xref: /freebsd/sbin/ipfw/nat64stl.c (revision 3c4ba5f55438f7afd4f4b0b56f88f2bb505fd6a6)
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 (g_co.use_set != 0)
132 		set = g_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 			else
253 				errx(EX_USAGE,
254 				    "Prefix length required: %s", *av);
255 			if (inet_pton(AF_INET6, *av, &cfg->prefix6) != 1)
256 				errx(EX_USAGE,
257 				    "Bad prefix: %s", *av);
258 			cfg->plen6 = strtol(p, NULL, 10);
259 			if (ipfw_check_nat64prefix(&cfg->prefix6,
260 			    cfg->plen6) != 0)
261 				errx(EX_USAGE,
262 				    "Bad prefix length: %s", p);
263 			flags |= NAT64STL_HAS_PREFIX6;
264 			ac--; av++;
265 			break;
266 		case TOK_LOG:
267 			cfg->flags |= NAT64_LOG;
268 			break;
269 		case TOK_LOGOFF:
270 			cfg->flags &= ~NAT64_LOG;
271 			break;
272 		case TOK_PRIVATE:
273 			cfg->flags |= NAT64_ALLOW_PRIVATE;
274 			break;
275 		case TOK_PRIVATEOFF:
276 			cfg->flags &= ~NAT64_ALLOW_PRIVATE;
277 			break;
278 		}
279 	}
280 
281 	/* Check validness */
282 	if ((flags & NAT64STL_HAS_TABLE4) != NAT64STL_HAS_TABLE4)
283 		errx(EX_USAGE, "table4 required");
284 	if ((flags & NAT64STL_HAS_TABLE6) != NAT64STL_HAS_TABLE6)
285 		errx(EX_USAGE, "table6 required");
286 	if ((flags & NAT64STL_HAS_PREFIX6) != NAT64STL_HAS_PREFIX6)
287 		errx(EX_USAGE, "prefix6 required");
288 
289 	olh->count = 1;
290 	olh->objsize = sizeof(*cfg);
291 	olh->size = sizeof(buf);
292 	strlcpy(cfg->name, name, sizeof(cfg->name));
293 	if (do_set3(IP_FW_NAT64STL_CREATE, &olh->opheader, sizeof(buf)) != 0)
294 		err(EX_OSERR, "nat64stl instance creation failed");
295 }
296 
297 /*
298  * Configures existing nat64stl instance
299  * ipfw nat64stl <NAME> config <options>
300  * Request: [ ipfw_obj_header ipfw_nat64stl_cfg ]
301  */
302 static void
303 nat64stl_config(const char *name, uint8_t set, int ac, char **av)
304 {
305 	char buf[sizeof(ipfw_obj_header) + sizeof(ipfw_nat64stl_cfg)];
306 	ipfw_nat64stl_cfg *cfg;
307 	ipfw_obj_header *oh;
308 	char *opt;
309 	size_t sz;
310 	int tcmd;
311 
312 	if (ac == 0)
313 		errx(EX_USAGE, "config options required");
314 	memset(&buf, 0, sizeof(buf));
315 	oh = (ipfw_obj_header *)buf;
316 	cfg = (ipfw_nat64stl_cfg *)(oh + 1);
317 	sz = sizeof(buf);
318 
319 	nat64stl_fill_ntlv(&oh->ntlv, name, set);
320 	if (do_get3(IP_FW_NAT64STL_CONFIG, &oh->opheader, &sz) != 0)
321 		err(EX_OSERR, "failed to get config for instance %s", name);
322 
323 	while (ac > 0) {
324 		tcmd = get_token(nat64newcmds, *av, "option");
325 		opt = *av;
326 		ac--; av++;
327 
328 		switch (tcmd) {
329 #if 0
330 		case TOK_TABLE4:
331 			NEED1("table name required");
332 			table_fill_ntlv(&cfg->ntlv4, *av, set, 4);
333 			ac--; av++;
334 			break;
335 		case TOK_TABLE6:
336 			NEED1("table name required");
337 			table_fill_ntlv(&cfg->ntlv6, *av, set, 6);
338 			ac--; av++;
339 			break;
340 #endif
341 		case TOK_LOG:
342 			cfg->flags |= NAT64_LOG;
343 			break;
344 		case TOK_LOGOFF:
345 			cfg->flags &= ~NAT64_LOG;
346 			break;
347 		case TOK_PRIVATE:
348 			cfg->flags |= NAT64_ALLOW_PRIVATE;
349 			break;
350 		case TOK_PRIVATEOFF:
351 			cfg->flags &= ~NAT64_ALLOW_PRIVATE;
352 			break;
353 		default:
354 			errx(EX_USAGE, "Can't change %s option", opt);
355 		}
356 	}
357 
358 	if (do_set3(IP_FW_NAT64STL_CONFIG, &oh->opheader, sizeof(buf)) != 0)
359 		err(EX_OSERR, "nat64stl instance configuration failed");
360 }
361 
362 /*
363  * Destroys nat64stl instance.
364  * Request: [ ipfw_obj_header ]
365  */
366 static void
367 nat64stl_destroy(const char *name, uint8_t set)
368 {
369 	ipfw_obj_header oh;
370 
371 	memset(&oh, 0, sizeof(oh));
372 	nat64stl_fill_ntlv(&oh.ntlv, name, set);
373 	if (do_set3(IP_FW_NAT64STL_DESTROY, &oh.opheader, sizeof(oh)) != 0)
374 		err(EX_OSERR, "failed to destroy nat instance %s", name);
375 }
376 
377 /*
378  * Get nat64stl instance statistics.
379  * Request: [ ipfw_obj_header ]
380  * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ] ]
381  */
382 static int
383 nat64stl_get_stats(const char *name, uint8_t set,
384     struct ipfw_nat64stl_stats *stats)
385 {
386 	ipfw_obj_header *oh;
387 	ipfw_obj_ctlv *oc;
388 	size_t sz;
389 
390 	sz = sizeof(*oh) + sizeof(*oc) + sizeof(*stats);
391 	oh = calloc(1, sz);
392 	nat64stl_fill_ntlv(&oh->ntlv, name, set);
393 	if (do_get3(IP_FW_NAT64STL_STATS, &oh->opheader, &sz) == 0) {
394 		oc = (ipfw_obj_ctlv *)(oh + 1);
395 		memcpy(stats, oc + 1, sizeof(*stats));
396 		free(oh);
397 		return (0);
398 	}
399 	free(oh);
400 	return (-1);
401 }
402 
403 static void
404 nat64stl_stats(const char *name, uint8_t set)
405 {
406 	struct ipfw_nat64stl_stats stats;
407 
408 	if (nat64stl_get_stats(name, set, &stats) != 0)
409 		err(EX_OSERR, "Error retrieving stats");
410 
411 	if (g_co.use_set != 0 || set != 0)
412 		printf("set %u ", set);
413 	printf("nat64stl %s\n", name);
414 
415 	printf("\t%ju packets translated from IPv6 to IPv4\n",
416 	    (uintmax_t)stats.opcnt64);
417 	printf("\t%ju packets translated from IPv4 to IPv6\n",
418 	    (uintmax_t)stats.opcnt46);
419 	printf("\t%ju IPv6 fragments created\n",
420 	    (uintmax_t)stats.ofrags);
421 	printf("\t%ju IPv4 fragments received\n",
422 	    (uintmax_t)stats.ifrags);
423 	printf("\t%ju output packets dropped due to no bufs, etc.\n",
424 	    (uintmax_t)stats.oerrors);
425 	printf("\t%ju output packets discarded due to no IPv4 route\n",
426 	    (uintmax_t)stats.noroute4);
427 	printf("\t%ju output packets discarded due to no IPv6 route\n",
428 	    (uintmax_t)stats.noroute6);
429 	printf("\t%ju packets discarded due to unsupported protocol\n",
430 	    (uintmax_t)stats.noproto);
431 	printf("\t%ju packets discarded due to memory allocation problems\n",
432 	    (uintmax_t)stats.nomem);
433 	printf("\t%ju packets discarded due to some errors\n",
434 	    (uintmax_t)stats.dropped);
435 }
436 
437 /*
438  * Reset nat64stl instance statistics specified by @oh->ntlv.
439  * Request: [ ipfw_obj_header ]
440  */
441 static void
442 nat64stl_reset_stats(const char *name, uint8_t set)
443 {
444 	ipfw_obj_header oh;
445 
446 	memset(&oh, 0, sizeof(oh));
447 	nat64stl_fill_ntlv(&oh.ntlv, name, set);
448 	if (do_set3(IP_FW_NAT64STL_RESET_STATS, &oh.opheader, sizeof(oh)) != 0)
449 		err(EX_OSERR, "failed to reset stats for instance %s", name);
450 }
451 
452 static int
453 nat64stl_show_cb(ipfw_nat64stl_cfg *cfg, const char *name, uint8_t set)
454 {
455 	char abuf[INET6_ADDRSTRLEN];
456 
457 	if (name != NULL && strcmp(cfg->name, name) != 0)
458 		return (ESRCH);
459 
460 	if (g_co.use_set != 0 && cfg->set != set)
461 		return (ESRCH);
462 
463 	if (g_co.use_set != 0 || cfg->set != 0)
464 		printf("set %u ", cfg->set);
465 
466 	printf("nat64stl %s table4 %s table6 %s",
467 	    cfg->name, cfg->ntlv4.name, cfg->ntlv6.name);
468 	inet_ntop(AF_INET6, &cfg->prefix6, abuf, sizeof(abuf));
469 	printf(" prefix6 %s/%u", abuf, cfg->plen6);
470 	if (cfg->flags & NAT64_LOG)
471 		printf(" log");
472 	if (cfg->flags & NAT64_ALLOW_PRIVATE)
473 		printf(" allow_private");
474 	printf("\n");
475 	return (0);
476 }
477 
478 static int
479 nat64stl_destroy_cb(ipfw_nat64stl_cfg *cfg, const char *name __unused,
480     uint8_t set)
481 {
482 
483 	if (g_co.use_set != 0 && cfg->set != set)
484 		return (ESRCH);
485 
486 	nat64stl_destroy(cfg->name, cfg->set);
487 	return (0);
488 }
489 
490 
491 /*
492  * Compare nat64stl instances names.
493  * Honor number comparison.
494  */
495 static int
496 nat64name_cmp(const void *a, const void *b)
497 {
498 	const ipfw_nat64stl_cfg *ca, *cb;
499 
500 	ca = (const ipfw_nat64stl_cfg *)a;
501 	cb = (const ipfw_nat64stl_cfg *)b;
502 
503 	if (ca->set > cb->set)
504 		return (1);
505 	else if (ca->set < cb->set)
506 		return (-1);
507 	return (stringnum_cmp(ca->name, cb->name));
508 }
509 
510 /*
511  * Retrieves nat64stl instance list from kernel,
512  * optionally sorts it and calls requested function for each instance.
513  *
514  * Request: [ ipfw_obj_lheader ]
515  * Reply: [ ipfw_obj_lheader ipfw_nat64stl_cfg x N ]
516  */
517 static int
518 nat64stl_foreach(nat64stl_cb_t *f, const char *name, uint8_t set, int sort)
519 {
520 	ipfw_obj_lheader *olh;
521 	ipfw_nat64stl_cfg *cfg;
522 	size_t sz;
523 	uint32_t i;
524 	int error;
525 
526 	/* Start with reasonable default */
527 	sz = sizeof(*olh) + 16 * sizeof(*cfg);
528 	for (;;) {
529 		if ((olh = calloc(1, sz)) == NULL)
530 			return (ENOMEM);
531 
532 		olh->size = sz;
533 		if (do_get3(IP_FW_NAT64STL_LIST, &olh->opheader, &sz) != 0) {
534 			sz = olh->size;
535 			free(olh);
536 			if (errno != ENOMEM)
537 				return (errno);
538 			continue;
539 		}
540 
541 		if (sort != 0)
542 			qsort(olh + 1, olh->count, olh->objsize,
543 			    nat64name_cmp);
544 
545 		cfg = (ipfw_nat64stl_cfg *)(olh + 1);
546 		for (i = 0; i < olh->count; i++) {
547 			error = f(cfg, name, set); /* Ignore errors for now */
548 			cfg = (ipfw_nat64stl_cfg *)((caddr_t)cfg +
549 			    olh->objsize);
550 		}
551 		free(olh);
552 		break;
553 	}
554 	return (0);
555 }
556 
557