xref: /freebsd/sbin/ipfw/ipv6.c (revision 123af6ec70016f5556da5972d4d63c7d175c06d3)
1 /*-
2  * Copyright (c) 2002-2003 Luigi Rizzo
3  * Copyright (c) 1996 Alex Nash, Paul Traina, Poul-Henning Kamp
4  * Copyright (c) 1994 Ugen J.S.Antsilevich
5  *
6  * Idea and grammar partially left from:
7  * Copyright (c) 1993 Daniel Boulet
8  *
9  * Redistribution and use in source forms, with and without modification,
10  * are permitted provided that this entire comment appears intact.
11  *
12  * Redistribution in binary form may occur without any restrictions.
13  * Obviously, it would be nice if you gave credit where credit is due
14  * but requiring it would be too onerous.
15  *
16  * This software is provided ``AS IS'' without any warranties of any kind.
17  *
18  * NEW command line interface for IP firewall facility
19  *
20  * $FreeBSD$
21  *
22  * ipv6 support
23  */
24 
25 #include <sys/types.h>
26 #include <sys/socket.h>
27 
28 #include "ipfw2.h"
29 
30 #include <err.h>
31 #include <netdb.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <sysexits.h>
36 
37 #include <net/if.h>
38 #include <netinet/in.h>
39 #include <netinet/in_systm.h>
40 #include <netinet/ip.h>
41 #include <netinet/icmp6.h>
42 #include <netinet/ip_fw.h>
43 #include <arpa/inet.h>
44 
45 #define	CHECK_LENGTH(v, len) do {			\
46 	if ((v) < (len))				\
47 		errx(EX_DATAERR, "Rule too long");	\
48 	} while (0)
49 
50 static struct _s_x icmp6codes[] = {
51 	{ "no-route",		ICMP6_DST_UNREACH_NOROUTE },
52 	{ "admin-prohib",		ICMP6_DST_UNREACH_ADMIN },
53 	{ "address",		ICMP6_DST_UNREACH_ADDR },
54 	{ "port",			ICMP6_DST_UNREACH_NOPORT },
55 	{ NULL, 0 }
56 };
57 
58 void
59 fill_unreach6_code(u_short *codep, char *str)
60 {
61 	int val;
62 	char *s;
63 
64 	val = strtoul(str, &s, 0);
65 	if (s == str || *s != '\0' || val >= 0x100)
66 		val = match_token(icmp6codes, str);
67 	if (val < 0)
68 		errx(EX_DATAERR, "unknown ICMPv6 unreachable code ``%s''", str);
69 	*codep = val;
70 	return;
71 }
72 
73 void
74 print_unreach6_code(struct buf_pr *bp, uint16_t code)
75 {
76 	char const *s = match_value(icmp6codes, code);
77 
78 	if (s != NULL)
79 		bprintf(bp, "unreach6 %s", s);
80 	else
81 		bprintf(bp, "unreach6 %u", code);
82 }
83 
84 /*
85  * Print the ip address contained in a command.
86  */
87 void
88 print_ip6(struct buf_pr *bp, ipfw_insn_ip6 *cmd)
89 {
90 	char trad[255];
91 	struct hostent *he = NULL;
92 	struct in6_addr *a = &(cmd->addr6);
93 	int len, mb;
94 
95 	len = F_LEN((ipfw_insn *) cmd) - 1;
96 	if (cmd->o.opcode == O_IP6_SRC_ME || cmd->o.opcode == O_IP6_DST_ME) {
97 		bprintf(bp, " me6");
98 		return;
99 	}
100 	if (cmd->o.opcode == O_IP6) {
101 		bprintf(bp, " ip6");
102 		return;
103 	}
104 
105 	/*
106 	 * len == 4 indicates a single IP, whereas lists of 1 or more
107 	 * addr/mask pairs have len = (2n+1). We convert len to n so we
108 	 * use that to count the number of entries.
109 	 */
110 	bprintf(bp, " ");
111 	for (len = len / 4; len > 0; len -= 2, a += 2) {
112 		/* mask length */
113 		mb = (cmd->o.opcode == O_IP6_SRC ||
114 		    cmd->o.opcode == O_IP6_DST) ?  128:
115 		    contigmask((uint8_t *)&(a[1]), 128);
116 
117 		if (mb == 128 && co.do_resolv)
118 			he = gethostbyaddr((char *)a, sizeof(*a), AF_INET6);
119 
120 		if (he != NULL)	     /* resolved to name */
121 			bprintf(bp, "%s", he->h_name);
122 		else if (mb == 0)	   /* any */
123 			bprintf(bp, "any");
124 		else {	  /* numeric IP followed by some kind of mask */
125 			if (inet_ntop(AF_INET6,  a, trad,
126 			    sizeof(trad)) == NULL)
127 				bprintf(bp, "Error ntop in print_ip6\n");
128 			bprintf(bp, "%s",  trad );
129 			if (mb < 0) /* mask not contiguous */
130 				bprintf(bp, "/%s", inet_ntop(AF_INET6, &a[1],
131 				    trad, sizeof(trad)));
132 			else if (mb < 128)
133 				bprintf(bp, "/%d", mb);
134 		}
135 		if (len > 2)
136 			bprintf(bp, ",");
137 	}
138 }
139 
140 void
141 fill_icmp6types(ipfw_insn_icmp6 *cmd, char *av, int cblen)
142 {
143        uint8_t type;
144 
145        CHECK_LENGTH(cblen, F_INSN_SIZE(ipfw_insn_icmp6));
146        while (*av) {
147 	       if (*av == ',')
148 		       av++;
149 	       type = strtoul(av, &av, 0);
150 	       if (*av != ',' && *av != '\0')
151 		       errx(EX_DATAERR, "invalid ICMP6 type");
152 	       /*
153 		* XXX: shouldn't this be 0xFF?  I can't see any reason why
154 		* we shouldn't be able to filter all possiable values
155 		* regardless of the ability of the rest of the kernel to do
156 		* anything useful with them.
157 		*/
158 	       if (type > ICMP6_MAXTYPE)
159 		       errx(EX_DATAERR, "ICMP6 type out of range");
160 	       cmd->d[type / 32] |= ( 1 << (type % 32));
161        }
162        cmd->o.opcode = O_ICMP6TYPE;
163        cmd->o.len |= F_INSN_SIZE(ipfw_insn_icmp6);
164 }
165 
166 void
167 print_icmp6types(struct buf_pr *bp, ipfw_insn_u32 *cmd)
168 {
169 	int i, j;
170 	char sep= ' ';
171 
172 	bprintf(bp, " icmp6types");
173 	for (i = 0; i < 7; i++)
174 		for (j=0; j < 32; ++j) {
175 			if ( (cmd->d[i] & (1 << (j))) == 0)
176 				continue;
177 			bprintf(bp, "%c%d", sep, (i*32 + j));
178 			sep = ',';
179 		}
180 }
181 
182 void
183 print_flow6id(struct buf_pr *bp, ipfw_insn_u32 *cmd)
184 {
185 	uint16_t i, limit = cmd->o.arg1;
186 	char sep = ',';
187 
188 	bprintf(bp, " flow-id ");
189 	for( i=0; i < limit; ++i) {
190 		if (i == limit - 1)
191 			sep = ' ';
192 		bprintf(bp, "%d%c", cmd->d[i], sep);
193 	}
194 }
195 
196 /* structure and define for the extension header in ipv6 */
197 static struct _s_x ext6hdrcodes[] = {
198 	{ "frag",       EXT_FRAGMENT },
199 	{ "hopopt",     EXT_HOPOPTS },
200 	{ "route",      EXT_ROUTING },
201 	{ "dstopt",     EXT_DSTOPTS },
202 	{ "ah",	 EXT_AH },
203 	{ "esp",	EXT_ESP },
204 	{ "rthdr0",     EXT_RTHDR0 },
205 	{ "rthdr2",     EXT_RTHDR2 },
206 	{ NULL,	 0 }
207 };
208 
209 /* fills command for the extension header filtering */
210 int
211 fill_ext6hdr( ipfw_insn *cmd, char *av)
212 {
213 	int tok;
214 	char *s = av;
215 
216 	cmd->arg1 = 0;
217 	while(s) {
218 		av = strsep( &s, ",") ;
219 		tok = match_token(ext6hdrcodes, av);
220 		switch (tok) {
221 		case EXT_FRAGMENT:
222 			cmd->arg1 |= EXT_FRAGMENT;
223 			break;
224 		case EXT_HOPOPTS:
225 			cmd->arg1 |= EXT_HOPOPTS;
226 			break;
227 		case EXT_ROUTING:
228 			cmd->arg1 |= EXT_ROUTING;
229 			break;
230 		case EXT_DSTOPTS:
231 			cmd->arg1 |= EXT_DSTOPTS;
232 			break;
233 		case EXT_AH:
234 			cmd->arg1 |= EXT_AH;
235 			break;
236 		case EXT_ESP:
237 			cmd->arg1 |= EXT_ESP;
238 			break;
239 		case EXT_RTHDR0:
240 			cmd->arg1 |= EXT_RTHDR0;
241 			break;
242 		case EXT_RTHDR2:
243 			cmd->arg1 |= EXT_RTHDR2;
244 			break;
245 		default:
246 			errx(EX_DATAERR,
247 			    "invalid option for ipv6 exten header");
248 			break;
249 		}
250 	}
251 	if (cmd->arg1 == 0)
252 		return (0);
253 	cmd->opcode = O_EXT_HDR;
254 	cmd->len |= F_INSN_SIZE(ipfw_insn);
255 	return (1);
256 }
257 
258 void
259 print_ext6hdr(struct buf_pr *bp, ipfw_insn *cmd )
260 {
261 	char sep = ' ';
262 
263 	bprintf(bp, " extension header:");
264 	if (cmd->arg1 & EXT_FRAGMENT) {
265 		bprintf(bp, "%cfragmentation", sep);
266 		sep = ',';
267 	}
268 	if (cmd->arg1 & EXT_HOPOPTS) {
269 		bprintf(bp, "%chop options", sep);
270 		sep = ',';
271 	}
272 	if (cmd->arg1 & EXT_ROUTING) {
273 		bprintf(bp, "%crouting options", sep);
274 		sep = ',';
275 	}
276 	if (cmd->arg1 & EXT_RTHDR0) {
277 		bprintf(bp, "%crthdr0", sep);
278 		sep = ',';
279 	}
280 	if (cmd->arg1 & EXT_RTHDR2) {
281 		bprintf(bp, "%crthdr2", sep);
282 		sep = ',';
283 	}
284 	if (cmd->arg1 & EXT_DSTOPTS) {
285 		bprintf(bp, "%cdestination options", sep);
286 		sep = ',';
287 	}
288 	if (cmd->arg1 & EXT_AH) {
289 		bprintf(bp, "%cauthentication header", sep);
290 		sep = ',';
291 	}
292 	if (cmd->arg1 & EXT_ESP) {
293 		bprintf(bp, "%cencapsulated security payload", sep);
294 	}
295 }
296 
297 /* Try to find ipv6 address by hostname */
298 static int
299 lookup_host6 (char *host, struct in6_addr *ip6addr)
300 {
301 	struct hostent *he;
302 
303 	if (!inet_pton(AF_INET6, host, ip6addr)) {
304 		if ((he = gethostbyname2(host, AF_INET6)) == NULL)
305 			return(-1);
306 		memcpy(ip6addr, he->h_addr_list[0], sizeof( struct in6_addr));
307 	}
308 	return (0);
309 }
310 
311 
312 /*
313  * fill the addr and mask fields in the instruction as appropriate from av.
314  * Update length as appropriate.
315  * The following formats are allowed:
316  *     any     matches any IP6. Actually returns an empty instruction.
317  *     me      returns O_IP6_*_ME
318  *
319  *     03f1::234:123:0342			single IP6 address
320  *     03f1::234:123:0342/24			address/masklen
321  *     03f1::234:123:0342/ffff::ffff:ffff	address/mask
322  *     03f1::234:123:0342/24,03f1::234:123:0343/	List of address
323  *
324  * Set of address (as in ipv6) not supported because ipv6 address
325  * are typically random past the initial prefix.
326  * Return 1 on success, 0 on failure.
327  */
328 static int
329 fill_ip6(ipfw_insn_ip6 *cmd, char *av, int cblen, struct tidx *tstate)
330 {
331 	int len = 0;
332 	struct in6_addr *d = &(cmd->addr6);
333 	char *oav;
334 	/*
335 	 * Needed for multiple address.
336 	 * Note d[1] points to struct in6_add r mask6 of cmd
337 	 */
338 
339 	cmd->o.len &= ~F_LEN_MASK;	/* zero len */
340 
341 	if (strcmp(av, "any") == 0)
342 		return (1);
343 
344 
345 	if (strcmp(av, "me") == 0) {	/* Set the data for "me" opt*/
346 		cmd->o.len |= F_INSN_SIZE(ipfw_insn);
347 		return (1);
348 	}
349 
350 	if (strcmp(av, "me6") == 0) {	/* Set the data for "me" opt*/
351 		cmd->o.len |= F_INSN_SIZE(ipfw_insn);
352 		return (1);
353 	}
354 
355 	if (strncmp(av, "table(", 6) == 0) {
356 		fill_table(&cmd->o, av, O_IP_DST_LOOKUP, tstate);
357 		return (1);
358 	}
359 
360 	oav = av = strdup(av);
361 	while (av) {
362 		/*
363 		 * After the address we can have '/' indicating a mask,
364 		 * or ',' indicating another address follows.
365 		 */
366 
367 		char *p, *q;
368 		int masklen;
369 		char md = '\0';
370 
371 		CHECK_LENGTH(cblen, 1 + len + 2 * F_INSN_SIZE(struct in6_addr));
372 
373 		if ((q = strchr(av, ',')) ) {
374 			*q = '\0';
375 			q++;
376 		}
377 
378 		if ((p = strchr(av, '/')) ) {
379 			md = *p;	/* save the separator */
380 			*p = '\0';	/* terminate address string */
381 			p++;		/* and skip past it */
382 		}
383 		/* now p points to NULL, mask or next entry */
384 
385 		/* lookup stores address in *d as a side effect */
386 		if (lookup_host6(av, d) != 0) {
387 			/* XXX: failed. Free memory and go */
388 			errx(EX_DATAERR, "bad address \"%s\"", av);
389 		}
390 		/* next, look at the mask, if any */
391 		if (md == '/' && strchr(p, ':')) {
392 			if (!inet_pton(AF_INET6, p, &d[1]))
393 				errx(EX_DATAERR, "bad mask \"%s\"", p);
394 
395 			masklen = contigmask((uint8_t *)&(d[1]), 128);
396 		} else {
397 			masklen = (md == '/') ? atoi(p) : 128;
398 			if (masklen > 128 || masklen < 0)
399 				errx(EX_DATAERR, "bad width \"%s\''", p);
400 			else
401 				n2mask(&d[1], masklen);
402 		}
403 
404 		APPLY_MASK(d, &d[1]);   /* mask base address with mask */
405 
406 		av = q;
407 
408 		/* Check this entry */
409 		if (masklen == 0) {
410 			/*
411 			 * 'any' turns the entire list into a NOP.
412 			 * 'not any' never matches, so it is removed from the
413 			 * list unless it is the only item, in which case we
414 			 * report an error.
415 			 */
416 			if (cmd->o.len & F_NOT && av == NULL && len == 0)
417 				errx(EX_DATAERR, "not any never matches");
418 			continue;
419 		}
420 
421 		/*
422 		 * A single IP can be stored alone
423 		 */
424 		if (masklen == 128 && av == NULL && len == 0) {
425 			len = F_INSN_SIZE(struct in6_addr);
426 			break;
427 		}
428 
429 		/* Update length and pointer to arguments */
430 		len += F_INSN_SIZE(struct in6_addr)*2;
431 		d += 2;
432 	} /* end while */
433 
434 	/*
435 	 * Total length of the command, remember that 1 is the size of
436 	 * the base command.
437 	 */
438 	if (len + 1 > F_LEN_MASK)
439 		errx(EX_DATAERR, "address list too long");
440 	cmd->o.len |= len+1;
441 	free(oav);
442 	return (1);
443 }
444 
445 /*
446  * fills command for ipv6 flow-id filtering
447  * note that the 20 bit flow number is stored in a array of u_int32_t
448  * it's supported lists of flow-id, so in the o.arg1 we store how many
449  * additional flow-id we want to filter, the basic is 1
450  */
451 void
452 fill_flow6( ipfw_insn_u32 *cmd, char *av, int cblen)
453 {
454 	u_int32_t type;	 /* Current flow number */
455 	u_int16_t nflow = 0;    /* Current flow index */
456 	char *s = av;
457 	cmd->d[0] = 0;	  /* Initializing the base number*/
458 
459 	while (s) {
460 		CHECK_LENGTH(cblen, F_INSN_SIZE(ipfw_insn_u32) + nflow + 1);
461 
462 		av = strsep( &s, ",") ;
463 		type = strtoul(av, &av, 0);
464 		if (*av != ',' && *av != '\0')
465 			errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
466 		if (type > 0xfffff)
467 			errx(EX_DATAERR, "flow number out of range %s", av);
468 		cmd->d[nflow] |= type;
469 		nflow++;
470 	}
471 	if( nflow > 0 ) {
472 		cmd->o.opcode = O_FLOW6ID;
473 		cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32) + nflow;
474 		cmd->o.arg1 = nflow;
475 	}
476 	else {
477 		errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
478 	}
479 }
480 
481 ipfw_insn *
482 add_srcip6(ipfw_insn *cmd, char *av, int cblen, struct tidx *tstate)
483 {
484 
485 	fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen, tstate);
486 	if (cmd->opcode == O_IP_DST_SET)			/* set */
487 		cmd->opcode = O_IP_SRC_SET;
488 	else if (cmd->opcode == O_IP_DST_LOOKUP)		/* table */
489 		cmd->opcode = O_IP_SRC_LOOKUP;
490 	else if (F_LEN(cmd) == 0) {				/* any */
491 	} else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) {	/* "me" */
492 		cmd->opcode = O_IP6_SRC_ME;
493 	} else if (F_LEN(cmd) ==
494 	    (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
495 		/* single IP, no mask*/
496 		cmd->opcode = O_IP6_SRC;
497 	} else {					/* addr/mask opt */
498 		cmd->opcode = O_IP6_SRC_MASK;
499 	}
500 	return cmd;
501 }
502 
503 ipfw_insn *
504 add_dstip6(ipfw_insn *cmd, char *av, int cblen, struct tidx *tstate)
505 {
506 
507 	fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen, tstate);
508 	if (cmd->opcode == O_IP_DST_SET)			/* set */
509 		;
510 	else if (cmd->opcode == O_IP_DST_LOOKUP)		/* table */
511 		;
512 	else if (F_LEN(cmd) == 0) {				/* any */
513 	} else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) {	/* "me" */
514 		cmd->opcode = O_IP6_DST_ME;
515 	} else if (F_LEN(cmd) ==
516 	    (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
517 		/* single IP, no mask*/
518 		cmd->opcode = O_IP6_DST;
519 	} else {					/* addr/mask opt */
520 		cmd->opcode = O_IP6_DST_MASK;
521 	}
522 	return cmd;
523 }
524