xref: /freebsd/sbin/ipfw/ipv6.c (revision 70e0bbedef95258a4dadc996d641a9bebd3f107d) 
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 static struct _s_x icmp6codes[] = {
46       { "no-route",		ICMP6_DST_UNREACH_NOROUTE },
47       { "admin-prohib",		ICMP6_DST_UNREACH_ADMIN },
48       { "address",		ICMP6_DST_UNREACH_ADDR },
49       { "port",			ICMP6_DST_UNREACH_NOPORT },
50       { NULL, 0 }
51 };
52 
53 void
54 fill_unreach6_code(u_short *codep, char *str)
55 {
56 	int val;
57 	char *s;
58 
59 	val = strtoul(str, &s, 0);
60 	if (s == str || *s != '\0' || val >= 0x100)
61 		val = match_token(icmp6codes, str);
62 	if (val < 0)
63 		errx(EX_DATAERR, "unknown ICMPv6 unreachable code ``%s''", str);
64 	*codep = val;
65 	return;
66 }
67 
68 void
69 print_unreach6_code(uint16_t code)
70 {
71 	char const *s = match_value(icmp6codes, code);
72 
73 	if (s != NULL)
74 		printf("unreach6 %s", s);
75 	else
76 		printf("unreach6 %u", code);
77 }
78 
79 /*
80  * Print the ip address contained in a command.
81  */
82 void
83 print_ip6(ipfw_insn_ip6 *cmd, char const *s)
84 {
85        struct hostent *he = NULL;
86        int len = F_LEN((ipfw_insn *) cmd) - 1;
87        struct in6_addr *a = &(cmd->addr6);
88        char trad[255];
89 
90        printf("%s%s ", cmd->o.len & F_NOT ? " not": "", s);
91 
92        if (cmd->o.opcode == O_IP6_SRC_ME || cmd->o.opcode == O_IP6_DST_ME) {
93 	       printf("me6");
94 	       return;
95        }
96        if (cmd->o.opcode == O_IP6) {
97 	       printf(" ip6");
98 	       return;
99        }
100 
101        /*
102 	* len == 4 indicates a single IP, whereas lists of 1 or more
103 	* addr/mask pairs have len = (2n+1). We convert len to n so we
104 	* use that to count the number of entries.
105 	*/
106 
107        for (len = len / 4; len > 0; len -= 2, a += 2) {
108 	   int mb =	/* mask length */
109 	       (cmd->o.opcode == O_IP6_SRC || cmd->o.opcode == O_IP6_DST) ?
110 	       128 : contigmask((uint8_t *)&(a[1]), 128);
111 
112 	   if (mb == 128 && co.do_resolv)
113 	       he = gethostbyaddr((char *)a, sizeof(*a), AF_INET6);
114 	   if (he != NULL)	     /* resolved to name */
115 	       printf("%s", he->h_name);
116 	   else if (mb == 0)	   /* any */
117 	       printf("any");
118 	   else {	  /* numeric IP followed by some kind of mask */
119 	       if (inet_ntop(AF_INET6,  a, trad, sizeof( trad ) ) == NULL)
120 		   printf("Error ntop in print_ip6\n");
121 	       printf("%s",  trad );
122 	       if (mb < 0)     /* XXX not really legal... */
123 		   printf(":%s",
124 		       inet_ntop(AF_INET6, &a[1], trad, sizeof(trad)));
125 	       else if (mb < 128)
126 		   printf("/%d", mb);
127 	   }
128 	   if (len > 2)
129 	       printf(",");
130        }
131 }
132 
133 void
134 fill_icmp6types(ipfw_insn_icmp6 *cmd, char *av)
135 {
136        uint8_t type;
137 
138        bzero(cmd, sizeof(*cmd));
139        while (*av) {
140 	   if (*av == ',')
141 	       av++;
142 	   type = strtoul(av, &av, 0);
143 	   if (*av != ',' && *av != '\0')
144 	       errx(EX_DATAERR, "invalid ICMP6 type");
145 	   /*
146 	    * XXX: shouldn't this be 0xFF?  I can't see any reason why
147 	    * we shouldn't be able to filter all possiable values
148 	    * regardless of the ability of the rest of the kernel to do
149 	    * anything useful with them.
150 	    */
151 	   if (type > ICMP6_MAXTYPE)
152 	       errx(EX_DATAERR, "ICMP6 type out of range");
153 	   cmd->d[type / 32] |= ( 1 << (type % 32));
154        }
155        cmd->o.opcode = O_ICMP6TYPE;
156        cmd->o.len |= F_INSN_SIZE(ipfw_insn_icmp6);
157 }
158 
159 
160 void
161 print_icmp6types(ipfw_insn_u32 *cmd)
162 {
163        int i, j;
164        char sep= ' ';
165 
166        printf(" ip6 icmp6types");
167        for (i = 0; i < 7; i++)
168 	       for (j=0; j < 32; ++j) {
169 		       if ( (cmd->d[i] & (1 << (j))) == 0)
170 			       continue;
171 		       printf("%c%d", sep, (i*32 + j));
172 		       sep = ',';
173 	       }
174 }
175 
176 void
177 print_flow6id( ipfw_insn_u32 *cmd)
178 {
179        uint16_t i, limit = cmd->o.arg1;
180        char sep = ',';
181 
182        printf(" flow-id ");
183        for( i=0; i < limit; ++i) {
184 	       if (i == limit - 1)
185 		       sep = ' ';
186 	       printf("%d%c", cmd->d[i], sep);
187        }
188 }
189 
190 /* structure and define for the extension header in ipv6 */
191 static struct _s_x ext6hdrcodes[] = {
192        { "frag",       EXT_FRAGMENT },
193        { "hopopt",     EXT_HOPOPTS },
194        { "route",      EXT_ROUTING },
195        { "dstopt",     EXT_DSTOPTS },
196        { "ah",	 EXT_AH },
197        { "esp",	EXT_ESP },
198        { "rthdr0",     EXT_RTHDR0 },
199        { "rthdr2",     EXT_RTHDR2 },
200        { NULL,	 0 }
201 };
202 
203 /* fills command for the extension header filtering */
204 int
205 fill_ext6hdr( ipfw_insn *cmd, char *av)
206 {
207        int tok;
208        char *s = av;
209 
210        cmd->arg1 = 0;
211 
212        while(s) {
213 	   av = strsep( &s, ",") ;
214 	   tok = match_token(ext6hdrcodes, av);
215 	   switch (tok) {
216 	   case EXT_FRAGMENT:
217 	       cmd->arg1 |= EXT_FRAGMENT;
218 	       break;
219 
220 	   case EXT_HOPOPTS:
221 	       cmd->arg1 |= EXT_HOPOPTS;
222 	       break;
223 
224 	   case EXT_ROUTING:
225 	       cmd->arg1 |= EXT_ROUTING;
226 	       break;
227 
228 	   case EXT_DSTOPTS:
229 	       cmd->arg1 |= EXT_DSTOPTS;
230 	       break;
231 
232 	   case EXT_AH:
233 	       cmd->arg1 |= EXT_AH;
234 	       break;
235 
236 	   case EXT_ESP:
237 	       cmd->arg1 |= EXT_ESP;
238 	       break;
239 
240 	   case EXT_RTHDR0:
241 	       cmd->arg1 |= EXT_RTHDR0;
242 	       break;
243 
244 	   case EXT_RTHDR2:
245 	       cmd->arg1 |= EXT_RTHDR2;
246 	       break;
247 
248 	   default:
249 	       errx( EX_DATAERR, "invalid option for ipv6 exten header" );
250 	       break;
251 	   }
252        }
253        if (cmd->arg1 == 0 )
254 	   return 0;
255        cmd->opcode = O_EXT_HDR;
256        cmd->len |= F_INSN_SIZE( ipfw_insn );
257        return 1;
258 }
259 
260 void
261 print_ext6hdr( ipfw_insn *cmd )
262 {
263        char sep = ' ';
264 
265        printf(" extension header:");
266        if (cmd->arg1 & EXT_FRAGMENT ) {
267 	   printf("%cfragmentation", sep);
268 	   sep = ',';
269        }
270        if (cmd->arg1 & EXT_HOPOPTS ) {
271 	   printf("%chop options", sep);
272 	   sep = ',';
273        }
274        if (cmd->arg1 & EXT_ROUTING ) {
275 	   printf("%crouting options", sep);
276 	   sep = ',';
277        }
278        if (cmd->arg1 & EXT_RTHDR0 ) {
279 	   printf("%crthdr0", sep);
280 	   sep = ',';
281        }
282        if (cmd->arg1 & EXT_RTHDR2 ) {
283 	   printf("%crthdr2", sep);
284 	   sep = ',';
285        }
286        if (cmd->arg1 & EXT_DSTOPTS ) {
287 	   printf("%cdestination options", sep);
288 	   sep = ',';
289        }
290        if (cmd->arg1 & EXT_AH ) {
291 	   printf("%cauthentication header", sep);
292 	   sep = ',';
293        }
294        if (cmd->arg1 & EXT_ESP ) {
295 	   printf("%cencapsulated security payload", sep);
296        }
297 }
298 
299 /* Try to find ipv6 address by hostname */
300 static int
301 lookup_host6 (char *host, struct in6_addr *ip6addr)
302 {
303 	struct hostent *he;
304 
305 	if (!inet_pton(AF_INET6, host, ip6addr)) {
306 		if ((he = gethostbyname2(host, AF_INET6)) == NULL)
307 			return(-1);
308 		memcpy(ip6addr, he->h_addr_list[0], sizeof( struct in6_addr));
309 	}
310 	return(0);
311 }
312 
313 
314 /*
315  * fill the addr and mask fields in the instruction as appropriate from av.
316  * Update length as appropriate.
317  * The following formats are allowed:
318  *     any     matches any IP6. Actually returns an empty instruction.
319  *     me      returns O_IP6_*_ME
320  *
321  *     03f1::234:123:0342		single IP6 addres
322  *     03f1::234:123:0342/24	    address/mask
323  *     03f1::234:123:0342/24,03f1::234:123:0343/	       List of address
324  *
325  * Set of address (as in ipv6) not supported because ipv6 address
326  * are typically random past the initial prefix.
327  * Return 1 on success, 0 on failure.
328  */
329 static int
330 fill_ip6(ipfw_insn_ip6 *cmd, char *av)
331 {
332 	int len = 0;
333 	struct in6_addr *d = &(cmd->addr6);
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        av = strdup(av);
356        while (av) {
357 		/*
358 		 * After the address we can have '/' indicating a mask,
359 		 * or ',' indicating another address follows.
360 		 */
361 
362 		char *p;
363 		int masklen;
364 		char md = '\0';
365 
366 		if ((p = strpbrk(av, "/,")) ) {
367 			md = *p;	/* save the separator */
368 			*p = '\0';	/* terminate address string */
369 			p++;		/* and skip past it */
370 		}
371 		/* now p points to NULL, mask or next entry */
372 
373 		/* lookup stores address in *d as a side effect */
374 		if (lookup_host6(av, d) != 0) {
375 			/* XXX: failed. Free memory and go */
376 			errx(EX_DATAERR, "bad address \"%s\"", av);
377 		}
378 		/* next, look at the mask, if any */
379 		masklen = (md == '/') ? atoi(p) : 128;
380 		if (masklen > 128 || masklen < 0)
381 			errx(EX_DATAERR, "bad width \"%s\''", p);
382 		else
383 			n2mask(&d[1], masklen);
384 
385 		APPLY_MASK(d, &d[1])   /* mask base address with mask */
386 
387 		/* find next separator */
388 
389 		if (md == '/') {	/* find separator past the mask */
390 			p = strpbrk(p, ",");
391 			if (p != NULL)
392 				p++;
393 		}
394 		av = p;
395 
396 		/* Check this entry */
397 		if (masklen == 0) {
398 			/*
399 			 * 'any' turns the entire list into a NOP.
400 			 * 'not any' never matches, so it is removed from the
401 			 * list unless it is the only item, in which case we
402 			 * report an error.
403 			 */
404 			if (cmd->o.len & F_NOT && av == NULL && len == 0)
405 				errx(EX_DATAERR, "not any never matches");
406 			continue;
407 		}
408 
409 		/*
410 		 * A single IP can be stored alone
411 		 */
412 		if (masklen == 128 && av == NULL && len == 0) {
413 			len = F_INSN_SIZE(struct in6_addr);
414 			break;
415 		}
416 
417 		/* Update length and pointer to arguments */
418 		len += F_INSN_SIZE(struct in6_addr)*2;
419 		d += 2;
420 	} /* end while */
421 
422 	/*
423 	 * Total length of the command, remember that 1 is the size of
424 	 * the base command.
425 	 */
426 	if (len + 1 > F_LEN_MASK)
427 		errx(EX_DATAERR, "address list too long");
428 	cmd->o.len |= len+1;
429 	free(av);
430 	return (1);
431 }
432 
433 /*
434  * fills command for ipv6 flow-id filtering
435  * note that the 20 bit flow number is stored in a array of u_int32_t
436  * it's supported lists of flow-id, so in the o.arg1 we store how many
437  * additional flow-id we want to filter, the basic is 1
438  */
439 void
440 fill_flow6( ipfw_insn_u32 *cmd, char *av )
441 {
442 	u_int32_t type;	 /* Current flow number */
443 	u_int16_t nflow = 0;    /* Current flow index */
444 	char *s = av;
445 	cmd->d[0] = 0;	  /* Initializing the base number*/
446 
447 	while (s) {
448 		av = strsep( &s, ",") ;
449 		type = strtoul(av, &av, 0);
450 		if (*av != ',' && *av != '\0')
451 			errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
452 		if (type > 0xfffff)
453 			errx(EX_DATAERR, "flow number out of range %s", av);
454 		cmd->d[nflow] |= type;
455 		nflow++;
456 	}
457 	if( nflow > 0 ) {
458 		cmd->o.opcode = O_FLOW6ID;
459 		cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32) + nflow;
460 		cmd->o.arg1 = nflow;
461 	}
462 	else {
463 		errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
464 	}
465 }
466 
467 ipfw_insn *
468 add_srcip6(ipfw_insn *cmd, char *av)
469 {
470 
471 	fill_ip6((ipfw_insn_ip6 *)cmd, av);
472 	if (F_LEN(cmd) == 0) {				/* any */
473 	} else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) {	/* "me" */
474 		cmd->opcode = O_IP6_SRC_ME;
475 	} else if (F_LEN(cmd) ==
476 	    (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
477 		/* single IP, no mask*/
478 		cmd->opcode = O_IP6_SRC;
479 	} else {					/* addr/mask opt */
480 		cmd->opcode = O_IP6_SRC_MASK;
481 	}
482 	return cmd;
483 }
484 
485 ipfw_insn *
486 add_dstip6(ipfw_insn *cmd, char *av)
487 {
488 
489 	fill_ip6((ipfw_insn_ip6 *)cmd, av);
490 	if (F_LEN(cmd) == 0) {				/* any */
491 	} else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) {	/* "me" */
492 		cmd->opcode = O_IP6_DST_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_DST;
497 	} else {					/* addr/mask opt */
498 		cmd->opcode = O_IP6_DST_MASK;
499 	}
500 	return cmd;
501 }
502