xref: /freebsd/sbin/ipfw/nptv6.c (revision 315ee00f) 
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 #include <sys/param.h>
30 #include <sys/socket.h>
31 
32 #include "ipfw2.h"
33 
34 #include <ctype.h>
35 #include <err.h>
36 #include <errno.h>
37 #include <inttypes.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <sysexits.h>
42 
43 #include <net/if.h>
44 #include <netinet/in.h>
45 #include <netinet/ip_fw.h>
46 #include <netinet6/ip_fw_nptv6.h>
47 #include <arpa/inet.h>
48 
49 
50 typedef int (nptv6_cb_t)(ipfw_nptv6_cfg *i, const char *name, uint8_t set);
51 static int nptv6_foreach(nptv6_cb_t *f, const char *name, uint8_t set,
52     int sort);
53 
54 static void nptv6_create(const char *name, uint8_t set, int ac, char **av);
55 static void nptv6_destroy(const char *name, uint8_t set);
56 static void nptv6_stats(const char *name, uint8_t set);
57 static void nptv6_reset_stats(const char *name, uint8_t set);
58 static int nptv6_show_cb(ipfw_nptv6_cfg *cfg, const char *name, uint8_t set);
59 static int nptv6_destroy_cb(ipfw_nptv6_cfg *cfg, const char *name, uint8_t set);
60 
61 static struct _s_x nptv6cmds[] = {
62       { "create",	TOK_CREATE },
63       { "destroy",	TOK_DESTROY },
64       { "list",		TOK_LIST },
65       { "show",		TOK_LIST },
66       { "stats",	TOK_STATS },
67       { NULL, 0 }
68 };
69 
70 static struct _s_x nptv6statscmds[] = {
71       { "reset",	TOK_RESET },
72       { NULL, 0 }
73 };
74 
75 /*
76  * This one handles all NPTv6-related commands
77  *	ipfw [set N] nptv6 NAME {create | config} ...
78  *	ipfw [set N] nptv6 NAME stats [reset]
79  *	ipfw [set N] nptv6 {NAME | all} destroy
80  *	ipfw [set N] nptv6 {NAME | all} {list | show}
81  */
82 #define	nptv6_check_name	table_check_name
83 void
84 ipfw_nptv6_handler(int ac, char *av[])
85 {
86 	const char *name;
87 	int tcmd;
88 	uint8_t set;
89 
90 	if (g_co.use_set != 0)
91 		set = g_co.use_set - 1;
92 	else
93 		set = 0;
94 	ac--; av++;
95 
96 	NEED1("nptv6 needs instance name");
97 	name = *av;
98 	if (nptv6_check_name(name) != 0) {
99 		if (strcmp(name, "all") == 0) {
100 			name = NULL;
101 		} else
102 			errx(EX_USAGE, "nptv6 instance name %s is invalid",
103 			    name);
104 	}
105 	ac--; av++;
106 	NEED1("nptv6 needs command");
107 
108 	tcmd = get_token(nptv6cmds, *av, "nptv6 command");
109 	if (name == NULL && tcmd != TOK_DESTROY && tcmd != TOK_LIST)
110 		errx(EX_USAGE, "nptv6 instance name required");
111 	switch (tcmd) {
112 	case TOK_CREATE:
113 		ac--; av++;
114 		nptv6_create(name, set, ac, av);
115 		break;
116 	case TOK_LIST:
117 		nptv6_foreach(nptv6_show_cb, name, set, 1);
118 		break;
119 	case TOK_DESTROY:
120 		if (name == NULL)
121 			nptv6_foreach(nptv6_destroy_cb, NULL, set, 0);
122 		else
123 			nptv6_destroy(name, set);
124 		break;
125 	case TOK_STATS:
126 		ac--; av++;
127 		if (ac == 0) {
128 			nptv6_stats(name, set);
129 			break;
130 		}
131 		tcmd = get_token(nptv6statscmds, *av, "stats command");
132 		if (tcmd == TOK_RESET)
133 			nptv6_reset_stats(name, set);
134 	}
135 }
136 
137 
138 static void
139 nptv6_fill_ntlv(ipfw_obj_ntlv *ntlv, const char *name, uint8_t set)
140 {
141 
142 	ntlv->head.type = IPFW_TLV_EACTION_NAME(1); /* it doesn't matter */
143 	ntlv->head.length = sizeof(ipfw_obj_ntlv);
144 	ntlv->idx = 1;
145 	ntlv->set = set;
146 	strlcpy(ntlv->name, name, sizeof(ntlv->name));
147 }
148 
149 static struct _s_x nptv6newcmds[] = {
150       { "int_prefix",	TOK_INTPREFIX },
151       { "ext_prefix",	TOK_EXTPREFIX },
152       { "prefixlen",	TOK_PREFIXLEN },
153       { "ext_if",	TOK_EXTIF },
154       { NULL, 0 }
155 };
156 
157 
158 static void
159 nptv6_parse_prefix(const char *arg, struct in6_addr *prefix, int *len)
160 {
161 	char *p, *l;
162 
163 	p = strdup(arg);
164 	if (p == NULL)
165 		err(EX_OSERR, NULL);
166 	if ((l = strchr(p, '/')) != NULL)
167 		*l++ = '\0';
168 	if (inet_pton(AF_INET6, p, prefix) != 1)
169 		errx(EX_USAGE, "Bad prefix: %s", p);
170 	if (l != NULL) {
171 		*len = (int)strtol(l, &l, 10);
172 		if (*l != '\0' || *len <= 0 || *len > 64)
173 			errx(EX_USAGE, "Bad prefix length: %s", arg);
174 	} else
175 		*len = 0;
176 	free(p);
177 }
178 /*
179  * Creates new nptv6 instance
180  * ipfw nptv6 <NAME> create int_prefix <prefix> ext_prefix <prefix>
181  * Request: [ ipfw_obj_lheader ipfw_nptv6_cfg ]
182  */
183 #define	NPTV6_HAS_INTPREFIX	0x01
184 #define	NPTV6_HAS_EXTPREFIX	0x02
185 #define	NPTV6_HAS_PREFIXLEN	0x04
186 static void
187 nptv6_create(const char *name, uint8_t set, int ac, char *av[])
188 {
189 	char buf[sizeof(ipfw_obj_lheader) + sizeof(ipfw_nptv6_cfg)];
190 	struct in6_addr mask;
191 	ipfw_nptv6_cfg *cfg;
192 	ipfw_obj_lheader *olh;
193 	int tcmd, flags, plen;
194 	char *p;
195 
196 	plen = 0;
197 	memset(buf, 0, sizeof(buf));
198 	olh = (ipfw_obj_lheader *)buf;
199 	cfg = (ipfw_nptv6_cfg *)(olh + 1);
200 	cfg->set = set;
201 	flags = 0;
202 	while (ac > 0) {
203 		tcmd = get_token(nptv6newcmds, *av, "option");
204 		ac--; av++;
205 
206 		switch (tcmd) {
207 		case TOK_INTPREFIX:
208 			NEED1("IPv6 prefix required");
209 			nptv6_parse_prefix(*av, &cfg->internal, &plen);
210 			flags |= NPTV6_HAS_INTPREFIX;
211 			if (plen > 0)
212 				goto check_prefix;
213 			ac--; av++;
214 			break;
215 		case TOK_EXTPREFIX:
216 			if (flags & NPTV6_HAS_EXTPREFIX)
217 				errx(EX_USAGE,
218 				    "Only one ext_prefix or ext_if allowed");
219 			NEED1("IPv6 prefix required");
220 			nptv6_parse_prefix(*av, &cfg->external, &plen);
221 			flags |= NPTV6_HAS_EXTPREFIX;
222 			if (plen > 0)
223 				goto check_prefix;
224 			ac--; av++;
225 			break;
226 		case TOK_EXTIF:
227 			if (flags & NPTV6_HAS_EXTPREFIX)
228 				errx(EX_USAGE,
229 				    "Only one ext_prefix or ext_if allowed");
230 			NEED1("Interface name required");
231 			if (strlen(*av) >= sizeof(cfg->if_name))
232 				errx(EX_USAGE, "Invalid interface name");
233 			flags |= NPTV6_HAS_EXTPREFIX;
234 			cfg->flags |= NPTV6_DYNAMIC_PREFIX;
235 			strncpy(cfg->if_name, *av, sizeof(cfg->if_name));
236 			ac--; av++;
237 			break;
238 		case TOK_PREFIXLEN:
239 			NEED1("IPv6 prefix length required");
240 			plen = strtol(*av, &p, 10);
241 check_prefix:
242 			if (*p != '\0' || plen < 8 || plen > 64)
243 				errx(EX_USAGE, "wrong prefix length: %s", *av);
244 			/* RFC 6296 Sec. 3.1 */
245 			if (cfg->plen > 0 && cfg->plen != plen) {
246 				warnx("Prefix length mismatch (%d vs %d).  "
247 				    "It was extended up to %d",
248 				    cfg->plen, plen, MAX(plen, cfg->plen));
249 				plen = MAX(plen, cfg->plen);
250 			}
251 			cfg->plen = plen;
252 			flags |= NPTV6_HAS_PREFIXLEN;
253 			ac--; av++;
254 			break;
255 		}
256 	}
257 
258 	/* Check validness */
259 	if ((flags & NPTV6_HAS_INTPREFIX) != NPTV6_HAS_INTPREFIX)
260 		errx(EX_USAGE, "int_prefix required");
261 	if ((flags & NPTV6_HAS_EXTPREFIX) != NPTV6_HAS_EXTPREFIX)
262 		errx(EX_USAGE, "ext_prefix or ext_if required");
263 	if ((flags & NPTV6_HAS_PREFIXLEN) != NPTV6_HAS_PREFIXLEN)
264 		errx(EX_USAGE, "prefixlen required");
265 
266 	n2mask(&mask, cfg->plen);
267 	APPLY_MASK(&cfg->internal, &mask);
268 	if ((cfg->flags & NPTV6_DYNAMIC_PREFIX) == 0)
269 		APPLY_MASK(&cfg->external, &mask);
270 
271 	olh->count = 1;
272 	olh->objsize = sizeof(*cfg);
273 	olh->size = sizeof(buf);
274 	strlcpy(cfg->name, name, sizeof(cfg->name));
275 	if (do_set3(IP_FW_NPTV6_CREATE, &olh->opheader, sizeof(buf)) != 0)
276 		err(EX_OSERR, "nptv6 instance creation failed");
277 }
278 
279 /*
280  * Destroys NPTv6 instance.
281  * Request: [ ipfw_obj_header ]
282  */
283 static void
284 nptv6_destroy(const char *name, uint8_t set)
285 {
286 	ipfw_obj_header oh;
287 
288 	memset(&oh, 0, sizeof(oh));
289 	nptv6_fill_ntlv(&oh.ntlv, name, set);
290 	if (do_set3(IP_FW_NPTV6_DESTROY, &oh.opheader, sizeof(oh)) != 0)
291 		err(EX_OSERR, "failed to destroy nat instance %s", name);
292 }
293 
294 /*
295  * Get NPTv6 instance statistics.
296  * Request: [ ipfw_obj_header ]
297  * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ] ]
298  */
299 static int
300 nptv6_get_stats(const char *name, uint8_t set, struct ipfw_nptv6_stats *stats)
301 {
302 	ipfw_obj_header *oh;
303 	ipfw_obj_ctlv *oc;
304 	size_t sz;
305 
306 	sz = sizeof(*oh) + sizeof(*oc) + sizeof(*stats);
307 	oh = calloc(1, sz);
308 	nptv6_fill_ntlv(&oh->ntlv, name, set);
309 	if (do_get3(IP_FW_NPTV6_STATS, &oh->opheader, &sz) == 0) {
310 		oc = (ipfw_obj_ctlv *)(oh + 1);
311 		memcpy(stats, oc + 1, sizeof(*stats));
312 		free(oh);
313 		return (0);
314 	}
315 	free(oh);
316 	return (-1);
317 }
318 
319 static void
320 nptv6_stats(const char *name, uint8_t set)
321 {
322 	struct ipfw_nptv6_stats stats;
323 
324 	if (nptv6_get_stats(name, set, &stats) != 0)
325 		err(EX_OSERR, "Error retrieving stats");
326 
327 	if (g_co.use_set != 0 || set != 0)
328 		printf("set %u ", set);
329 	printf("nptv6 %s\n", name);
330 	printf("\t%ju packets translated (internal to external)\n",
331 	    (uintmax_t)stats.in2ex);
332 	printf("\t%ju packets translated (external to internal)\n",
333 	    (uintmax_t)stats.ex2in);
334 	printf("\t%ju packets dropped due to some error\n",
335 	    (uintmax_t)stats.dropped);
336 }
337 
338 /*
339  * Reset NPTv6 instance statistics specified by @oh->ntlv.
340  * Request: [ ipfw_obj_header ]
341  */
342 static void
343 nptv6_reset_stats(const char *name, uint8_t set)
344 {
345 	ipfw_obj_header oh;
346 
347 	memset(&oh, 0, sizeof(oh));
348 	nptv6_fill_ntlv(&oh.ntlv, name, set);
349 	if (do_set3(IP_FW_NPTV6_RESET_STATS, &oh.opheader, sizeof(oh)) != 0)
350 		err(EX_OSERR, "failed to reset stats for instance %s", name);
351 }
352 
353 static int
354 nptv6_show_cb(ipfw_nptv6_cfg *cfg, const char *name, uint8_t set)
355 {
356 	char abuf[INET6_ADDRSTRLEN];
357 
358 	if (name != NULL && strcmp(cfg->name, name) != 0)
359 		return (ESRCH);
360 
361 	if (g_co.use_set != 0 && cfg->set != set)
362 		return (ESRCH);
363 
364 	if (g_co.use_set != 0 || cfg->set != 0)
365 		printf("set %u ", cfg->set);
366 	inet_ntop(AF_INET6, &cfg->internal, abuf, sizeof(abuf));
367 	printf("nptv6 %s int_prefix %s ", cfg->name, abuf);
368 	if (cfg->flags & NPTV6_DYNAMIC_PREFIX)
369 		printf("ext_if %s ", cfg->if_name);
370 	else {
371 		inet_ntop(AF_INET6, &cfg->external, abuf, sizeof(abuf));
372 		printf("ext_prefix %s ", abuf);
373 	}
374 	printf("prefixlen %u\n", cfg->plen);
375 	return (0);
376 }
377 
378 static int
379 nptv6_destroy_cb(ipfw_nptv6_cfg *cfg, const char *name __unused, uint8_t set)
380 {
381 
382 	if (g_co.use_set != 0 && cfg->set != set)
383 		return (ESRCH);
384 
385 	nptv6_destroy(cfg->name, cfg->set);
386 	return (0);
387 }
388 
389 
390 /*
391  * Compare NPTv6 instances names.
392  * Honor number comparison.
393  */
394 static int
395 nptv6name_cmp(const void *a, const void *b)
396 {
397 	const ipfw_nptv6_cfg *ca, *cb;
398 
399 	ca = (const ipfw_nptv6_cfg *)a;
400 	cb = (const ipfw_nptv6_cfg *)b;
401 
402 	if (ca->set > cb->set)
403 		return (1);
404 	else if (ca->set < cb->set)
405 		return (-1);
406 	return (stringnum_cmp(ca->name, cb->name));
407 }
408 
409 /*
410  * Retrieves NPTv6 instance list from kernel,
411  * Request: [ ipfw_obj_lheader ]
412  * Reply: [ ipfw_obj_lheader ipfw_nptv6_cfg x N ]
413  */
414 static int
415 nptv6_foreach(nptv6_cb_t *f, const char *name, uint8_t set, int sort)
416 {
417 	ipfw_obj_lheader *olh;
418 	ipfw_nptv6_cfg *cfg;
419 	size_t sz;
420 	uint32_t i;
421 
422 	/* Start with reasonable default */
423 	sz = sizeof(*olh) + 16 * sizeof(*cfg);
424 	for (;;) {
425 		if ((olh = calloc(1, sz)) == NULL)
426 			return (ENOMEM);
427 
428 		olh->size = sz;
429 		if (do_get3(IP_FW_NPTV6_LIST, &olh->opheader, &sz) != 0) {
430 			sz = olh->size;
431 			free(olh);
432 			if (errno != ENOMEM)
433 				return (errno);
434 			continue;
435 		}
436 
437 		if (sort != 0)
438 			qsort(olh + 1, olh->count, olh->objsize, nptv6name_cmp);
439 
440 		cfg = (ipfw_nptv6_cfg *)(olh + 1);
441 		for (i = 0; i < olh->count; i++) {
442 			(void)f(cfg, name, set);
443 			cfg = (ipfw_nptv6_cfg *)((caddr_t)cfg + olh->objsize);
444 		}
445 		free(olh);
446 		break;
447 	}
448 	return (0);
449 }
450 
451