ipv6.c revision 340278 
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 340278 2018-11-09 08:15:58Z 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)
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
140void
141fill_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
166void
167print_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
182void
183print_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 */
197static 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 */
210int
211fill_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
258void
259print_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 */
298static int
299lookup_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 */
328static int
329fill_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 */
451void
452fill_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
481ipfw_insn *
482add_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
503ipfw_insn *
504add_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