xref: /freebsd/sbin/ipfw/nat.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
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  	{ NULL, 0 }	/* terminator */
71 };
72 
73 
74 /*
75  * Search for interface with name "ifn", and fill n accordingly:
76  *
77  * n->ip	ip address of interface "ifn"
78  * n->if_name   copy of interface name "ifn"
79  */
80 static void
set_addr_dynamic(const char * ifn,struct nat44_cfg_nat * n)81 set_addr_dynamic(const char *ifn, struct nat44_cfg_nat *n)
82 {
83 	size_t needed;
84 	int mib[6];
85 	char *buf, *lim, *next;
86 	struct if_msghdr *ifm;
87 	struct ifa_msghdr *ifam;
88 	struct sockaddr_dl *sdl;
89 	struct sockaddr_in *sin;
90 	int ifIndex;
91 
92 	mib[0] = CTL_NET;
93 	mib[1] = PF_ROUTE;
94 	mib[2] = 0;
95 	mib[3] = AF_INET;
96 	mib[4] = NET_RT_IFLIST;
97 	mib[5] = 0;
98 /*
99  * Get interface data.
100  */
101 	if (sysctl(mib, 6, NULL, &needed, NULL, 0) == -1)
102 		err(1, "iflist-sysctl-estimate");
103 	buf = safe_calloc(1, needed);
104 	if (sysctl(mib, 6, buf, &needed, NULL, 0) == -1)
105 		err(1, "iflist-sysctl-get");
106 	lim = buf + needed;
107 /*
108  * Loop through interfaces until one with
109  * given name is found. This is done to
110  * find correct interface index for routing
111  * message processing.
112  */
113 	ifIndex	= 0;
114 	next = buf;
115 	while (next < lim) {
116 		ifm = (struct if_msghdr *)next;
117 		next += ifm->ifm_msglen;
118 		if (ifm->ifm_version != RTM_VERSION) {
119 			if (g_co.verbose)
120 				warnx("routing message version %d "
121 				    "not understood", ifm->ifm_version);
122 			continue;
123 		}
124 		if (ifm->ifm_type == RTM_IFINFO) {
125 			sdl = (struct sockaddr_dl *)(ifm + 1);
126 			if (strlen(ifn) == sdl->sdl_nlen &&
127 			    strncmp(ifn, sdl->sdl_data, sdl->sdl_nlen) == 0) {
128 				ifIndex = ifm->ifm_index;
129 				break;
130 			}
131 		}
132 	}
133 	if (!ifIndex)
134 		errx(1, "unknown interface name %s", ifn);
135 /*
136  * Get interface address.
137  */
138 	sin = NULL;
139 	while (next < lim) {
140 		ifam = (struct ifa_msghdr *)next;
141 		next += ifam->ifam_msglen;
142 		if (ifam->ifam_version != RTM_VERSION) {
143 			if (g_co.verbose)
144 				warnx("routing message version %d "
145 				    "not understood", ifam->ifam_version);
146 			continue;
147 		}
148 		if (ifam->ifam_type != RTM_NEWADDR)
149 			break;
150 		if (ifam->ifam_addrs & RTA_IFA) {
151 			int i;
152 			char *cp = (char *)(ifam + 1);
153 
154 			for (i = 1; i < RTA_IFA; i <<= 1) {
155 				if (ifam->ifam_addrs & i)
156 					cp += SA_SIZE((struct sockaddr *)cp);
157 			}
158 			if (((struct sockaddr *)cp)->sa_family == AF_INET) {
159 				sin = (struct sockaddr_in *)cp;
160 				break;
161 			}
162 		}
163 	}
164 	if (sin == NULL)
165 		n->ip.s_addr = htonl(INADDR_ANY);
166 	else
167 		n->ip = sin->sin_addr;
168 	strncpy(n->if_name, ifn, IF_NAMESIZE);
169 
170 	free(buf);
171 }
172 
173 /*
174  * XXX - The following functions, macros and definitions come from natd.c:
175  * it would be better to move them outside natd.c, in a file
176  * (redirect_support.[ch]?) shared by ipfw and natd, but for now i can live
177  * with it.
178  */
179 
180 /*
181  * Definition of a port range, and macros to deal with values.
182  * FORMAT:  HI 16-bits == first port in range, 0 == all ports.
183  *	  LO 16-bits == number of ports in range
184  * NOTES:   - Port values are not stored in network byte order.
185  */
186 
187 #define port_range u_long
188 
189 #define GETLOPORT(x)	((x) >> 0x10)
190 #define GETNUMPORTS(x)	((x) & 0x0000ffff)
191 #define GETHIPORT(x)	(GETLOPORT((x)) + GETNUMPORTS((x)))
192 
193 /* Set y to be the low-port value in port_range variable x. */
194 #define SETLOPORT(x,y)   ((x) = ((x) & 0x0000ffff) | ((y) << 0x10))
195 
196 /* Set y to be the number of ports in port_range variable x. */
197 #define SETNUMPORTS(x,y) ((x) = ((x) & 0xffff0000) | (y))
198 
199 static void
StrToAddr(const char * str,struct in_addr * addr)200 StrToAddr (const char* str, struct in_addr* addr)
201 {
202 	struct hostent* hp;
203 
204 	if (inet_aton (str, addr))
205 		return;
206 
207 	hp = gethostbyname (str);
208 	if (!hp)
209 		errx (1, "unknown host %s", str);
210 
211 	memcpy (addr, hp->h_addr, sizeof (struct in_addr));
212 }
213 
214 static int
StrToPortRange(const char * str,const char * proto,port_range * portRange)215 StrToPortRange (const char* str, const char* proto, port_range *portRange)
216 {
217 	char*	   sep;
218 	struct servent*	sp;
219 	char*		end;
220 	u_short	 loPort;
221 	u_short	 hiPort;
222 
223 	/* First see if this is a service, return corresponding port if so. */
224 	sp = getservbyname (str,proto);
225 	if (sp) {
226 		SETLOPORT(*portRange, ntohs(sp->s_port));
227 		SETNUMPORTS(*portRange, 1);
228 		return 0;
229 	}
230 
231 	/* Not a service, see if it's a single port or port range. */
232 	sep = strchr (str, '-');
233 	if (sep == NULL) {
234 		SETLOPORT(*portRange, strtol(str, &end, 10));
235 		if (end != str) {
236 			/* Single port. */
237 			SETNUMPORTS(*portRange, 1);
238 			return 0;
239 		}
240 
241 		/* Error in port range field. */
242 		errx (EX_DATAERR, "%s/%s: unknown service", str, proto);
243 	}
244 
245 	/* Port range, get the values and sanity check. */
246 	sscanf (str, "%hu-%hu", &loPort, &hiPort);
247 	SETLOPORT(*portRange, loPort);
248 	SETNUMPORTS(*portRange, 0);	/* Error by default */
249 	if (loPort <= hiPort)
250 		SETNUMPORTS(*portRange, hiPort - loPort + 1);
251 
252 	if (GETNUMPORTS(*portRange) == 0)
253 		errx (EX_DATAERR, "invalid port range %s", str);
254 
255 	return 0;
256 }
257 
258 static int
StrToProto(const char * str)259 StrToProto (const char* str)
260 {
261 	if (!strcmp (str, "tcp"))
262 		return IPPROTO_TCP;
263 
264 	if (!strcmp (str, "udp"))
265 		return IPPROTO_UDP;
266 
267 	if (!strcmp (str, "sctp"))
268 		return IPPROTO_SCTP;
269 	errx (EX_DATAERR, "unknown protocol %s. Expected sctp, tcp or udp", str);
270 }
271 
272 static int
StrToAddrAndPortRange(const char * str,struct in_addr * addr,char * proto,port_range * portRange)273 StrToAddrAndPortRange (const char* str, struct in_addr* addr, char* proto,
274 			port_range *portRange)
275 {
276 	char*	ptr;
277 
278 	ptr = strchr (str, ':');
279 	if (!ptr)
280 		errx (EX_DATAERR, "%s is missing port number", str);
281 
282 	*ptr = '\0';
283 	++ptr;
284 
285 	StrToAddr (str, addr);
286 	return StrToPortRange (ptr, proto, portRange);
287 }
288 
289 /* End of stuff taken from natd.c. */
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 nat44_cfg_redir) and zero or more server pool entry
298  * (struct nat44_cfg_spool) in buf.
299  *
300  * The format of data in buf is:
301  *
302  *  nat44_cfg_nat nat44_cfg_redir nat44_cfg_spool    ......  nat44_cfg_spool
303  *
304  *    -------------------------------------        ------------
305  *   |           | .....X ..... |          |         |           |  .....
306  *    ------------------------------------- ...... ------------
307  *                     ^
308  *                spool_cnt       n=0       ......   n=(X-1)
309  *
310  * len points to the amount of available space in buf
311  * space counts the memory consumed by every function
312  *
313  * XXX - Every function get all the argv params so it
314  * has to check, in optional parameters, that the next
315  * args is a valid option for the redir entry and not
316  * another token. Only redir_port and redir_proto are
317  * affected by this.
318  */
319 
320 static int
estimate_redir_addr(int * ac,char *** av)321 estimate_redir_addr(int *ac, char ***av)
322 {
323 	size_t space = sizeof(struct nat44_cfg_redir);
324 	char *sep = **av;
325 	u_int c = 0;
326 
327 	(void)ac;	/* UNUSED */
328 	while ((sep = strchr(sep, ',')) != NULL) {
329 		c++;
330 		sep++;
331 	}
332 
333 	if (c > 0)
334 		c++;
335 
336 	space += c * sizeof(struct nat44_cfg_spool);
337 
338 	return (space);
339 }
340 
341 static int
setup_redir_addr(char * buf,int * ac,char *** av)342 setup_redir_addr(char *buf, int *ac, char ***av)
343 {
344 	struct nat44_cfg_redir *r;
345 	char *sep;
346 	size_t space;
347 
348 	r = (struct nat44_cfg_redir *)buf;
349 	r->mode = REDIR_ADDR;
350 	/* Skip nat44_cfg_redir at beginning of buf. */
351 	buf = &buf[sizeof(struct nat44_cfg_redir)];
352 	space = sizeof(struct nat44_cfg_redir);
353 
354 	/* Extract local address. */
355 	if (strchr(**av, ',') != NULL) {
356 		struct nat44_cfg_spool *spool;
357 
358 		/* Setup LSNAT server pool. */
359 		r->laddr.s_addr = INADDR_NONE;
360 		sep = strtok(**av, ",");
361 		while (sep != NULL) {
362 			spool = (struct nat44_cfg_spool *)buf;
363 			space += sizeof(struct nat44_cfg_spool);
364 			StrToAddr(sep, &spool->addr);
365 			spool->port = ~0;
366 			r->spool_cnt++;
367 			/* Point to the next possible nat44_cfg_spool. */
368 			buf = &buf[sizeof(struct nat44_cfg_spool)];
369 			sep = strtok(NULL, ",");
370 		}
371 	} else
372 		StrToAddr(**av, &r->laddr);
373 	(*av)++; (*ac)--;
374 
375 	/* Extract public address. */
376 	StrToAddr(**av, &r->paddr);
377 	(*av)++; (*ac)--;
378 
379 	return (space);
380 }
381 
382 static int
estimate_redir_port(int * ac,char *** av)383 estimate_redir_port(int *ac, char ***av)
384 {
385 	size_t space = sizeof(struct nat44_cfg_redir);
386 	char *sep = **av;
387 	u_int c = 0;
388 
389 	(void)ac;	/* UNUSED */
390 	while ((sep = strchr(sep, ',')) != NULL) {
391 		c++;
392 		sep++;
393 	}
394 
395 	if (c > 0)
396 		c++;
397 
398 	space += c * sizeof(struct nat44_cfg_spool);
399 
400 	return (space);
401 }
402 
403 static int
setup_redir_port(char * buf,int * ac,char *** av)404 setup_redir_port(char *buf, int *ac, char ***av)
405 {
406 	struct nat44_cfg_redir *r;
407 	char *sep, *protoName, *lsnat = NULL;
408 	size_t space;
409 	u_short numLocalPorts;
410 	port_range portRange;
411 
412 	numLocalPorts = 0;
413 
414 	r = (struct nat44_cfg_redir *)buf;
415 	r->mode = REDIR_PORT;
416 	/* Skip nat44_cfg_redir at beginning of buf. */
417 	buf = &buf[sizeof(struct nat44_cfg_redir)];
418 	space = sizeof(struct nat44_cfg_redir);
419 
420 	/*
421 	 * Extract protocol.
422 	 */
423 	r->proto = StrToProto(**av);
424 	protoName = **av;
425 	(*av)++; (*ac)--;
426 
427 	/*
428 	 * Extract local address.
429 	 */
430 	if (strchr(**av, ',') != NULL) {
431 		r->laddr.s_addr = INADDR_NONE;
432 		r->lport = ~0;
433 		numLocalPorts = 1;
434 		lsnat = **av;
435 	} else {
436 		/*
437 		 * The sctp nat does not allow the port numbers to be mapped to
438 		 * new port numbers. Therefore, no ports are to be specified
439 		 * in the target port field.
440 		 */
441 		if (r->proto == IPPROTO_SCTP) {
442 			if (strchr(**av, ':'))
443 				errx(EX_DATAERR, "redirect_port:"
444 				    "port numbers do not change in sctp, so do "
445 				    "not specify them as part of the target");
446 			else
447 				StrToAddr(**av, &r->laddr);
448 		} else {
449 			if (StrToAddrAndPortRange(**av, &r->laddr, protoName,
450 			    &portRange) != 0)
451 				errx(EX_DATAERR, "redirect_port: "
452 				    "invalid local port range");
453 
454 			r->lport = GETLOPORT(portRange);
455 			numLocalPorts = GETNUMPORTS(portRange);
456 		}
457 	}
458 	(*av)++; (*ac)--;
459 
460 	/*
461 	 * Extract public port and optionally address.
462 	 */
463 	if (strchr(**av, ':') != NULL) {
464 		if (StrToAddrAndPortRange(**av, &r->paddr, protoName,
465 		    &portRange) != 0)
466 			errx(EX_DATAERR, "redirect_port: "
467 			    "invalid public port range");
468 	} else {
469 		r->paddr.s_addr = INADDR_ANY;
470 		if (StrToPortRange(**av, protoName, &portRange) != 0)
471 			errx(EX_DATAERR, "redirect_port: "
472 			    "invalid public port range");
473 	}
474 
475 	r->pport = GETLOPORT(portRange);
476 	if (r->proto == IPPROTO_SCTP) { /* so the logic below still works */
477 		numLocalPorts = GETNUMPORTS(portRange);
478 		r->lport = r->pport;
479 	}
480 	r->pport_cnt = GETNUMPORTS(portRange);
481 	(*av)++; (*ac)--;
482 
483 	/*
484 	 * Extract remote address and optionally port.
485 	 */
486 	/*
487 	 * NB: isdigit(**av) => we've to check that next parameter is really an
488 	 * option for this redirect entry, else stop here processing arg[cv].
489 	 */
490 	if (*ac != 0 && isdigit(***av)) {
491 		if (strchr(**av, ':') != NULL) {
492 			if (StrToAddrAndPortRange(**av, &r->raddr, protoName,
493 			    &portRange) != 0)
494 				errx(EX_DATAERR, "redirect_port: "
495 				    "invalid remote port range");
496 		} else {
497 			SETLOPORT(portRange, 0);
498 			SETNUMPORTS(portRange, 1);
499 			StrToAddr(**av, &r->raddr);
500 		}
501 		(*av)++; (*ac)--;
502 	} else {
503 		SETLOPORT(portRange, 0);
504 		SETNUMPORTS(portRange, 1);
505 		r->raddr.s_addr = INADDR_ANY;
506 	}
507 	r->rport = GETLOPORT(portRange);
508 	r->rport_cnt = GETNUMPORTS(portRange);
509 
510 	/*
511 	 * Make sure port ranges match up, then add the redirect ports.
512 	 */
513 	if (numLocalPorts != r->pport_cnt)
514 		errx(EX_DATAERR, "redirect_port: "
515 		    "port ranges must be equal in size");
516 
517 	/* Remote port range is allowed to be '0' which means all ports. */
518 	if (r->rport_cnt != numLocalPorts &&
519 	    (r->rport_cnt != 1 || r->rport != 0))
520 		errx(EX_DATAERR, "redirect_port: remote port must"
521 		    "be 0 or equal to local port range in size");
522 
523 	/* Setup LSNAT server pool. */
524 	if (lsnat != NULL) {
525 		struct nat44_cfg_spool *spool;
526 
527 		sep = strtok(lsnat, ",");
528 		while (sep != NULL) {
529 			spool = (struct nat44_cfg_spool *)buf;
530 			space += sizeof(struct nat44_cfg_spool);
531 			/*
532 			 * The sctp nat does not allow the port numbers to
533 			 * be mapped to new port numbers. Therefore, no ports
534 			 * are to be specified in the target port field.
535 			 */
536 			if (r->proto == IPPROTO_SCTP) {
537 				if (strchr (sep, ':')) {
538 					errx(EX_DATAERR, "redirect_port:"
539 					    "port numbers do not change in "
540 					    "sctp, so do not specify them as "
541 					    "part of the target");
542 				} else {
543 					StrToAddr(sep, &spool->addr);
544 					spool->port = r->pport;
545 				}
546 			} else {
547 				if (StrToAddrAndPortRange(sep, &spool->addr,
548 					protoName, &portRange) != 0)
549 					errx(EX_DATAERR, "redirect_port:"
550 					    "invalid local port range");
551 				if (GETNUMPORTS(portRange) != 1)
552 					errx(EX_DATAERR, "redirect_port: "
553 					    "local port must be single in "
554 					    "this context");
555 				spool->port = GETLOPORT(portRange);
556 			}
557 			r->spool_cnt++;
558 			/* Point to the next possible nat44_cfg_spool. */
559 			buf = &buf[sizeof(struct nat44_cfg_spool)];
560 			sep = strtok(NULL, ",");
561 		}
562 	}
563 
564 	return (space);
565 }
566 
567 static int
setup_redir_proto(char * buf,int * ac,char *** av)568 setup_redir_proto(char *buf, int *ac, char ***av)
569 {
570 	struct nat44_cfg_redir *r;
571 	struct protoent *protoent;
572 	size_t space;
573 
574 	r = (struct nat44_cfg_redir *)buf;
575 	r->mode = REDIR_PROTO;
576 	/* Skip nat44_cfg_redir at beginning of buf. */
577 	buf = &buf[sizeof(struct nat44_cfg_redir)];
578 	space = sizeof(struct nat44_cfg_redir);
579 
580 	/*
581 	 * Extract protocol.
582 	 */
583 	protoent = getprotobyname(**av);
584 	if (protoent == NULL)
585 		errx(EX_DATAERR, "redirect_proto: unknown protocol %s", **av);
586 	else
587 		r->proto = protoent->p_proto;
588 
589 	(*av)++; (*ac)--;
590 
591 	/*
592 	 * Extract local address.
593 	 */
594 	StrToAddr(**av, &r->laddr);
595 
596 	(*av)++; (*ac)--;
597 
598 	/*
599 	 * Extract optional public address.
600 	 */
601 	if (*ac == 0) {
602 		r->paddr.s_addr = INADDR_ANY;
603 		r->raddr.s_addr = INADDR_ANY;
604 	} else {
605 		/* see above in setup_redir_port() */
606 		if (isdigit(***av)) {
607 			StrToAddr(**av, &r->paddr);
608 			(*av)++; (*ac)--;
609 
610 			/*
611 			 * Extract optional remote address.
612 			 */
613 			/* see above in setup_redir_port() */
614 			if (*ac != 0 && isdigit(***av)) {
615 				StrToAddr(**av, &r->raddr);
616 				(*av)++; (*ac)--;
617 			}
618 		}
619 	}
620 
621 	return (space);
622 }
623 
624 static void
nat_show_log(struct nat44_cfg_nat * n,void * arg __unused)625 nat_show_log(struct nat44_cfg_nat *n, void *arg __unused)
626 {
627 	char *buf;
628 
629 	buf = (char *)(n + 1);
630 	if (buf[0] != '\0')
631 		printf("nat %s: %s\n", n->name, buf);
632 }
633 
634 static void
nat_show_cfg(struct nat44_cfg_nat * n,void * arg __unused)635 nat_show_cfg(struct nat44_cfg_nat *n, void *arg __unused)
636 {
637 	struct nat44_cfg_redir *t;
638 	struct nat44_cfg_spool *s;
639 	caddr_t buf;
640 	struct protoent *p;
641 	uint32_t cnt;
642 	int i, off;
643 
644 	buf = (caddr_t)n;
645 	off = sizeof(*n);
646 	printf("ipfw nat %s config", n->name);
647 	if (strlen(n->if_name) != 0)
648 		printf(" if %s", n->if_name);
649 	else if (n->ip.s_addr != 0)
650 		printf(" ip %s", inet_ntoa(n->ip));
651 	while (n->mode != 0) {
652 		if (n->mode & PKT_ALIAS_LOG) {
653 			printf(" log");
654 			n->mode &= ~PKT_ALIAS_LOG;
655 		} else if (n->mode & PKT_ALIAS_DENY_INCOMING) {
656 			printf(" deny_in");
657 			n->mode &= ~PKT_ALIAS_DENY_INCOMING;
658 		} else if (n->mode & PKT_ALIAS_SAME_PORTS) {
659 			printf(" same_ports");
660 			n->mode &= ~PKT_ALIAS_SAME_PORTS;
661 		} else if (n->mode & PKT_ALIAS_SKIP_GLOBAL) {
662 			printf(" skip_global");
663 			n->mode &= ~PKT_ALIAS_SKIP_GLOBAL;
664 		} else if (n->mode & PKT_ALIAS_UNREGISTERED_ONLY) {
665 			printf(" unreg_only");
666 			n->mode &= ~PKT_ALIAS_UNREGISTERED_ONLY;
667 		} else if (n->mode & PKT_ALIAS_UNREGISTERED_CGN) {
668 			printf(" unreg_cgn");
669 			n->mode &= ~PKT_ALIAS_UNREGISTERED_CGN;
670 		} else if (n->mode & PKT_ALIAS_RESET_ON_ADDR_CHANGE) {
671 			printf(" reset");
672 			n->mode &= ~PKT_ALIAS_RESET_ON_ADDR_CHANGE;
673 		} else if (n->mode & PKT_ALIAS_REVERSE) {
674 			printf(" reverse");
675 			n->mode &= ~PKT_ALIAS_REVERSE;
676 		} else if (n->mode & PKT_ALIAS_PROXY_ONLY) {
677 			printf(" proxy_only");
678 			n->mode &= ~PKT_ALIAS_PROXY_ONLY;
679 		}
680 	}
681 	/* Print all the redirect's data configuration. */
682 	for (cnt = 0; cnt < n->redir_cnt; cnt++) {
683 		t = (struct nat44_cfg_redir *)&buf[off];
684 		off += sizeof(struct nat44_cfg_redir);
685 		switch (t->mode) {
686 		case REDIR_ADDR:
687 			printf(" redirect_addr");
688 			if (t->spool_cnt == 0)
689 				printf(" %s", inet_ntoa(t->laddr));
690 			else
691 				for (i = 0; i < t->spool_cnt; i++) {
692 					s = (struct nat44_cfg_spool *)&buf[off];
693 					if (i)
694 						printf(",");
695 					else
696 						printf(" ");
697 					printf("%s", inet_ntoa(s->addr));
698 					off += sizeof(struct nat44_cfg_spool);
699 				}
700 			printf(" %s", inet_ntoa(t->paddr));
701 			break;
702 		case REDIR_PORT:
703 			p = getprotobynumber(t->proto);
704 			printf(" redirect_port %s ", p->p_name);
705 			if (!t->spool_cnt) {
706 				printf("%s:%u", inet_ntoa(t->laddr), t->lport);
707 				if (t->pport_cnt > 1)
708 					printf("-%u", t->lport +
709 					    t->pport_cnt - 1);
710 			} else
711 				for (i=0; i < t->spool_cnt; i++) {
712 					s = (struct nat44_cfg_spool *)&buf[off];
713 					if (i)
714 						printf(",");
715 					printf("%s:%u", inet_ntoa(s->addr),
716 					    s->port);
717 					off += sizeof(struct nat44_cfg_spool);
718 				}
719 
720 			printf(" ");
721 			if (t->paddr.s_addr)
722 				printf("%s:", inet_ntoa(t->paddr));
723 			printf("%u", t->pport);
724 			if (!t->spool_cnt && t->pport_cnt > 1)
725 				printf("-%u", t->pport + t->pport_cnt - 1);
726 
727 			if (t->raddr.s_addr) {
728 				printf(" %s", inet_ntoa(t->raddr));
729 				if (t->rport) {
730 					printf(":%u", t->rport);
731 					if (!t->spool_cnt && t->rport_cnt > 1)
732 						printf("-%u", t->rport +
733 						    t->rport_cnt - 1);
734 				}
735 			}
736 			break;
737 		case REDIR_PROTO:
738 			p = getprotobynumber(t->proto);
739 			printf(" redirect_proto %s %s", p->p_name,
740 			    inet_ntoa(t->laddr));
741 			if (t->paddr.s_addr != 0) {
742 				printf(" %s", inet_ntoa(t->paddr));
743 				if (t->raddr.s_addr)
744 					printf(" %s", inet_ntoa(t->raddr));
745 			}
746 			break;
747 		default:
748 			errx(EX_DATAERR, "unknown redir mode");
749 			break;
750 		}
751 	}
752 	printf("\n");
753 }
754 
755 static int
nat_port_alias_parse(char * str,u_short * lpout,u_short * hpout)756 nat_port_alias_parse(char *str, u_short *lpout, u_short *hpout) {
757 	long lp, hp;
758 	char *ptr;
759 	/* Lower port parsing */
760 	lp = (long) strtol(str, &ptr, 10);
761 	if (lp < 1024 || lp > 65535)
762 		return 0;
763 	if (!ptr || *ptr != '-')
764 		return 0;
765 	/* Upper port parsing */
766 	hp = (long) strtol(ptr, &ptr, 10);
767 	if (hp < 1024 || hp > 65535)
768 		return 0;
769 	if (ptr)
770 		return 0;
771 
772 	*lpout = (u_short) lp;
773 	*hpout = (u_short) hp;
774 	return 1;
775 }
776 
777 void
ipfw_config_nat(int ac,char ** av)778 ipfw_config_nat(int ac, char **av)
779 {
780 	ipfw_obj_header *oh;
781 	struct nat44_cfg_nat *n;		/* Nat instance configuration. */
782 	int i, off, tok, ac1;
783 	u_short lp, hp;
784 	char *id, *buf, **av1, *end;
785 	size_t len;
786 
787 	av++;
788 	ac--;
789 	/* Nat id. */
790 	if (ac == 0)
791 		errx(EX_DATAERR, "missing nat id");
792 	id = *av;
793 	i = (int)strtol(id, &end, 0);
794 	if (i <= 0 || *end != '\0')
795 		errx(EX_DATAERR, "illegal nat id: %s", id);
796 	av++;
797 	ac--;
798 	if (ac == 0)
799 		errx(EX_DATAERR, "missing option");
800 
801 	len = sizeof(*oh) + sizeof(*n);
802 	ac1 = ac;
803 	av1 = av;
804 	while (ac1 > 0) {
805 		tok = match_token(nat_params, *av1);
806 		ac1--;
807 		av1++;
808 		switch (tok) {
809 		case TOK_IP:
810 		case TOK_IF:
811 		case TOK_PORT_ALIAS:
812 			ac1--;
813 			av1++;
814 			break;
815 		case TOK_ALOG:
816 		case TOK_DENY_INC:
817 		case TOK_SAME_PORTS:
818 		case TOK_SKIP_GLOBAL:
819 		case TOK_UNREG_ONLY:
820 		case TOK_UNREG_CGN:
821 		case TOK_RESET_ADDR:
822 		case TOK_ALIAS_REV:
823 		case TOK_PROXY_ONLY:
824 			break;
825 		case TOK_REDIR_ADDR:
826 			if (ac1 < 2)
827 				errx(EX_DATAERR, "redirect_addr: "
828 				    "not enough arguments");
829 			len += estimate_redir_addr(&ac1, &av1);
830 			av1 += 2;
831 			ac1 -= 2;
832 			break;
833 		case TOK_REDIR_PORT:
834 			if (ac1 < 3)
835 				errx(EX_DATAERR, "redirect_port: "
836 				    "not enough arguments");
837 			av1++;
838 			ac1--;
839 			len += estimate_redir_port(&ac1, &av1);
840 			av1 += 2;
841 			ac1 -= 2;
842 			/* Skip optional remoteIP/port */
843 			if (ac1 != 0 && isdigit(**av1)) {
844 				av1++;
845 				ac1--;
846 			}
847 			break;
848 		case TOK_REDIR_PROTO:
849 			if (ac1 < 2)
850 				errx(EX_DATAERR, "redirect_proto: "
851 				    "not enough arguments");
852 			len += sizeof(struct nat44_cfg_redir);
853 			av1 += 2;
854 			ac1 -= 2;
855 			/* Skip optional remoteIP/port */
856 			if (ac1 != 0 && isdigit(**av1)) {
857 				av1++;
858 				ac1--;
859 			}
860 			if (ac1 != 0 && isdigit(**av1)) {
861 				av1++;
862 				ac1--;
863 			}
864 			break;
865 		default:
866 			errx(EX_DATAERR, "unrecognised option ``%s''", av1[-1]);
867 		}
868 	}
869 
870 	if ((buf = malloc(len)) == NULL)
871 		errx(EX_OSERR, "malloc failed");
872 
873 	/* Offset in buf: save space for header at the beginning. */
874 	off = sizeof(*oh) + sizeof(*n);
875 	memset(buf, 0, len);
876 	oh = (ipfw_obj_header *)buf;
877 	n = (struct nat44_cfg_nat *)(oh + 1);
878 	oh->ntlv.head.length = sizeof(oh->ntlv);
879 	snprintf(oh->ntlv.name, sizeof(oh->ntlv.name), "%d", i);
880 	snprintf(n->name, sizeof(n->name), "%d", i);
881 
882 	while (ac > 0) {
883 		tok = match_token(nat_params, *av);
884 		ac--;
885 		av++;
886 		switch (tok) {
887 		case TOK_IP:
888 			if (ac == 0)
889 				errx(EX_DATAERR, "missing option");
890 			if (!inet_aton(av[0], &(n->ip)))
891 				errx(EX_DATAERR, "bad ip address ``%s''",
892 				    av[0]);
893 			ac--;
894 			av++;
895 			break;
896 		case TOK_IF:
897 			if (ac == 0)
898 				errx(EX_DATAERR, "missing option");
899 			set_addr_dynamic(av[0], n);
900 			ac--;
901 			av++;
902 			break;
903 		case TOK_ALOG:
904 			n->mode |= PKT_ALIAS_LOG;
905 			break;
906 		case TOK_DENY_INC:
907 			n->mode |= PKT_ALIAS_DENY_INCOMING;
908 			break;
909 		case TOK_SAME_PORTS:
910 			n->mode |= PKT_ALIAS_SAME_PORTS;
911 			break;
912 		case TOK_UNREG_ONLY:
913 			n->mode |= PKT_ALIAS_UNREGISTERED_ONLY;
914 			break;
915 		case TOK_UNREG_CGN:
916 			n->mode |= PKT_ALIAS_UNREGISTERED_CGN;
917 			break;
918 		case TOK_SKIP_GLOBAL:
919 			n->mode |= PKT_ALIAS_SKIP_GLOBAL;
920 			break;
921 		case TOK_RESET_ADDR:
922 			n->mode |= PKT_ALIAS_RESET_ON_ADDR_CHANGE;
923 			break;
924 		case TOK_ALIAS_REV:
925 			n->mode |= PKT_ALIAS_REVERSE;
926 			break;
927 		case TOK_PROXY_ONLY:
928 			n->mode |= PKT_ALIAS_PROXY_ONLY;
929 			break;
930 			/*
931 			 * All the setup_redir_* functions work directly in
932 			 * the final buffer, see above for details.
933 			 */
934 		case TOK_REDIR_ADDR:
935 		case TOK_REDIR_PORT:
936 		case TOK_REDIR_PROTO:
937 			switch (tok) {
938 			case TOK_REDIR_ADDR:
939 				i = setup_redir_addr(&buf[off], &ac, &av);
940 				break;
941 			case TOK_REDIR_PORT:
942 				i = setup_redir_port(&buf[off], &ac, &av);
943 				break;
944 			case TOK_REDIR_PROTO:
945 				i = setup_redir_proto(&buf[off], &ac, &av);
946 				break;
947 			}
948 			n->redir_cnt++;
949 			off += i;
950 			break;
951 		case TOK_PORT_ALIAS:
952 			if (ac == 0)
953 				errx(EX_DATAERR, "missing option");
954 			if (!nat_port_alias_parse(av[0], &lp, &hp))
955 				errx(EX_DATAERR,
956 				    "You need a range of port(s) from 1024 <= x < 65536");
957 			if (lp >= hp)
958 				errx(EX_DATAERR,
959 				    "Upper port has to be greater than lower port");
960 			n->alias_port_lo = lp;
961 			n->alias_port_hi = hp;
962 			ac--;
963 			av++;
964 			break;
965 		}
966 	}
967 	if (n->mode & PKT_ALIAS_SAME_PORTS && n->alias_port_lo)
968 		errx(EX_DATAERR, "same_ports and port_range cannot both be selected");
969 
970 	i = do_set3(IP_FW_NAT44_XCONFIG, &oh->opheader, len);
971 	if (i != 0)
972 		err(1, "setsockopt(%s)", "IP_FW_NAT44_XCONFIG");
973 
974 	if (!g_co.do_quiet) {
975 		/* After every modification, we show the resultant rule. */
976 		int _ac = 3;
977 		const char *_av[] = {"show", "config", id};
978 		ipfw_show_nat(_ac, (char **)(void *)_av);
979 	}
980 }
981 
982 static void
nat_fill_ntlv(ipfw_obj_ntlv * ntlv,int i)983 nat_fill_ntlv(ipfw_obj_ntlv *ntlv, int i)
984 {
985 
986 	ntlv->head.type = IPFW_TLV_EACTION_NAME(1); /* it doesn't matter */
987 	ntlv->head.length = sizeof(ipfw_obj_ntlv);
988 	ntlv->idx = 1;
989 	ntlv->set = 0; /* not yet */
990 	snprintf(ntlv->name, sizeof(ntlv->name), "%d", i);
991 }
992 
993 int
ipfw_delete_nat(int i)994 ipfw_delete_nat(int i)
995 {
996 	ipfw_obj_header oh;
997 	int ret;
998 
999 	memset(&oh, 0, sizeof(oh));
1000 	nat_fill_ntlv(&oh.ntlv, i);
1001 	ret = do_set3(IP_FW_NAT44_DESTROY, &oh.opheader, sizeof(oh));
1002 	if (ret == -1) {
1003 		if (!g_co.do_quiet)
1004 			warn("nat %u not available", i);
1005 		return (EX_UNAVAILABLE);
1006 	}
1007 	return (EX_OK);
1008 }
1009 
1010 struct nat_list_arg {
1011 	uint16_t	cmd;
1012 	int		is_all;
1013 };
1014 
1015 static int
nat_show_data(struct nat44_cfg_nat * cfg,void * arg)1016 nat_show_data(struct nat44_cfg_nat *cfg, void *arg)
1017 {
1018 	struct nat_list_arg *nla;
1019 	ipfw_obj_header *oh;
1020 
1021 	nla = (struct nat_list_arg *)arg;
1022 
1023 	switch (nla->cmd) {
1024 	case IP_FW_NAT44_XGETCONFIG:
1025 		if (nat_get_cmd(cfg->name, nla->cmd, &oh) != 0) {
1026 			warnx("Error getting nat instance %s info", cfg->name);
1027 			break;
1028 		}
1029 		nat_show_cfg((struct nat44_cfg_nat *)(oh + 1), NULL);
1030 		free(oh);
1031 		break;
1032 	case IP_FW_NAT44_XGETLOG:
1033 		if (nat_get_cmd(cfg->name, nla->cmd, &oh) == 0) {
1034 			nat_show_log((struct nat44_cfg_nat *)(oh + 1), NULL);
1035 			free(oh);
1036 			break;
1037 		}
1038 		/* Handle error */
1039 		if (nla->is_all != 0 && errno == ENOENT)
1040 			break;
1041 		warn("Error getting nat instance %s info", cfg->name);
1042 		break;
1043 	}
1044 
1045 	return (0);
1046 }
1047 
1048 /*
1049  * Compare nat names.
1050  * Honor number comparison.
1051  */
1052 static int
natname_cmp(const void * a,const void * b)1053 natname_cmp(const void *a, const void *b)
1054 {
1055 	const struct nat44_cfg_nat *ia, *ib;
1056 
1057 	ia = (const struct nat44_cfg_nat *)a;
1058 	ib = (const struct nat44_cfg_nat *)b;
1059 
1060 	return (stringnum_cmp(ia->name, ib->name));
1061 }
1062 
1063 /*
1064  * Retrieves nat list from kernel,
1065  * optionally sorts it and calls requested function for each table.
1066  * Returns 0 on success.
1067  */
1068 static int
nat_foreach(nat_cb_t * f,void * arg,int sort)1069 nat_foreach(nat_cb_t *f, void *arg, int sort)
1070 {
1071 	ipfw_obj_lheader *olh;
1072 	struct nat44_cfg_nat *cfg;
1073 	size_t sz;
1074 	uint32_t i;
1075 
1076 	/* Start with reasonable default */
1077 	sz = sizeof(*olh) + 16 * sizeof(struct nat44_cfg_nat);
1078 
1079 	for (;;) {
1080 		if ((olh = calloc(1, sz)) == NULL)
1081 			return (ENOMEM);
1082 
1083 		olh->size = sz;
1084 		if (do_get3(IP_FW_NAT44_LIST_NAT, &olh->opheader, &sz) != 0) {
1085 			sz = olh->size;
1086 			free(olh);
1087 			if (errno == ENOMEM)
1088 				continue;
1089 			return (errno);
1090 		}
1091 
1092 		if (sort != 0)
1093 			qsort(olh + 1, olh->count, olh->objsize, natname_cmp);
1094 
1095 		cfg = (struct nat44_cfg_nat*)(olh + 1);
1096 		for (i = 0; i < olh->count; i++) {
1097 			(void)f(cfg, arg); /* Ignore errors for now */
1098 			cfg = (struct nat44_cfg_nat *)((caddr_t)cfg +
1099 			    olh->objsize);
1100 		}
1101 
1102 		free(olh);
1103 		break;
1104 	}
1105 
1106 	return (0);
1107 }
1108 
1109 static int
nat_get_cmd(char * name,uint16_t cmd,ipfw_obj_header ** ooh)1110 nat_get_cmd(char *name, uint16_t cmd, ipfw_obj_header **ooh)
1111 {
1112 	ipfw_obj_header *oh;
1113 	struct nat44_cfg_nat *cfg;
1114 	size_t sz;
1115 
1116 	/* Start with reasonable default */
1117 	sz = sizeof(*oh) + sizeof(*cfg) + 128;
1118 
1119 	for (;;) {
1120 		if ((oh = calloc(1, sz)) == NULL)
1121 			return (ENOMEM);
1122 		cfg = (struct nat44_cfg_nat *)(oh + 1);
1123 		oh->ntlv.head.length = sizeof(oh->ntlv);
1124 		strlcpy(oh->ntlv.name, name, sizeof(oh->ntlv.name));
1125 		strlcpy(cfg->name, name, sizeof(cfg->name));
1126 
1127 		if (do_get3(cmd, &oh->opheader, &sz) != 0) {
1128 			sz = cfg->size;
1129 			free(oh);
1130 			if (errno == ENOMEM)
1131 				continue;
1132 			return (errno);
1133 		}
1134 
1135 		*ooh = oh;
1136 		break;
1137 	}
1138 
1139 	return (0);
1140 }
1141 
1142 void
ipfw_show_nat(int ac,char ** av)1143 ipfw_show_nat(int ac, char **av)
1144 {
1145 	ipfw_obj_header *oh;
1146 	char *name;
1147 	int cmd;
1148 	struct nat_list_arg nla;
1149 
1150 	ac--;
1151 	av++;
1152 
1153 	if (g_co.test_only)
1154 		return;
1155 
1156 	/* Parse parameters. */
1157 	cmd = 0; /* XXX: Change to IP_FW_NAT44_XGETLOG @ MFC */
1158 	name = NULL;
1159 	for ( ; ac != 0; ac--, av++) {
1160 		if (!strncmp(av[0], "config", strlen(av[0]))) {
1161 			cmd = IP_FW_NAT44_XGETCONFIG;
1162 			continue;
1163 		}
1164 		if (strcmp(av[0], "log") == 0) {
1165 			cmd = IP_FW_NAT44_XGETLOG;
1166 			continue;
1167 		}
1168 		if (name != NULL)
1169 			err(EX_USAGE,"only one instance name may be specified");
1170 		name = av[0];
1171 	}
1172 
1173 	if (cmd == 0)
1174 		errx(EX_USAGE, "Please specify action. Available: config,log");
1175 
1176 	if (name == NULL) {
1177 		memset(&nla, 0, sizeof(nla));
1178 		nla.cmd = cmd;
1179 		nla.is_all = 1;
1180 		nat_foreach(nat_show_data, &nla, 1);
1181 	} else {
1182 		if (nat_get_cmd(name, cmd, &oh) != 0)
1183 			err(EX_OSERR, "Error getting nat %s instance info", name);
1184 		nat_show_cfg((struct nat44_cfg_nat *)(oh + 1), NULL);
1185 		free(oh);
1186 	}
1187 }
1188 
1189