ipv6.c revision 353797 
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 353797 2019-10-21 14:34:40Z 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       memset(cmd, 0, sizeof(*cmd));
147       while (*av) {
148	       if (*av == ',')
149		       av++;
150	       type = strtoul(av, &av, 0);
151	       if (*av != ',' && *av != '\0')
152		       errx(EX_DATAERR, "invalid ICMP6 type");
153	       /*
154		* XXX: shouldn't this be 0xFF?  I can't see any reason why
155		* we shouldn't be able to filter all possiable values
156		* regardless of the ability of the rest of the kernel to do
157		* anything useful with them.
158		*/
159	       if (type > ICMP6_MAXTYPE)
160		       errx(EX_DATAERR, "ICMP6 type out of range");
161	       cmd->d[type / 32] |= ( 1 << (type % 32));
162       }
163       cmd->o.opcode = O_ICMP6TYPE;
164       cmd->o.len |= F_INSN_SIZE(ipfw_insn_icmp6);
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, " 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	while(s) {
219		av = strsep( &s, ",") ;
220		tok = match_token(ext6hdrcodes, av);
221		switch (tok) {
222		case EXT_FRAGMENT:
223			cmd->arg1 |= EXT_FRAGMENT;
224			break;
225		case EXT_HOPOPTS:
226			cmd->arg1 |= EXT_HOPOPTS;
227			break;
228		case EXT_ROUTING:
229			cmd->arg1 |= EXT_ROUTING;
230			break;
231		case EXT_DSTOPTS:
232			cmd->arg1 |= EXT_DSTOPTS;
233			break;
234		case EXT_AH:
235			cmd->arg1 |= EXT_AH;
236			break;
237		case EXT_ESP:
238			cmd->arg1 |= EXT_ESP;
239			break;
240		case EXT_RTHDR0:
241			cmd->arg1 |= EXT_RTHDR0;
242			break;
243		case EXT_RTHDR2:
244			cmd->arg1 |= EXT_RTHDR2;
245			break;
246		default:
247			errx(EX_DATAERR,
248			    "invalid option for ipv6 exten header");
249			break;
250		}
251	}
252	if (cmd->arg1 == 0)
253		return (0);
254	cmd->opcode = O_EXT_HDR;
255	cmd->len |= F_INSN_SIZE(ipfw_insn);
256	return (1);
257}
258
259void
260print_ext6hdr(struct buf_pr *bp, ipfw_insn *cmd )
261{
262	char sep = ' ';
263
264	bprintf(bp, " extension header:");
265	if (cmd->arg1 & EXT_FRAGMENT) {
266		bprintf(bp, "%cfragmentation", sep);
267		sep = ',';
268	}
269	if (cmd->arg1 & EXT_HOPOPTS) {
270		bprintf(bp, "%chop options", sep);
271		sep = ',';
272	}
273	if (cmd->arg1 & EXT_ROUTING) {
274		bprintf(bp, "%crouting options", sep);
275		sep = ',';
276	}
277	if (cmd->arg1 & EXT_RTHDR0) {
278		bprintf(bp, "%crthdr0", sep);
279		sep = ',';
280	}
281	if (cmd->arg1 & EXT_RTHDR2) {
282		bprintf(bp, "%crthdr2", sep);
283		sep = ',';
284	}
285	if (cmd->arg1 & EXT_DSTOPTS) {
286		bprintf(bp, "%cdestination options", sep);
287		sep = ',';
288	}
289	if (cmd->arg1 & EXT_AH) {
290		bprintf(bp, "%cauthentication header", sep);
291		sep = ',';
292	}
293	if (cmd->arg1 & EXT_ESP) {
294		bprintf(bp, "%cencapsulated security payload", sep);
295	}
296}
297
298/* Try to find ipv6 address by hostname */
299static int
300lookup_host6 (char *host, struct in6_addr *ip6addr)
301{
302	struct hostent *he;
303
304	if (!inet_pton(AF_INET6, host, ip6addr)) {
305		if ((he = gethostbyname2(host, AF_INET6)) == NULL)
306			return(-1);
307		memcpy(ip6addr, he->h_addr_list[0], sizeof( struct in6_addr));
308	}
309	return (0);
310}
311
312
313/*
314 * fill the addr and mask fields in the instruction as appropriate from av.
315 * Update length as appropriate.
316 * The following formats are allowed:
317 *     any     matches any IP6. Actually returns an empty instruction.
318 *     me      returns O_IP6_*_ME
319 *
320 *     03f1::234:123:0342			single IP6 address
321 *     03f1::234:123:0342/24			address/masklen
322 *     03f1::234:123:0342/ffff::ffff:ffff	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, int cblen, struct tidx *tstate)
331{
332	int len = 0;
333	struct in6_addr *d = &(cmd->addr6);
334	char *oav;
335	/*
336	 * Needed for multiple address.
337	 * Note d[1] points to struct in6_add r mask6 of cmd
338	 */
339
340	cmd->o.len &= ~F_LEN_MASK;	/* zero len */
341
342	if (strcmp(av, "any") == 0)
343		return (1);
344
345
346	if (strcmp(av, "me") == 0) {	/* Set the data for "me" opt*/
347		cmd->o.len |= F_INSN_SIZE(ipfw_insn);
348		return (1);
349	}
350
351	if (strcmp(av, "me6") == 0) {	/* Set the data for "me" opt*/
352		cmd->o.len |= F_INSN_SIZE(ipfw_insn);
353		return (1);
354	}
355
356	if (strncmp(av, "table(", 6) == 0) {
357		fill_table(&cmd->o, av, O_IP_DST_LOOKUP, tstate);
358		return (1);
359	}
360
361	oav = av = strdup(av);
362	while (av) {
363		/*
364		 * After the address we can have '/' indicating a mask,
365		 * or ',' indicating another address follows.
366		 */
367
368		char *p, *q;
369		int masklen;
370		char md = '\0';
371
372		CHECK_LENGTH(cblen, 1 + len + 2 * F_INSN_SIZE(struct in6_addr));
373
374		if ((q = strchr(av, ',')) ) {
375			*q = '\0';
376			q++;
377		}
378
379		if ((p = strchr(av, '/')) ) {
380			md = *p;	/* save the separator */
381			*p = '\0';	/* terminate address string */
382			p++;		/* and skip past it */
383		}
384		/* now p points to NULL, mask or next entry */
385
386		/* lookup stores address in *d as a side effect */
387		if (lookup_host6(av, d) != 0) {
388			/* XXX: failed. Free memory and go */
389			errx(EX_DATAERR, "bad address \"%s\"", av);
390		}
391		/* next, look at the mask, if any */
392		if (md == '/' && strchr(p, ':')) {
393			if (!inet_pton(AF_INET6, p, &d[1]))
394				errx(EX_DATAERR, "bad mask \"%s\"", p);
395
396			masklen = contigmask((uint8_t *)&(d[1]), 128);
397		} else {
398			masklen = (md == '/') ? atoi(p) : 128;
399			if (masklen > 128 || masklen < 0)
400				errx(EX_DATAERR, "bad width \"%s\''", p);
401			else
402				n2mask(&d[1], masklen);
403		}
404
405		APPLY_MASK(d, &d[1]);   /* mask base address with mask */
406
407		av = q;
408
409		/* Check this entry */
410		if (masklen == 0) {
411			/*
412			 * 'any' turns the entire list into a NOP.
413			 * 'not any' never matches, so it is removed from the
414			 * list unless it is the only item, in which case we
415			 * report an error.
416			 */
417			if (cmd->o.len & F_NOT && av == NULL && len == 0)
418				errx(EX_DATAERR, "not any never matches");
419			continue;
420		}
421
422		/*
423		 * A single IP can be stored alone
424		 */
425		if (masklen == 128 && av == NULL && len == 0) {
426			len = F_INSN_SIZE(struct in6_addr);
427			break;
428		}
429
430		/* Update length and pointer to arguments */
431		len += F_INSN_SIZE(struct in6_addr)*2;
432		d += 2;
433	} /* end while */
434
435	/*
436	 * Total length of the command, remember that 1 is the size of
437	 * the base command.
438	 */
439	if (len + 1 > F_LEN_MASK)
440		errx(EX_DATAERR, "address list too long");
441	cmd->o.len |= len+1;
442	free(oav);
443	return (1);
444}
445
446/*
447 * fills command for ipv6 flow-id filtering
448 * note that the 20 bit flow number is stored in a array of u_int32_t
449 * it's supported lists of flow-id, so in the o.arg1 we store how many
450 * additional flow-id we want to filter, the basic is 1
451 */
452void
453fill_flow6( ipfw_insn_u32 *cmd, char *av, int cblen)
454{
455	u_int32_t type;	 /* Current flow number */
456	u_int16_t nflow = 0;    /* Current flow index */
457	char *s = av;
458	cmd->d[0] = 0;	  /* Initializing the base number*/
459
460	while (s) {
461		CHECK_LENGTH(cblen, F_INSN_SIZE(ipfw_insn_u32) + nflow + 1);
462
463		av = strsep( &s, ",") ;
464		type = strtoul(av, &av, 0);
465		if (*av != ',' && *av != '\0')
466			errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
467		if (type > 0xfffff)
468			errx(EX_DATAERR, "flow number out of range %s", av);
469		cmd->d[nflow] |= type;
470		nflow++;
471	}
472	if( nflow > 0 ) {
473		cmd->o.opcode = O_FLOW6ID;
474		cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32) + nflow;
475		cmd->o.arg1 = nflow;
476	}
477	else {
478		errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
479	}
480}
481
482ipfw_insn *
483add_srcip6(ipfw_insn *cmd, char *av, int cblen, struct tidx *tstate)
484{
485
486	fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen, tstate);
487	if (cmd->opcode == O_IP_DST_SET)			/* set */
488		cmd->opcode = O_IP_SRC_SET;
489	else if (cmd->opcode == O_IP_DST_LOOKUP)		/* table */
490		cmd->opcode = O_IP_SRC_LOOKUP;
491	else if (F_LEN(cmd) == 0) {				/* any */
492	} else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) {	/* "me" */
493		cmd->opcode = O_IP6_SRC_ME;
494	} else if (F_LEN(cmd) ==
495	    (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
496		/* single IP, no mask*/
497		cmd->opcode = O_IP6_SRC;
498	} else {					/* addr/mask opt */
499		cmd->opcode = O_IP6_SRC_MASK;
500	}
501	return cmd;
502}
503
504ipfw_insn *
505add_dstip6(ipfw_insn *cmd, char *av, int cblen, struct tidx *tstate)
506{
507
508	fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen, tstate);
509	if (cmd->opcode == O_IP_DST_SET)			/* set */
510		;
511	else if (cmd->opcode == O_IP_DST_LOOKUP)		/* table */
512		;
513	else if (F_LEN(cmd) == 0) {				/* any */
514	} else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) {	/* "me" */
515		cmd->opcode = O_IP6_DST_ME;
516	} else if (F_LEN(cmd) ==
517	    (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
518		/* single IP, no mask*/
519		cmd->opcode = O_IP6_DST;
520	} else {					/* addr/mask opt */
521		cmd->opcode = O_IP6_DST_MASK;
522	}
523	return cmd;
524}
525