ipv6.c revision 316445 
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: stable/11/sbin/ipfw/ipv6.c 316445 2017-04-03 07:40:38Z ae $
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
50static 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
58void
59fill_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
73void
74print_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 */
87void
88print_ip6(struct buf_pr *bp, ipfw_insn_ip6 *cmd, char const *s)
89{
90       struct hostent *he = NULL;
91       int len = F_LEN((ipfw_insn *) cmd) - 1;
92       struct in6_addr *a = &(cmd->addr6);
93       char trad[255];
94
95       bprintf(bp, "%s%s ", cmd->o.len & F_NOT ? " not": "", s);
96
97       if (cmd->o.opcode == O_IP6_SRC_ME || cmd->o.opcode == O_IP6_DST_ME) {
98	       bprintf(bp, "me6");
99	       return;
100       }
101       if (cmd->o.opcode == O_IP6) {
102	       bprintf(bp, " ip6");
103	       return;
104       }
105
106       /*
107	* len == 4 indicates a single IP, whereas lists of 1 or more
108	* addr/mask pairs have len = (2n+1). We convert len to n so we
109	* use that to count the number of entries.
110	*/
111
112       for (len = len / 4; len > 0; len -= 2, a += 2) {
113	   int mb =	/* mask length */
114	       (cmd->o.opcode == O_IP6_SRC || cmd->o.opcode == O_IP6_DST) ?
115	       128 : contigmask((uint8_t *)&(a[1]), 128);
116
117	   if (mb == 128 && co.do_resolv)
118	       he = gethostbyaddr((char *)a, sizeof(*a), AF_INET6);
119	   if (he != NULL)	     /* resolved to name */
120	       bprintf(bp, "%s", he->h_name);
121	   else if (mb == 0)	   /* any */
122	       bprintf(bp, "any");
123	   else {	  /* numeric IP followed by some kind of mask */
124	       if (inet_ntop(AF_INET6,  a, trad, sizeof( trad ) ) == NULL)
125		   bprintf(bp, "Error ntop in print_ip6\n");
126	       bprintf(bp, "%s",  trad );
127	       if (mb < 0) /* mask not contiguous */
128		   bprintf(bp, "/%s",
129		       inet_ntop(AF_INET6, &a[1], trad, sizeof(trad)));
130	       else if (mb < 128)
131		   bprintf(bp, "/%d", mb);
132	   }
133	   if (len > 2)
134	       bprintf(bp, ",");
135       }
136}
137
138void
139fill_icmp6types(ipfw_insn_icmp6 *cmd, char *av, int cblen)
140{
141       uint8_t type;
142
143       CHECK_LENGTH(cblen, F_INSN_SIZE(ipfw_insn_icmp6));
144
145       bzero(cmd, sizeof(*cmd));
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
167void
168print_icmp6types(struct buf_pr *bp, ipfw_insn_u32 *cmd)
169{
170       int i, j;
171       char sep= ' ';
172
173       bprintf(bp, " ip6 icmp6types");
174       for (i = 0; i < 7; i++)
175	       for (j=0; j < 32; ++j) {
176		       if ( (cmd->d[i] & (1 << (j))) == 0)
177			       continue;
178		       bprintf(bp, "%c%d", sep, (i*32 + j));
179		       sep = ',';
180	       }
181}
182
183void
184print_flow6id(struct buf_pr *bp, ipfw_insn_u32 *cmd)
185{
186       uint16_t i, limit = cmd->o.arg1;
187       char sep = ',';
188
189       bprintf(bp, " flow-id ");
190       for( i=0; i < limit; ++i) {
191	       if (i == limit - 1)
192		       sep = ' ';
193	       bprintf(bp, "%d%c", cmd->d[i], sep);
194       }
195}
196
197/* structure and define for the extension header in ipv6 */
198static struct _s_x ext6hdrcodes[] = {
199       { "frag",       EXT_FRAGMENT },
200       { "hopopt",     EXT_HOPOPTS },
201       { "route",      EXT_ROUTING },
202       { "dstopt",     EXT_DSTOPTS },
203       { "ah",	 EXT_AH },
204       { "esp",	EXT_ESP },
205       { "rthdr0",     EXT_RTHDR0 },
206       { "rthdr2",     EXT_RTHDR2 },
207       { NULL,	 0 }
208};
209
210/* fills command for the extension header filtering */
211int
212fill_ext6hdr( ipfw_insn *cmd, char *av)
213{
214       int tok;
215       char *s = av;
216
217       cmd->arg1 = 0;
218
219       while(s) {
220	   av = strsep( &s, ",") ;
221	   tok = match_token(ext6hdrcodes, av);
222	   switch (tok) {
223	   case EXT_FRAGMENT:
224	       cmd->arg1 |= EXT_FRAGMENT;
225	       break;
226
227	   case EXT_HOPOPTS:
228	       cmd->arg1 |= EXT_HOPOPTS;
229	       break;
230
231	   case EXT_ROUTING:
232	       cmd->arg1 |= EXT_ROUTING;
233	       break;
234
235	   case EXT_DSTOPTS:
236	       cmd->arg1 |= EXT_DSTOPTS;
237	       break;
238
239	   case EXT_AH:
240	       cmd->arg1 |= EXT_AH;
241	       break;
242
243	   case EXT_ESP:
244	       cmd->arg1 |= EXT_ESP;
245	       break;
246
247	   case EXT_RTHDR0:
248	       cmd->arg1 |= EXT_RTHDR0;
249	       break;
250
251	   case EXT_RTHDR2:
252	       cmd->arg1 |= EXT_RTHDR2;
253	       break;
254
255	   default:
256	       errx( EX_DATAERR, "invalid option for ipv6 exten header" );
257	       break;
258	   }
259       }
260       if (cmd->arg1 == 0 )
261	   return 0;
262       cmd->opcode = O_EXT_HDR;
263       cmd->len |= F_INSN_SIZE( ipfw_insn );
264       return 1;
265}
266
267void
268print_ext6hdr(struct buf_pr *bp, ipfw_insn *cmd )
269{
270       char sep = ' ';
271
272       bprintf(bp, " extension header:");
273       if (cmd->arg1 & EXT_FRAGMENT ) {
274	   bprintf(bp, "%cfragmentation", sep);
275	   sep = ',';
276       }
277       if (cmd->arg1 & EXT_HOPOPTS ) {
278	   bprintf(bp, "%chop options", sep);
279	   sep = ',';
280       }
281       if (cmd->arg1 & EXT_ROUTING ) {
282	   bprintf(bp, "%crouting options", sep);
283	   sep = ',';
284       }
285       if (cmd->arg1 & EXT_RTHDR0 ) {
286	   bprintf(bp, "%crthdr0", sep);
287	   sep = ',';
288       }
289       if (cmd->arg1 & EXT_RTHDR2 ) {
290	   bprintf(bp, "%crthdr2", sep);
291	   sep = ',';
292       }
293       if (cmd->arg1 & EXT_DSTOPTS ) {
294	   bprintf(bp, "%cdestination options", sep);
295	   sep = ',';
296       }
297       if (cmd->arg1 & EXT_AH ) {
298	   bprintf(bp, "%cauthentication header", sep);
299	   sep = ',';
300       }
301       if (cmd->arg1 & EXT_ESP ) {
302	   bprintf(bp, "%cencapsulated security payload", sep);
303       }
304}
305
306/* Try to find ipv6 address by hostname */
307static int
308lookup_host6 (char *host, struct in6_addr *ip6addr)
309{
310	struct hostent *he;
311
312	if (!inet_pton(AF_INET6, host, ip6addr)) {
313		if ((he = gethostbyname2(host, AF_INET6)) == NULL)
314			return(-1);
315		memcpy(ip6addr, he->h_addr_list[0], sizeof( struct in6_addr));
316	}
317	return(0);
318}
319
320
321/*
322 * fill the addr and mask fields in the instruction as appropriate from av.
323 * Update length as appropriate.
324 * The following formats are allowed:
325 *     any     matches any IP6. Actually returns an empty instruction.
326 *     me      returns O_IP6_*_ME
327 *
328 *     03f1::234:123:0342			single IP6 address
329 *     03f1::234:123:0342/24			address/masklen
330 *     03f1::234:123:0342/ffff::ffff:ffff	address/mask
331 *     03f1::234:123:0342/24,03f1::234:123:0343/	List of address
332 *
333 * Set of address (as in ipv6) not supported because ipv6 address
334 * are typically random past the initial prefix.
335 * Return 1 on success, 0 on failure.
336 */
337static int
338fill_ip6(ipfw_insn_ip6 *cmd, char *av, int cblen, struct tidx *tstate)
339{
340	int len = 0;
341	struct in6_addr *d = &(cmd->addr6);
342	/*
343	 * Needed for multiple address.
344	 * Note d[1] points to struct in6_add r mask6 of cmd
345	 */
346
347	cmd->o.len &= ~F_LEN_MASK;	/* zero len */
348
349	if (strcmp(av, "any") == 0)
350		return (1);
351
352
353	if (strcmp(av, "me") == 0) {	/* Set the data for "me" opt*/
354		cmd->o.len |= F_INSN_SIZE(ipfw_insn);
355		return (1);
356	}
357
358	if (strcmp(av, "me6") == 0) {	/* Set the data for "me" opt*/
359		cmd->o.len |= F_INSN_SIZE(ipfw_insn);
360		return (1);
361	}
362
363	if (strncmp(av, "table(", 6) == 0) {
364		fill_table(&cmd->o, av, O_IP_DST_LOOKUP, tstate);
365		return (1);
366	}
367
368	av = strdup(av);
369	while (av) {
370		/*
371		 * After the address we can have '/' indicating a mask,
372		 * or ',' indicating another address follows.
373		 */
374
375		char *p, *q;
376		int masklen;
377		char md = '\0';
378
379		CHECK_LENGTH(cblen, 1 + len + 2 * F_INSN_SIZE(struct in6_addr));
380
381		if ((q = strchr(av, ',')) ) {
382			*q = '\0';
383			q++;
384		}
385
386		if ((p = strchr(av, '/')) ) {
387			md = *p;	/* save the separator */
388			*p = '\0';	/* terminate address string */
389			p++;		/* and skip past it */
390		}
391		/* now p points to NULL, mask or next entry */
392
393		/* lookup stores address in *d as a side effect */
394		if (lookup_host6(av, d) != 0) {
395			/* XXX: failed. Free memory and go */
396			errx(EX_DATAERR, "bad address \"%s\"", av);
397		}
398		/* next, look at the mask, if any */
399		if (md == '/' && strchr(p, ':')) {
400			if (!inet_pton(AF_INET6, p, &d[1]))
401				errx(EX_DATAERR, "bad mask \"%s\"", p);
402
403			masklen = contigmask((uint8_t *)&(d[1]), 128);
404		} else {
405			masklen = (md == '/') ? atoi(p) : 128;
406			if (masklen > 128 || masklen < 0)
407				errx(EX_DATAERR, "bad width \"%s\''", p);
408			else
409				n2mask(&d[1], masklen);
410		}
411
412		APPLY_MASK(d, &d[1])   /* mask base address with mask */
413
414		av = q;
415
416		/* Check this entry */
417		if (masklen == 0) {
418			/*
419			 * 'any' turns the entire list into a NOP.
420			 * 'not any' never matches, so it is removed from the
421			 * list unless it is the only item, in which case we
422			 * report an error.
423			 */
424			if (cmd->o.len & F_NOT && av == NULL && len == 0)
425				errx(EX_DATAERR, "not any never matches");
426			continue;
427		}
428
429		/*
430		 * A single IP can be stored alone
431		 */
432		if (masklen == 128 && av == NULL && len == 0) {
433			len = F_INSN_SIZE(struct in6_addr);
434			break;
435		}
436
437		/* Update length and pointer to arguments */
438		len += F_INSN_SIZE(struct in6_addr)*2;
439		d += 2;
440	} /* end while */
441
442	/*
443	 * Total length of the command, remember that 1 is the size of
444	 * the base command.
445	 */
446	if (len + 1 > F_LEN_MASK)
447		errx(EX_DATAERR, "address list too long");
448	cmd->o.len |= len+1;
449	free(av);
450	return (1);
451}
452
453/*
454 * fills command for ipv6 flow-id filtering
455 * note that the 20 bit flow number is stored in a array of u_int32_t
456 * it's supported lists of flow-id, so in the o.arg1 we store how many
457 * additional flow-id we want to filter, the basic is 1
458 */
459void
460fill_flow6( ipfw_insn_u32 *cmd, char *av, int cblen)
461{
462	u_int32_t type;	 /* Current flow number */
463	u_int16_t nflow = 0;    /* Current flow index */
464	char *s = av;
465	cmd->d[0] = 0;	  /* Initializing the base number*/
466
467	while (s) {
468		CHECK_LENGTH(cblen, F_INSN_SIZE(ipfw_insn_u32) + nflow + 1);
469
470		av = strsep( &s, ",") ;
471		type = strtoul(av, &av, 0);
472		if (*av != ',' && *av != '\0')
473			errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
474		if (type > 0xfffff)
475			errx(EX_DATAERR, "flow number out of range %s", av);
476		cmd->d[nflow] |= type;
477		nflow++;
478	}
479	if( nflow > 0 ) {
480		cmd->o.opcode = O_FLOW6ID;
481		cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32) + nflow;
482		cmd->o.arg1 = nflow;
483	}
484	else {
485		errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
486	}
487}
488
489ipfw_insn *
490add_srcip6(ipfw_insn *cmd, char *av, int cblen, struct tidx *tstate)
491{
492
493	fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen, tstate);
494	if (cmd->opcode == O_IP_DST_SET)			/* set */
495		cmd->opcode = O_IP_SRC_SET;
496	else if (cmd->opcode == O_IP_DST_LOOKUP)		/* table */
497		cmd->opcode = O_IP_SRC_LOOKUP;
498	else if (F_LEN(cmd) == 0) {				/* any */
499	} else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) {	/* "me" */
500		cmd->opcode = O_IP6_SRC_ME;
501	} else if (F_LEN(cmd) ==
502	    (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
503		/* single IP, no mask*/
504		cmd->opcode = O_IP6_SRC;
505	} else {					/* addr/mask opt */
506		cmd->opcode = O_IP6_SRC_MASK;
507	}
508	return cmd;
509}
510
511ipfw_insn *
512add_dstip6(ipfw_insn *cmd, char *av, int cblen, struct tidx *tstate)
513{
514
515	fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen, tstate);
516	if (cmd->opcode == O_IP_DST_SET)			/* set */
517		;
518	else if (cmd->opcode == O_IP_DST_LOOKUP)		/* table */
519		;
520	else if (F_LEN(cmd) == 0) {				/* any */
521	} else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) {	/* "me" */
522		cmd->opcode = O_IP6_DST_ME;
523	} else if (F_LEN(cmd) ==
524	    (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
525		/* single IP, no mask*/
526		cmd->opcode = O_IP6_DST;
527	} else {					/* addr/mask opt */
528		cmd->opcode = O_IP6_DST_MASK;
529	}
530	return cmd;
531}
532