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/12/sbin/ipfw/ipv6.c 363605 2020-07-27 14:15:50Z markj $
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
50 static 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
58 void
fill_unreach6_code(u_short * codep,char * str)59 fill_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
73 void
print_unreach6_code(struct buf_pr * bp,uint16_t code)74 print_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 */
87 void
print_ip6(struct buf_pr * bp,const ipfw_insn_ip6 * cmd)88 print_ip6(struct buf_pr *bp, const ipfw_insn_ip6 *cmd)
89 {
90 char trad[255];
91 struct hostent *he = NULL;
92 const struct in6_addr *a = &(cmd->addr6);
93 int len, mb;
94
95 len = F_LEN((const 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((const uint8_t *)&(a[1]), 128);
116
117 if (mb == 128 && g_co.do_resolv)
118 he = gethostbyaddr((const char *)a, sizeof(*a),
119 AF_INET6);
120
121 if (he != NULL) /* resolved to name */
122 bprintf(bp, "%s", he->h_name);
123 else if (mb == 0) /* any */
124 bprintf(bp, "any");
125 else { /* numeric IP followed by some kind of mask */
126 if (inet_ntop(AF_INET6, a, trad,
127 sizeof(trad)) == NULL)
128 bprintf(bp, "Error ntop in print_ip6\n");
129 bprintf(bp, "%s", trad );
130 if (mb < 0) /* mask not contiguous */
131 bprintf(bp, "/%s", inet_ntop(AF_INET6, &a[1],
132 trad, sizeof(trad)));
133 else if (mb < 128)
134 bprintf(bp, "/%d", mb);
135 }
136 if (len > 2)
137 bprintf(bp, ",");
138 }
139 }
140
141 void
fill_icmp6types(ipfw_insn_icmp6 * cmd,char * av,int cblen)142 fill_icmp6types(ipfw_insn_icmp6 *cmd, char *av, int cblen)
143 {
144 uint8_t type;
145
146 CHECK_LENGTH(cblen, (int)F_INSN_SIZE(ipfw_insn_icmp6));
147 memset(cmd, 0, sizeof(*cmd));
148 while (*av) {
149 if (*av == ',')
150 av++;
151 type = strtoul(av, &av, 0);
152 if (*av != ',' && *av != '\0')
153 errx(EX_DATAERR, "invalid ICMP6 type");
154 /*
155 * XXX: shouldn't this be 0xFF? I can't see any reason why
156 * we shouldn't be able to filter all possiable values
157 * regardless of the ability of the rest of the kernel to do
158 * anything useful with them.
159 */
160 if (type > ICMP6_MAXTYPE)
161 errx(EX_DATAERR, "ICMP6 type out of range");
162 cmd->d[type / 32] |= ( 1 << (type % 32));
163 }
164 cmd->o.opcode = O_ICMP6TYPE;
165 cmd->o.len |= F_INSN_SIZE(ipfw_insn_icmp6);
166 }
167
168 void
print_icmp6types(struct buf_pr * bp,const ipfw_insn_u32 * cmd)169 print_icmp6types(struct buf_pr *bp, const ipfw_insn_u32 *cmd)
170 {
171 int i, j;
172 char sep= ' ';
173
174 bprintf(bp, " icmp6types");
175 for (i = 0; i < 7; i++)
176 for (j=0; j < 32; ++j) {
177 if ( (cmd->d[i] & (1 << (j))) == 0)
178 continue;
179 bprintf(bp, "%c%d", sep, (i*32 + j));
180 sep = ',';
181 }
182 }
183
184 void
print_flow6id(struct buf_pr * bp,const ipfw_insn_u32 * cmd)185 print_flow6id(struct buf_pr *bp, const ipfw_insn_u32 *cmd)
186 {
187 uint16_t i, limit = cmd->o.arg1;
188 char sep = ',';
189
190 bprintf(bp, " flow-id ");
191 for( i=0; i < limit; ++i) {
192 if (i == limit - 1)
193 sep = ' ';
194 bprintf(bp, "%d%c", cmd->d[i], sep);
195 }
196 }
197
198 /* structure and define for the extension header in ipv6 */
199 static struct _s_x ext6hdrcodes[] = {
200 { "frag", EXT_FRAGMENT },
201 { "hopopt", EXT_HOPOPTS },
202 { "route", EXT_ROUTING },
203 { "dstopt", EXT_DSTOPTS },
204 { "ah", EXT_AH },
205 { "esp", EXT_ESP },
206 { "rthdr0", EXT_RTHDR0 },
207 { "rthdr2", EXT_RTHDR2 },
208 { NULL, 0 }
209 };
210
211 /* fills command for the extension header filtering */
212 int
fill_ext6hdr(ipfw_insn * cmd,char * av)213 fill_ext6hdr( ipfw_insn *cmd, char *av)
214 {
215 int tok;
216 char *s = av;
217
218 cmd->arg1 = 0;
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 case EXT_HOPOPTS:
227 cmd->arg1 |= EXT_HOPOPTS;
228 break;
229 case EXT_ROUTING:
230 cmd->arg1 |= EXT_ROUTING;
231 break;
232 case EXT_DSTOPTS:
233 cmd->arg1 |= EXT_DSTOPTS;
234 break;
235 case EXT_AH:
236 cmd->arg1 |= EXT_AH;
237 break;
238 case EXT_ESP:
239 cmd->arg1 |= EXT_ESP;
240 break;
241 case EXT_RTHDR0:
242 cmd->arg1 |= EXT_RTHDR0;
243 break;
244 case EXT_RTHDR2:
245 cmd->arg1 |= EXT_RTHDR2;
246 break;
247 default:
248 errx(EX_DATAERR,
249 "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
print_ext6hdr(struct buf_pr * bp,const ipfw_insn * cmd)261 print_ext6hdr(struct buf_pr *bp, const ipfw_insn *cmd )
262 {
263 char sep = ' ';
264
265 bprintf(bp, " extension header:");
266 if (cmd->arg1 & EXT_FRAGMENT) {
267 bprintf(bp, "%cfragmentation", sep);
268 sep = ',';
269 }
270 if (cmd->arg1 & EXT_HOPOPTS) {
271 bprintf(bp, "%chop options", sep);
272 sep = ',';
273 }
274 if (cmd->arg1 & EXT_ROUTING) {
275 bprintf(bp, "%crouting options", sep);
276 sep = ',';
277 }
278 if (cmd->arg1 & EXT_RTHDR0) {
279 bprintf(bp, "%crthdr0", sep);
280 sep = ',';
281 }
282 if (cmd->arg1 & EXT_RTHDR2) {
283 bprintf(bp, "%crthdr2", sep);
284 sep = ',';
285 }
286 if (cmd->arg1 & EXT_DSTOPTS) {
287 bprintf(bp, "%cdestination options", sep);
288 sep = ',';
289 }
290 if (cmd->arg1 & EXT_AH) {
291 bprintf(bp, "%cauthentication header", sep);
292 sep = ',';
293 }
294 if (cmd->arg1 & EXT_ESP) {
295 bprintf(bp, "%cencapsulated security payload", sep);
296 }
297 }
298
299 /* Try to find ipv6 address by hostname */
300 static int
lookup_host6(char * host,struct in6_addr * ip6addr)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 address
322 * 03f1::234:123:0342/24 address/masklen
323 * 03f1::234:123:0342/ffff::ffff:ffff address/mask
324 * 03f1::234:123:0342/24,03f1::234:123:0343/ List of address
325 *
326 * Set of address (as in ipv6) not supported because ipv6 address
327 * are typically random past the initial prefix.
328 * Return 1 on success, 0 on failure.
329 */
330 static int
fill_ip6(ipfw_insn_ip6 * cmd,char * av,int cblen,struct tidx * tstate)331 fill_ip6(ipfw_insn_ip6 *cmd, char *av, int cblen, struct tidx *tstate)
332 {
333 int len = 0;
334 struct in6_addr *d = &(cmd->addr6);
335 char *oav;
336 /*
337 * Needed for multiple address.
338 * Note d[1] points to struct in6_add r mask6 of cmd
339 */
340
341 cmd->o.len &= ~F_LEN_MASK; /* zero len */
342
343 if (strcmp(av, "any") == 0)
344 return (1);
345
346 /* Set the data for "me" opt */
347 if (strcmp(av, "me") == 0 || strcmp(av, "me6") == 0) {
348 cmd->o.len |= F_INSN_SIZE(ipfw_insn);
349 return (1);
350 }
351
352 if (strncmp(av, "table(", 6) == 0) {
353 fill_table(&cmd->o, av, O_IP_DST_LOOKUP, tstate);
354 return (1);
355 }
356
357 oav = av = strdup(av);
358 while (av) {
359 /*
360 * After the address we can have '/' indicating a mask,
361 * or ',' indicating another address follows.
362 */
363
364 char *p, *q;
365 int masklen;
366 char md = '\0';
367
368 CHECK_LENGTH(cblen,
369 1 + len + 2 * (int)F_INSN_SIZE(struct in6_addr));
370
371 if ((q = strchr(av, ',')) ) {
372 *q = '\0';
373 q++;
374 }
375
376 if ((p = strchr(av, '/')) ) {
377 md = *p; /* save the separator */
378 *p = '\0'; /* terminate address string */
379 p++; /* and skip past it */
380 }
381 /* now p points to NULL, mask or next entry */
382
383 /* lookup stores address in *d as a side effect */
384 if (lookup_host6(av, d) != 0) {
385 /* XXX: failed. Free memory and go */
386 errx(EX_DATAERR, "bad address \"%s\"", av);
387 }
388 /* next, look at the mask, if any */
389 if (md == '/' && strchr(p, ':')) {
390 if (!inet_pton(AF_INET6, p, &d[1]))
391 errx(EX_DATAERR, "bad mask \"%s\"", p);
392
393 masklen = contigmask((uint8_t *)&(d[1]), 128);
394 } else {
395 masklen = (md == '/') ? atoi(p) : 128;
396 if (masklen > 128 || masklen < 0)
397 errx(EX_DATAERR, "bad width \"%s\''", p);
398 else
399 n2mask(&d[1], masklen);
400 }
401
402 APPLY_MASK(d, &d[1]); /* mask base address with mask */
403
404 av = q;
405
406 /* Check this entry */
407 if (masklen == 0) {
408 /*
409 * 'any' turns the entire list into a NOP.
410 * 'not any' never matches, so it is removed from the
411 * list unless it is the only item, in which case we
412 * report an error.
413 */
414 if (cmd->o.len & F_NOT && av == NULL && len == 0)
415 errx(EX_DATAERR, "not any never matches");
416 continue;
417 }
418
419 /*
420 * A single IP can be stored alone
421 */
422 if (masklen == 128 && av == NULL && len == 0) {
423 len = F_INSN_SIZE(struct in6_addr);
424 break;
425 }
426
427 /* Update length and pointer to arguments */
428 len += F_INSN_SIZE(struct in6_addr)*2;
429 d += 2;
430 } /* end while */
431
432 /*
433 * Total length of the command, remember that 1 is the size of
434 * the base command.
435 */
436 if (len + 1 > F_LEN_MASK)
437 errx(EX_DATAERR, "address list too long");
438 cmd->o.len |= len+1;
439 free(oav);
440 return (1);
441 }
442
443 /*
444 * fills command for ipv6 flow-id filtering
445 * note that the 20 bit flow number is stored in a array of u_int32_t
446 * it's supported lists of flow-id, so in the o.arg1 we store how many
447 * additional flow-id we want to filter, the basic is 1
448 */
449 void
fill_flow6(ipfw_insn_u32 * cmd,char * av,int cblen)450 fill_flow6( ipfw_insn_u32 *cmd, char *av, int cblen)
451 {
452 u_int32_t type; /* Current flow number */
453 u_int16_t nflow = 0; /* Current flow index */
454 char *s = av;
455 cmd->d[0] = 0; /* Initializing the base number*/
456
457 while (s) {
458 CHECK_LENGTH(cblen,
459 (int)F_INSN_SIZE(ipfw_insn_u32) + nflow + 1);
460
461 av = strsep( &s, ",") ;
462 type = strtoul(av, &av, 0);
463 if (*av != ',' && *av != '\0')
464 errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
465 if (type > 0xfffff)
466 errx(EX_DATAERR, "flow number out of range %s", av);
467 cmd->d[nflow] |= type;
468 nflow++;
469 }
470 if( nflow > 0 ) {
471 cmd->o.opcode = O_FLOW6ID;
472 cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32) + nflow;
473 cmd->o.arg1 = nflow;
474 }
475 else {
476 errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
477 }
478 }
479
480 ipfw_insn *
add_srcip6(ipfw_insn * cmd,char * av,int cblen,struct tidx * tstate)481 add_srcip6(ipfw_insn *cmd, char *av, int cblen, struct tidx *tstate)
482 {
483
484 fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen, tstate);
485 if (cmd->opcode == O_IP_DST_SET) /* set */
486 cmd->opcode = O_IP_SRC_SET;
487 else if (cmd->opcode == O_IP_DST_LOOKUP) /* table */
488 cmd->opcode = O_IP_SRC_LOOKUP;
489 else if (F_LEN(cmd) == 0) { /* any */
490 } else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) { /* "me" */
491 cmd->opcode = O_IP6_SRC_ME;
492 } else if (F_LEN(cmd) ==
493 (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
494 /* single IP, no mask*/
495 cmd->opcode = O_IP6_SRC;
496 } else { /* addr/mask opt */
497 cmd->opcode = O_IP6_SRC_MASK;
498 }
499 return cmd;
500 }
501
502 ipfw_insn *
add_dstip6(ipfw_insn * cmd,char * av,int cblen,struct tidx * tstate)503 add_dstip6(ipfw_insn *cmd, char *av, int cblen, struct tidx *tstate)
504 {
505
506 fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen, tstate);
507 if (cmd->opcode == O_IP_DST_SET) /* set */
508 ;
509 else if (cmd->opcode == O_IP_DST_LOOKUP) /* table */
510 ;
511 else if (F_LEN(cmd) == 0) { /* any */
512 } else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) { /* "me" */
513 cmd->opcode = O_IP6_DST_ME;
514 } else if (F_LEN(cmd) ==
515 (F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
516 /* single IP, no mask*/
517 cmd->opcode = O_IP6_DST;
518 } else { /* addr/mask opt */
519 cmd->opcode = O_IP6_DST_MASK;
520 }
521 return cmd;
522 }
523