xref: /freebsd/sbin/ipfw/nptv6.c (revision 4d65a7c6951cea0333f1a0c1b32c38489cdfa6c5) 
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/param.h>
29 #include <sys/socket.h>
30 
31 #include "ipfw2.h"
32 
33 #include <ctype.h>
34 #include <err.h>
35 #include <errno.h>
36 #include <inttypes.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <sysexits.h>
41 
42 #include <net/if.h>
43 #include <netinet/in.h>
44 #include <netinet/ip_fw.h>
45 #include <netinet6/ip_fw_nptv6.h>
46 #include <arpa/inet.h>
47 
48 
49 typedef int (nptv6_cb_t)(ipfw_nptv6_cfg *i, const char *name, uint8_t set);
50 static int nptv6_foreach(nptv6_cb_t *f, const char *name, uint8_t set,
51     int sort);
52 
53 static void nptv6_create(const char *name, uint8_t set, int ac, char **av);
54 static void nptv6_destroy(const char *name, uint8_t set);
55 static void nptv6_stats(const char *name, uint8_t set);
56 static void nptv6_reset_stats(const char *name, uint8_t set);
57 static int nptv6_show_cb(ipfw_nptv6_cfg *cfg, const char *name, uint8_t set);
58 static int nptv6_destroy_cb(ipfw_nptv6_cfg *cfg, const char *name, uint8_t set);
59 
60 static struct _s_x nptv6cmds[] = {
61       { "create",	TOK_CREATE },
62       { "destroy",	TOK_DESTROY },
63       { "list",		TOK_LIST },
64       { "show",		TOK_LIST },
65       { "stats",	TOK_STATS },
66       { NULL, 0 }
67 };
68 
69 static struct _s_x nptv6statscmds[] = {
70       { "reset",	TOK_RESET },
71       { NULL, 0 }
72 };
73 
74 /*
75  * This one handles all NPTv6-related commands
76  *	ipfw [set N] nptv6 NAME {create | config} ...
77  *	ipfw [set N] nptv6 NAME stats [reset]
78  *	ipfw [set N] nptv6 {NAME | all} destroy
79  *	ipfw [set N] nptv6 {NAME | all} {list | show}
80  */
81 #define	nptv6_check_name	table_check_name
82 void
83 ipfw_nptv6_handler(int ac, char *av[])
84 {
85 	const char *name;
86 	int tcmd;
87 	uint8_t set;
88 
89 	if (g_co.use_set != 0)
90 		set = g_co.use_set - 1;
91 	else
92 		set = 0;
93 	ac--; av++;
94 
95 	NEED1("nptv6 needs instance name");
96 	name = *av;
97 	if (nptv6_check_name(name) != 0) {
98 		if (strcmp(name, "all") == 0) {
99 			name = NULL;
100 		} else
101 			errx(EX_USAGE, "nptv6 instance name %s is invalid",
102 			    name);
103 	}
104 	ac--; av++;
105 	NEED1("nptv6 needs command");
106 
107 	tcmd = get_token(nptv6cmds, *av, "nptv6 command");
108 	if (name == NULL && tcmd != TOK_DESTROY && tcmd != TOK_LIST)
109 		errx(EX_USAGE, "nptv6 instance name required");
110 	switch (tcmd) {
111 	case TOK_CREATE:
112 		ac--; av++;
113 		nptv6_create(name, set, ac, av);
114 		break;
115 	case TOK_LIST:
116 		nptv6_foreach(nptv6_show_cb, name, set, 1);
117 		break;
118 	case TOK_DESTROY:
119 		if (name == NULL)
120 			nptv6_foreach(nptv6_destroy_cb, NULL, set, 0);
121 		else
122 			nptv6_destroy(name, set);
123 		break;
124 	case TOK_STATS:
125 		ac--; av++;
126 		if (ac == 0) {
127 			nptv6_stats(name, set);
128 			break;
129 		}
130 		tcmd = get_token(nptv6statscmds, *av, "stats command");
131 		if (tcmd == TOK_RESET)
132 			nptv6_reset_stats(name, set);
133 	}
134 }
135 
136 
137 static void
138 nptv6_fill_ntlv(ipfw_obj_ntlv *ntlv, const char *name, uint8_t set)
139 {
140 
141 	ntlv->head.type = IPFW_TLV_EACTION_NAME(1); /* it doesn't matter */
142 	ntlv->head.length = sizeof(ipfw_obj_ntlv);
143 	ntlv->idx = 1;
144 	ntlv->set = set;
145 	strlcpy(ntlv->name, name, sizeof(ntlv->name));
146 }
147 
148 static struct _s_x nptv6newcmds[] = {
149       { "int_prefix",	TOK_INTPREFIX },
150       { "ext_prefix",	TOK_EXTPREFIX },
151       { "prefixlen",	TOK_PREFIXLEN },
152       { "ext_if",	TOK_EXTIF },
153       { NULL, 0 }
154 };
155 
156 
157 static void
158 nptv6_parse_prefix(const char *arg, struct in6_addr *prefix, int *len)
159 {
160 	char *p, *l;
161 
162 	p = strdup(arg);
163 	if (p == NULL)
164 		err(EX_OSERR, NULL);
165 	if ((l = strchr(p, '/')) != NULL)
166 		*l++ = '\0';
167 	if (inet_pton(AF_INET6, p, prefix) != 1)
168 		errx(EX_USAGE, "Bad prefix: %s", p);
169 	if (l != NULL) {
170 		*len = (int)strtol(l, &l, 10);
171 		if (*l != '\0' || *len <= 0 || *len > 64)
172 			errx(EX_USAGE, "Bad prefix length: %s", arg);
173 	} else
174 		*len = 0;
175 	free(p);
176 }
177 /*
178  * Creates new nptv6 instance
179  * ipfw nptv6 <NAME> create int_prefix <prefix> ext_prefix <prefix>
180  * Request: [ ipfw_obj_lheader ipfw_nptv6_cfg ]
181  */
182 #define	NPTV6_HAS_INTPREFIX	0x01
183 #define	NPTV6_HAS_EXTPREFIX	0x02
184 #define	NPTV6_HAS_PREFIXLEN	0x04
185 static void
186 nptv6_create(const char *name, uint8_t set, int ac, char *av[])
187 {
188 	char buf[sizeof(ipfw_obj_lheader) + sizeof(ipfw_nptv6_cfg)];
189 	struct in6_addr mask;
190 	ipfw_nptv6_cfg *cfg;
191 	ipfw_obj_lheader *olh;
192 	int tcmd, flags, plen;
193 	char *p;
194 
195 	plen = 0;
196 	memset(buf, 0, sizeof(buf));
197 	olh = (ipfw_obj_lheader *)buf;
198 	cfg = (ipfw_nptv6_cfg *)(olh + 1);
199 	cfg->set = set;
200 	flags = 0;
201 	while (ac > 0) {
202 		tcmd = get_token(nptv6newcmds, *av, "option");
203 		ac--; av++;
204 
205 		switch (tcmd) {
206 		case TOK_INTPREFIX:
207 			NEED1("IPv6 prefix required");
208 			nptv6_parse_prefix(*av, &cfg->internal, &plen);
209 			flags |= NPTV6_HAS_INTPREFIX;
210 			if (plen > 0)
211 				goto check_prefix;
212 			ac--; av++;
213 			break;
214 		case TOK_EXTPREFIX:
215 			if (flags & NPTV6_HAS_EXTPREFIX)
216 				errx(EX_USAGE,
217 				    "Only one ext_prefix or ext_if allowed");
218 			NEED1("IPv6 prefix required");
219 			nptv6_parse_prefix(*av, &cfg->external, &plen);
220 			flags |= NPTV6_HAS_EXTPREFIX;
221 			if (plen > 0)
222 				goto check_prefix;
223 			ac--; av++;
224 			break;
225 		case TOK_EXTIF:
226 			if (flags & NPTV6_HAS_EXTPREFIX)
227 				errx(EX_USAGE,
228 				    "Only one ext_prefix or ext_if allowed");
229 			NEED1("Interface name required");
230 			if (strlen(*av) >= sizeof(cfg->if_name))
231 				errx(EX_USAGE, "Invalid interface name");
232 			flags |= NPTV6_HAS_EXTPREFIX;
233 			cfg->flags |= NPTV6_DYNAMIC_PREFIX;
234 			strncpy(cfg->if_name, *av, sizeof(cfg->if_name));
235 			ac--; av++;
236 			break;
237 		case TOK_PREFIXLEN:
238 			NEED1("IPv6 prefix length required");
239 			plen = strtol(*av, &p, 10);
240 check_prefix:
241 			if (*p != '\0' || plen < 8 || plen > 64)
242 				errx(EX_USAGE, "wrong prefix length: %s", *av);
243 			/* RFC 6296 Sec. 3.1 */
244 			if (cfg->plen > 0 && cfg->plen != plen) {
245 				warnx("Prefix length mismatch (%d vs %d).  "
246 				    "It was extended up to %d",
247 				    cfg->plen, plen, MAX(plen, cfg->plen));
248 				plen = MAX(plen, cfg->plen);
249 			}
250 			cfg->plen = plen;
251 			flags |= NPTV6_HAS_PREFIXLEN;
252 			ac--; av++;
253 			break;
254 		}
255 	}
256 
257 	/* Check validness */
258 	if ((flags & NPTV6_HAS_INTPREFIX) != NPTV6_HAS_INTPREFIX)
259 		errx(EX_USAGE, "int_prefix required");
260 	if ((flags & NPTV6_HAS_EXTPREFIX) != NPTV6_HAS_EXTPREFIX)
261 		errx(EX_USAGE, "ext_prefix or ext_if required");
262 	if ((flags & NPTV6_HAS_PREFIXLEN) != NPTV6_HAS_PREFIXLEN)
263 		errx(EX_USAGE, "prefixlen required");
264 
265 	n2mask(&mask, cfg->plen);
266 	APPLY_MASK(&cfg->internal, &mask);
267 	if ((cfg->flags & NPTV6_DYNAMIC_PREFIX) == 0)
268 		APPLY_MASK(&cfg->external, &mask);
269 
270 	olh->count = 1;
271 	olh->objsize = sizeof(*cfg);
272 	olh->size = sizeof(buf);
273 	strlcpy(cfg->name, name, sizeof(cfg->name));
274 	if (do_set3(IP_FW_NPTV6_CREATE, &olh->opheader, sizeof(buf)) != 0)
275 		err(EX_OSERR, "nptv6 instance creation failed");
276 }
277 
278 /*
279  * Destroys NPTv6 instance.
280  * Request: [ ipfw_obj_header ]
281  */
282 static void
283 nptv6_destroy(const char *name, uint8_t set)
284 {
285 	ipfw_obj_header oh;
286 
287 	memset(&oh, 0, sizeof(oh));
288 	nptv6_fill_ntlv(&oh.ntlv, name, set);
289 	if (do_set3(IP_FW_NPTV6_DESTROY, &oh.opheader, sizeof(oh)) != 0)
290 		err(EX_OSERR, "failed to destroy nat instance %s", name);
291 }
292 
293 /*
294  * Get NPTv6 instance statistics.
295  * Request: [ ipfw_obj_header ]
296  * Reply: [ ipfw_obj_header ipfw_obj_ctlv [ uint64_t x N ] ]
297  */
298 static int
299 nptv6_get_stats(const char *name, uint8_t set, struct ipfw_nptv6_stats *stats)
300 {
301 	ipfw_obj_header *oh;
302 	ipfw_obj_ctlv *oc;
303 	size_t sz;
304 
305 	sz = sizeof(*oh) + sizeof(*oc) + sizeof(*stats);
306 	oh = calloc(1, sz);
307 	nptv6_fill_ntlv(&oh->ntlv, name, set);
308 	if (do_get3(IP_FW_NPTV6_STATS, &oh->opheader, &sz) == 0) {
309 		oc = (ipfw_obj_ctlv *)(oh + 1);
310 		memcpy(stats, oc + 1, sizeof(*stats));
311 		free(oh);
312 		return (0);
313 	}
314 	free(oh);
315 	return (-1);
316 }
317 
318 static void
319 nptv6_stats(const char *name, uint8_t set)
320 {
321 	struct ipfw_nptv6_stats stats;
322 
323 	if (nptv6_get_stats(name, set, &stats) != 0)
324 		err(EX_OSERR, "Error retrieving stats");
325 
326 	if (g_co.use_set != 0 || set != 0)
327 		printf("set %u ", set);
328 	printf("nptv6 %s\n", name);
329 	printf("\t%ju packets translated (internal to external)\n",
330 	    (uintmax_t)stats.in2ex);
331 	printf("\t%ju packets translated (external to internal)\n",
332 	    (uintmax_t)stats.ex2in);
333 	printf("\t%ju packets dropped due to some error\n",
334 	    (uintmax_t)stats.dropped);
335 }
336 
337 /*
338  * Reset NPTv6 instance statistics specified by @oh->ntlv.
339  * Request: [ ipfw_obj_header ]
340  */
341 static void
342 nptv6_reset_stats(const char *name, uint8_t set)
343 {
344 	ipfw_obj_header oh;
345 
346 	memset(&oh, 0, sizeof(oh));
347 	nptv6_fill_ntlv(&oh.ntlv, name, set);
348 	if (do_set3(IP_FW_NPTV6_RESET_STATS, &oh.opheader, sizeof(oh)) != 0)
349 		err(EX_OSERR, "failed to reset stats for instance %s", name);
350 }
351 
352 static int
353 nptv6_show_cb(ipfw_nptv6_cfg *cfg, const char *name, uint8_t set)
354 {
355 	char abuf[INET6_ADDRSTRLEN];
356 
357 	if (name != NULL && strcmp(cfg->name, name) != 0)
358 		return (ESRCH);
359 
360 	if (g_co.use_set != 0 && cfg->set != set)
361 		return (ESRCH);
362 
363 	if (g_co.use_set != 0 || cfg->set != 0)
364 		printf("set %u ", cfg->set);
365 	inet_ntop(AF_INET6, &cfg->internal, abuf, sizeof(abuf));
366 	printf("nptv6 %s int_prefix %s ", cfg->name, abuf);
367 	if (cfg->flags & NPTV6_DYNAMIC_PREFIX)
368 		printf("ext_if %s ", cfg->if_name);
369 	else {
370 		inet_ntop(AF_INET6, &cfg->external, abuf, sizeof(abuf));
371 		printf("ext_prefix %s ", abuf);
372 	}
373 	printf("prefixlen %u\n", cfg->plen);
374 	return (0);
375 }
376 
377 static int
378 nptv6_destroy_cb(ipfw_nptv6_cfg *cfg, const char *name __unused, uint8_t set)
379 {
380 
381 	if (g_co.use_set != 0 && cfg->set != set)
382 		return (ESRCH);
383 
384 	nptv6_destroy(cfg->name, cfg->set);
385 	return (0);
386 }
387 
388 
389 /*
390  * Compare NPTv6 instances names.
391  * Honor number comparison.
392  */
393 static int
394 nptv6name_cmp(const void *a, const void *b)
395 {
396 	const ipfw_nptv6_cfg *ca, *cb;
397 
398 	ca = (const ipfw_nptv6_cfg *)a;
399 	cb = (const ipfw_nptv6_cfg *)b;
400 
401 	if (ca->set > cb->set)
402 		return (1);
403 	else if (ca->set < cb->set)
404 		return (-1);
405 	return (stringnum_cmp(ca->name, cb->name));
406 }
407 
408 /*
409  * Retrieves NPTv6 instance list from kernel,
410  * Request: [ ipfw_obj_lheader ]
411  * Reply: [ ipfw_obj_lheader ipfw_nptv6_cfg x N ]
412  */
413 static int
414 nptv6_foreach(nptv6_cb_t *f, const char *name, uint8_t set, int sort)
415 {
416 	ipfw_obj_lheader *olh;
417 	ipfw_nptv6_cfg *cfg;
418 	size_t sz;
419 	uint32_t i;
420 
421 	/* Start with reasonable default */
422 	sz = sizeof(*olh) + 16 * sizeof(*cfg);
423 	for (;;) {
424 		if ((olh = calloc(1, sz)) == NULL)
425 			return (ENOMEM);
426 
427 		olh->size = sz;
428 		if (do_get3(IP_FW_NPTV6_LIST, &olh->opheader, &sz) != 0) {
429 			sz = olh->size;
430 			free(olh);
431 			if (errno != ENOMEM)
432 				return (errno);
433 			continue;
434 		}
435 
436 		if (sort != 0)
437 			qsort(olh + 1, olh->count, olh->objsize, nptv6name_cmp);
438 
439 		cfg = (ipfw_nptv6_cfg *)(olh + 1);
440 		for (i = 0; i < olh->count; i++) {
441 			(void)f(cfg, name, set);
442 			cfg = (ipfw_nptv6_cfg *)((caddr_t)cfg + olh->objsize);
443 		}
444 		free(olh);
445 		break;
446 	}
447 	return (0);
448 }
449 
450