xref: /freebsd/sbin/ipfw/nptv6.c (revision 535af610) 
1 /*-
2  * Copyright (c) 2016 Yandex LLC
3  * Copyright (c) 2016 Andrey V. Elsukov <ae@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/socket.h>
33 
34 #include "ipfw2.h"
35 
36 #include <ctype.h>
37 #include <err.h>
38 #include <errno.h>
39 #include <inttypes.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <sysexits.h>
44 
45 #include <net/if.h>
46 #include <netinet/in.h>
47 #include <netinet/ip_fw.h>
48 #include <netinet6/ip_fw_nptv6.h>
49 #include <arpa/inet.h>
50 
51 
52 typedef int (nptv6_cb_t)(ipfw_nptv6_cfg *i, const char *name, uint8_t set);
53 static int nptv6_foreach(nptv6_cb_t *f, const char *name, uint8_t set,
54     int sort);
55 
56 static void nptv6_create(const char *name, uint8_t set, int ac, char **av);
57 static void nptv6_destroy(const char *name, uint8_t set);
58 static void nptv6_stats(const char *name, uint8_t set);
59 static void nptv6_reset_stats(const char *name, uint8_t set);
60 static int nptv6_show_cb(ipfw_nptv6_cfg *cfg, const char *name, uint8_t set);
61 static int nptv6_destroy_cb(ipfw_nptv6_cfg *cfg, const char *name, uint8_t set);
62 
63 static struct _s_x nptv6cmds[] = {
64       { "create",	TOK_CREATE },
65       { "destroy",	TOK_DESTROY },
66       { "list",		TOK_LIST },
67       { "show",		TOK_LIST },
68       { "stats",	TOK_STATS },
69       { NULL, 0 }
70 };
71 
72 static struct _s_x nptv6statscmds[] = {
73       { "reset",	TOK_RESET },
74       { NULL, 0 }
75 };
76 
77 /*
78  * This one handles all NPTv6-related commands
79  *	ipfw [set N] nptv6 NAME {create | config} ...
80  *	ipfw [set N] nptv6 NAME stats [reset]
81  *	ipfw [set N] nptv6 {NAME | all} destroy
82  *	ipfw [set N] nptv6 {NAME | all} {list | show}
83  */
84 #define	nptv6_check_name	table_check_name
85 void
86 ipfw_nptv6_handler(int ac, char *av[])
87 {
88 	const char *name;
89 	int tcmd;
90 	uint8_t set;
91 
92 	if (g_co.use_set != 0)
93 		set = g_co.use_set - 1;
94 	else
95 		set = 0;
96 	ac--; av++;
97 
98 	NEED1("nptv6 needs instance name");
99 	name = *av;
100 	if (nptv6_check_name(name) != 0) {
101 		if (strcmp(name, "all") == 0) {
102 			name = NULL;
103 		} else
104 			errx(EX_USAGE, "nptv6 instance name %s is invalid",
105 			    name);
106 	}
107 	ac--; av++;
108 	NEED1("nptv6 needs command");
109 
110 	tcmd = get_token(nptv6cmds, *av, "nptv6 command");
111 	if (name == NULL && tcmd != TOK_DESTROY && tcmd != TOK_LIST)
112 		errx(EX_USAGE, "nptv6 instance name required");
113 	switch (tcmd) {
114 	case TOK_CREATE:
115 		ac--; av++;
116 		nptv6_create(name, set, ac, av);
117 		break;
118 	case TOK_LIST:
119 		nptv6_foreach(nptv6_show_cb, name, set, 1);
120 		break;
121 	case TOK_DESTROY:
122 		if (name == NULL)
123 			nptv6_foreach(nptv6_destroy_cb, NULL, set, 0);
124 		else
125 			nptv6_destroy(name, set);
126 		break;
127 	case TOK_STATS:
128 		ac--; av++;
129 		if (ac == 0) {
130 			nptv6_stats(name, set);
131 			break;
132 		}
133 		tcmd = get_token(nptv6statscmds, *av, "stats command");
134 		if (tcmd == TOK_RESET)
135 			nptv6_reset_stats(name, set);
136 	}
137 }
138 
139 
140 static void
141 nptv6_fill_ntlv(ipfw_obj_ntlv *ntlv, const char *name, uint8_t set)
142 {
143 
144 	ntlv->head.type = IPFW_TLV_EACTION_NAME(1); /* it doesn't matter */
145 	ntlv->head.length = sizeof(ipfw_obj_ntlv);
146 	ntlv->idx = 1;
147 	ntlv->set = set;
148 	strlcpy(ntlv->name, name, sizeof(ntlv->name));
149 }
150 
151 static struct _s_x nptv6newcmds[] = {
152       { "int_prefix",	TOK_INTPREFIX },
153       { "ext_prefix",	TOK_EXTPREFIX },
154       { "prefixlen",	TOK_PREFIXLEN },
155       { "ext_if",	TOK_EXTIF },
156       { NULL, 0 }
157 };
158 
159 
160 static void
161 nptv6_parse_prefix(const char *arg, struct in6_addr *prefix, int *len)
162 {
163 	char *p, *l;
164 
165 	p = strdup(arg);
166 	if (p == NULL)
167 		err(EX_OSERR, NULL);
168 	if ((l = strchr(p, '/')) != NULL)
169 		*l++ = '\0';
170 	if (inet_pton(AF_INET6, p, prefix) != 1)
171 		errx(EX_USAGE, "Bad prefix: %s", p);
172 	if (l != NULL) {
173 		*len = (int)strtol(l, &l, 10);
174 		if (*l != '\0' || *len <= 0 || *len > 64)
175 			errx(EX_USAGE, "Bad prefix length: %s", arg);
176 	} else
177 		*len = 0;
178 	free(p);
179 }
180 /*
181  * Creates new nptv6 instance
182  * ipfw nptv6 <NAME> create int_prefix <prefix> ext_prefix <prefix>
183  * Request: [ ipfw_obj_lheader ipfw_nptv6_cfg ]
184  */
185 #define	NPTV6_HAS_INTPREFIX	0x01
186 #define	NPTV6_HAS_EXTPREFIX	0x02
187 #define	NPTV6_HAS_PREFIXLEN	0x04
188 static void
189 nptv6_create(const char *name, uint8_t set, int ac, char *av[])
190 {
191 	char buf[sizeof(ipfw_obj_lheader) + sizeof(ipfw_nptv6_cfg)];
192 	struct in6_addr mask;
193 	ipfw_nptv6_cfg *cfg;
194 	ipfw_obj_lheader *olh;
195 	int tcmd, flags, plen;
196 	char *p;
197 
198 	plen = 0;
199 	memset(buf, 0, sizeof(buf));
200 	olh = (ipfw_obj_lheader *)buf;
201 	cfg = (ipfw_nptv6_cfg *)(olh + 1);
202 	cfg->set = set;
203 	flags = 0;
204 	while (ac > 0) {
205 		tcmd = get_token(nptv6newcmds, *av, "option");
206 		ac--; av++;
207 
208 		switch (tcmd) {
209 		case TOK_INTPREFIX:
210 			NEED1("IPv6 prefix required");
211 			nptv6_parse_prefix(*av, &cfg->internal, &plen);
212 			flags |= NPTV6_HAS_INTPREFIX;
213 			if (plen > 0)
214 				goto check_prefix;
215 			ac--; av++;
216 			break;
217 		case TOK_EXTPREFIX:
218 			if (flags & NPTV6_HAS_EXTPREFIX)
219 				errx(EX_USAGE,
220 				    "Only one ext_prefix or ext_if allowed");
221 			NEED1("IPv6 prefix required");
222 			nptv6_parse_prefix(*av, &cfg->external, &plen);
223 			flags |= NPTV6_HAS_EXTPREFIX;
224 			if (plen > 0)
225 				goto check_prefix;
226 			ac--; av++;
227 			break;
228 		case TOK_EXTIF:
229 			if (flags & NPTV6_HAS_EXTPREFIX)
230 				errx(EX_USAGE,
231 				    "Only one ext_prefix or ext_if allowed");
232 			NEED1("Interface name required");
233 			if (strlen(*av) >= sizeof(cfg->if_name))
234 				errx(EX_USAGE, "Invalid interface name");
235 			flags |= NPTV6_HAS_EXTPREFIX;
236 			cfg->flags |= NPTV6_DYNAMIC_PREFIX;
237 			strncpy(cfg->if_name, *av, sizeof(cfg->if_name));
238 			ac--; av++;
239 			break;
240 		case TOK_PREFIXLEN:
241 			NEED1("IPv6 prefix length required");
242 			plen = strtol(*av, &p, 10);
243 check_prefix:
244 			if (*p != '\0' || plen < 8 || plen > 64)
245 				errx(EX_USAGE, "wrong prefix length: %s", *av);
246 			/* RFC 6296 Sec. 3.1 */
247 			if (cfg->plen > 0 && cfg->plen != plen) {
248 				warnx("Prefix length mismatch (%d vs %d).  "
249 				    "It was extended up to %d",
250 				    cfg->plen, plen, MAX(plen, cfg->plen));
251 				plen = MAX(plen, cfg->plen);
252 			}
253 			cfg->plen = plen;
254 			flags |= NPTV6_HAS_PREFIXLEN;
255 			ac--; av++;
256 			break;
257 		}
258 	}
259 
260 	/* Check validness */
261 	if ((flags & NPTV6_HAS_INTPREFIX) != NPTV6_HAS_INTPREFIX)
262 		errx(EX_USAGE, "int_prefix required");
263 	if ((flags & NPTV6_HAS_EXTPREFIX) != NPTV6_HAS_EXTPREFIX)
264 		errx(EX_USAGE, "ext_prefix or ext_if required");
265 	if ((flags & NPTV6_HAS_PREFIXLEN) != NPTV6_HAS_PREFIXLEN)
266 		errx(EX_USAGE, "prefixlen required");
267 
268 	n2mask(&mask, cfg->plen);
269 	APPLY_MASK(&cfg->internal, &mask);
270 	if ((cfg->flags & NPTV6_DYNAMIC_PREFIX) == 0)
271 		APPLY_MASK(&cfg->external, &mask);
272 
273 	olh->count = 1;
274 	olh->objsize = sizeof(*cfg);
275 	olh->size = sizeof(buf);
276 	strlcpy(cfg->name, name, sizeof(cfg->name));
277 	if (do_set3(IP_FW_NPTV6_CREATE, &olh->opheader, sizeof(buf)) != 0)
278 		err(EX_OSERR, "nptv6 instance creation failed");
279 }
280 
281 /*
282  * Destroys NPTv6 instance.
283  * Request: [ ipfw_obj_header ]
284  */
285 static void
286 nptv6_destroy(const char *name, uint8_t set)
287 {
288 	ipfw_obj_header oh;
289 
290 	memset(&oh, 0, sizeof(oh));
291 	nptv6_fill_ntlv(&oh.ntlv, name, set);
292 	if (do_set3(IP_FW_NPTV6_DESTROY, &oh.opheader, sizeof(oh)) != 0)
293 		err(EX_OSERR, "failed to destroy nat instance %s", name);
294 }
295 
296 /*
297  * Get NPTv6 instance statistics.
298  * Request: [ ipfw_obj_header ]
299  * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ] ]
300  */
301 static int
302 nptv6_get_stats(const char *name, uint8_t set, struct ipfw_nptv6_stats *stats)
303 {
304 	ipfw_obj_header *oh;
305 	ipfw_obj_ctlv *oc;
306 	size_t sz;
307 
308 	sz = sizeof(*oh) + sizeof(*oc) + sizeof(*stats);
309 	oh = calloc(1, sz);
310 	nptv6_fill_ntlv(&oh->ntlv, name, set);
311 	if (do_get3(IP_FW_NPTV6_STATS, &oh->opheader, &sz) == 0) {
312 		oc = (ipfw_obj_ctlv *)(oh + 1);
313 		memcpy(stats, oc + 1, sizeof(*stats));
314 		free(oh);
315 		return (0);
316 	}
317 	free(oh);
318 	return (-1);
319 }
320 
321 static void
322 nptv6_stats(const char *name, uint8_t set)
323 {
324 	struct ipfw_nptv6_stats stats;
325 
326 	if (nptv6_get_stats(name, set, &stats) != 0)
327 		err(EX_OSERR, "Error retrieving stats");
328 
329 	if (g_co.use_set != 0 || set != 0)
330 		printf("set %u ", set);
331 	printf("nptv6 %s\n", name);
332 	printf("\t%ju packets translated (internal to external)\n",
333 	    (uintmax_t)stats.in2ex);
334 	printf("\t%ju packets translated (external to internal)\n",
335 	    (uintmax_t)stats.ex2in);
336 	printf("\t%ju packets dropped due to some error\n",
337 	    (uintmax_t)stats.dropped);
338 }
339 
340 /*
341  * Reset NPTv6 instance statistics specified by @oh->ntlv.
342  * Request: [ ipfw_obj_header ]
343  */
344 static void
345 nptv6_reset_stats(const char *name, uint8_t set)
346 {
347 	ipfw_obj_header oh;
348 
349 	memset(&oh, 0, sizeof(oh));
350 	nptv6_fill_ntlv(&oh.ntlv, name, set);
351 	if (do_set3(IP_FW_NPTV6_RESET_STATS, &oh.opheader, sizeof(oh)) != 0)
352 		err(EX_OSERR, "failed to reset stats for instance %s", name);
353 }
354 
355 static int
356 nptv6_show_cb(ipfw_nptv6_cfg *cfg, const char *name, uint8_t set)
357 {
358 	char abuf[INET6_ADDRSTRLEN];
359 
360 	if (name != NULL && strcmp(cfg->name, name) != 0)
361 		return (ESRCH);
362 
363 	if (g_co.use_set != 0 && cfg->set != set)
364 		return (ESRCH);
365 
366 	if (g_co.use_set != 0 || cfg->set != 0)
367 		printf("set %u ", cfg->set);
368 	inet_ntop(AF_INET6, &cfg->internal, abuf, sizeof(abuf));
369 	printf("nptv6 %s int_prefix %s ", cfg->name, abuf);
370 	if (cfg->flags & NPTV6_DYNAMIC_PREFIX)
371 		printf("ext_if %s ", cfg->if_name);
372 	else {
373 		inet_ntop(AF_INET6, &cfg->external, abuf, sizeof(abuf));
374 		printf("ext_prefix %s ", abuf);
375 	}
376 	printf("prefixlen %u\n", cfg->plen);
377 	return (0);
378 }
379 
380 static int
381 nptv6_destroy_cb(ipfw_nptv6_cfg *cfg, const char *name __unused, uint8_t set)
382 {
383 
384 	if (g_co.use_set != 0 && cfg->set != set)
385 		return (ESRCH);
386 
387 	nptv6_destroy(cfg->name, cfg->set);
388 	return (0);
389 }
390 
391 
392 /*
393  * Compare NPTv6 instances names.
394  * Honor number comparison.
395  */
396 static int
397 nptv6name_cmp(const void *a, const void *b)
398 {
399 	const ipfw_nptv6_cfg *ca, *cb;
400 
401 	ca = (const ipfw_nptv6_cfg *)a;
402 	cb = (const ipfw_nptv6_cfg *)b;
403 
404 	if (ca->set > cb->set)
405 		return (1);
406 	else if (ca->set < cb->set)
407 		return (-1);
408 	return (stringnum_cmp(ca->name, cb->name));
409 }
410 
411 /*
412  * Retrieves NPTv6 instance list from kernel,
413  * Request: [ ipfw_obj_lheader ]
414  * Reply: [ ipfw_obj_lheader ipfw_nptv6_cfg x N ]
415  */
416 static int
417 nptv6_foreach(nptv6_cb_t *f, const char *name, uint8_t set, int sort)
418 {
419 	ipfw_obj_lheader *olh;
420 	ipfw_nptv6_cfg *cfg;
421 	size_t sz;
422 	uint32_t i;
423 
424 	/* Start with reasonable default */
425 	sz = sizeof(*olh) + 16 * sizeof(*cfg);
426 	for (;;) {
427 		if ((olh = calloc(1, sz)) == NULL)
428 			return (ENOMEM);
429 
430 		olh->size = sz;
431 		if (do_get3(IP_FW_NPTV6_LIST, &olh->opheader, &sz) != 0) {
432 			sz = olh->size;
433 			free(olh);
434 			if (errno != ENOMEM)
435 				return (errno);
436 			continue;
437 		}
438 
439 		if (sort != 0)
440 			qsort(olh + 1, olh->count, olh->objsize, nptv6name_cmp);
441 
442 		cfg = (ipfw_nptv6_cfg *)(olh + 1);
443 		for (i = 0; i < olh->count; i++) {
444 			(void)f(cfg, name, set);
445 			cfg = (ipfw_nptv6_cfg *)((caddr_t)cfg + olh->objsize);
446 		}
447 		free(olh);
448 		break;
449 	}
450 	return (0);
451 }
452 
453