xref: /freebsd/sbin/ipfw/nat64stl.c (revision 2f513db7) 
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2015-2019 Yandex LLC
5  * Copyright (c) 2015-2019 Andrey V. Elsukov <ae@FreeBSD.org>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/types.h>
33 #include <sys/socket.h>
34 
35 #include "ipfw2.h"
36 
37 #include <ctype.h>
38 #include <err.h>
39 #include <errno.h>
40 #include <inttypes.h>
41 #include <netdb.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <sysexits.h>
46 
47 #include <net/if.h>
48 #include <netinet/in.h>
49 #include <netinet/ip_fw.h>
50 #include <netinet6/ip_fw_nat64.h>
51 #include <arpa/inet.h>
52 
53 typedef int (nat64stl_cb_t)(ipfw_nat64stl_cfg *i, const char *name,
54     uint8_t set);
55 static int nat64stl_foreach(nat64stl_cb_t *f, const char *name, uint8_t set,
56     int sort);
57 
58 static void nat64stl_create(const char *name, uint8_t set, int ac, char **av);
59 static void nat64stl_config(const char *name, uint8_t set, int ac, char **av);
60 static void nat64stl_destroy(const char *name, uint8_t set);
61 static void nat64stl_stats(const char *name, uint8_t set);
62 static void nat64stl_reset_stats(const char *name, uint8_t set);
63 static int nat64stl_show_cb(ipfw_nat64stl_cfg *cfg, const char *name,
64     uint8_t set);
65 static int nat64stl_destroy_cb(ipfw_nat64stl_cfg *cfg, const char *name,
66     uint8_t set);
67 
68 static struct _s_x nat64cmds[] = {
69       { "create",	TOK_CREATE },
70       { "config",	TOK_CONFIG },
71       { "destroy",	TOK_DESTROY },
72       { "list",		TOK_LIST },
73       { "show",		TOK_LIST },
74       { "stats",	TOK_STATS },
75       { NULL, 0 }
76 };
77 
78 #define	IPV6_ADDR_INT32_WKPFX	htonl(0x64ff9b)
79 #define	IN6_IS_ADDR_WKPFX(a)					\
80     ((a)->__u6_addr.__u6_addr32[0] == IPV6_ADDR_INT32_WKPFX &&	\
81 	(a)->__u6_addr.__u6_addr32[1] == 0 &&			\
82 	(a)->__u6_addr.__u6_addr32[2] == 0)
83 int
84 ipfw_check_nat64prefix(const struct in6_addr *prefix, int length)
85 {
86 
87 	switch (length) {
88 	case 32:
89 	case 40:
90 	case 48:
91 	case 56:
92 	case 64:
93 		/* Well-known prefix has 96 prefix length */
94 		if (IN6_IS_ADDR_WKPFX(prefix))
95 			return (EINVAL);
96 		/* FALLTHROUGH */
97 	case 96:
98 		/* Bits 64 to 71 must be set to zero */
99 		if (prefix->__u6_addr.__u6_addr8[8] != 0)
100 			return (EINVAL);
101 		/* XXX: looks incorrect */
102 		if (IN6_IS_ADDR_MULTICAST(prefix) ||
103 		    IN6_IS_ADDR_UNSPECIFIED(prefix) ||
104 		    IN6_IS_ADDR_LOOPBACK(prefix))
105 			return (EINVAL);
106 		return (0);
107 	}
108 	return (EINVAL);
109 }
110 
111 static struct _s_x nat64statscmds[] = {
112       { "reset",	TOK_RESET },
113       { NULL, 0 }
114 };
115 
116 /*
117  * This one handles all nat64stl-related commands
118  *	ipfw [set N] nat64stl NAME {create | config} ...
119  *	ipfw [set N] nat64stl NAME stats [reset]
120  *	ipfw [set N] nat64stl {NAME | all} destroy
121  *	ipfw [set N] nat64stl {NAME | all} {list | show}
122  */
123 #define	nat64stl_check_name	table_check_name
124 void
125 ipfw_nat64stl_handler(int ac, char *av[])
126 {
127 	const char *name;
128 	int tcmd;
129 	uint8_t set;
130 
131 	if (co.use_set != 0)
132 		set = co.use_set - 1;
133 	else
134 		set = 0;
135 	ac--; av++;
136 
137 	NEED1("nat64stl needs instance name");
138 	name = *av;
139 	if (nat64stl_check_name(name) != 0) {
140 		if (strcmp(name, "all") == 0)
141 			name = NULL;
142 		else
143 			errx(EX_USAGE, "nat64stl instance name %s is invalid",
144 			    name);
145 	}
146 	ac--; av++;
147 	NEED1("nat64stl needs command");
148 
149 	tcmd = get_token(nat64cmds, *av, "nat64stl command");
150 	if (name == NULL && tcmd != TOK_DESTROY && tcmd != TOK_LIST)
151 		errx(EX_USAGE, "nat64stl instance name required");
152 	switch (tcmd) {
153 	case TOK_CREATE:
154 		ac--; av++;
155 		nat64stl_create(name, set, ac, av);
156 		break;
157 	case TOK_CONFIG:
158 		ac--; av++;
159 		nat64stl_config(name, set, ac, av);
160 		break;
161 	case TOK_LIST:
162 		nat64stl_foreach(nat64stl_show_cb, name, set, 1);
163 		break;
164 	case TOK_DESTROY:
165 		if (name == NULL)
166 			nat64stl_foreach(nat64stl_destroy_cb, NULL, set, 0);
167 		else
168 			nat64stl_destroy(name, set);
169 		break;
170 	case TOK_STATS:
171 		ac--; av++;
172 		if (ac == 0) {
173 			nat64stl_stats(name, set);
174 			break;
175 		}
176 		tcmd = get_token(nat64statscmds, *av, "stats command");
177 		if (tcmd == TOK_RESET)
178 			nat64stl_reset_stats(name, set);
179 	}
180 }
181 
182 
183 static void
184 nat64stl_fill_ntlv(ipfw_obj_ntlv *ntlv, const char *name, uint8_t set)
185 {
186 
187 	ntlv->head.type = IPFW_TLV_EACTION_NAME(1); /* it doesn't matter */
188 	ntlv->head.length = sizeof(ipfw_obj_ntlv);
189 	ntlv->idx = 1;
190 	ntlv->set = set;
191 	strlcpy(ntlv->name, name, sizeof(ntlv->name));
192 }
193 
194 static struct _s_x nat64newcmds[] = {
195       { "table4",	TOK_TABLE4 },
196       { "table6",	TOK_TABLE6 },
197       { "prefix6",	TOK_PREFIX6 },
198       { "log",		TOK_LOG },
199       { "-log",		TOK_LOGOFF },
200       { "allow_private", TOK_PRIVATE },
201       { "-allow_private", TOK_PRIVATEOFF },
202       { NULL, 0 }
203 };
204 
205 /*
206  * Creates new nat64stl instance
207  * ipfw nat64stl <NAME> create table4 <name> table6 <name> [ prefix6 <prefix>]
208  * Request: [ ipfw_obj_lheader ipfw_nat64stl_cfg ]
209  */
210 #define	NAT64STL_HAS_TABLE4	0x01
211 #define	NAT64STL_HAS_TABLE6	0x02
212 #define	NAT64STL_HAS_PREFIX6	0x04
213 static void
214 nat64stl_create(const char *name, uint8_t set, int ac, char *av[])
215 {
216 	char buf[sizeof(ipfw_obj_lheader) + sizeof(ipfw_nat64stl_cfg)];
217 	ipfw_nat64stl_cfg *cfg;
218 	ipfw_obj_lheader *olh;
219 	int tcmd, flags;
220 	char *p;
221 
222 	memset(buf, 0, sizeof(buf));
223 	olh = (ipfw_obj_lheader *)buf;
224 	cfg = (ipfw_nat64stl_cfg *)(olh + 1);
225 
226 	/* Some reasonable defaults */
227 	inet_pton(AF_INET6, "64:ff9b::", &cfg->prefix6);
228 	cfg->plen6 = 96;
229 	cfg->set = set;
230 	flags = NAT64STL_HAS_PREFIX6;
231 	while (ac > 0) {
232 		tcmd = get_token(nat64newcmds, *av, "option");
233 		ac--; av++;
234 
235 		switch (tcmd) {
236 		case TOK_TABLE4:
237 			NEED1("table name required");
238 			table_fill_ntlv(&cfg->ntlv4, *av, set, 4);
239 			flags |= NAT64STL_HAS_TABLE4;
240 			ac--; av++;
241 			break;
242 		case TOK_TABLE6:
243 			NEED1("table name required");
244 			table_fill_ntlv(&cfg->ntlv6, *av, set, 6);
245 			flags |= NAT64STL_HAS_TABLE6;
246 			ac--; av++;
247 			break;
248 		case TOK_PREFIX6:
249 			NEED1("IPv6 prefix6 required");
250 			if ((p = strchr(*av, '/')) != NULL)
251 				*p++ = '\0';
252 			if (inet_pton(AF_INET6, *av, &cfg->prefix6) != 1)
253 				errx(EX_USAGE,
254 				    "Bad prefix: %s", *av);
255 			cfg->plen6 = strtol(p, NULL, 10);
256 			if (ipfw_check_nat64prefix(&cfg->prefix6,
257 			    cfg->plen6) != 0)
258 				errx(EX_USAGE,
259 				    "Bad prefix length: %s", p);
260 			flags |= NAT64STL_HAS_PREFIX6;
261 			ac--; av++;
262 			break;
263 		case TOK_LOG:
264 			cfg->flags |= NAT64_LOG;
265 			break;
266 		case TOK_LOGOFF:
267 			cfg->flags &= ~NAT64_LOG;
268 			break;
269 		case TOK_PRIVATE:
270 			cfg->flags |= NAT64_ALLOW_PRIVATE;
271 			break;
272 		case TOK_PRIVATEOFF:
273 			cfg->flags &= ~NAT64_ALLOW_PRIVATE;
274 			break;
275 		}
276 	}
277 
278 	/* Check validness */
279 	if ((flags & NAT64STL_HAS_TABLE4) != NAT64STL_HAS_TABLE4)
280 		errx(EX_USAGE, "table4 required");
281 	if ((flags & NAT64STL_HAS_TABLE6) != NAT64STL_HAS_TABLE6)
282 		errx(EX_USAGE, "table6 required");
283 	if ((flags & NAT64STL_HAS_PREFIX6) != NAT64STL_HAS_PREFIX6)
284 		errx(EX_USAGE, "prefix6 required");
285 
286 	olh->count = 1;
287 	olh->objsize = sizeof(*cfg);
288 	olh->size = sizeof(buf);
289 	strlcpy(cfg->name, name, sizeof(cfg->name));
290 	if (do_set3(IP_FW_NAT64STL_CREATE, &olh->opheader, sizeof(buf)) != 0)
291 		err(EX_OSERR, "nat64stl instance creation failed");
292 }
293 
294 /*
295  * Configures existing nat64stl instance
296  * ipfw nat64stl <NAME> config <options>
297  * Request: [ ipfw_obj_header ipfw_nat64stl_cfg ]
298  */
299 static void
300 nat64stl_config(const char *name, uint8_t set, int ac, char **av)
301 {
302 	char buf[sizeof(ipfw_obj_header) + sizeof(ipfw_nat64stl_cfg)];
303 	ipfw_nat64stl_cfg *cfg;
304 	ipfw_obj_header *oh;
305 	char *opt;
306 	size_t sz;
307 	int tcmd;
308 
309 	if (ac == 0)
310 		errx(EX_USAGE, "config options required");
311 	memset(&buf, 0, sizeof(buf));
312 	oh = (ipfw_obj_header *)buf;
313 	cfg = (ipfw_nat64stl_cfg *)(oh + 1);
314 	sz = sizeof(buf);
315 
316 	nat64stl_fill_ntlv(&oh->ntlv, name, set);
317 	if (do_get3(IP_FW_NAT64STL_CONFIG, &oh->opheader, &sz) != 0)
318 		err(EX_OSERR, "failed to get config for instance %s", name);
319 
320 	while (ac > 0) {
321 		tcmd = get_token(nat64newcmds, *av, "option");
322 		opt = *av;
323 		ac--; av++;
324 
325 		switch (tcmd) {
326 #if 0
327 		case TOK_TABLE4:
328 			NEED1("table name required");
329 			table_fill_ntlv(&cfg->ntlv4, *av, set, 4);
330 			ac--; av++;
331 			break;
332 		case TOK_TABLE6:
333 			NEED1("table name required");
334 			table_fill_ntlv(&cfg->ntlv6, *av, set, 6);
335 			ac--; av++;
336 			break;
337 #endif
338 		case TOK_LOG:
339 			cfg->flags |= NAT64_LOG;
340 			break;
341 		case TOK_LOGOFF:
342 			cfg->flags &= ~NAT64_LOG;
343 			break;
344 		case TOK_PRIVATE:
345 			cfg->flags |= NAT64_ALLOW_PRIVATE;
346 			break;
347 		case TOK_PRIVATEOFF:
348 			cfg->flags &= ~NAT64_ALLOW_PRIVATE;
349 			break;
350 		default:
351 			errx(EX_USAGE, "Can't change %s option", opt);
352 		}
353 	}
354 
355 	if (do_set3(IP_FW_NAT64STL_CONFIG, &oh->opheader, sizeof(buf)) != 0)
356 		err(EX_OSERR, "nat64stl instance configuration failed");
357 }
358 
359 /*
360  * Destroys nat64stl instance.
361  * Request: [ ipfw_obj_header ]
362  */
363 static void
364 nat64stl_destroy(const char *name, uint8_t set)
365 {
366 	ipfw_obj_header oh;
367 
368 	memset(&oh, 0, sizeof(oh));
369 	nat64stl_fill_ntlv(&oh.ntlv, name, set);
370 	if (do_set3(IP_FW_NAT64STL_DESTROY, &oh.opheader, sizeof(oh)) != 0)
371 		err(EX_OSERR, "failed to destroy nat instance %s", name);
372 }
373 
374 /*
375  * Get nat64stl instance statistics.
376  * Request: [ ipfw_obj_header ]
377  * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ] ]
378  */
379 static int
380 nat64stl_get_stats(const char *name, uint8_t set,
381     struct ipfw_nat64stl_stats *stats)
382 {
383 	ipfw_obj_header *oh;
384 	ipfw_obj_ctlv *oc;
385 	size_t sz;
386 
387 	sz = sizeof(*oh) + sizeof(*oc) + sizeof(*stats);
388 	oh = calloc(1, sz);
389 	nat64stl_fill_ntlv(&oh->ntlv, name, set);
390 	if (do_get3(IP_FW_NAT64STL_STATS, &oh->opheader, &sz) == 0) {
391 		oc = (ipfw_obj_ctlv *)(oh + 1);
392 		memcpy(stats, oc + 1, sizeof(*stats));
393 		free(oh);
394 		return (0);
395 	}
396 	free(oh);
397 	return (-1);
398 }
399 
400 static void
401 nat64stl_stats(const char *name, uint8_t set)
402 {
403 	struct ipfw_nat64stl_stats stats;
404 
405 	if (nat64stl_get_stats(name, set, &stats) != 0)
406 		err(EX_OSERR, "Error retrieving stats");
407 
408 	if (co.use_set != 0 || set != 0)
409 		printf("set %u ", set);
410 	printf("nat64stl %s\n", name);
411 
412 	printf("\t%ju packets translated from IPv6 to IPv4\n",
413 	    (uintmax_t)stats.opcnt64);
414 	printf("\t%ju packets translated from IPv4 to IPv6\n",
415 	    (uintmax_t)stats.opcnt46);
416 	printf("\t%ju IPv6 fragments created\n",
417 	    (uintmax_t)stats.ofrags);
418 	printf("\t%ju IPv4 fragments received\n",
419 	    (uintmax_t)stats.ifrags);
420 	printf("\t%ju output packets dropped due to no bufs, etc.\n",
421 	    (uintmax_t)stats.oerrors);
422 	printf("\t%ju output packets discarded due to no IPv4 route\n",
423 	    (uintmax_t)stats.noroute4);
424 	printf("\t%ju output packets discarded due to no IPv6 route\n",
425 	    (uintmax_t)stats.noroute6);
426 	printf("\t%ju packets discarded due to unsupported protocol\n",
427 	    (uintmax_t)stats.noproto);
428 	printf("\t%ju packets discarded due to memory allocation problems\n",
429 	    (uintmax_t)stats.nomem);
430 	printf("\t%ju packets discarded due to some errors\n",
431 	    (uintmax_t)stats.dropped);
432 }
433 
434 /*
435  * Reset nat64stl instance statistics specified by @oh->ntlv.
436  * Request: [ ipfw_obj_header ]
437  */
438 static void
439 nat64stl_reset_stats(const char *name, uint8_t set)
440 {
441 	ipfw_obj_header oh;
442 
443 	memset(&oh, 0, sizeof(oh));
444 	nat64stl_fill_ntlv(&oh.ntlv, name, set);
445 	if (do_set3(IP_FW_NAT64STL_RESET_STATS, &oh.opheader, sizeof(oh)) != 0)
446 		err(EX_OSERR, "failed to reset stats for instance %s", name);
447 }
448 
449 static int
450 nat64stl_show_cb(ipfw_nat64stl_cfg *cfg, const char *name, uint8_t set)
451 {
452 	char abuf[INET6_ADDRSTRLEN];
453 
454 	if (name != NULL && strcmp(cfg->name, name) != 0)
455 		return (ESRCH);
456 
457 	if (co.use_set != 0 && cfg->set != set)
458 		return (ESRCH);
459 
460 	if (co.use_set != 0 || cfg->set != 0)
461 		printf("set %u ", cfg->set);
462 
463 	printf("nat64stl %s table4 %s table6 %s",
464 	    cfg->name, cfg->ntlv4.name, cfg->ntlv6.name);
465 	inet_ntop(AF_INET6, &cfg->prefix6, abuf, sizeof(abuf));
466 	printf(" prefix6 %s/%u", abuf, cfg->plen6);
467 	if (cfg->flags & NAT64_LOG)
468 		printf(" log");
469 	if (cfg->flags & NAT64_ALLOW_PRIVATE)
470 		printf(" allow_private");
471 	printf("\n");
472 	return (0);
473 }
474 
475 static int
476 nat64stl_destroy_cb(ipfw_nat64stl_cfg *cfg, const char *name, uint8_t set)
477 {
478 
479 	if (co.use_set != 0 && cfg->set != set)
480 		return (ESRCH);
481 
482 	nat64stl_destroy(cfg->name, cfg->set);
483 	return (0);
484 }
485 
486 
487 /*
488  * Compare nat64stl instances names.
489  * Honor number comparison.
490  */
491 static int
492 nat64name_cmp(const void *a, const void *b)
493 {
494 	ipfw_nat64stl_cfg *ca, *cb;
495 
496 	ca = (ipfw_nat64stl_cfg *)a;
497 	cb = (ipfw_nat64stl_cfg *)b;
498 
499 	if (ca->set > cb->set)
500 		return (1);
501 	else if (ca->set < cb->set)
502 		return (-1);
503 	return (stringnum_cmp(ca->name, cb->name));
504 }
505 
506 /*
507  * Retrieves nat64stl instance list from kernel,
508  * optionally sorts it and calls requested function for each instance.
509  *
510  * Request: [ ipfw_obj_lheader ]
511  * Reply: [ ipfw_obj_lheader ipfw_nat64stl_cfg x N ]
512  */
513 static int
514 nat64stl_foreach(nat64stl_cb_t *f, const char *name, uint8_t set, int sort)
515 {
516 	ipfw_obj_lheader *olh;
517 	ipfw_nat64stl_cfg *cfg;
518 	size_t sz;
519 	int i, error;
520 
521 	/* Start with reasonable default */
522 	sz = sizeof(*olh) + 16 * sizeof(*cfg);
523 	for (;;) {
524 		if ((olh = calloc(1, sz)) == NULL)
525 			return (ENOMEM);
526 
527 		olh->size = sz;
528 		if (do_get3(IP_FW_NAT64STL_LIST, &olh->opheader, &sz) != 0) {
529 			sz = olh->size;
530 			free(olh);
531 			if (errno != ENOMEM)
532 				return (errno);
533 			continue;
534 		}
535 
536 		if (sort != 0)
537 			qsort(olh + 1, olh->count, olh->objsize,
538 			    nat64name_cmp);
539 
540 		cfg = (ipfw_nat64stl_cfg *)(olh + 1);
541 		for (i = 0; i < olh->count; i++) {
542 			error = f(cfg, name, set); /* Ignore errors for now */
543 			cfg = (ipfw_nat64stl_cfg *)((caddr_t)cfg +
544 			    olh->objsize);
545 		}
546 		free(olh);
547 		break;
548 	}
549 	return (0);
550 }
551 
552