ipv6.c revision 187770 
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: head/sbin/ipfw/ipv6.c 187770 2009-01-27 12:01:30Z luigi $
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
45static 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
53void
54fill_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
68void
69print_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 */
82void
83print_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
133void
134fill_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
160void
161print_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
176void
177print_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 */
191static 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 */
204int
205fill_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
260void
261print_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 */
300static int
301lookup_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 */
329static int
330fill_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 */
439void
440fill_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
467ipfw_insn *
468add_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
485ipfw_insn *
486add_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