
1110 		free(olh);
1111 		break;
1112 	}
1113 
1114 	return (0);
1115 }
1116 
1117 static int
1118 nat_get_cmd(char *name, uint16_t cmd, ipfw_obj_header **ooh)
1119 {
1120 	ipfw_obj_header *oh;
1121 	struct nat44_cfg_nat *cfg;
1122 	size_t sz;
1123 
1124 	/* Start with reasonable default */
1125 	sz = sizeof(*oh) + sizeof(*cfg) + 128;
1126 
1127 	for (;;) {
1128 		if ((oh = calloc(1, sz)) == NULL)
1129 			return (ENOMEM);
1130 		cfg = (struct nat44_cfg_nat *)(oh + 1);
1131 		oh->ntlv.head.length = sizeof(oh->ntlv);
1132 		strlcpy(oh->ntlv.name, name, sizeof(oh->ntlv.name));
1133 		strlcpy(cfg->name, name, sizeof(cfg->name));
1134 
1135 		if (do_get3(cmd, &oh->opheader, &sz) != 0) {
1136 			sz = cfg->size;
1137 			free(oh);
1138 			if (errno == ENOMEM)
1139 				continue;
1140 			return (errno);
1141 		}
1142 
1143 		*ooh = oh;
1144 		break;
1145 	}
1146 
1147 	return (0);
1148 }
1149 
1150 void
1151 ipfw_show_nat(int ac, char **av)
1152 {
1153 	ipfw_obj_header *oh;
1154 	char *name;
1155 	int cmd;
1156 	struct nat_list_arg nla;
1157 
1158 	ac--;
1159 	av++;
1160 
1161 	if (g_co.test_only)
1162 		return;
1163 
1164 	/* Parse parameters. */
1165 	cmd = 0; /* XXX: Change to IP_FW_NAT44_XGETLOG @ MFC */
1166 	name = NULL;
1167 	for ( ; ac != 0; ac--, av++) {
1168 		if (!strncmp(av[0], "config", strlen(av[0]))) {
1169 			cmd = IP_FW_NAT44_XGETCONFIG;
1170 			continue;
1171 		}
1172 		if (strcmp(av[0], "log") == 0) {
1173 			cmd = IP_FW_NAT44_XGETLOG;
1174 			continue;
1175 		}
1176 		if (name != NULL)
1177 			err(EX_USAGE,"only one instance name may be specified");
1178 		name = av[0];
1179 	}
1180 
1181 	if (cmd == 0)
1182 		errx(EX_USAGE, "Please specify action. Available: config,log");
1183 
1184 	if (name == NULL) {
1185 		memset(&nla, 0, sizeof(nla));
1186 		nla.cmd = cmd;
1187 		nla.is_all = 1;
1188 		nat_foreach(nat_show_data, &nla, 1);
1189 	} else {
1190 		if (nat_get_cmd(name, cmd, &oh) != 0)
1191 			err(EX_OSERR, "Error getting nat %s instance info", name);
1192 		nat_show_cfg((struct nat44_cfg_nat *)(oh + 1), NULL);
1193 		free(oh);
1194 	}
1195 }
1196 
1197